Incidence of influenza-like illness and severe acute respiratory infection during three influenza seasons in Bangladesh, 2008-2010

Incidence of Hospitalization due to Influenza-Associated Severe Acute Respiratory Infection During 2010-2019 in Bangladesh

BACKGROUND

Global influenza-associated acute respiratory infections contribute to 3-5 million severe illnesses requiring hospitalization annually, with 90% of hospitalizations occurring among children < 5 years in developing countries. In Bangladesh, the inadequate availability of nationally representative, robust estimates of influenza-associated hospitalizations limits allocation of resources for prevention and control measures.

METHODS

This study used data from the hospital-based influenza surveillance (HBIS) system in Bangladesh from 2010 to 2019 and healthcare utilization surveys to determine hospital utilization patterns in the catchment area. We estimated annual influenza-associated hospitalization numbers and rates for all age groups in Bangladesh using WHO methods, adjusted for a 6-day-a-week enrollment schedule, selective testing of specimens from children under five, and healthcare-seeking behavior, based on the proportion of symptomatic community participants seeking healthcare within the past week. We then estimated national hospitalization rates by multiplying age-specific hospitalization rates with the corresponding annual national census population.

RESULTS

Annual influenza-associated hospitalization rates per 100,000 population for all ages ranged from 31 (95% CI: 27-36) in 2011 to 139 (95% CI: 130-149) in 2019. Children < 5 years old had the highest rates of influenza-associated hospitalization, ranging from 114 (95% CI: 90-138) in 2011 to 529 (95% CI: 481-578) in 2019, followed by adults aged ≥ 65 years with rates ranging from 46 (95% CI: 34-57) in 2012 to 252 (95% CI: 213-292) in 2019. The national hospitalization estimates for all ages during 2010-2019 ranged from 47,891 to 236,380 per year.

CONCLUSIONS

The impact of influenza-associated hospitalizations in Bangladesh may be considerable, particularly for young children and older adults. Targeted interventions, such as influenza vaccination for these age groups, should be prioritized and evaluated.

Acceptability, cost-effectiveness, and capacity of a facility-based seasonal influenza vaccination among high-risk groups: a study protocol in selected tertiary care hospitals of Bangladesh

BACKGROUND

In Bangladesh, seasonal influenza imposes considerable disease and economic burden, especially for those at high-risk of severe disease. The most successful approach for influenza prevention is the administration of a vaccine. Many poor and middle-income nations, including Bangladesh, do not have a national strategy or program in place for seasonal influenza vaccines, despite the World Health Organization's (WHO) advice to prioritize high-risk populations. Additionally, there is a scarcity of substantial data on the cost-effectiveness of seasonal influenza vaccination in these countries. The aim of our study is to determine acceptability, health beliefs, barriers, and intention of receiving influenza vaccine among high-risk populations, assess the cost-effectiveness of implementing a facility-based seasonal influenza vaccination programme, and investigate the required capacity for a potential seasonal influenza vaccination programme.

METHODS

We will undertake this study following STROBE guidelines. We will conduct the study in inpatient and outpatient departments of three selected tertiary-level hospitals leveraging the ongoing hospital-based influenza surveillance (HBIS) platform. The study population will include the WHO-defined four high-risk groups excluding healthcare workers: children six months to eight years, pregnant women, elderly ≥ 60 years, and adults with chronic diseases. We will collect quantitative data on participants' acceptability, health beliefs, barriers, and vaccination intentions using the health belief model (HBM) from patients meeting the criteria for high-risk populations attending two public tertiary-level hospitals. In one of the two public tertiary-level hospitals, we will arrange an influenza vaccination campaign before the influenza season, where the vaccine will be offered free of cost to high-risk patients, and in the second hospital, vaccination will not be offered. Both the vaccinated and unvaccinated participants will then be followed-up once a month for one year to record any influenza-like illness, hospitalization, and death. Additional data for objective two will be collected from patients with symptoms of influenza-like illness (ILI) and severe acute respiratory infection (SARI) at one public and one private hospital to determine both direct and indirect costs associated with influenza illness. We will estimate the required number of influenza vaccines, safe injections, and total storage volume utilizing secondary data. We will use a deterministic Markov decision-analytic model to estimate the cost-effectiveness of facility-based influenza vaccination in Bangladesh.

DISCUSSION

The results of this study will enable the National Immunization Technical Advisory Group and the Ministry of Health & Family Welfare of Bangladesh to decide what steps to take to develop and implement an influenza vaccination strategy targeting high-risk populations.

TRIAL REGISTRATION

The Clinicaltrials.gov registration number is NCT05996549. The registration for the protocol version 2.0 took place in August 2023, with the initial participant being enrolled in March 2022.

Re-examining the Nexus Between Maternal Smoking Behavior and Under-Five Children's ARI in India: A Comprehensive Study

Background

The burden of acute respiratory infections (ARIs) among children under-five is a serious concern in lower and middle-income countries (LMICs), including India, where it is positively associated with indoor smoking exposures. This study re-examines the impact of maternal smoking on ARIs among children under 5 in India, considering other indoor air pollutant factors and covariates. The aim is to establish existing findings and capture any differentials in results using comprehensive analytical approaches.

Methods

Data from the National Family Health Survey (NFHS-5), 2019 - 21, was used. Descriptive statistics, bivariate analysis, multivariable logistic regression models, and interaction analysis were applied to accomplish the study objective.

Results

The adjusted likelihood of ARI was 1.24 (95% CI: 1.04-1.48) times higher in under-five children with smoking mothers than those with non-smoking mothers. The result was also observed to be almost similar across all seasons. Moreover, the combined effect of maternal smoking with other household members smoking and using unclean cooking fuel without a separate ventilated kitchen escalated the risk (AOR: 2.01; 95% CI: 1.98-2.67). Breastfeeding was found to be a preventive measure for reducing the risk of indoor smoking exposure. The children who were never breastfed and were born large or small were more susceptible to maternal smoking.

Conclusion

The study highlights the association between maternal smoking and ARIs in Indian under-five children. Interventions include reducing maternal smoking, promoting breastfeeding, and improving respiratory health in fuel-exposed households.

Self-medication and ILI etiologies among individuals presenting at pharmacies with influenza-like illness: Guatemala City, 2018 influenza season

Objectives

We aimed to characterize the proportion of clients presenting to community pharmacies with influenza-like illness (ILI) and the severity of their illness; the proportion with detectable influenza A, influenza B, and other pathogens (i.e., parainfluenza I, II, and III, adenovirus, respiratory syncytial virus, human metapneumovirus); and to describe their self-medication practices.

Methods

A cross-sectional study was conducted in six pharmacies in Guatemala City. Study personnel collected nasopharyngeal and oropharyngeal swabs from participants who met the ILI case definition and who were self-medicating for the current episode. Participants were tested for influenza A and B and other pathogens using real-time RT-PCR. Participants’ ILI-associated self-medication practices were documented using a questionnaire.

Results

Of all patients entering the pharmacy during peak hours who responded to a screening survey (n = 18,016) 6% (n = 1029) self-reported ILI symptoms, of which 45% (n = 470/1029) met the study case definition of ILI. Thirty-one percent (148/470) met inclusion criteria, of which 87% (130/148) accepted participation and were enrolled in the study. Among 130 participants, nearly half tested positive for viral infection (n = 55, 42.3%) and belonged to groups at low risk for complications from influenza. The prevalence of influenza A was 29% (n = 35). Thirteen percent of the study population (n = 17) tested positive for a respiratory virus other than influenza. Sixty-four percent of participants (n = 83) reported interest in receiving influenza vaccination if it were to become available in the pharmacy. Medications purchased included symptom-relieving multi-ingredient cold medications (n = 43/100, 43%), nonsteroidal anti-inflammatory drugs (n = 23, 23%), and antibiotics (n = 16, 16%). Antibiotic use was essentially equal among antibiotic users regardless of viral status. The broad-spectrum antibiotics ceftriaxone and azithromycin were the most common antibiotics purchased.

Conclusions

During a typical influenza season, a relatively low proportion of all pharmacy visitors were experiencing influenza symptoms. A high proportion of clients presenting to pharmacies with ILI tested positive for a respiratory virus. Programs that guide appropriate use of antibiotics in this population are needed and become increasingly important during pandemics caused by respiratory viral pathogens.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13962-8.

SARS-CoV-2 and influenza virus coinfection among patients with severe acute respiratory infection during the first wave of COVID-19 pandemic in Bangladesh: a hospital-based descriptive study

OBJECTIVE

To estimate the proportion of SARS-CoV-2 and influenza virus coinfection among severe acute respiratory infection (SARI) cases-patients during the first wave of COVID-19 pandemic in Bangladesh.

DESIGN

Descriptive study.

SETTING

Nine tertiary level hospitals across Bangladesh.

PARTICIPANTS

Patients admitted as SARI (defined as cases with subjective or measured fever of ≥38 C° and cough with onset within the last 10 days and requiring hospital admission) case-patients.

PRIMARY AND SECONDARY OUTCOMES

Proportion of SARS-CoV-2 and influenza virus coinfection and proportion of mortality among SARI case-patients.

RESULTS

We enrolled 1986 SARI case-patients with a median age: 28 years (IQR: 1.2-53 years), and 67.6% were male. Among them, 285 (14.3%) were infected with SARS-CoV-2; 175 (8.8%) were infected with the influenza virus, and five (0.3%) were coinfected with both viruses. There was a non-appearance of influenza during the usual peak season (May to July) in Bangladesh. SARS-CoV-2 infection was significantly more associated with diabetes (14.0% vs 5.9%, p<0.001) and hypertension (26.7% vs 11.5%, p<0.001). But influenza among SARI case-patients was significantly less associated with diabetes (4.0% vs 7.4%, p=0.047) and hypertension (5.7% vs 14.4%, p=0.001). The proportion of in-hospital deaths among SARS-CoV-2 infected SARI case-patients were higher (10.9% (n=31) vs 4.4% (n=75), p<0.001) than those without SARS-CoV-2 infection; the proportion of postdischarge deaths within 30 days was also higher (9.1% (n=25) vs 4.6% (n=74), p=0.001) among SARS-CoV-2 infected SARI case-patients than those without infection. No in-hospital mortality or postdischarge mortality was registered among the five coinfected SARI case-patients.

CONCLUSIONS

Our findings suggest that coinfection with SARS-CoV-2 and influenza virus was not very common and had less disease severity considering mortality in Bangladesh. There was no circulating influenza virus during the influenza peak season during the COVID-19 pandemic in 2020. Future studies are warranted for further exploration.

The Etiology of Childhood Pneumonia in Bangladesh: Findings From the Pneumonia Etiology Research for Child Health (PERCH) Study

BACKGROUND

Pneumonia remains the leading infectious cause of death among children <5 years, but its cause in most children is unknown. We estimated etiology for each child in 2 Bangladesh sites that represent rural and urban South Asian settings with moderate child mortality.

METHODS

As part of the Pneumonia Etiology Research for Child Health study, we enrolled children 1-59 months of age with World Health Organization-defined severe and very severe pneumonia, plus age-frequency-matched controls, in Matlab and Dhaka, Bangladesh. We applied microbiologic methods to nasopharyngeal/oropharyngeal swabs, blood, induced sputum, gastric and lung aspirates. Etiology was estimated using Bayesian methods that integrated case and control data and accounted for imperfect sensitivity and specificity of the measurements.

RESULTS

We enrolled 525 cases and 772 controls over 24 months. Of the cases, 9.1% had very severe pneumonia and 42.0% (N = 219) had infiltrates on chest radiograph. Three cases (1.5%) had positive blood cultures (2 Salmonella typhi, 1 Escherichia coli and Klebsiella pneumoniae). All 4 lung aspirates were negative. The etiology among chest radiograph-positive cases was predominantly viral [77.7%, 95% credible interval (CrI): 65.3-88.6], primarily respiratory syncytial virus (31.2%, 95% CrI: 24.7-39.3). Influenza virus had very low estimated etiology (0.6%, 95% CrI: 0.0-2.3). Mycobacterium tuberculosis (3.6%, 95% CrI: 0.5-11.0), Enterobacteriaceae (3.0%, 95% CrI: 0.5-10.0) and Streptococcus pneumoniae (1.8%, 95% CrI: 0.0-5.9) were the only nonviral pathogens in the top 10 etiologies.

CONCLUSIONS

Childhood severe and very severe pneumonia in young children in Bangladesh is predominantly viral, notably respiratory syncytial virus.

Influenza-like illness is associated with high pneumococcal carriage density in Malawian children

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Influenza-like illness (ILI) in children is associated with high pneumococcal carriage density.

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Children with ILI harboured more viral organisms than asymptomatic healthy children.

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Children with ILI patients had higher IL-8 levels in nasal aspirates than asymptomatic healthy children.

Background

High pneumococcal carriage density is a risk factor for invasive pneumococcal disease (IPD) and transmission, but factors that increase pneumococcal carriage density are still unclear.

Methods

We undertook a cross-sectional study to evaluate the microbial composition, cytokine levels and pneumococcal carriage densities in samples from children presenting with an influenza-like illness (ILI) and asymptomatic healthy controls (HC).

Results

The proportion of children harbouring viral organisms (Relative risk (RR) 1.4, p = 0.0222) or ≥ 4 microbes at a time (RR 1.9, p < 0.0001), was higher in ILI patients than HC. ILI patients had higher IL-8 levels in nasal aspirates than HC (median [IQR], 265.7 [0 – 452.3] vs. 0 [0 – 127.3] pg/ml; p = 0.0154). Having an ILI was associated with higher pneumococcal carriage densities compared to HC (RR 4.2, p < 0.0001).

Conclusion

These findings suggest that children with an ILI have an increased propensity for high pneumococcal carriage density. This could in part contribute to increased susceptibility to IPD and transmission in the community.

The burden of laboratory-confirmed influenza infection in Lebanon between 2008 and 2016: a single tertiary care center experience

BACKGROUND

Influenza is a major cause of morbidity and mortality worldwide. Following the 2009 pandemic, there was widened interest in studying influenza burden in all regions. However, since data from the World Health Organization (WHO) Middle East and North Africa (MENA) region remain limited, we aimed to contribute to the understanding of influenza burden in Lebanon.

METHODS

A retrospective chart review extending over a period of 8 seasons from Jan 1st, 2008 till June 30th, 2016 at a tertiary care center in Beirut was performed. All cases confirmed to have influenza based on rapid antigen detection or/and polymerase chain reaction on a respiratory sample were included for analysis. Data on epidemiology, clinical presentation, complications, antiviral use and mortality were collected for analysis.

RESULTS

A total of 1829 cases of laboratory-confirmed influenza were identified. Average annual positivity rate was 14% (positive tests over total requested). Both influenza A and B co-circulated in each season with predominance of influenza A. Influenza virus started circulating in December and peaked in January and February. The age group of 19-50 years accounted for the largest proportion of cases (22.5%) followed by the age group of 5-19 years (18%). Pneumonia was the most common complication reported in 33% of cases. Mortality reached 3.8%. The two extremes of age (< 2 years and ≥ 65 years) were associated with a more severe course of disease, hospitalization, intensive care unit (ICU) admission, complications, and mortality rate. Of all the identified cases, 26% were hospitalized. Moderate-to-severe disease was more likely in influenza B cases but no difference in mortality was reported between the two types. Antivirals were prescribed in 68.8% and antibiotics in 41% of cases. There seemed to be an increasing trend in the number of diagnosed and hospitalized cases over the years of the study.

CONCLUSION

Patients with laboratory-confirmed influenza at our center had a high rate of hospitalization and mortality. A population based prospective surveillance study is needed to better estimate the burden of Influenza in Lebanon that would help formulate a policy on influenza control.

Malnutrition trends in Rohingya children aged 6-59 months residing in informal settlements in Cox's Bazar District, Bangladesh: An analysis of cross-sectional, population-representative surveys

BACKGROUND

More than 700,000 ethnic Rohingya have crossed the border from Rakhine State, Myanmar to Cox's Bazar District, Bangladesh, following escalated violence by Myanmar security forces. The majority of these displaced Rohingya settled in informal sites on previously forested land, in areas without basic infrastructure or access to services.

METHODS AND FINDINGS

Three cross-sectional population-representative cluster surveys were conducted, including all informal settlements of Rohingya refugees in the Ukhia and Teknaf Upazilas of Cox's Bazar District. The first survey was conducted during the acute phase of the humanitarian response (October-November 2017), and the second and third surveys were conducted 6 (April-May 2018) and 12 (October-November 2018) months later. Anthropometric indices (weight, height, mid-upper arm circumference [MUAC], oedema) and haemoglobin (Hb) were measured in children aged 6-59 months following standard procedures. Final samples for survey rounds 1, 2, and 3 (R1, R2, and R3) included 1,113, 628, and 683 children, respectively, of which approximately half were male (50.7%-53.5% per round) and a third were 6-23 months of age (32.4%-33.3% per round). Prevalence of global acute malnutrition (GAM) as assessed by weight for height in R2 (12.1%, 95% CI: 9.6-15.1) and R3 (11.0%, 95% CI: 8.4-14.2) represent a significant decline from the observed prevalence in R1 (19.4%, 95% CI: 16.8-22.3) (p < 0.001 for both comparisons). Overall, the prevalence of anaemia significantly declined (p < 0.001) between the first 2 rounds (47.9%, 95% CI: 44.1-51.7 and 32.3%, 95% CI: 27.8-37.1, respectively); prevalence increased significantly (p = 0.04) to 39.8% (95% CI, 34.1-45.4) during R3 but remained below R1 levels. Reported receipt of both fortified blended foods (12.8%) and micronutrient powders (10.3%) were low during R1 but increased significantly (p < 0.001 for both) within the first 6 months to 49.8% and 29.9%, respectively. Although findings demonstrate improvement in anthropometric indicators during a period in which nutrition programme coverage increased, causation cannot be determined from the cross-sectional design.

CONCLUSIONS

These data document significant improvements in both acute and micronutrient malnutrition among Rohingya children in makeshift settlements. These declines coincide with a scaleup of services aimed at prevention and treatment of malnutrition. Ongoing activities to improve access to nutritional services may facilitate further reductions in malnutrition levels to sustained below-crisis levels.

Trivalent influenza vaccination randomized control trial of pregnant women and adverse fetal outcomes

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A two-year randomized controlled trial of seasonal IIV3.

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Over 2000 mothers in South Africa, from March 2011 until post 2012 influenza season.

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Birth outcomes investigated were fetal death, SGA, birth weight and prematurity.

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Vaccine demonstrated no appreciable impact of maternal IIV3 immunization.

Introduction

The purpose of this study was to evaluate the association of influenza vaccine during pregnancy and adverse fetal outcomes. Preventing fetal death, low birth weight, small for gestational age birth and preterm birth are important potential effects of antenatal maternal influenza immunization for which there are conflicting data.

Materials and methods

A double-blind, randomized, placebo-controlled clinical trial of trivalent inactivated influenza vaccine was conducted in South Africa from March 2011 until after the 2012 influenza season when the infants born had reached the age of 24 weeks. Mothers were administered the vaccine or placebo during pregnancy at a gestation of 20 to 36 weeks. A comparison of rates of fetal death, low birth weight, small for gestational age birth, and preterm birth, between vaccinated and placebo groups was made. Fetal outcome differences between the groups were measured using Student’s t-tests, vaccine efficacy with 95% confidence intervals, and Poisson regression for incidence rates. All analyses except fetal death excluded mothers who were administered vaccine or placebo after 34 weeks gestational age.

Results

There were 2116 HIV-uninfected pregnant women age 18 to 38 years in the trial; 2005 infants were born to mothers where vaccine or placebo had been administered ≥ 14 days prior to delivery, and there were 6 miscarriages and 23 stillbirths. There was no significant vaccine efficacy (with [95% confidence interval]) on fetal death (−21.2% [−150.8, 41.4]), low birth weight (−11.1% [−42.3, 12.5]), small for gestational age birth (−9.9% [−35.6, 11.0]), or preterm birth (−21.3% [−60.5, 8.3]). Neither was vaccine efficacy demonstrated when the analysis was restricted to infants of mothers who were exposed to an influenza season (1832 outcomes available).

Conclusion

We did not find a beneficial effect of trivalent inactivated influenza vaccine during pregnancy on adverse fetal outcomes.

Surveillance and characterisation of influenza viruses among patients with influenza-like illness in Bali, Indonesia, July 2010-June 2014

BACKGROUND

Although Indonesia has high fatality rate of human A/H5N1 cases, epidemiological and clinical data on influenza virus circulation among humans has been limited. Within Indonesia, Bali province is of interest due to high population densities of humans, pigs and poultry. This study aims to characterize and compare the epidemiological and clinical patterns of influenza viruses in humans through surveillance among patients with influenza-like illness (ILI) in Bali, Indonesia.

METHODS

ILI patients were recruited at 21 sentinel health facilities across all nine regencies in Bali, from July 2010 to June 2014. PCR-based assays were used for detection and subtyping of influenza viruses. Demographic, behavioural and clinical data were tested for associations with influenza using chi-squared tests and logistic regression.

RESULTS

Of 2077 ILI patients, 291 (14.0%) tested positive for influenza A, 152 (7.3%) for influenza B, and 16 (0.77%) for both influenza A and B. Of the influenza A isolates, the majority 61.2% were A/H3N2, followed by A/H1N1-pdm09 (80; 26.1%). Two A/H5N1 were identified. Influenza positive rates were significantly higher during wet season months (28.3%), compared with the dry season (13.8%; χ2 = 61.1; df = 1; p < 0.0001). Clinical predictors for infection varied by virus type, with measured fever (≥38 °C) more strongly associated with influenza B (AOR: 1.62; 95% CI: 1.10, 2.39).

CONCLUSION

Influenza circulates year-round among humans in Bali with higher activity during the wet season. High contact rates with poultry and pigs, along with influenza virus detection that could not be subtyped through conventional assays, highlight the need for molecular studies to characterize epidemiological and evolutionary dynamics of influenza in this setting.

Prevalence, determinants and health care-seeking behavior of childhood acute respiratory tract infections in Bangladesh

Background

Acute respiratory infections (ARIs) are one of the leading causes of child mortality worldwide and contribute significant health burden for developing nations such as Bangladesh. Seeking care and prompt management is crucial to reduce disease severity and to prevent associated morbidity and mortality.

Objective

This study investigated the prevalence and care-seeking behaviors among under-five children in Bangladesh and identified factors associated with ARI prevalence and subsequent care-seeking behaviors.

Method

The present study analyzed cross-sectional data from the 2014 Bangladesh Demographic Health Survey. Bivariate analysis was performed to estimate the prevalence of ARIs and associated care-seeking. Logistic regression analysis was used to determine the influencing socio-economic and demographic predictors. A p-value of <0.05 was considered as the level of significance.

Result

Among 6,566 under-five children, 5.42% had experienced ARI symptoms, care being sought for 90% of affected children. Prevalence was significantly higher among children < 2 years old, and among males. Children from poorer and the poorest quintiles of households were 2.40 (95% CI = 1.12, 5.15) and 2.36 (95% CI = 1.06, 5.24) times more likely to suffer from ARIs compared to the wealthiest group. Seeking care was significantly higher among female children (AOR = 2.19, 95% CI = 0.94, 5.12). The likelihood of seeking care was less for children belonging to the poorest quintile compared to the richest (AOR = 0.03, 95% CI = 0.01, 0.55). Seeking care from untrained providers was 3.74 more likely among rural residents compared to urban (RRR = 3.74, 95% CI = 1.10, 12.77).

Conclusion

ARIs continue to contribute high disease burden among under-five children in Bangladesh lacking of appropriate care-seeking behavior. Various factors, such as age and sex of the children, wealth index, the education of the mother, and household lifestyle factors were significantly associated with ARI prevalence and care-seeking behaviors. In addition to public-private actions to increase service accessibility for poorer households, equitable and efficient service distribution and interventions targeting households with low socio-economic status and lower education level, are recommended.

Estimation of the burden of flu-association influenza-like illness visits on total clinic visits through the sentinel influenza monitoring system in Senegal during the 2013-2015 influenza seasons

Knowing the burden of influenza is helpful for policy decisions. Here we estimated the contribution of influenza-like illness (ILI) visits associated with laboratory-confirmed influenza among all clinic visits in a Senegal sentinel network. ILI data from ten sentinel sites were collected from January 2013 to December 2015. ILI was defined as an axillary measured fever of more than 37.5 °C with a cough or a sore throat. Collected nasopharyngeal swabs were tested for influenza viruses by rRT-PCR. Influenza-associated ILI was defined as ILI with laboratory-confirmed influenza. For the influenza disease burden estimation, we used all-case outpatient visits during the study period who sought care at selected sites. Of 4030 ILI outpatients tested, 1022 were influenza positive. The estimated proportional contribution of influenza-associated ILI was, per 100 outpatients, 1.2 (95% CI 1.1-1.3), 0.32 (95% CI 0.28-0.35), 1.11 (95% CI 1.05-1.16) during 2013, 2014, 2015, respectively. The age-specific outpatient visits proportions of influenza-associated ILI were higher among children under 5 years (0.68%, 95% CI: 0.62-0.70). The predominant virus during years 2013 and 2015 was influenza B while A/H3N2 subtype was predominant during 2014. Influenza viruses cause a substantial burden of outpatient visits particularly among children under 5 of age in Senegal and highlight the need of vaccination in risk groups.

Nonannual seasonality of influenza-like illness in a tropical urban setting

BACKGROUND

In temperate and subtropical climates, respiratory diseases exhibit seasonal peaks in winter. In the tropics, with no winter, peak timings are irregular.

METHODS

To obtain a detailed picture of influenza-like illness (ILI) patterns in the tropics, we established an mHealth study in community clinics in Ho Chi Minh City (HCMC). During 2009-2015, clinics reported daily case numbers via SMS, with a subset performing molecular diagnostics for influenza virus. This real-time epidemiology network absorbs 6000 ILI reports annually, one or two orders of magnitude more than typical surveillance systems. A real-time online ILI indicator was developed to inform clinicians of the daily ILI activity in HCMC.

RESULTS

From August 2009 to December 2015, 63 clinics were enrolled and 36 920 SMS reports were received, covering approximately 1.7M outpatient visits. Approximately 10.6% of outpatients met the ILI case definition. ILI activity in HCMC exhibited strong nonannual dynamics with a dominant periodicity of 206 days. This was confirmed by time series decomposition, stepwise regression, and a forecasting exercise showing that median forecasting errors are 30%-40% lower when using a 206-day cycle. In ILI patients from whom nasopharyngeal swabs were taken, 31.2% were positive for influenza. There was no correlation between the ILI time series and the time series of influenza, influenza A, or influenza B (all P > 0.15).

CONCLUSION

This suggests, for the first time, that a nonannual cycle may be an essential driver of respiratory disease dynamics in the tropics. An immunological interference hypothesis is discussed as a potential underlying mechanism.

The burden of influenza-associated respiratory hospitalizations in Bhutan, 2015-2016

BACKGROUND

Influenza burden estimates help provide evidence to support influenza prevention and control programs. In this study, we estimated influenza-associated respiratory hospitalization rates in Bhutan, a country considering influenza vaccine introduction.

METHODS

Using real-time reverse transcription-polymerase chain reaction laboratory results from severe acute respiratory infection (SARI) surveillance, we estimated the proportion of respiratory hospitalizations attributable to influenza each month among patients aged <5, 5-49, and ≥50 years in six Bhutanese districts for 2015 and 2016. We divided the sum of the monthly influenza-attributed hospitalizations by the total of the six district populations to generate age-specific rates for each year.

RESULTS

In 2015, 10% of SARI patients tested positive for influenza (64/659) and 18% tested positive (129/736) in 2016. The incidence of influenza-associated hospitalizations among all age groups was 50/100 000 persons (95% confidence interval [CI]: 45-55) in 2015 and 118/100 000 persons (95% CI: 110-127) in 2016. The highest rates were among children <5 years: 182/100 000 (95% CI: 153-210) in 2015 and 532/100 000 (95% CI: 473-591) in 2016. The second highest influenza-associated hospitalization rates were among adults ≥50 years: 110/100 000 (95% CI: 91-130) in 2015 and 193/100 000 (95% CI: 165-221) in 2016.

CONCLUSIONS

Influenza viruses were associated with a substantial burden of severe illness requiring hospitalization especially among children and older adults. These findings can be used to understand the potential impact of seasonal influenza vaccination in these age groups.

Health status of returning refugees, internally displaced persons, and the host community in a post-conflict district in northern Sri Lanka: a cross-sectional survey

Background

Although the adverse impacts of conflict-driven displacement on health are well-documented, less is known about how health status and associated risk factors differ according to displacement experience. This study quantifies health status and quality of life among returning refugees, internally displaced persons, and the host community in a post-conflict district in Northern Sri Lanka, and explores associated risk factors.

Methods

We analysed data collected through a household survey (n = 570) in Vavuniya district, Sri Lanka. The effect of displacement status and other risk factors on perceived quality of life as estimated from the 36-item Short Form Questionnaire, mental health status from 9-item Patient Health Questionnaire, and self-reported chronic disease status were examined using univariable analyses and multivariable regressions.

Results

We found strong evidence that perceived quality of life was significantly lower for internally displaced persons than for the host community and returning refugees, after adjusting for covariates. Both mental health status and chronic disease status did not vary remarkably among the groups, suggesting that other risk factors might be more important determinants of these outcomes.

Conclusions

Our study provides important insights into the overall health and well-being of the different displaced sub-populations in a post-conflict setting. Findings reinforce existing evidence on the relationship between displacement and health but also highlight gaps in research on the long-term health effects of prolonged displacement. Understanding the heterogeneity of conflict-affected populations has important implications for effective and equitable humanitarian service delivery in a post-conflict setting.

Effectiveness of an educational intervention to improve antibiotic dispensing practices for acute respiratory illness among drug sellers in pharmacies, a pilot study in Bangladesh

BACKGROUND

Inappropriate dispensing of antibiotics for acute respiratory illness (ARI) is common among drug sellers in Bangladesh. In this study, we evaluated the impact of an educational intervention to promote guidelines for better ARI management among drug sellers.

METHODS

From June 2012 to December 2013, we conducted baseline and post-intervention surveys on dispensing practices in 100 pharmacies within Dhaka city. In these surveys, drug sellers participated in 6 standardized role-playing scenarios led by study staffs acting as caregivers of ARI patients and drug sellers were blinded to these surveys. After the baseline survey, we developed ARI guidelines and facilitated a one-day educational intervention about ARI management for drug sellers. Our guidelines only recommended antibiotics for children with complicated ARI. Finally, we conducted the six month post-intervention survey using the same scenarios to record changes in drug dispensing practices.

RESULTS

Only 2/3 of participating pharmacies were licensed and few (11%) of drug sellers had pharmacy training. All the drug sellers were male, had a median age of 34 years (IQR 28-41). For children, dispensing of antibiotics for uncomplicated ARI decreased (30% baseline vs. 21% post-intervention; p = 0.04), but drug sellers were equally likely to dispense antibiotics for complicated ARI (15% baseline vs. 17% post-intervention; p = 0.6) and referrals to physicians for complicated ARIs decreased (70% baseline vs. 58% post-intervention; p = 0.03). For adults, antibiotic dispensing remained similar for uncomplicated ARI (48% baseline vs. 40% post-intervention; p = 0.1) but increased among those with complicated ARI (44% baseline vs. 78% post-intervention; p < 0.001). Although our evidence-based guidelines recommended against prescribing antihistamines for children, drug sellers continued to sell similar amounts for uncomplicated ARI (33% baseline vs. 32% post-intervention; p = 0.9).

CONCLUSIONS

Despite the intervention, drug sellers continued to frequently dispense antibiotics for ARI, except for children with uncomplicated ARI. Pairing educational interventions among drug sellers with raising awareness about proper antibiotic use among general population should be further explored. In addition, annual licensing and an reaccreditation system with comprehensive monitoring should be enforced, using penalties for non-compliant pharmacies as possible incentives for appropriate dispensing practices.

Healthcare utilization for common infectious disease syndromes in Soweto and Klerksdorp, South Africa

Introduction

Understanding healthcare utilization helps characterize access to healthcare, identify barriers and improve surveillance data interpretation. We describe healthcare-seeking behaviors for common infectious syndromes and identify reasons for seeking care.

Methods

We conducted a cross-sectional survey among residents in Soweto and Klerksdorp, South Africa. Households were interviewed about demographic characteristics; recent self-reported episodes of pneumonia, influenza-like illness (ILI), chronic febrile respiratory illness and meningitis in individuals of all ages; recent diarrhea in children aged < 5 years; and consultation with healthcare facilities and providers.

Results

From July-October 2012, we interviewed 1,442 households in Klerksdorp and 973 households in Soweto. Public clinics were consulted most frequently for pneumonia, ILI and diarrhea in a child <5 years old at both sites; public hospitals were most frequently consulted for chronic respiratory and meningitis syndromes. Of all illness episodes reported, there were 110 (35%) in Klerksdorp and 127 (32%) in Soweto for which the person did not seek care with a licensed medical provider. Pharmacies were often consulted by individuals with pneumonia (Klerksdorp: 17, 16%; Soweto: 38, 22%) or ILI (Klerksdorp: 35, 24%; 44, 28%). Patients who did not seek care with a licensed provider reported insufficient time (Klerksdorp: 7%; Soweto, 20%) and lack of medications at the facility (Klerksdorp: 4%; Soweto: 8%) as barriers.

Conclusion

Public government healthcare facilities are commonly consulted for infectious syndromes and pharmacies are frequently consulted particularly for respiratory diseases. Improving medication availability at healthcare facilities and streamlining healthcare delivery may improve access of licensed providers for serious illnesses.

Responses to hypothetical health scenarios overestimate healthcare utilization for common infectious syndromes: a cross-sectional survey, South Africa, 2012

Background

Asking people how they would seek healthcare in a hypothetical situation can be an efficient way to estimate healthcare utilization, but it is unclear how intended healthcare use corresponds to actual healthcare use.

Methods

We performed a cross-sectional survey between August and September 2012 among households in Soweto and Klerksdorp, South Africa, to compare healthcare seeking behaviors intended for hypothetical common infectious syndromes (pneumonia, influenza-like illness [ILI], chronic respiratory illness, meningitis in persons of any age, and diarrhea in a child < 5 years old) with the self-reported healthcare use among patients with those syndromes.

Results

For most syndromes, the proportion of respondents who intended to seek healthcare at any facility or provider (99–100%) in a hypothetical scenario exceeded the proportion that did seek care (78–100%). More people intended to seek care for a child < 5 years old with diarrhea (186/188 [99%]) than actually did seek care (32/41 [78%], P < 0.01). Although most people faced with hypothetical scenarios intended to seek care with licensed medical providers such as hospitals and clinics (97–100%), patients who were ill reported lower use of licensed medical providers (55–95%).

Conclusions

People overestimated their intended healthcare utilization, especially with licensed medical providers, compared with reported healthcare utilization among patients with these illnesses. Studies that measure intended healthcare utilization should consider that actual use of healthcare facilities may be lower than intended use.

Influenza Among Young Children in Bangladesh: Clinical Characteristics and Outcomes From a Randomized Clinical Trial

Background

Influenza causes substantial morbidity in children worldwide, although influenza vaccine is seldom used in low-resource settings. More information on the clinical presentation of influenza and the efficacy of vaccine is needed to inform policy.

Methods

In 2013 we conducted a randomized, placebo-controlled clinical trial of live attenuated influenza vaccine (LAIV) in children aged 24-59 months in Bangladesh (N = 1761). If participants met prespecified specimen collection criteria, we collected nasopharyngeal washes for testing by singleplex reverse-transcription polymerase chain reaction (RT-PCR) for laboratory-confirmed influenza virus infection (LCI). A panel of RT-PCR assays was used to detect noninfluenza respiratory viruses. Primary efficacy results have been reported. In this analysis of prespecified and post hoc objectives from the trial, we compared signs and symptoms between LCI and non-LCI cases and estimated the efficacy of LAIV against moderate-to-severe LCI and other prespecified non-LCI clinical outcomes including all-cause pneumonia and acute otitis media.

Results

The most common signs and symptoms of LCI were fever, cough, and runny nose. The combination of subjective fever and cough had a 63% sensitivity for LCI. The combination of measured fever, cough, and runny nose was most specific (90%) but had low sensitivity (32%) for LCI. The efficacy of LAIV against vaccine-strain moderate-to-severe LCI was 56.7% (95% confidence interval, 9.5%-79.2%). No statistically significant vaccine efficacy was found against the non-laboratory-confirmed clinical outcomes.

Conclusions

It was not possible to distinguish LCI from noninfluenza viral infections on clinical evaluations alone in this population of Bangladeshi children. LAIV was efficacious against moderate-to-severe LCI.

Clinical Trials Registration

NCT01797029.

Avian influenza surveillance in domestic waterfowl and environment of live bird markets in Bangladesh, 2007-2012

Avian influenza viruses, including highly pathogenic strains, pose severe economic, animal and public health concerns. We implemented live bird market surveillance in Bangladesh to identify the subtypes of avian influenza A viruses in domestic waterfowl and market environments. We collected waterfowl samples monthly from 4 rural sites from 2007 to 2012 and environmental samples from 4 rural and 16 urban sites from 2009 to 2012. Samples were tested through real-time RT-PCR, virus culture, and sequencing to detect and characterize avian influenza A viruses. Among 4,308 waterfowl tested, 191 (4.4%) were positive for avian influenza A virus, including 74 (1.9%) avian influenza A/H5 subtype. The majority (99%, n = 73) of the influenza A/H5-positive samples were from healthy appearing waterfowl. Multiple subtypes, including H1N1, H1N3, H3N2, H3N6, H3N8, H4N1, H4N2, H4N6, H5N1 (clades 2.2.2, 2.3.2.1a, 2.3.4.2), H5N2, H6N1, H7N9, H9N2, H11N2 and H11N3, H11N6 were detected in waterfowl and environmental samples. Environmental samples tested positive for influenza A viruses throughout the year. Avian influenza viruses, including H5N1 and H9N2 subtypes were also identified in backyard and small-scale raised poultry. Live bird markets could be high-risk sites for harboring the viruses and have the potential to infect naive birds and humans exposed to them.

Estimation of community-level influenza-associated illness in a low resource rural setting in India

Objective

To estimate rates of community-level influenza-like-illness (ILI) and influenza-associated ILI in rural north India.

Methods

During 2011, we conducted household-based healthcare utilization surveys (HUS) for any acute medical illness (AMI) in preceding 14days among residents of 28villages of Ballabgarh, in north India. Concurrently, we conducted clinic-based surveillance (CBS) in the area for AMI episodes with illness onset ≤3days and collected nasal and throat swabs for influenza virus testing using real-time polymerase chain reaction. Retrospectively, we applied ILI case definition (measured/reported fever and cough) to HUS and CBS data. We attributed 14days of risk-time per person surveyed in HUS and estimated community ILI rate by dividing the number of ILI cases in HUS by total risk-time. We used CBS data on influenza positivity and applied it to HUS-based community ILI rates by age, month, and clinic type, to estimate the community influenza-associated ILI rates.

Findings

The HUS of 69,369 residents during the year generated risk-time of 3945 person-years (p-y) and identified 150 (5%, 95%CI: 4–6) ILI episodes (38 ILI episodes/1,000 p-y; 95% CI 32–44). Among 1,372 ILI cases enrolled from clinics, 126 (9%; 95% CI 8–11) had laboratory-confirmed influenza (A (H3N2) = 72; B = 54). After adjusting for age, month, and clinic type, overall influenza-associated ILI rate was 4.8/1,000 p-y; rates were highest among children <5 years (13; 95% CI: 4–29) and persons≥60 years (11; 95%CI: 2–30).

Conclusion

We present a novel way to use HUS and CBS data to generate estimates of community burden of influenza. Although the confidence intervals overlapped considerably, higher point estimates for burden among young children and older adults shows the utility for exploring the value of influenza vaccination among target groups.

Costs of hospitalization with respiratory syncytial virus illness among children aged <5 years and the financial impact on households in Bangladesh, 2010

Background

Respiratory syncytial virus (RSV) is the leading cause of acute respiratory illness in young children and results in significant economic burden. There is no vaccine to prevent RSV illness but a number of vaccines are in development. We conducted this study to estimate the costs of severe RSV illness requiring hospitalization among children <5 years and associated financial impact on households in Bangladesh. Data of this study could be useful for RSV vaccine development and also the value of various preventive strategies, including use of an RSV vaccine in children if one becomes available.

Methods

From May through October 2010, children aged <5 years with laboratory–confirmed RSV were identified from a sentinel influenza program database at four tertiary hospitals. Research assistants visited case–patients’ homes after hospital discharge and administered a structured questionnaire to record direct medical costs (physician consultation fee, costs for hospital bed, medicines and diagnostic tests); non–medical costs (costs for food, lodging and transportation); indirect costs (caregivers’ productivity loss), and coping strategies used by families to pay for treatment. We used WHO–Choice estimates for routine health care service costs. We added direct, indirect and health care service costs to calculate cost–per–episode of severe RSV illness. We used Monte Carlo simulation to estimate annual economic burden for severe RSV illness.

Findings

We interviewed caregivers of 39 persons hospitalized for RSV illness. The median direct cost for hospitalization was US$ 62 (interquartile range [IQR] = 43–101), indirect cost was US$ 19 (IQR = 11–29) and total cost was US$ 94 (IQR = 67–127). The median out–of–pocket cost was 24% of monthly household income of affected families (US$ 143), and >50% families borrowed money to meet treatment cost. We estimated that the median direct cost of RSV–associated hospitalization in children aged <5 years in Bangladesh was US$ 10 million (IQR: US$ 7–16 million), the median indirect cost was US$ 3.0 million (IQR: 2–5 million) in 2010.

Conclusion

RSV–associated hospitalization among children aged <5 years represents a substantial economic burden in Bangladesh. Affected families frequently incurred considerable out of pocket and indirect costs for treatment that resulted in financial hardship.

Burden of Influenza in 4 Ecologically Distinct Regions of Peru: Household Active Surveillance of a Community Cohort, 2009-2015

BACKGROUND

There are limited data on the burden of disease posed by influenza in low- and middle-income countries. Furthermore, most estimates of influenza disease burden worldwide rely on passive sentinel surveillance at health clinics and hospitals that lack accurate population denominators.

METHODS

We documented influenza incidence, seasonality, health-system utilization with influenza illness, and vaccination coverage through active community-based surveillance in 4 ecologically distinct regions of Peru over 6 years. Approximately 7200 people in 1500 randomly selected households were visited 3 times per week. Naso- and oropharyngeal swabs were collected from persons with influenza-like illness and tested for influenza virus by real-time reverse-transcription polymerase chain reaction.

RESULTS

We followed participants for 35353 person-years (PY). The overall incidence of influenza was 100 per 1000 PY (95% confidence interval [CI], 97-104) and was highest in children aged 2-4 years (256/1000 PY [95% CI, 236-277]). Seasonal incidence trends were similar across sites, with 61% of annual influenza cases occurring during the austral winter (May-September). Of all participants, 44 per 1000 PY (95% CI, 42-46) sought medical care, 0.7 per 1000 PY (95% CI, 0.4-1.0) were hospitalized, and 1 person died (2.8/100000 PY). Influenza vaccine coverage was 27% among children aged 6-23 months and 26% among persons aged ≥65 years.

CONCLUSIONS

Our results indicate that 1 in 10 persons develops influenza each year in Peru, with the highest incidence in young children. Active community-based surveillance allows for a better understanding of the true burden and seasonality of disease that is essential to plan the optimal target groups, timing, and cost of national influenza vaccination programs.

Mild Respiratory Illness Among Young Children Caused by Highly Pathogenic Avian Influenza A (H5N1) Virus Infection in Dhaka, Bangladesh, 2011

Background

In March 2011, a multidisciplinary team investigated 2 human cases of highly pathogenic avian influenza A(H5N1) virus infection, detected through population-based active surveillance for influenza in Bangladesh, to assess transmission and contain further spread.

Methods

We collected clinical and exposure history of the case patients and monitored persons coming within 1 m of a case patient during their infectious period. Nasopharyngeal wash specimens from case patients and contacts were tested with real-time reverse-transcription polymerase chain reaction, and virus culture and isolates were characterized. Serum samples were tested with microneutralization and hemagglutination inhibition assays. We tested poultry, wild bird, and environmental samples from case patient households and surrounding areas for influenza viruses.

Results

Two previously healthy case patients, aged 13 and 31 months, had influenzalike illness and fully recovered. They had contact with poultry 7 and 10 days before illness onset, respectively. None of their 57 contacts were subsequently ill. Clade 2.2.2.1 highly pathogenic avian influenza H5N1 viruses were isolated from the case patients and from chicken fecal samples collected at the live bird markets near the patients' dwellings.

Conclusion

Identification of H5N1 cases through population-based surveillance suggests possible additional undetected cases throughout Bangladesh and highlights the importance of surveillance for mild respiratory illness among populations frequently exposed to infected poultry.

Influenza: A Global Perspective

Influenza is a common respiratory illness in children and accounts for substantial morbidity and mortality on an annual basis. Inactivated and live influenza vaccines are approved for children and are safe and efficacious. The absolute effectiveness of vaccines varies by year and is influenced by several factors. The reason for recent reduced performance of live-attenuated influenza vaccines is poorly understood, and active research is ongoing. Vaccination programs are less common in tropical and subtropical countries, where unique logistical and feasibility challenges exist. Antiviral medications for prevention and treatment of influenza in children are an important adjunct to vaccines.

Infection with influenza A(H1N1)pdm09 during the first wave of the 2009 pandemic: Evidence from a longitudinal seroepidemiologic study in Dhaka, Bangladesh

Background

We determined influenza A(H1N1)pdm09 antibody levels before and after the first wave of the pandemic in an urban community in Dhaka, Bangladesh.

Methods

We identified a cohort of households by stratified random sampling. We collected baseline serum specimens during July‐August 2009, just prior to the initial wave of the 2009 pandemic in this community and a second specimen during November 2009, after the pandemic peak. Paired sera were tested for antibodies against A(H1N1)pdm09 virus using microneutralization assay and hemagglutinin inhibition (HI) assay. A fourfold increase in antibody titer by either assay with a titer of ≥40 in the convalescent sera was considered a seroconversion. At baseline, an HI titer of ≥40 was considered seropositive. We collected information on clinical illness from weekly home visits.

Results

We tested 779 paired sera from the participants. At baseline, before the pandemic wave, 1% overall and 3% of persons >60 years old were seropositive. After the first wave of the pandemic, 211 (27%) individuals seroconverted against A(H1N1)pdm09. Children aged 5‐17 years had the highest proportion (37%) of seroconversion. Among 264 (34%) persons with information on clinical illness, 191 (72%) had illness >3 weeks prior to collection of the follow‐up sera and 73 (38%) seroconverted. Sixteen (22%) of these 73 seroconverted participants reported no clinical illness.

Conclusion

After the first pandemic wave in Dhaka, one in four persons were infected by A(H1N1)pdm09 virus and the highest burden of infection was among the school‐aged children. Seroprevalence studies supplement traditional surveillance systems to estimate infection burden.

History and current trends in influenza virus infections with special reference to Sri Lanka

The World Health Organization (WHO) estimates that approximately one billion people are infected and up to 500,000 people die from influenza each year in the world. Influenza is considered to be the greatest killer of the human populations, due to the 1918 Spanish flu, which killed millions around the world. Despite the effective treatment available against influenza, it still contributes to significant morbidity and mortality. Currently circulating influenza strains in humans include influenza A (H1N1)pdm09, influenza A (H3N2) and influenza B viruses, (B/Victoria and B/Yamagata). Influenza has been prevalent in Sri Lanka from 1969, since then it continued to cause morbidity and mortality in children and adults. The current global influenza surveillance network monitors the global influenza activity through WHO collaborating centres. The Medical Research Institute monitors and diagnoses influenza cases in the country as part of the WHO network laboratories. Vaccinations to high risk groups and antiviral therapy for the successful prevention of influenza have been practiced in Sri Lanka. This review highlights the impact of influenza on public health in Sri Lanka including the historical aspects, current diagnostic practices and prevention approaches in high risk individuals in the country.

Estimates of influenza and respiratory syncytial virus incidences with fraction modeling approach in Baguio City, the Philippines, 2012-2014

BACKGROUND

Estimation of the incidences of influenza and respiratory syncytial virus (RSV) infection is important for disease control. Previous estimate in the city showed a substantial burden of influenza in both outpatients and inpatients while it did not account for individuals who do not seek medical attention nor RSV.

PATIENTS/METHODS

A total of 17 674 influenza-like illness (ILI) and 13 242 severe acute respiratory illness (SARI) cases were recruited, and samples were collected from 6267 and 2962 of ILI and SARI cases, respectively. RT-PCR assays were performed to detect influenza and RSV in the samples. A health-seeking behavior survey was conducted from February 2014 to April 2014 to estimate the fraction of infected individuals who did not seek medical attention between rainy and dry season.

RESULTS

Average influenza and RSV incidence rates in outpatients were 1.6 and 1.4 per 1000 individuals, respectively, and the highest incidence rate for both viruses was found in the of 6-23 month age group. Average influenza and RSV hospitalization incidence rates were 1.7 and 1.9 per 1000 individuals, respectively. Further, we estimated that the incidence rates of influenza and RSV in individuals who did not seek medical attention were threefold and 1.6-fold those in the medically attended population.

CONCLUSIONS

Respiratory syncytial virus and influenza pose a substantial disease burden, particularly in hospitalized cases. The implementation of either a community-based approach or an enhanced surveillance system in combination with a community survey will allow a better understanding of the disease burdens of RSV and influenza in the Philippines.

Comparison of Influenza Epidemiological and Virological Characteristics between Outpatients and Inpatients in Zhejiang Province, China, March 2011-June 2015

Given the rapid rate of global spread and consequently healthcare costs related to influenza, surveillance plays an important role in monitoring the emerging pandemics in China. However, the characteristics of influenza in Southeast of China haven’t been fully studied. Our study use the surveillance data collected from 16 sentinel hospitals across Zhejiang Province during March 2011 through June 2015, including the demographic information and respiratory specimens from influenza-like illness (ILI) patients and severe acute respiratory illness (SARI) patients. As analysis results, most SARI and ILI patients were in the age group of 0–4 years old (62.38% of ILI and 71.54% of SARI). The respiratory specimens have statistically significantly higher positive rate for influenza among ILI patients than that among SARI patients (p < 0.001). The comparison between ILI patients and SARI patients shows no statistically significantly difference in detecting influenza virus type and influenza A virus subtype. The SARI and ILI patients were found to be positively correlated for overall positive rate (r = 0.63, p < 0.001), the weekly percentage of A(H1N1)pdm09 (r = 0.51, p < 0.001), influenza B virus (r = 0.17, p = 0.013), and A/H3N2 (r = 0.43, p < 0.001) among all the positive numbers. Our study demonstrated that the activities of influenza virus, including its subtypes, had a similar temporal pattern between ILI and SARI cases.

Multiple Viral Infection Detected from Influenza-Like Illness Cases in Indonesia

Influenza is one of the common etiologies of the upper respiratory tract infection (URTI). However, influenza virus only contributes about 20 percent of influenza-like illness patients. The aim of the study is to investigate the other viral etiologies from ILI cases in Indonesia. Of the 334 samples, 266 samples (78%) were positive at least for one virus, including 107 (42%) cases of multiple infections. Influenza virus is the most detected virus. The most frequent combination of viruses identified was adenovirus and human rhinovirus. This recent study demonstrated high detection rate of several respiratory viruses from ILI cases in Indonesia. Further studies to determine the relationship between viruses and clinical features are needed to improve respiratory disease control program.

Establishing seasonal and alert influenza thresholds in Cambodia using the WHO method: implications for effective utilization of influenza surveillance in the tropics and subtropics

OBJECTIVE

To establish seasonal and alert thresholds and transmission intensity categories for influenza to provide timely triggers for preventive measures or upscaling control measures in Cambodia.

METHODS

Using Cambodia's influenza-like illness (ILI) and laboratory-confirmed influenza surveillance data from 2009 to 2015, three parameters were assessed to monitor influenza activity: the proportion of ILI patients among all outpatients, proportion of ILI samples positive for influenza and the product of the two. With these parameters, four threshold levels (seasonal, moderate, high and alert) were established and transmission intensity was categorized based on a World Health Organization alignment method. Parameters were compared against their respective thresholds.

RESULTS

Distinct seasonality was observed using the two parameters that incorporated laboratory data. Thresholds established using the composite parameter, combining syndromic and laboratory data, had the least number of false alarms in declaring season onset and were most useful in monitoring intensity. Unlike in temperate regions, the syndromic parameter was less useful in monitoring influenza activity or for setting thresholds.

CONCLUSION

Influenza thresholds based on appropriate parameters have the potential to provide timely triggers for public health measures in a tropical country where monitoring and assessing influenza activity has been challenging. Based on these findings, the Ministry of Health plans to raise general awareness regarding influenza among the medical community and the general public. Our findings have important implications for countries in the tropics/subtropics and in resource-limited settings, and categorized transmission intensity can be used to assess severity of potential pandemic influenza as well as seasonal influenza.

Factors driving customers to seek health care from pharmacies for acute respiratory illness and treatment recommendations from drug sellers in Dhaka city, Bangladesh

BACKGROUND

Pharmacies in Bangladesh serve as an important source of health service. A survey in Dhaka reported that 48% of respondents with symptoms of acute respiratory illness (ARI) identified local pharmacies as their first point of care. This study explores the factors driving urban customers to seek health care from pharmacies for ARI, their treatment adherence, and outcome.

METHODS

A cross-sectional study was conducted among 100 selected pharmacies within Dhaka from June to December 2012. Study participants were patients or patients' relatives aged >18 years seeking care for ARI from pharmacies without prescription. Structured interviews were conducted with customers after they sought health service from drug sellers and again over phone 5 days postinterview to discuss treatment adherence and outcome.

RESULTS

We interviewed 302 customers patronizing 76 pharmacies; 186 (62%) sought care for themselves and 116 (38%) sought care for a sick relative. Most customers (215; 71%) were males. The majority (90%) of customers sought care from the study pharmacy as their first point of care, while 18 (6%) had previously sought care from another pharmacy and 11 (4%) from a physician for their illness episodes. The most frequently reported reasons for seeking care from pharmacies were ease of access to pharmacies (86%), lower cost (46%), availability of medicine (33%), knowing the drug seller (20%), and convenient hours of operation (19%). The most commonly recommended drugs were acetaminophen dispensed in 76% (228) of visits, antihistamine in 69% (208), and antibiotics in 42% (126). On follow-up, most (86%) of the customers had recovered and 12% had sought further treatment.

CONCLUSION

People with ARI preferred to seek care at pharmacies rather than clinics because these pharmacies were more accessible and provided prompt treatment and medicine with no service charge. We recommend raising awareness among drug sellers on proper dispensing practices and enforcement of laws and regulations for drug sales.

Household-level risk factors for secondary influenza-like illness in a rural area of Bangladesh

Objective

To describe household‐level risk factors for secondary influenza‐like illness (ILI), an important public health concern in the low‐income population of Bangladesh.

Methods

Secondary analysis of control participants in a randomised controlled trial evaluating the effect of handwashing to prevent household ILI transmission. We recruited index‐case patients with ILI – fever (<5 years); fever, cough or sore throat (≥5 years) – from health facilities, collected information on household factors and conducted syndromic surveillance among household contacts for 10 days after resolution of index‐case patients’ symptoms. We evaluated the associations between household factors at baseline and secondary ILI among household contacts using negative binomial regression, accounting for clustering by household.

Results

Our sample was 1491 household contacts of 184 index‐case patients. Seventy‐one percentage reported that smoking occurred in their home, 27% shared a latrine with one other household and 36% shared a latrine with >1 other household. A total of 114 household contacts (7.6%) had symptoms of ILI during follow‐up. Smoking in the home (RR_adj 1.9, 95% CI: 1.2, 3.0) and sharing a latrine with one household (RR_adj 2.1, 95% CI: 1.2, 3.6) or >1 household (RR_adj 3.1, 95% CI: 1.8–5.2) were independently associated with increased risk of secondary ILI.

Conclusion

Tobacco use in homes could increase respiratory illness in Bangladesh. The mechanism between use of shared latrines and household ILI transmission is not clear. It is possible that respiratory pathogens could be transmitted through faecal contact or contaminated fomites in shared latrines.

Efficacy of a Russian-backbone live attenuated influenza vaccine among young children in Bangladesh: a randomised, double-blind, placebo-controlled trial

Background

The rates of influenza illness and associated complications are high among children in Bangladesh. We assessed the clinical efficacy and safety of a Russian-backbone live attenuated influenza vaccine (LAIV) at two field sites in Bangladesh.

Methods

Between Feb 27 and April 9, 2013, children aged 2–4 years in urban Kamalapur and rural Matlab, Bangladesh, were randomly assigned in a 2:1 ratio, according to a computer-generated schedule, to receive one intranasal dose of LAIV or placebo. After vaccination, we monitored children in weekly home visits until Dec 31, 2013, with study clinic surveillance for influenza illness. The primary outcome was symptomatic, laboratory-confirmed influenza illness due to vaccine-matched strains. Analysis was per protocol. The trial is registered with ClinicalTrials.gov, number NCT01797029.

Findings

Of 1761 children enrolled, 1174 received LAIV and 587 received placebo. Laboratory-confirmed influenza illness due to vaccine-matched strains was seen in 93 (15·8%) children in the placebo group and 79 (6·7%) in the LAIV group. Vaccine efficacy of LAIV for vaccine-matched strains was 57·5% (95% CI 43·6–68·0). The vaccine was well tolerated, and adverse events were balanced between the groups. The most frequent adverse events were tachypnoea (n=86 in the LAIV group and n=54 in the placebo group), cough (n=73 and n=43), and runny nose (n=68 and n=39), most of which were mild.

Interpretation

This single-dose Russian-backbone LAIV was safe and efficacious at preventing symptomatic laboratory-confirmed influenza illness due to vaccine-matched strains. LAIV programmes might reduce the burden of influenza illness in Bangladesh.

Funding

The Bill & Melinda Gates Foundation.

Morbidity, Mortality, and Seasonality of Influenza Hospitalizations in Egypt, November 2007-November 2014

BACKGROUND

Influenza typically comprises a substantial portion of acute respiratory infections, a leading cause of mortality worldwide. However, influenza epidemiology data are lacking in Egypt. We describe seven years of Egypt's influenza hospitalizations from a multi-site influenza surveillance system.

METHODS

Syndromic case definitions identified individuals with severe acute respiratory infection (SARI) admitted to eight hospitals in Egypt. Standardized demographic and clinical data were collected. Nasopharyngeal and oropharyngeal swabs were tested for influenza using real-time reverse transcription polymerase chain reaction and typed as influenza A or B, and influenza A specimens subtyped.

RESULTS

From November 2007-November 2014, 2,936/17,441 (17%) SARI cases were influenza-positive. Influenza-positive patients were more likely to be older, female, pregnant, and have chronic condition(s) (all p<0.05). Among them, 53 (2%) died, and death was associated with older age, five or more days from symptom onset to hospitalization, chronic condition(s), and influenza A (all p<0.05). An annual seasonal influenza pattern occurred from July-June. Each season, the proportion of the season's influenza-positive cases peaked during November-May (19-41%).

CONCLUSIONS

In Egypt, influenza causes considerable morbidity and mortality and influenza SARI hospitalization patterns mirror those of the Northern Hemisphere. Additional assessment of influenza epidemiology in Egypt may better guide disease control activities and vaccine policy.

Evolution and Transmission of Respiratory Syncytial Group A (RSV-A) Viruses in Guangdong, China 2008-2015

Respiratory syncytial viruses (RSVs) including subgroups A (RSV-A) and B (RSV-B) are an important cause of acute respiratory tract infections worldwide. RSV-A include major epidemic strains. Fundamental questions concerning the evolution, persistence and transmission of RSV-A are critical for disease control and prevention, yet remain unanswered. In this study, we generated 64 complete G gene sequences of RSV-A strains collected between 2008 and 2015 in Guangdong, China. Phylogenetic analysis was undertaken by incorporating 572 publicly available RSV-A sequences. Current data indicate that genotypes GA1, GA4, and GA5 are endemic with limited epidemic activity. In contrast, the GA2 genotype which likely originated in 1980 has spread rapidly and caused epidemics worldwide. By analyzing GA2 genotype sequences across epidemic seasons within Guangdong, we find that RSV-A epidemics in Guangdong are caused by a combination of virus importation and local persistence, although the magnitude of the latter is likely overestimated due to infrequent sampling in other regions. Our results provide new insights into RSV-A evolution and transmission at global and local scales and highlights the rapid and wide spread of genotype GA2 compared to other genotypes. In order to control RSV transmission and outbreak, both local persistence and external introduction should be taken into account when designing optimal strategies.

Association between serum vitamin D, retinol and zinc status, and acute respiratory infections in underweight and normal-weight children aged 6–24 months living in an urban slum in Bangladesh

We conducted a longitudinal assessment in 466 underweight and 446 normal-weight children aged 6–24 months living in the urban slum of Dhaka, Bangladesh to determine the association between vitamin D and other micronutrient status with upper respiratory tract infection (URI) and acute lower respiratory infection (ALRI). Incidence rate ratios of URI and ALRI were estimated using multivariable generalized estimating equations. Our results indicate that underweight children with insufficient and deficient vitamin D status were associated with 20% and 23–25% reduced risk of URI, respectively, compared to children with sufficient status. Underweight children, those with serum retinol deficiency were at 1·8 [95% confidence interval (CI) 1·4–2·4] times higher risk of ALRI than those with retinol sufficiency. In normal-weight children there were no significant differences between different vitamin D status and the incidence of URI and ALRI. However, normal-weight children with zinc insufficiency and those that were serum retinol deficient had 1·2 (95% CI 1·0–1·5) times higher risk of URI and 1·9 (95% CI 1·4–2·6) times higher risk of ALRI, respectively. Thus, our results should encourage efforts to increase the intake of retinol-enriched food or supplementation in this population. However, the mechanisms through which vitamin D exerts beneficial effects on the incidence of childhood respiratory tract infection still needs further research.

Influenza-associated outpatient visits among children less than 5 years of age in eastern China, 2011-2014

BACKGROUND

The disease burden of influenza in China has not been well described, especially among young children. The aim of this study was to estimate the incidence of outpatient visits associated with influenza in young children in Suzhou, a city of more than 11 million residents in Jiangsu Province in eastern China.

METHODS

Influenza-like illness (ILI) was defined as the presence of fever (axillary temperature ≥38 °C) and cough or sore throat. We collected throat swabs for children less than 5 years of age with ILI who visited Suzhou University Affiliated Children's Hospital (SCH) outpatient clinic or emergency room between April 2011 and March 2014. Suzhou CDC, a national influenza surveillance network laboratory, tested for influenza viruses by real-time reverse transcription-polymerase chain reaction assay (rRT-PCR). Influenza-associated ILI was defined as ILI with laboratory-confirmed influenza by rRT-PCR. To calculate the incidence of influenza-associated outpatient visits, we conducted community-based healthcare utilization surveys to determine the proportion of hospital catchment area residents who sought care at SCH.

RESULTS

The estimated incidence of influenza-associated ILI outpatient visits among children aged <5 years in the catchment area of Suzhou was, per 100 population, 17.4 (95 % CI 11.0-25.3) during April 2011-March 2012, 14.6 (95 % CI 5.2-26.2) during April 2012-March 2013 and 21.4 (95 % CI: 10.9-33.5) during April 2013-March 2014. The age-specific outpatient visit rates of influenza-associated ILI were 4.9, 21.1 and 21.2 per 100 children aged 0- <6 months, 6- <24 months and 24- <60 months, respectively.

CONCLUSION

Influenza virus infection causes a substantial burden of outpatient visits among young children in Suzhou, China. Targeted influenza prevention and control strategies for young children in Suzhou are needed to reduce influenza-associated outpatient visits in this age group.

Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance

The 2009 influenza A(H1N1)pdm09 pandemic highlighted the need for improved scientific knowledge to support better pandemic preparedness and seasonal influenza control. The Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance (SHIVERS) project, a 5-year (2012–2016) multiagency and multidisciplinary collaboration, aimed to measure disease burden, epidemiology, aetiology, risk factors, immunology, effectiveness of vaccination and other prevention strategies for influenza and other respiratory infectious diseases of public health importance. Two active, prospective, population-based surveillance systems were established for monitoring influenza and other respiratory pathogens among those hospitalized patients with acute respiratory illness and those enrolled patients seeking consultations at sentinel general practices. In 2015, a sero-epidemiological study will use a sample of patients from the same practices. These data will provide a full picture of the disease burden and risk factors from asymptomatic infections to severe hospitalized disease and deaths and related economic burden. The results during the first 2 years (2012–2013) provided scientific evidence to (a) support a change to NZ's vaccination policy for young children due to high influenza hospitalizations in these children; (b) contribute to the revision of the World Health Organization's case definition for severe acute respiratory illness for global influenza surveillance; and (c) contribute in part to vaccine strain selection using vaccine effectiveness assessment in the prevention of influenza-related consultations and hospitalizations. In summary, SHIVERS provides valuable international platforms for supporting seasonal influenza control and pandemic preparedness, and responding to other emerging/endemic respiratory-related infections.

Influenza hospitalization epidemiology from a severe acute respiratory infection surveillance system in Jordan, January 2008-February 2014

Background

Acute respiratory infections (ARIs) are a major cause of morbidity and mortality worldwide. Influenza typically contributes substantially to the burden of ARI, but only limited data are available on influenza activity and seasonality in Jordan.

Methods

Syndromic case definitions were used to identify individuals with severe acute respiratory infections (SARI) admitted to four sentinel hospitals in Jordan. Demographic and clinical data were collected. Nasopharyngeal and oropharyngeal swabs were tested for influenza using real‐time reverse transcription polymerase chain reaction and typed as influenza A or B, with influenza A further subtyped.

Results

From January 2008–February 2014, 2891 SARI cases were tested for influenza, and 257 (9%) were positive. While 73% of all SARI cases were under 5 years of age, only 57% of influenza‐positive cases were under 5 years of age. Eight (3%) influenza‐positive cases died. An annual seasonal pattern of influenza activity was observed. The proportion of influenza‐positive cases peaked during November–January (14–42%) in the non‐pandemic years.

Conclusions

Influenza is associated with substantial morbidity and mortality in Jordan. The seasonal pattern of influenza aligns with known Northern Hemisphere seasonality. Further characterization of the clinical and financial burden of influenza in Jordan will be critical in supporting decisions regarding disease control activities.

The Burden of Influenza-Associated Hospitalizations in Oman, January 2008-June 2013

Introduction

Acute respiratory infections (ARI), including influenza, comprise a leading cause of morbidity and mortality worldwide. Influenza surveillance provides important information to inform policy on influenza control and vaccination. While the epidemiology of influenza has been well characterized in western countries, few data exist on influenza epidemiology in the Eastern Mediterranean Region. We describe the epidemiology of influenza virus in Oman.

Methods

Using syndromic case definitions and protocols, patients from four regional hospitals in Oman were enrolled in a descriptive prospective study to characterize the burden of severe acute respiratory infections (SARI) and influenza. Eligible patients provided demographic information as well as oropharyngeal (OP) and nasopharyngeal (NP) swabs. Specimens were tested for influenza A and influenza B; influenza A viruses were subtyped using RT-PCR.

Results

From January 2008 through June 2013, a total of 5,147 cases were enrolled and tested for influenza. Influenza strains were detected in 8% of cases for whom samples were available. Annual incidence rates ranged from 0.5 to 15.4 cases of influenza-associated SARI per 100,000 population. The median age of influenza patients was 6 years with children 0–2 years accounting for 34% of all influenza-associated hospitalizations. By contrast, the median age of non-influenza SARI cases was 1 year with children 0–2 years comprising 59% of SARI. Compared to non-influenza SARI cases, a greater proportion of influenza cases had pre-existing chronic conditions and underwent ventilation during hospitalization.

Conclusions

Influenza virus is associated with a substantial proportion of SARI in Oman. Influenza in Oman approximately follows northern hemisphere seasonality, with major peaks in October to December and a lesser peak around April. The burden of influenza was greatest in children and the elderly. Future efforts should examine the burden of influenza in other potential risk groups such as pregnant women to inform interventions including targeted vaccination.

Incidence of viral respiratory infections in a prospective cohort of outpatient and hospitalized children aged ≤5 years and its associated cost in Buenos Aires, Argentina

Background

Although information about the incidence of viral respiratory illnesses and their associated cost can help health officials explore the value of interventions, data are limited from middle-income countries.

Methods

During 2008–2010, we conducted a prospective cohort study and followed ~1,800 Argentinian children aged ≤5 years to identify those children who were hospitalized or who sought care at an emergency room with any acute respiratory infection sign or symptom (e.g., rhinorrhea, cough, wheezing, tachypnea, retractions, or cyanosis). Respiratory samples were obtained for respiratory syncytial virus, influenza, parainfluenza, adenovirus, and metapneumovirus testing by immunofluorescence and for rhinovirus by real-time reverse transcription polymerase chain reaction.

Results

The incidence of respiratory syncytial virus (24/1000 children-years), human metapneumovirus (8/1000 children-years), and influenza (8/1000 children-years) illnesses was highest among hospitalized children aged <6 months and decreased among older children. In contrast, the incidence of rhinovirus was highest (12/1000 children-years) among those aged 6–23 months. In the emergency room, the incidence of rhinovirus was 459; respiratory syncytial virus 352; influenza 185; parainfluenza 177; metapneumovirus 130; and adenovirus 73/1,000 children-years. The total cost of hospitalization was a median of US$529 (Interquartile range, US$362–789).

Conclusions

Our findings indicate that respiratory viruses, in particular rhinovirus, respiratory syncytial virus, metapneumovirus, and influenza may be associated with severe illness causing substantial economic burden.

Influenza-Associated Disease Burden in Kenya: A Systematic Review of Literature

Background

In Kenya data on the burden of influenza disease are needed to inform influenza control policies.

Methods

We conducted a systematic review of published data describing the influenza disease burden in Kenya using surveillance data collected until December 2013. We included studies with laboratory confirmation of influenza, well-defined catchment populations, case definitions used to sample patients for testing and a description of the laboratory methods used for influenza testing. Studies with or without any adjustments on the incidence rates were included.

Results

Ten studies reporting the incidence of medically-attended and non-medically attended influenza were reviewed. For all age groups, the influenza positive proportion ranged from 5–10% among hospitalized patients, and 5–27% among all medically-attended patients (a combination of in- and outpatients). The adjusted incidence rate of hospitalizations with influenza among children <5 years ranged from 2.7–4.7 per 1,000 [5.7 per 1,000 in children <6 months old], and were 7–10 times higher compared to persons aged ≥5 years. The adjusted incidence of all medically-attended influenza among children aged <5 years ranged from 13.0–58.0 per 1,000 compared to 4.3–26.0 per 1,000 among persons aged ≥5 years.

Conclusions

Our review shows an expanding set of literature on disease burden associated with influenza in Kenya, with a substantial burden in children under five years of age. Hospitalizations with influenza in these children were 2–3 times higher than reported in the United States. These findings highlight the possible value of an influenza vaccination program in Kenya, with children <5 years and pregnant women being potentially important targets.

Respiratory viruses and torque teno virus in adults with acute respiratory infections

Objective

To define the molecular epidemiology of respiratory viral infections in adult patients.

Methods

Nasal and throat swabs were collected from all adult patients with influenza-like illness (ILI), acute respiratory infection (ARI), or severe ARI (SARI) admitted to a tertiary hospital in Surakarta, Indonesia, between March 2010 and April 2011 and analyzed for 19 respiratory viruses and for torque teno virus (TTV) and human gyrovirus (HGyV).

Results

Respiratory viruses were detected in 61.3% of the subjects, most of whom had ARI (90.8%, OR = 11.39), were hospitalized (96.9%, OR = 22.31), had asthma exacerbation (90.9%, OR = 8.67), and/or had pneumonia (80%, OR = 4.0). Human rhinovirus (HRV) A43 predominated. Influenza A H3N2, human metapneumovirus (HMPV) subtypes A1 and A2, the influenza B virus, human adenovirus B, and human coronavirus OC43 were also detected. All respiratory viruses were detected in the transition month between the rainy and dry seasons. No mixed respiratory virus infection was found. Coinfections of the influenza A H3N2 virus with TTV, HMPV with TTV, HRV with TTV, and human parainfluenza virus-3 with TTV were found in 4.7, 2.8, 19.8, and 0.9% of the samples, respectively.

Conclusions

This study highlights the need to perform routine detection of respiratory viruses in adults hospitalized with ARI, asthma exacerbation, and/or pneumonia.

The East Jakarta Project: surveillance for highly pathogenic avian influenza A(H5N1) and seasonal influenza viruses in patients seeking care for respiratory disease, Jakarta, Indonesia, October 2011-September 2012

Indonesia has reported the most human infections with highly pathogenic avian influenza (HPAI) A(H5N1) virus worldwide. We implemented enhanced surveillance in four outpatient clinics and six hospitals for HPAI H5N1 and seasonal influenza viruses in East Jakarta district to assess the public health impact of influenza in Indonesia. Epidemiological and clinical data were collected from outpatients with influenza-like illness (ILI) and hospitalized patients with severe acute respiratory infection (SARI); respiratory specimens were obtained for influenza testing by real-time reverse transcription-polymerase chain reaction. During October 2011-September 2012, 1131/3278 specimens from ILI cases (34·5%) and 276/1787 specimens from SARI cases (15·4%) tested positive for seasonal influenza viruses. The prevalence of influenza virus infections was highest during December-May and the proportion testing positive was 76% for ILI and 36% for SARI during their respective weeks of peak activity. No HPAI H5N1 virus infections were identified, including hundreds of ILI and SARI patients with recent poultry exposures, whereas seasonal influenza was an important contributor to acute respiratory disease in East Jakarta. Overall, 668 (47%) of influenza viruses were influenza B, 384 (27%) were A(H1N1)pdm09, and 359 (25%) were H3. While additional data over multiple years are needed, our findings suggest that seasonal influenza prevention efforts, including influenza vaccination, should target the months preceding the rainy season.

Influenza and other respiratory viruses detected by influenza-like illness surveillance in Leyte Island, the Philippines, 2010-2013

This study aimed to determine the role of influenza-like illness (ILI) surveillance conducted on Leyte Island, the Philippines, including involvement of other respiratory viruses, from 2010 to 2013. ILI surveillance was conducted from January 2010 to March 2013 with 3 sentinel sites located in Tacloban city, Palo and Tanauan of Leyte Island. ILI was defined as fever ≥38°C or feverish feeling and either cough or running nose in a patient of any age. Influenza virus and other 5 respiratory viruses were searched. A total of 5,550 ILI cases visited the 3 sites and specimens were collected from 2,031 (36.6%) cases. Among the cases sampled, 1,637 (75.6%) were children aged <5 years. 874 (43.0%) cases were positive for at least one of the respiratory viruses tested. Influenza virus and respiratory syncytial virus (RSV) were predominantly detected (both were 25.7%) followed by human rhinovirus (HRV) (17.5%). The age distributions were significantly different between those who were positive for influenza, HRV, and RSV. ILI cases were reported throughout the year and influenza virus was co-detected with those viruses on approximately half of the weeks of study period (RSV in 60.5% and HRV 47.4%). In terms of clinical manifestations, only the rates of headache and sore throat were significantly higher in influenza positive cases than cases positive to other viruses. In conclusion, syndromic ILI surveillance in this area is difficult to detect the start of influenza epidemic without laboratory confirmation which requires huge resources. Age was an important factor that affected positive rates of influenza and other respiratory viruses. Involvement of older age children may be useful to detect influenza more effectively.

Epidemiology of severe acute respiratory illness (SARI) among adults and children aged ≥5 years in a high HIV-prevalence setting, 2009-2012

OBJECTIVE

There are few published studies describing severe acute respiratory illness (SARI) epidemiology amongst older children and adults from high HIV-prevalence settings. We aimed to describe SARI epidemiology amongst individuals aged ≥5 years in South Africa.

METHODS

We conducted prospective surveillance for individuals with SARI from 2009-2012. Using polymerase chain reaction, respiratory samples were tested for ten viruses, and blood for pneumococcal DNA. Cumulative annual SARI incidence was estimated at one site with population denominators.

FINDINGS

We enrolled 7193 individuals, 9% (621/7067) tested positive for influenza and 9% (600/6519) for pneumococcus. HIV-prevalence was 74% (4663/6334). Among HIV-infected individuals with available data, 41% of 2629 were receiving antiretroviral therapy (ART). The annual SARI hospitalisation incidence ranged from 325-617/100,000 population. HIV-infected individuals experienced a 13-19 times greater SARI incidence than HIV-uninfected individuals (p<0.001). On multivariable analysis, compared to HIV-uninfected individuals, HIV-infected individuals were more likely to be receiving tuberculosis treatment (odds ratio (OR):1.7; 95%CI:1.1-2.7), have pneumococcal infection (OR 2.4; 95%CI:1.7-3.3) be hospitalised for >7 days rather than <2 days (OR1.7; 95%CI:1.2-2.2) and had a higher case-fatality ratio (8% vs 5%;OR1.7; 95%CI:1.2-2.3), but were less likely to be infected with influenza (OR 0.6; 95%CI:0.5-0.8). On multivariable analysis, independent risk indicators associated with death included HIV infection (OR 1.8;95%CI:1.3-2.4), increasing age-group, receiving mechanical ventilation (OR 6.5; 95%CI:1.3-32.0) and supplemental-oxygen therapy (OR 2.6; 95%CI:2.1-3.2).

CONCLUSION

The burden of hospitalized SARI amongst individuals aged ≥5 years is high in South Africa. HIV-infected individuals are the most important risk group for SARI hospitalization and mortality in this setting.