Unacceptably high mortality related to measles epidemics in Niger, Nigeria, and Chad

Maternal Education and Children Home Alone in 63 Low- and Middle-Income Countries

Background. Maternal education may influence child supervision practices in low-and middle-income countries (LMIC). However, little is known about the maternal factors that can improve child supervision in LMIC with scarce childcare facilities. Objective. To investigate the prevalence of children under 5 years home alone and examine the association between mother's formal education and children home alone across 63 LMIC. Methods. The study used data from 50 Multiple Indicator Cluster Surveys and 13 Demographic and Health Surveys with a sample of 501 769 children. We estimated Prevalence Ratios (PRs) for the association between maternal education and children home alone using multivariable Poisson regression, adjusting for covariates such as child's age and sex, mother's age and marital status, number of adults inhabiting the households, and urbanicity. Results. Prevalence of children home alone across 63 LMIC ranged from 1.1% to 50.1%. A significant negative association between mothers with more years of formal education and children home alone was found across 16 LMIC. However, the opposite trend was observed in Nigeria, Senegal, and Côte d'Ivoire. Null association was found across 44 LMIC. Conclusions. The varied pattern of the associations observed across LMIC underscores the importance of regional and local factors when developing policies and interventions to ensure safety and adequate care for children aged under 5 years in LMIC.

Population-Level Risk Factors Related to Measles Case Fatality: A Conceptual Framework Based on Expert Consultation and Literature Review

A better understanding of population-level factors related to measles case fatality is needed to estimate measles mortality burden and impact of interventions such as vaccination. This study aimed to develop a conceptual framework of mechanisms associated with measles case fatality ratios (CFRs) and assess the scope of evidence available for related indicators. Using expert consultation, we developed a conceptual framework of mechanisms associated with measles CFR and identified population-level indicators potentially associated with each mechanism. We conducted a literature review by searching PubMed on 31 October 2021 to determine the scope of evidence for the expert-identified indicators. Studies were included if they contained evidence of an association between an indicator and CFR and were excluded if they were from non-human studies or reported non-original data. Included studies were assessed for study quality. Expert consultation identified five mechanisms in a conceptual framework of factors related to measles CFR. We identified 3772 studies for review and found 49 studies showing at least one significant association with CFR for 15 indicators (average household size, educational attainment, first- and second-dose coverage of measles-containing vaccine, human immunodeficiency virus prevalence, level of health care available, stunting prevalence, surrounding conflict, travel time to major city or settlement, travel time to nearest health care facility, under-five mortality rate, underweight prevalence, vitamin A deficiency prevalence, vitamin A treatment, and general malnutrition) and only non-significant associations for five indicators (antibiotic use for measles-related pneumonia, malaria prevalence, percent living in urban settings, pneumococcal conjugate vaccination coverage, vitamin A supplementation). Our study used expert consultation and a literature review to provide additional insights and a summary of the available evidence of these underlying mechanisms and indicators that could inform future measles CFR estimations.

Second-dose measles vaccination and associated factors among under-five children in urban areas of North Shoa Zone, Central Ethiopia, 2022

Introduction

Measles remain a leading cause of vaccine-preventable infant mortality. In Africa, about 13 million cases and 6,50,000 deaths occur annually, with Sub-Saharan Africa having the highest morbidity and mortality. Ethiopia launched second-dose measles vaccination into the routine immunization program in the second year of life in 2019. However, little has been known about the coverage of the second-dose measles vaccine. Therefore, the purpose of this study was to assess the level of second-dose measles vaccine uptake and associated factors in North Shoa Zone, Central Ethiopia.

Objective

To assess second-dose measles vaccination and associated factors among under-five children and to identify reasons for not being vaccinated in urban areas of North Shoa Zone, Central Ethiopia, 2022.

Method

A community-based cross-sectional study was conducted from 1 February to 15 March 2022. The sample size was 410, and it was allocated proportionally to each kebelle. The study units were selected consecutively. The data were collected using structured interviewer-administered questionnaires. Four nurses were used as data collectors. Data were coded manually and entered into Epi-data Version 4.4.2.1. Frequency and cross-tabs were used for data cleaning. Data were analyzed using SPSS Version 21 software. Multicollinearity and model goodness-of-fit tests were checked. A multivariable logistic regression model at 95% CI was used to identify factors associated with the dependent variable.

Result

The response rate was 90.7%. The level of second-dose measles vaccination among children in urban areas of North Shoa Zone was 42.5% [95% CI (36.8, 47.3)]. Maternal age of ≤ 25 years [AOR = 9.12: 95% CI (1.97, 42.19)], 26-30 years [AOR = 9.49: 95% CI (2.33, 38.63)], 31-35 years [AOR = 7.87: 95% CI (1.78, 34.79)]; average time mothers had been waiting for vaccination at the health facility [AOR = 3.68: 95% CI (1.33, 10.23)]; awareness about vaccine-preventable diseases [AOR = 4.15: 95% CI (1.53, 11.26)]; and awareness on recommended measles doses [AOR = 17.81: 95% CI (3.91, 81.22)] were identified as factors associated with MCV2 vaccination. The major reason (48.1%) reported by mothers for not vaccinating second-dose measles vaccine was being unaware of the need to return for second-dose measles vaccination.

Conclusion and recommendation

The level of second-dose measles vaccination (MCV2) among children in urban areas of the North Shoa Zone was low. Maternal age, average time mothers had been waiting for vaccination at the health facility, awareness about vaccine-preventable diseases, recommended age for the last vaccination, and recommended measles doses were identified as factors associated with MCV2 uptake. The major reason for not vaccinating MCV2 was a lack of information (unaware of the need to return for MCV2, unaware of the need to return for MCV2, and the place and/or time of immunization unknown). Hence, enhancing awareness about vaccine-preventable diseases, shortening the average time for vaccination at the health facility by half an hour, creating an alerting mechanism for MCV2 appointments, and future studies on the effect of healthcare provider-related factors on MCV2 uptake are recommended.

Investigating persistent measles dynamics in Niger and associations with rainfall

Measles is a major cause of child mortality in sub-Saharan Africa. Current immunization strategies achieve low coverage in areas where transmission drivers differ substantially from those in high-income countries. A better understanding of measles transmission in areas with measles persistence will increase vaccination coverage and reduce ongoing transmission. We analysed weekly reported measles cases at the district level in Niger from 1995 to 2004 to identify underlying transmission mechanisms. We identified dominant periodicities and the associated spatial clustering patterns. We also investigated associations between reported measles cases and environmental drivers associated with human activities, particularly rainfall. The annual and 2-3-year periodicities dominated the reporting data spectrum. The annual periodicity was strong with contiguous spatial clustering, consistent with the latitudinal gradient of population density, and stable over time. The 2-3-year periodicities were weaker, unstable over time and had spatially fragmented clustering. The rainy season was associated with a lower risk of measles case reporting. The annual periodicity likely reflects seasonal agricultural labour migration, whereas the 2-3-year periodicity potentially results from multiple mechanisms such as reintroductions and vaccine coverage heterogeneity. Our findings suggest that improving vaccine coverage in seasonally mobile populations could reduce strong measles seasonality in Niger and across similar settings.

Changing trends in measles vaccination status between 2004 and 2014 among children aged 12-23 months in Bangladesh

OBJECTIVE

To assess the current measles vaccination status in Bangladesh, explain changing differentials in measles vaccination, and determine contexts that may improve measles vaccination coverage.

METHODS

Secondary data analysis of datasets (2004-2014) from the nationally representative Bangladesh Demographic and Health Surveys that followed stratified, multi-stage cluster sampling design conducted both in urban and rural contexts.

RESULTS

5468 children aged 12-23 months were surveyed, of whom 892 (16%) reported non-compliance to measles vaccine. After simultaneous adjusting for covariates in multivariate logistic regression, children who came from a poor socio-economic background, who had mothers with no formal schooling, who were underweight, of higher birth order (≥4), who had adolescent mothers, who had a history of home delivery and who had no exposure to media were observed to be significantly associated with lack of measles vaccination. Measles vaccination coverage among children of adolescent mothers was consistently low. Despite lack of media exposure, measles vaccination status gradually increased from 26% in 2004 to 33% in 2014. Lack of maternal education was no longer associated with measles vaccination status in 2007, 2011 and 2014. Stunted children continued to be associated with lack of measles immunisation in 2014. Children with higher birth order demonstrated 53% excess risk for not being immunised with measles vaccine. Mothers with no exposure to mass media were two times more likely to have children without measles immunisation as indicated by BDHS 2014 data.

CONCLUSIONS

Our findings will help policy makers formulate strategies for expanding measles vaccination coverage in order to achieve further reduction in disease burden and mortality in Bangladesh.

Descriptive epidemiology of measles surveillance data, Osun state, Nigeria, 2016-2018

Background

Globally, an estimate of 254,928 measles cases in 2015 and 89,780 deaths in 2016 occur annually. In Nigeria, measles is the fifth leading causes of under-five child mortality with 342 confirmed cases found in the first 9 epidemic weeks in some states including Osun State. We described the distribution, trend and make projection of measles cases in Osun State.

Methods

The Osun State surveillance weekly reporting data on measles cases from all its 30 Local Government Area (LGA) were reviewed, from January 2016 to December 2018 (n = 1205). Data were analyzed using descriptive statistics and a multiplicative time series model (MTSM). The MTSM was used to determine the trend, seasonality in the data and make projections for 2019 and 2020.

Results

Cases of measles were reported across the 30 LGAs of the state between January 2016 and December 2018. The rate of reported cases of measles was 20.2, 34.4 and 28.8 per 100,000 populations in 2016, 2017 and 2018 respectively in Ede south LGA where the highest rates were reported in the 3-year period. Out of the three studied years, year 2017, recorded the highest number of reported cases of measles in Osun State. The trend line for the 3-year period showed a positive correlation (r = + 0.4979, p = 0.056). The computed quarterly variation for the studied years was 1.094 for the 1st quarter, 1.162 for the 2nd quarter, 0.861 for the 3rd quarter and 0.888 for the 4th quarter. A quarterly projection for 2019 and 2020 showed an increasing trend with the second quarter of each year likely to have the highest reported cases of measles.

Conclusions

Ede south LGA has the highest proportion of reported measles cases in Osun State. Measles cases may increase in years ahead, but the second quarter of a year has the highest number. Government should strengthen the existing framework on measles reduction and more attention should be given to the second quarter of each year.

Syndromic surveillance of potentially epidemic infectious diseases: Detection of a measles epidemic in two health centers in Gabon, Central Africa

Measles is a respiratory disease caused by the measles virus (MV) belonging to the Paramyxovirus family and the Morbillivirus genus. Due to a failure in maintaining immunization coverage in some countries, measles is a re-emerging disease in the human population, especially in Africa. The aim of this study was to describe a measles epidemic in Gabon. At first, a syndromic surveillance was set up. Blood samples from febrile patients with maculopapular rash were taken and sent to the measles reference center in Cameroon for laboratory confirmation. Between March and May 2016, 79 clinically suspected cases were reported including 82.3% (n=65) and 17.7% (n=14) in Oyem and Libreville, respectively. In total, 39.2% (n=31) of children were 11 months-old, 34.2% (n=27) were children aged 1 to 4 years, 11.4% (n=9) were older children from 5 to 9 years, 6.3% (n=5) of children were aged 10 to 15 years and 8.9% (n=7) were 15 years and older. 53.3% (16/30) were laboratory confirmed. This measles outbreak reiterates the importance of maintaining a high level of vaccine coverage in Gabon for vaccine-preventable diseases, as well as the usefulness of a near-real-time surveillance system for the detection of infectious diseases.

T Lymphocytes as Measurable Targets of Protection and Vaccination Against Viral Disorders

Continuous epidemiological surveillance of existing and emerging viruses and their associated disorders is gaining importance in light of their abilities to cause unpredictable outbreaks as a result of increased travel and vaccination choices by steadily growing and aging populations. Close surveillance of outbreaks and herd immunity are also at the forefront, even in industrialized countries, where previously eradicated viruses are now at risk of re-emergence due to instances of strain recombination, contractions in viral vector geographies, and from their potential use as agents of bioterrorism. There is a great need for the rational design of current and future vaccines targeting viruses, with a strong focus on vaccine targeting of adaptive immune effector memory T cells as the gold standard of immunity conferring long-lived protection against a wide variety of pathogens and malignancies. Here, we review viruses that have historically caused large outbreaks and severe lethal disorders, including respiratory, gastric, skin, hepatic, neurologic, and hemorrhagic fevers. To observe trends in vaccinology against these viral disorders, we describe viral genetic, replication, transmission, and tropism, host-immune evasion strategies, and the epidemiology and health risks of their associated syndromes. We focus on immunity generated against both natural infection and vaccination, where a steady shift in conferred vaccination immunogenicity is observed from quantifying activated and proliferating, long-lived effector memory T cell subsets, as the prominent biomarkers of long-term immunity against viruses and their associated disorders causing high morbidity and mortality rates.

The hidden burden of measles in Ethiopia: how distance to hospital shapes the disease mortality rate

BACKGROUND

A sequence of annual measles epidemics has been observed from January 2013 to April 2017 in the South West Shoa Zone of the Oromia Region, Ethiopia. We aimed at estimating the burden of disease in the affected area, taking into account inequalities in access to health care due to travel distances from the nearest hospital.

METHODS

We developed a dynamic transmission model calibrated on the time series of hospitalized measles cases. The model provided estimates of disease transmissibility and incidence at a population level. Model estimates were combined with a spatial analysis to quantify the hidden burden of disease and to identify spatial heterogeneities characterizing the effectiveness of the public health system in detecting severe measles infections and preventing deaths.

RESULTS

A total of 1819 case patients and 36 deaths were recorded at the hospital. The mean age was 6.0 years (range, 0-65). The estimated reproduction number was 16.5 (95% credible interval (CI) 14.5-18.3) with a cumulative disease incidence of 2.34% (95% CI 2.06-2.66). Three thousand eight hundred twenty-one (95% CI 1969-5671) severe cases, including 2337 (95% CI 716-4009) measles-related deaths, were estimated in the Woliso hospital's catchment area (521,771 inhabitants). The case fatality rate was found to remarkably increase with travel distance from the nearest hospital: ranging from 0.6% to more than 19% at 20 km. Accordingly, hospital treatment prevented 1049 (95% CI 757-1342) deaths in the area.

CONCLUSIONS

Spatial heterogeneity in the access to health care can dramatically affect the burden of measles disease in low-income settings. In sub-Saharan Africa, passive surveillance based on hospital admitted cases might miss up to 60% of severe cases and 98% of related deaths.

Measles outbreak propagated by children congregating at water collection points in Mayuge District, eastern Uganda, July - October, 2016

BACKGROUND

On 12 October, 2016 a measles outbreak was reported in Mayuge District, eastern Uganda. We investigated the outbreak to determine its scope, identify risk factors for transmission, evaluate vaccination coverage and vaccine effectiveness, and recommend evidence-based control measures.

METHODS

We defined a probable case as onset of fever (≥3 days) and generalized rash, plus ≥1 of the following: conjunctivitis, cough, and/or runny nose in a Mayuge District resident. A confirmed case was a probable case with measles-specific IgM (+) not explained by vaccination. We reviewed medical records and conducted active community case-finding. In a case-control investigation involving probable case-persons and controls matched by age and village, we evaluated risk factors for transmission for both cases and controls during the case-person's likely exposure period (i.e., 7-21 days prior to rash onset). We estimated vaccine effectiveness (VE) using the formula: VE ≈ (1-ORprotective) × 100. We calculated vaccination coverage using the percentage of controls vaccinated.

RESULTS

We identified 62 probable case-persons (attack rate [AR] = 4.0/10,000), including 3 confirmed. Of all age groups, children < 5 years were the most affected (AR = 14/10,000). The epidemic curve showed a propagated outbreak. Thirty-two percent (13/41) of case-persons and 13% (21/161) of control-persons visited water-collection sites (by themselves or with parents) during the case-persons' likely exposure period (ORM-H = 5.0; 95% CI = 1.5-17). Among children aged 9-59 months, the effectiveness of the single-dose measles vaccine was 75% (95% CI = 25-92); vaccination coverage was 68% (95% CI = 61-76).

CONCLUSIONS

Low vaccine effectiveness, inadequate vaccination coverage and congregation at water collection points facilitated measles transmission in this outbreak. We recommended increasing measles vaccination coverage and restriction of children with signs and symptoms of measles from accessing public gatherings.

Risk factors for measles mortality and the importance of decentralized case management during an unusually large measles epidemic in eastern Democratic Republic of Congo in 2013

In 2013, a large measles epidemic occurred in the Aketi Health Zone of the Democratic Republic of Congo. We conducted a two-stage, retrospective cluster survey to estimate the attack rate, the case fatality rate, and the measles-specific mortality rate during the epidemic. 1424 households containing 7880 individuals were included. The estimated attack rate was 14.0%, (35.0% among children aged <5 years). The estimated case fatality rate was 4.2% (6.1% among children aged <5 years). Spatial analysis and linear regression showed that younger children, those who did not receive care, and those living farther away from Aketi Hospital early in the epidemic had a higher risk of measles related death. Vaccination coverage prior to the outbreak was low (76%), and a delayed reactive vaccination campaign contributed to the high attack rate. We provide evidences suggesting that a comprehensive case management approach reduced measles fatality during this epidemic in rural, inaccessible resource-poor setting.

Serological Surveys for complementing assessments of vaccination coverage in sub-Saharan Africa: A systematic review

Background: Serosurveys of biomarkers of infection/vaccination are widely used for evaluating vaccine-induced immunity and monitoring the effectiveness of immunisation programmes in developed countries. In sub-Saharan Africa (sSA) where vaccination coverage (VC) estimates are often incomplete, inaccurate and overestimate effective population immunity, the use of serosurveys is limited. Methods: We conducted a review of the use of serosurveys to assess/complement assessments of VC in sSA by searching electronic databases (PubMed, Embase, Web of Science, Popline, Ovid and Africa Wide Information) for English language articles published from 1st January 1940 to 31st January 2017. We also searched the references of retrieved articles. SSA was defined as all of Africa excluding the countries in North Africa. We included only articles that measured VC and assessed the quality of these studies using the Newcastle-Ottawa Scale. Results: We found 1056 unique records, reviewed 20 eligible studies of which just 12 met our inclusion criteria. These 12 studies were serosurveys of measles, tetanus, polio and yellow fever. Antibodies induced by natural infection confounded serological test results and there was significant discordance between vaccination history and the presence of antibodies in all except for tetanus vaccine. No study looked at Hepatitis B. Conclusions: Serosurveys for tetanus or tetanus containing vaccines may be directly useful for ascertainment of vaccination exposure or reliably complement current survey methods that measure VC. Given the limited experience in using serosurveys for this purpose in sSA, well-designed serosurveys of tetanus and possibly hepatitis B are required to further validate/evaluate their performance.

Available studies fail to provide strong evidence of increased risk of diarrhea mortality due to measles in the period 4-26 weeks after measles rash onset

BACKGROUND

Measles vaccination effectiveness studies showed dramatic decreases in all-cause mortality in excess of what would be expected from the prevention of measles disease alone. This invited speculation that measles infection may increase the risk of diarrhea morbidity and mortality subsequent to the acute phase of the disease. The aim of the present systematic review is to summarize the existing evidence in the publically available literature pertaining to the putative causal link between measles and diarrhea in the period 4-26 weeks following measles rash onset.

METHODS

We searched the PubMed, Embase, Open Grey and Grey Literature Report databases for relevant literature using broad search terms. Prospective, retrospective and case-control studies in low- and middle-income countries involving children under five wherein relevant evidence were presented were included. Data were extracted from the articles and summarized.

RESULTS

Fifty abstracts retrieved through the database searches met the initial screening criteria. Twelve additional documents were identified by review of the references of the documents found in the initial searches. Six documents representing five unique studies that presented evidence relevant to the research question were found. Four of the included studies took place in Bangladesh. One of the included studies took place in Sudan. Some measles vaccine effectiveness studies show lower diarrhea morbidity and mortality among the vaccinated. However, children who received vaccine may have differed in important ways from children who did not, such as health service utilization. Additionally, cohort studies following unvaccinated children showed no difference in diarrhea morbidity and mortality between cases and controls more than 4 weeks after measles rash onset. One study showed some evidence that severe measles may predispose children to gastroenteritis, but was not able to show a corresponding increase in the risk of diarrhea mortality.

CONCLUSIONS

The available evidence suggests that the risk of measles-associated diarrhea mortality is largely limited to the 5-week period 1 week prior to and 4 weeks after measles rash onset, and that there is no increased risk of diarrhea mortality in the longer-term caused by measles.

Estimating the full public health value of vaccination

There is an enhanced focus on considering the full public health value (FPHV) of vaccination when setting priorities, making regulatory decisions and establishing implementation policy for public health activities. Historically, a therapeutic paradigm has been applied to the evaluation of prophylactic vaccines and focuses on an individual benefit-risk assessment in prospective and individually-randomized phase III trials to assess safety and efficacy against etiologically-confirmed clinical outcomes. By contrast, a public health paradigm considers the population impact and encompasses measures of community benefits against a range of outcomes. For example, measurement of the FPHV of vaccination may incorporate health inequity, social and political disruption, disruption of household integrity, school absenteeism and work loss, health care utilization, long-term/on-going disability, the development of antibiotic resistance, and a range of non-etiologically and etiologically defined clinical outcomes. Following an initial conference at the Fondation Mérieux in mid-2015, a second conference (December 2016) was held to further describe the efficacy of using the FPHV of vaccination on a variety of prophylactic vaccines. The wider scope of vaccine benefits, improvement in risk assessment, and the need for partnership and coalition building across interventions has also been discussed during the 2014 and 2016 Global Vaccine and Immunization Research Forums and the 2016 Geneva Health Forum, as well as in numerous publications including a special issue of Health Affairs in February 2016. The December 2016 expert panel concluded that while progress has been made, additional efforts will be necessary to have a more fully formulated assessment of the FPHV of vaccines included into the evidence-base for the value proposition and analysis of unmet medical need to prioritize vaccine development, vaccine licensure, implementation policies and financing decisions. The desired outcomes of these efforts to establish an alternative framework for vaccine evaluation are a more robust vaccine pipeline, improved appreciation of vaccine value and hence of its relative affordability, and greater public access and acceptance of vaccines.

Risk factors for measles death: Kyegegwa District, western Uganda, February-September, 2015

BACKGROUND

On 18 August 2015, Kyegegwa District reported eight deaths during a measles outbreak to the Uganda Ministry of Health (MoH). We investigated this death cluster to verify the cause, identify risk factors, and inform public health interventions.

METHODS

We defined a probable measles case as onset of fever and generalised rash in a Kyegegwa District resident from 1 February - 15 September 2015, plus ≥1 of the following: coryza, conjunctivitis, and cough. A confirmed measles case was a probable case with measles-specific IgM positivity. A measles death was a death of a probable or confirmed case-person. We conducted an active case-finding to identify measles patients who survived or died. In a case-control study, we compared risk factors between 16 measles patients who died (cases) and 48 who survived (controls), matched by age (±4 years) and village of residence.

RESULTS

We identified 94 probable measles cases, 10 (11%) were confirmed by positive measles-specific IgM. Of the 64 probable measles patients aged <5 years, 16 died (case-fatality rate = 25%). In the case-control study, no history of vaccination against measles was found in 94% (15/16) among the case-persons (i.e., measles patients who died) and 54% (26/48) among the controls (i.e., measles patients who survived) (OR_M-H = 12; 95% CI = 1.6-104), while 56% (9/16) of case-persons and 67% (17/48) of controls (OR_M-H = 2.3; 95% CI =0.74-7.4) did not receive vitamin A supplementation during illness. 63% (10/16) among the case-persons and 6.3% (3/48) of the controls (OR_M-H = 33; 95% CI = 6.8-159) were not treated for measles illness at a health facility (a proxy for more appropriate treatment), while 38% (6/16) of the case-persons and 25% (12/48) of the controls (OR_M-H = 2.5; 95% CI = 0.67-9.1) were malnourished.

CONCLUSION

Lack of vaccination and no treatment in a health facility increased the risk for measles deaths. The one-dose measles vaccination currently in the national vaccination schedule had a protective effect against measles death. We recommended enhancing measles vaccination and adherence to measles treatment guidelines.

Sociodemographic, behavioral, and environmental factors of child mortality in Eastern Region of Cameroon: results from a social autopsy study

BACKGROUND

While most child deaths are caused by highly preventable and treatable diseases such as pneumonia, diarrhea, and malaria, several sociodemographic, cultural and health system factors work against children surviving from these diseases.

METHODS

A retrospective verbal/social autopsy survey was conducted in 2012 to measure the biological causes and social determinants of under-five years old deaths from 2007 to 2010 in Doume, Nguelemendouka, and Abong-Mbang health districts in the Eastern Region of Cameroon. The present study sought to identify important sociodemographic and household characteristics of the 1-59 month old deaths, including the coverage of key preventive indicators of normal child care, and illness recognition and care-seeking for the children along the Pathway to Survival model.

FINDINGS

Of the 635 deceased children with a completed interview, just 26.8% and 11.2% lived in households with an improved source of drinking water and sanitation, respectively. Almost all of the households (96.1%) used firewood for cooking, and 79.2% (n = 187) of the 236 mothers who cooked inside their home usually had their children beside them when they cooked. When 614 of the children became fatally ill, the majority (83.7%) of caregivers sought or tried to seek formal health care, but with a median delay of 2 days from illness onset to the decision to seek formal care. As a result, many (n = 111) children were taken for care only after their illness progressed from mild or moderate to severe. The main barriers to accessing the formal health system were the expenses for transportation, health care and other related costs.

CONCLUSIONS

The most common social factors that contributed to the deaths of 1-59-month old children in the study setting included poor living conditions, prevailing customs that led to exposure to indoor smoke, and health-related behaviors such as delaying the decision to seek care. Increasing caregivers' ability to recognize the danger signs of childhood illnesses and to facilitate timely and appropriate health care-seeking, and improving standards of living such that parents or caregivers can overcome the economic obstacles, are measures that could make a difference in the survival of the ill children in the study area.

Evaluation of the Measles Surveillance System in Kaduna State, Nigeria (2010-2012)

Objective

To evaluate the case-based measles surveillance system in Kaduna State of Nigeria and identify gaps in its operation.

Introduction

In Africa, approximately 13 million cases, 650,000 deaths due to measles occur annually, with sub-Saharan Africa having the highest morbidity and mortality. Measles infection is endemic in Nigeria and has been documented to occur all year round, despite high measles routine and supplemental immunization coverage. The frequent outbreaks of measles in Kaduna State prompted the need for the evaluation of the measles case-based surveillance system.

Methods

We interviewed stakeholders and conducted a retrospective record review of the measles case-based surveillance data from 2010 – 2012 and adapted the 2001 CDC guidelines on surveillance evaluation and the Framework for Evaluating Public Health Surveillance Systems for Early Detection of Outbreaks, to assess the systems usefulness, representativeness, timeliness, stability, acceptability and data quality. We calculated the annualized detection rate of measles and non-measles febrile rash, proportion of available results, proportion of LGAs (Districts) that investigated at least one case with blood, proportion of cases that were IgM positive and the incidence of measles. We compared the results with WHO(2004) recommended performance indicators to determine the quality and effectiveness of measles surveillance system.

Results

According to the Stakeholders, the case-based surveillance system was useful and acceptable. Median interval between specimen collection and release of result was 7days (1 – 25 days) in 2010, 38 days (Range: 16 – 109 days) in 2011 and 11 days (Range: 1 – 105 days) in 2012. The annualized detection rate of measles rash in 2010 was 2.1 (target: ³2), 1.0 (target: ³2) in 2011 and 1.4 (target: ³2) in 2012. The annualized detection rate of non-measles febrile rash in 2010 was 2.1 (target: ³2), 0.6 (target: ³2) in 2011 and 0.8 (target: ³2) in 2012. Case definitions are simple and understood by all the operators.

Conclusion

This evaluation showed that the surveillance system was still useful. Also, the efficiency and effectiveness of the laboratory component as captured by the “median interval between specimen collection and the release of results improved in 2010 and 2012 compared to 2011. However, there was a progressive decline in the timeliness and completeness of weekly reports in the years under review.

Synthesis of Evidence to Characterize National Measles and Rubella Exposure and Immunization Histories

Population immunity depends on the dynamic levels of immunization coverage that countries achieve over time and any transmission of viruses that occur within the population that induce immunity. In the context of developing a dynamic transmission model for measles and rubella to support analyses of future immunization policy options, we assessed the model inputs required to reproduce past behavior and to provide some confidence about model performance at the national level. We reviewed the data available from the World Health Organization (WHO) and existing measles and rubella literature for evidence of historical reported routine and supplemental immunization activities and reported cases and outbreaks. We constructed model input profiles for 180 WHO member states and three other areas to support disease transmission model development and calibration. The profiles demonstrate the significant variability in immunization strategies used historically by regions and member states and the epidemiological implications of these historical choices. The profiles provide a historical perspective on measles and rubella immunization globally at the national level, and they may help immunization program managers identify existing immunity and/or knowledge gaps.

The 2013 measles outbreak in Sri Lanka: experience from a rural district and implications for measles elimination goals

BACKGROUND

Sri Lanka was the first country in the Southeast Asian region to achieve its measles elimination goal in 2011. In 2012, the measles immunization schedule changed from a measles vaccine at 9 months to a measles, mumps and rubella vaccine at 12 months. However in 2013, Sri Lanka reported its worst recent outbreak of measles. This study investigated a part of this outbreak in order to describe its epidemiology.

METHODS

A prospective study was carried out at the university medical unit of the Teaching Hospital, Anuradhapura (THA), the third largest hospital in Sri Lanka, from October 2013 until March 2014. An epidemiological profile of patients was constructed, case confirmation was done on all suspected cases and the basic demographic details of these suspected cases were obtained from the available records.

RESULTS

From January 2013 to March 2014, 101 measles suspects were admitted to the THA. Until June 2013, all suspected cases were aged below 12 months of age. During the study period (15 months), the total number of patients aged below 9 months, 9 to 12 months, 1 to 11 years, 12-29 years and over 29 years were 10 (9.9 %), 11 (10.9 %), 6 (5.9 %), 37 (36.6 %) and 36 (35.6 %), respectively (data missing-1). Out of the 33 patients clinically suspected, 32 tested positive for measles. Common clinical features included: fever (n = 33, 100 %), maculopapular rash (n = 33), conjunctivitis (n = 31), posterior cervical lymphadenopathy (n = 23) and Koplik's spots (n = 8). Features suggestive of pneumonia were observed among 30 (90.9 %) patients and 26 (78.8 %) had diarrhoea. Two patients (6.1 %) who developed severe pneumonia received care at an intensive care unit due to respiratory difficulties. Out of 33 patients, 15 (45.5 %) had prior immunization for measles, two (6.1 %) reported that they never had a measles immunization and 16 (48.5 %) were unsure about their immunization status. Out of those who reported they were previously immunized, 11 (73.3 %) belonged to the age group of 12-2 years.

CONCLUSION

Because the first cases of this outbreak were infants, an increase in susceptible infants due to the change in the vaccine schedule could partly explain the outbreak.

Dengue disease outbreak definitions are implicitly variable

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With appropriate and timely control, disease outbreak burden can be minimised.

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Many different case data-based statistical methods are used to trigger outbreak response.

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Here we show that these methods are inconsistent and incomparable.

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This may hinder the effectiveness of outbreak response.

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Clear quantitative definitions of an outbreak are a prerequisite for effective outbreak early warning and response.

Infectious diseases rarely exhibit simple dynamics. Outbreaks (defined as excess cases beyond response capabilities) have the potential to cause a disproportionately high burden due to overwhelming health care systems. The recommendations of international policy guidelines and research agendas are based on a perceived standardised definition of an outbreak characterised by a prolonged, high-caseload, extra-seasonal surge. In this analysis we apply multiple candidate outbreak definitions to reported dengue case data from Brazil to test this assumption. The methods identify highly heterogeneous outbreak characteristics in terms of frequency, duration and case burden. All definitions identify outbreaks with characteristics that vary over time and space. Further, definitions differ in their timeliness of outbreak onset, and thus may be more or less suitable for early intervention. This raises concerns about the application of current outbreak guidelines for early warning/identification systems. It is clear that quantitatively defining the characteristics of an outbreak is an essential prerequisite for effective reactive response. More work is needed so that definitions of disease outbreaks can take into account the baseline capacities of treatment, surveillance and control. This is essential if outbreak guidelines are to be effective and generalisable across a range of epidemiologically different settings.

Comparative seroprevalence of measles virus immunoglobulin M antibodies in children aged 0-8 months and a control population aged 9-23 months presenting with measles-like symptoms in selected hospitals in Kaduna State

Background

Measles remains the leading cause of vaccine-preventable childhood mortality in developing countries, with its greatest incidence in children younger than 2 years of age. The aim of this study was to determine the seroprevalence of measles virus in children (aged 0–8 months) and older children (aged 9–23 months) presenting with measles-like symptoms.

Methods

A total of 273 blood samples comprising 200 from children aged 0–8 months and 73 from children aged 9–23 months were collected and analyzed for measles virus IgM antibodies by enzyme-linked immunosorbent assay.

Results

An overall prevalence of 21.2% was obtained, with a prevalence of 6.5% in children aged 0–8 months and 61.6% in children aged 9–23 months. The prevalence of measles virus increased with age in children aged 0–8 months and decreased with age in older children (aged 9–23 months), showing a significant association between measles virus and age of the child (P=0.000). A higher prevalence was found in females (27.5%) than in males (16.3%) and this difference was significant (odds ratio 1.942, P=0.025). There was no significant association with the level of parental education, parental occupation, or number of children in the family (P>0.05). With respect to children’s vaccination status and breastfeeding, there was a significant association (P<0.05). The marital status of the family, place of residence, and household size showed no significant association with the prevalence of measles virus. However, a significant association was observed in relation to maternal measles history (odds ratio 2.535, P=0.005) and maternal vaccination status (odds ratio 1.791, P=0.049), as well as between measles virus infection and all presenting symptoms, except for vomiting, malaria, typhoid, and pneumonia, which showed no significant association (P>0.05).

Conclusion

The findings of this study confirm the presence of measles virus infection in children aged 0–8 months.

REGIONAL VARIATIONS IN INFANT AND CHILD MORTALITY IN NIGERIA: A MULTILEVEL ANALYSIS

There are substantial regional disparities in under-five mortality in Nigeria, and evidence suggests that both individual- and community-level characteristics have an influence on health outcomes. Using 2008 Nigeria Demographic and Health Survey data, this study (1) examines the effects of individual- and community-level characteristics on infant/child mortality in Nigeria and (2) determines the extent to which characteristics at these levels influence regional variations in infant/child mortality in the country. Multilevel Cox proportional hazard analysis was performed on a nationally representative sample of 28,647 children nested within 18,028 mothers of reproductive age, who were also nested within 886 communities. The results indicate that community-level variables (such as region, place of residence, community infrastructure, community hospital delivery and community poverty level) and individual-level factors (including child's sex, birth order, birth interval, maternal education, maternal age and wealth index) are important determinants of infant/child mortality in Nigeria. For instance, the results show a lower risk of death in infancy for children of mothers residing in communities with a high proportion of hospital delivery (HR: 0.70, p < 0.05) and for children whose mothers had secondary or higher education (HR: 0.84, p < 0.05). Although community factors appear to influence the association between individual-level factors and death during infancy and childhood, the findings consistently indicate that community-level characteristics are more important in explaining regional variations in child mortality, while individual-level factors are more important for regional variations in infant mortality. The results of this study underscore the need to look beyond the influence of individual-level factors in addressing regional variations in infant and child mortality in Nigeria.

Implication of vaccination on measles reduction and elimination in Nigeria

BACKGROUND

The availability of a safe and effective vaccine has encouraged the establishment of measles mortality reduction and elimination goals in six World Health Organization regions. In the WHO-AFRO region, they intend to eliminate measles by 2020. This initiative led to the successful elimination of measles in 2012 in the American region. This study mined data from independent investigations in two geographical regions in Nigeria in order to observe the prospects of preventive measures against wild measles virus in a resource limited setting.

MATERIALS AND METHODS

Retrospective data from 757 children between the ages of 10 months and 13years were used. 500 were from children in Kano, Northwest Nigeria and 257 from children in Ibadan, Southwest Nigeria. Data analysis was done using SPSS 16.0.

RESULTS

In all, 386 (75.4%) of the vaccinated children were protected while 121 (23.6%) were not protected. In the unvaccinated children, 63 (25.7%) were protected while 135 (55.1%) were not protected (X²=120.919, p=0.000). In Kano, 81 % of the vaccinated children were protected while 18.4% were not protected. In Ibadan, 95% of the vaccinated were protected (X²=22.129, p = 0.000).

CONCLUSION

The herd immunity in both Kano and Ibadan is good enough to reduce wild measles virus infection. This finding is encouraging because Kano has suffered several epidemics prior to the vaccination campaigns resulting from religious apathy which is the bane of vaccination efforts. Here is evidence that with the right approach in Northern Nigeria, it is possible to sustain national and global immunization drive.

Transport networks and inequities in vaccination: remoteness shapes measles vaccine coverage and prospects for elimination across Africa

Measles vaccination is estimated to have averted 13·8 million deaths between 2000 and 2012. Persisting heterogeneity in coverage is a major contributor to continued measles mortality, and a barrier to measles elimination and introduction of rubella-containing vaccine. Our objective is to identify determinants of inequities in coverage, and how vaccine delivery must change to achieve elimination goals, which is a focus of the WHO Decade of Vaccines. We combined estimates of travel time to the nearest urban centre (⩾50 000 people) with vaccination data from Demographic Health Surveys to assess how remoteness affects coverage in 26 African countries. Building on a statistical mapping of coverage against age and geographical isolation, we quantified how modifying the rate and age range of vaccine delivery affects national coverage. Our scenario analysis considers increasing the rate of delivery of routine vaccination, increasing the target age range of routine vaccination, and enhanced delivery to remote areas. Geographical isolation plays a key role in defining vaccine inequity, with greater inequity in countries with lower measles vaccine coverage. Eliminating geographical inequities alone will not achieve thresholds for herd immunity, indicating that changes in delivery rate or age range of routine vaccination will be required. Measles vaccine coverage remains far below targets for herd immunity in many countries on the African continent and is likely to be inadequate for achieving rubella elimination. The impact of strategies such as increasing the upper age range eligible for routine vaccination should be considered.

Description of a large measles epidemic in Democratic Republic of Congo, 2010-2013

BACKGROUND

Although measles mortality has declined dramatically in Sub-Saharan Africa, measles remains a major public health problem in countries like the Democratic Republic of Congo (DRC). Here, we describe the large measles epidemic that occurred in the Democratic Republic of Congo between 2010 and 2013 using data from the national surveillance system as well as vaccine coverage surveys to provide a snapshot of the epidemiology of measles in DRC.

METHODS

Standardized national surveillance data were used to describe measles cases from 2010 to 2013. Attack rates and case fatality ratios were calculated and the temporal and spatial evolution of the epidemic described. Data on laboratory confirmation and vaccination coverage surveys as a part of routine program monitoring are also presented.

FINDINGS

Between week 1 of 2010 and week 45 of 2013, a total of 294,455 cases and 5,045 deaths were reported. The cumulative attack rate (AR) was 0.4%. The Case Fatality Ratio (CFR) was 1.7% among cases reported in health structures through national surveillance. A total of 186,178 cases (63%) were under 5 years old, representing an estimated AR of 1.4% in this age group. Following the first mass vaccination campaigns, weekly reported cases decreased by 21.5%. Results of post-vaccination campaign coverage surveys indicated sub-optimal (under 95%) vaccination coverage among children surveyed.

CONCLUSIONS

The data reported here highlight the need to seek additional means to reinforce routine immunization as well as ensure the timely implementation of Supplementary Immunization Activities to prevent large and repeated measles epidemics in DRC. Although reactive campaigns were conducted in response to the epidemic, strategies to ensure that children are vaccinated in the routine system remains the foundation of measles control.

Measles in a South African paediatric intensive care unit: again!

AIM

The aim of this study is to evaluate the outcomes of children with measles-related disease (MRD) admitted to a paediatric intensive care unit (PICU) and the effect on PICU resources and elective surgery of a recent measles epidemic.

METHODS

This was a retrospective observational study of all patients admitted to the PICU of Red Cross War Memorial Children's Hospital, Cape Town, South Africa, with MRD from January to December 2010. Patient admission characteristics, duration of PICU admission and mortality were recorded. Costs were calculated using bed days utilised and estimated daily PICU admission cost.

RESULTS

A total of 1274 children were admitted over the study period, 58 (4.6%) with MRD (median (interquartile range) age 7 (5-9) months). Pneumonia was the most common reason for admission (81%) and the main cause of mortality. Non-MRD mortality was 8.8% compared with MRD mortality of 31% (P < 0.0001). Standardised mortality for non-MRD was 0.7 versus 1.7 in MRD (P = 0.002). HIV comorbidity and being underweight for age were associated with increased mortality. Patients with MRD occupied 379 bed days with a median (interquartile range) duration of stay of 5.5 (3.0-9.0) days at an estimated overall cost of R4,813,300 (approximately $543,900). During the study period, 67 children booked for elective surgery, and 87 other referrals were refused PICU admission.

CONCLUSIONS

MRD was associated with significant morbidity and mortality, and substantial strain on scarce PICU resources.

Barriers to accessing health care in Nigeria: implications for child survival

BACKGROUND

Existing studies indicate that about one in every six children dies before age five in Nigeria. While evidence suggests that improved access to adequate health care holds great potential for improved child survival, previous studies indicate that there are substantial barriers to accessing health care in Nigeria. There has not been a systematic attempt to examine the effects of barriers to health care on under-five mortality in Nigeria. This study is designed to address this knowledge gap.

DATA AND METHOD

Data came from a nationally representative sample of 18,028 women (aged 15-49) who had a total of 28,647 live births within the 5 years preceding the 2008 Nigeria Demographic and Health Survey. The risk of death in children below age five was estimated using Cox proportional hazard models and results are presented as hazards ratios (HR) with 95% confidence intervals (CI).

RESULTS

Results indicate higher under-five mortality risks for children whose mothers had cultural barriers and children whose mothers had resource-related barriers to health care (HR: 1.44, CI: 1.32-1.57, p<0.001), and those whose mothers had physical barriers (HR: 1.13, CI: 1.04-1.24, p<0.001), relative to children whose mothers reported no barriers. Barriers to health care remained an important predictor of child survival even after adjusting for the effects of possible confounders.

CONCLUSION

Findings of this study stressed the need for improved access to adequate health care in Nigeria through the elimination of barriers to access. This would enable the country to achieve a significant reduction in childhood mortality.

Measles outbreak response immunization is context-specific: insight from the recent experience of Médecins Sans Frontières

Andrea Minetti and colleagues compare measles outbreak responses from the Democratic Republic of the Congo and Malawi and argue that outbreak response strategies should be tailored to local measles epidemiology. Please see later in the article for the Editors' Summary.

A Mixed Outbreak of Rubeola-Rubella in District Kangra of Northern India

BACKGROUND

On 14(th) September 2006, a local community leader informed us about the sudden increase in number of cases of fever and rash in five villages of district Kangra. We investigated the suspected outbreak to confirm the diagnosis and recommend for prevention and control.

MATERIALS AND METHODS

We defined a case of rubeola as the occurrence of fever with rash in children from 3(rd) September to 13(th) January, 2007. We collected information on age, sex, date of onset, residence, signs, symptoms, vaccination and cold chain status. We described the outbreak by place, time and person characteristics. We conducted a retrospective cohort study to estimate vaccine efficacy (VE). We ascertained the measles immunization status by interviewing the mothers and reviewing immunization cards. We confirmed diagnosis clinically, epidemiologically and serologically.

RESULTS

We identified 60 case patients in five villages (41/60 rubeola and 11/60 confirmed epidemiologically linked unvaccinated rubella). The overall attack rate (AR) was 9%. Sex specific AR was 11% for male. Majorities of cases were >5 years of age. No death/minimal complications have occurred. Of 60 case-patients, 42 (70%) were vaccinated for rubeola. The AR of rubeola among unvaccinated children was 25.8% as compared to AR among vaccinated of 4.5% (relative risk: 5.75%; 95% confidence interval: 3.48-9.51 P < 0.001). We estimated general VE to be 83% while gender based VE for male was 84%. Eight case-patients were confirmed serologically for measles immunoglobin M antibodies, two nasopharyngeal swabs positive by polymerase chain reaction. Rubeola virus was genotyped D4. Only 30% (18/60) of the cases took the treatment from modern system of medicine.

CONCLUSION

A mixed outbreak of rubeola/rubella was confirmed clinically, epidemiologically and serologically. We recommend measles and rubella (MR) vaccination at the age of 18-24 months and aggressive Information, Education and Communication (IEC) activities to modify help seeking behavior of the community, especially in the measles affected areas.

Conducting operational research within a non governmental organization: the example of Medecins Sans Frontieres

Like many other non governmental organizations (NGOs) that provide assistance to vulnerable populations living in difficult and resource-limited settings, Médecins Sans Frontières (MSF) is confronted with situations for which proven, effective interventions are often lacking and/or where there is need for strong advocacy for improving medical care. As a result, MSF has become an important contributor to health research, and has dedicated resources to guide operational research by establishing its own Ethics Review Board, an innovation fund, an online publications repository and by regularly contributing to major scientific conferences. However, this increased research activity has led to concern that priorities and resources may be diverted away from the essential mandate of care provision for NGOs. In response, this article discusses the potential role operational research can play within medical NGOs such as MSF, and highlights the relevance of operational research, the essential elements of developing it within the organisation and some of the perceived barriers and solutions.

Risk factors for severe acute lower respiratory infections in children: a systematic review and meta-analysis

AIM

To identify the risk factors in children under five years of age for severe acute lower respiratory infections (ALRI), which are the leading cause of child mortality.

METHODS

We performed a systematic review of published literature available in the public domain. We conducted a quality assessment of all eligible studies according to GRADE criteria and performed a meta-analysis to report the odds ratios for all risk factors identified in these studies.

RESULTS

We identified 36 studies that investigated 19 risk factors for severe ALRI. Of these, 7 risk factors were significantly associated with severe ALRI in a consistent manner across studies, with the following meta-analysis estimates of odds ratios (with 95% confidence intervals): low birth weight 3.18 (1.02-9.90), lack of exclusive breastfeeding 2.34 (1.42-3.88), crowding - more than 7 persons per household 1.96 (1.53-2.52), exposure to indoor air pollution 1.57 (1.06-2.31), incomplete immunization 1.83 (1.32-2.52), undernutrition - weight-for-age less than 2 standard deviations 4.47 (2.10-9.49), and HIV infection 4.15 (2.57-9.74).

CONCLUSION

This study highlights the role of the above seven risk factors in the development of severe pneumonia in under-five children. In addition, it emphasizes the need for further studies investigating other potential risk factors. Since these risk factors are potentially preventable, health policies targeted at reducing their prevalence provide a basis for decreasing the burden of childhood pneumonia.

Lessons and challenges for measles control from unexpected large outbreak, Malawi

Supplementary immunization activities are crucial to reduce the number of susceptible children.

Despite high reported coverage for routine and supplementary immunization, in 2010 in Malawi, a large measles outbreak occurred that comprised 134,000 cases and 304 deaths. Although the highest attack rates were for young children (2.3%, 7.6%, and 4.5% for children <6, 6–8, and 9–11 months, respectively), persons >15 years of age were highly affected (1.0% and 0.4% for persons 15–19 and >19 years, respectively; 28% of all cases). A survey in 8 districts showed routine coverage of 95.0% for children 12–23 months; 57.9% for children 9–11 months; and 60.7% for children covered during the last supplementary immunization activities in 2008. Vaccine effectiveness was 83.9% for 1 dose and 90.5% for 2 doses. A continuous accumulation of susceptible persons during the past decade probably accounts for this outbreak. Countries en route to measles elimination, such as Malawi, should improve outbreak preparedness. Timeliness and the population chosen are crucial elements for reactive campaigns.

Factors precipitating outbreaks of measles in district Kangra of North India: A case-control study

Background:

Globally, measles is the fifth killer disease among children under five years of age. Despite high immunization coverage in Himachal, outbreaks are occurring. Upon two outbreaks in a hilly district in North India, a case control study was conducted to identify factors contributing to outbreaks and to recommend remedial measures to prevent further outbreaks.

Materials and Methods:

Factors were reviewed under three heads: program related, health care providers, and beneficiaries related. Cold chain maintenance was determined and responses were compared between workers from study Shahpur and control Nagrota Bagwan blocks. All 69 mothers of age and sex matched children with measles were enrolled. A pre-designed pre-tested data collection instrument was used. For statistical analysis, the odds ratio (OR) and adjusted odds ratio with 95% confidence interval (C.I.) among women of children exposed and unexposed to selected characteristics were calculated.

Results:

Poor cold chain maintenance and gaps in knowledge of health workers supplemented with beneficiary-related issues precipitated outbreaks in case area. Univariate analysis yielded strong statistical significance to 17 variables. Important statistically significant variables are educational status; OR 27.63 (C.I. 9.46-85.16); occupation; OR 0.35 (C.I. 0.16-0.75); income; OR 5.49 (C.I. 2.36-13.00); mode of transport to health care facility; OR 8.74 (C.I. 2.90-28.23); spread of illness from one person to another; OR 5.60 (95% C.I. 1.40-25.97); first help for sick child OR 2.12 (C.I. 1.00-4.50), and place of visit after recovery; OR 3.92 (C.I. 1.80-8.63). Multiple logistic regression yielded significant association with educational status, drinking water sources, and time taken to reach the nearest health facility.

Conclusion:

Measles outbreaks were confirmed in high immunization coverage areas. We recommend 2nd dose opportunity for measles (MR) between 5 and 17 years; refresher trainings to workers; mobile access to health care facility, and Information Education Communication activities for social behavioral change in affected areas.

Perceptions of the usefulness of external support to immunization coverage in Chad: an analysis of the GAVI-Alliance cash-based support

INTRODUCTION

Chad is one of the countries supported by the GAVI-Alliance that remains with unsatisfactory vaccination coverage. This paper tries to understand the main barriers to better coverage.

METHODS

These barriers were categorised as up or downstream against the health system building blocks as proposed by WHO and compared with barriers and activities identified by the country in its health system's strengthening grant proposal as approved by the GAVI Alliance in 2007. Data were collected using a modified Delphi system and by analysis of grant and annual report documents.

RESULTS

Most of the activities anticipated under the GAVI health system's strengthening proposal are activities targeting downstream barriers (the neglect of upstream issues is of major importance in a decentralised state like Chad) and aligned with, not complementary to, immunization services strengthening activities. Further, both set of cash grants are blind to important recommendations such as the need to address barriers at the level of leadership and governance and at the level of the financing system and also about initiatives to promote community demand of vaccination services.

CONCLUSION

IN CHAD SLOW VACCINATION PROGRESS IS AGGRAVATED BY SEVERAL CONTEXTUAL BARRIERS: the size of the country, the low population density, the nomadic nature of a significant part of its peoples, the recent civil war, associated with civil unrest and political instability and its geographical localization. In this situation it would be important to sustain downstream operations (the major focus of the ISS grant) while taking a long term view of the needs of the health system. The GAVI effectively supports downstream operations, but neglects the long term view.

Kinetics of measles antibody by hemagglutination inhibition assay in children in south-west and north-central Nigeria

OBJECTIVES

We investigated the antibody level of children against wild measles virus in view of recurrent measles epidemics, in order to provide information on immunization status for health policies and for the global measles mortality reduction initiative.

METHODS

Two hundred and seventy-three children between the ages of 10 months and 13 years were recruited for this study from three hospital facilities in south-west and north-central Nigeria. Serum samples were collected from February to July 2009, and laboratory examination commenced in August of the same year. Measles hemagglutinin (HA) antigen was prepared by culturing the measles vaccine virus strain (Edmonston-Zagreb) in a vero/hSLAM cell line. Serum samples were treated to get rid of potentiating factors, non-specific inhibitors, and agglutinins before the HA/hemagglutination inhibition (HI) procedure.

RESULTS

Out of the 175 children vaccinated in Ibadan, 60 (34.3%) had an antibody level not sufficient to protect against measles infection. Likewise, 12 (25.0%) vaccinated children from Ilorin had an antibody level not sufficient to protect against measles infection. There was no significant difference in the level of protection between the children in Ibadan and Ilorin (p>0.05). The geometric mean titer (GMT) was 53.83 for males and 48.64 for females. There was no significant difference between the GMTs of females and males in both locations (p>0.05). Also, no significant difference was observed in the GMTs of children in both locations (p>0.05).

CONCLUSIONS

Of the vaccinated children, 157 (57.5%) developed protective measles virus HI antibody, which is not enough to maintain protective herd immunity. Hence there is a need for catch-up and follow-up vaccination programs, especially in rural areas and places with difficult terrains, in order to reduce measles mortality.

Immature CD4+CD8+ thymocytes are preferentially infected by measles virus in human thymic organ cultures

Cells of the human immune system are important target cells for measles virus (MeV) infection and infection of these cells may contribute to the immunologic abnormalities and immune suppression that characterize measles. The thymus is the site for production of naïve T lymphocytes and is infected during measles. To determine which populations of thymocytes are susceptible to MeV infection and whether strains of MeV differ in their ability to infect thymocytes, we used ex vivo human thymus organ cultures to assess the relative susceptibility of different subpopulations of thymocytes to infection with wild type and vaccine strains of MeV. Thymocytes were susceptible to MeV infection with the most replication in immature CD4⁺CD8⁺ double positive cells. Susceptibility correlated with the level of expression of the MeV receptor CD150. Wild type strains of MeV infected thymocytes more efficiently than the Edmonston vaccine strain. Thymus cultures from children ≥3 years of age were less susceptible to MeV infection than cultures from children 5 to 15 months of age. Resistance in one 7 year-old child was associated with production of interferon-gamma suggesting that vaccination may result in MeV-specific memory T cells in the thymus. We conclude that immature thymocytes are susceptible to MeV infection and thymocyte infection may contribute to the immunologic abnormalities associated with measles.

Effect of thermal environment on the temporal, spatial and seasonal occurrence of measles in Ondo state, Nigeria

We investigated the temporal and spatial dynamics, as well as the seasonal occurrence of measles in Ondo state, Nigeria, to better understand the role of the thermal environment in the occurrence of the childhood killer disease measles, which ranks among the top ten leading causes of child deaths worldwide. The linkages between measles and atmospheric environmental factors were examined by correlating human-biometeorological parameters in the study area with reported clinical cases of measles for the period 1998-2008. We also applied stepwise regression analysis in order to determine the human-biometeorological parameters that lead to statistical changes in reported clinical cases of measles. We found that high reported cases of measles are associated with the least populated areas, where rearing and cohabitation of livestock/domestic animals within human communities are common. There was a significant correlation (P < 0.01) between monthly cases of measles and human-biometeorological parameters except wind speed and vapour pressure. High transmission of measles occurred in the months of January to May during the dry season when human thermal comfort indices are very high. This highlights the importance of the thermal environment in disease demographics since it accounted for more than 40% variation in measles transmission within the study period.

Spatial dynamics of meningococcal meningitis in Niger: observed patterns in comparison with measles

Throughout the African meningitis belt, meningococcal meningitis outbreaks occur only during the dry season. Measles in Niger exhibits similar seasonality, where increased population density during the dry season probably escalates measles transmission. Because meningococcal meningitis and measles are both directly transmitted, we propose that host aggregation also impacts the transmission of meningococcal meningitis. Although climate affects broad meningococcal meningitis seasonality, we focus on the less examined role of human density at a finer spatial scale. By analysing spatial patterns of suspected cases of meningococcal meningitis, we show fewer absences of suspected cases in districts along primary roads, similar to measles fadeouts in the same Nigerien metapopulation. We further show that, following periods during no suspected cases, districts with high reappearance rates of meningococcal meningitis also have high measles reintroduction rates. Despite many biological and epidemiological differences, similar seasonal and spatial patterns emerge from the dynamics of both diseases. This analysis enhances our understanding of spatial patterns and disease transmission and suggests hotspots for infection and potential target areas for meningococcal meningitis surveillance and intervention.

Paternal education status significantly influences infants' measles vaccination uptake, independent of maternal education status

BACKGROUND

Despite increased funding of measles vaccination programs by national governments and international aid agencies, structural factors encumber attainment of childhood measles immunisation to levels which may guarantee herd immunity. One of such factors is parental education status. Research on the links between parental education and vaccination has typically focused on the influence of maternal education status. This study aims to demonstrate the independent influence of paternal education status on measles immunisation.

METHODS

Comparable nationally representative survey data were obtained from six countries with the highest numbers of children missing the measles vaccine in 2008. Logistic regression analysis was applied to examine the influence of paternal education on uptake of the first dose of measles vaccination, independent of maternal education, whilst controlling for confounding factors such as respondent's age, urban/rural residence, province/state of residence, religion, wealth and occupation.

RESULTS

The results of the analysis show that even if a mother is illiterate, having a father with an education of Secondary (high school) schooling and above is statistically significant and positively correlated with the likelihood of a child being vaccinated for measles, in the six countries analysed. Paternal education of secondary or higher level was significantly and independently correlated with measles immunisation uptake after controlling for all potential confounders.

CONCLUSIONS

The influence of paternal education status on measles immunisation uptake was investigated and found to be statistically significant in six nations with the biggest gaps in measles immunisation coverage in 2008. This study underscores the imperative of utilising both maternal and paternal education as screening variables to identify children at risk of missing measles vaccination prospectively.

Measles virus, immune control, and persistence

Measles remains one of the most important causes of child morbidity and mortality worldwide with the greatest burden in the youngest children. Most acute measles deaths are owing to secondary infections that result from a poorly understood measles-induced suppression of immune responses. Young children are also vulnerable to late development of subacute sclerosing panencephalitis, a progressive, uniformly fatal neurologic disease caused by persistent measles virus (MeV) infection. During acute infection, the rash marks the appearance of the adaptive immune response and CD8(+) T cell-mediated clearance of infectious virus. However, after clearance of infectious virus, MeV RNA persists and can be detected in blood, respiratory secretions, urine, and lymphoid tissue for many weeks to months. This prolonged period of virus clearance may help to explain measles immunosuppression and the development of lifelong immunity to re-infection, as well as occasional infection of the nervous system. Once MeV infects neurons, the virus can spread trans-synaptically and the envelope proteins needed to form infectious virus are unnecessary, accumulate mutations, and can establish persistent infection. Identification of the immune mechanisms required for the clearance of MeV RNA from multiple sites will enlighten our understanding of the development of disease owing to persistent infection.

The optimal age of measles immunisation in low-income countries: a secondary analysis of the assumptions underlying the current policy

OBJECTIVE

The current policy of measles vaccination at 9 months of age was decided in the mid-1970s. The policy was not tested for impact on child survival but was based on studies of seroconversion after measles vaccination at different ages. The authors examined the empirical evidence for the six underlying assumptions.

DESIGN

Secondary analysis.

DATA SOURCES AND METHODS

These assumptions have not been research issues. Hence, the authors examined case reports to assess the empirical evidence for the original assumptions. The authors used existing reviews, and in December 2011, the authors made a PubMed search for relevant papers. The title and abstract of papers in English, French, Portuguese, Spanish, German and Scandinavian languages were assessed to ascertain whether the paper was potentially relevant. Based on cumulative measles incidence figures, the authors calculated how many measles cases had been prevented assuming everybody was vaccinated at a specific age, how many 'vaccine failures' would occur after the age of vaccination and how many cases would occur before the specific age of vaccination. In the combined analyses of several studies, the authors used the Mantel-Haenszel weighted RR stratifying for study or age groups to estimate common trends.

SETTING AND PARTICIPANTS

African community studies of measles infection.

PRIMARY AND SECONDARY OUTCOMES

Consistency between assumptions and empirical evidence and the predicted effect on mortality.

RESULTS

In retrospect, the major assumptions were based on false premises. First, in the single study examining this point, seronegative vaccinated children had considerable protection against measles infection. Second, in 18 community studies, vaccinated measles cases ('vaccine failures') had threefold lower case death than unvaccinated cases. Third, in 24 community studies, infants had twofold higher case death than older measles cases. Fourth, the only study examining the assumption that 'vaccine failures' lead to lack of confidence found the opposite because vaccinated children had milder measles infection. Fifth, a one-dose policy was recommended. However, the two randomised trials of early two-dose measles vaccination compared with one-dose vaccination found significantly reduced mortality until 3 years of age. Thus, current evidence suggests that the optimal age for a single dose of measles vaccine should have been 6 or 7 months resulting in fewer severe unvaccinated cases among infants but more mild 'vaccine failures' among older children. Furthermore, the two-dose trials indicate that measles vaccine reduces mortality from other causes than measles infection.

CONCLUSIONS

Many lives may have been lost by not determining the optimal age of measles vaccination. Since seroconversion continues to be the basis for policy, the current recommendation is to increase the age of measles vaccination to 12 months in countries with limited measles transmission. This policy may lead to an increase in child mortality.

Outbreak response immunisation: The experience of Chad during recurrent measles epidemics in 2005 and 2010

Despite impressive gains in measles control globally, measles epidemics continue to occur in countries with insufficient vaccination coverage. WHO guidelines now recommend outbreak response immunisation (ORI) for controlling measles outbreaks in certain contexts. The objective of this study was to describe late and early response vaccination activities during two consecutive measles outbreaks that occurred in 2005 and 2010 in N'Djamena, Chad. Using Lot Quality Assurance Sampling, vaccination coverage was estimated to be low before the interventions. Following mass vaccination campaigns, measles cases declined. The timeliness and quality of ORI activities are crucial determinants of success. However, effective outbreak response should be accompanied by strong routine vaccination programmes to ensure sustainable high vaccination coverage.

Measles in a tertiary institution in bida, niger state, Nigeria: prevalence, immunization status and mortality pattern

OBJECTIVES

Measles is a highly infectious immunizable disease with potential for eradication but is still responsible for high mortality among children, particularly in developing nations like Nigeria. This study aims to determine the hospital based prevalence of measles, describe the vaccination status of children managed for measles at the Federal Medical Centre, Bida, Niger state and to identify the parental disposition to measles vaccination.

METHODS

This is a cross-sectional study carried out over a period of 18 months beginning from July 2007. All children with a diagnosis of measles made clinically and reinforced with serological test in the WHO Measles, Rubella and Yellow Fever laboratory in Maitama District Hospital, Abuja were recruited. Informed consent was obtained from the parents/care givers. Structured questionnaire was used to obtain information and data analysis was by SPSS version 15.

RESULTS

One hundred and nine children were managed for measles, constituting 8% of total admission over the study period. The male to female ratio was 1.2:1. Of the 109 children with measles, 90 (82%) did not receive measles vaccination. Eighty-eight (80%) of the parents or guardian felt vaccination was bad for various reasons. Of the 23 (21.1%) children whose parents or guardians were positively disposed to vaccination, one death was recorded while the remaining seven deaths were recorded among children whose parents were negatively disposed to vaccination. All the deaths were in the non-vaccinated group below 2 years of age.

CONCLUSION

Measles is still a major health burden in our community. The majority of affected children were not vaccinated due to negative parental disposition. Continuous health education is required for change the disposition of the parents/guardian and improve vaccination coverage to minimize measles associated morbidity and mortality.

Measuring the performance of vaccination programs using cross-sectional surveys: a likelihood framework and retrospective analysis

BACKGROUND

The performance of routine and supplemental immunization activities is usually measured by the administrative method: dividing the number of doses distributed by the size of the target population. This method leads to coverage estimates that are sometimes impossible (e.g., vaccination of 102% of the target population), and are generally inconsistent with the proportion found to be vaccinated in Demographic and Health Surveys (DHS). We describe a method that estimates the fraction of the population accessible to vaccination activities, as well as within-campaign inefficiencies, thus providing a consistent estimate of vaccination coverage.

METHODS AND FINDINGS

We developed a likelihood framework for estimating the effective coverage of vaccination programs using cross-sectional surveys of vaccine coverage combined with administrative data. We applied our method to measles vaccination in three African countries: Ghana, Madagascar, and Sierra Leone, using data from each country's most recent DHS survey and administrative coverage data reported to the World Health Organization. We estimate that 93% (95% CI: 91, 94) of the population in Ghana was ever covered by any measles vaccination activity, 77% (95% CI: 78, 81) in Madagascar, and 69% (95% CI: 67, 70) in Sierra Leone. "Within-activity" inefficiencies were estimated to be low in Ghana, and higher in Sierra Leone and Madagascar. Our model successfully fits age-specific vaccination coverage levels seen in DHS data, which differ markedly from those predicted by naïve extrapolation from country-reported and World Health Organization-adjusted vaccination coverage.

CONCLUSIONS

Combining administrative data with survey data substantially improves estimates of vaccination coverage. Estimates of the inefficiency of past vaccination activities and the proportion not covered by any activity allow us to more accurately predict the results of future activities and provide insight into the ways in which vaccination programs are failing to meet their goals. Please see later in the article for the Editors' Summary.

Measles vaccination in humanitarian emergencies: a review of recent practice

BACKGROUND

The health needs of children and adolescents in humanitarian emergencies are critical to the success of relief efforts and reduction in mortality. Measles has been one of the major causes of child deaths in humanitarian emergencies and further contributes to mortality by exacerbating malnutrition and vitamin A deficiency. Here, we review measles vaccination activities in humanitarian emergencies as documented in published literature. Our main interest was to review the available evidence focusing on the target age range for mass vaccination campaigns either in response to a humanitarian emergency or in response to an outbreak of measles in a humanitarian context to determine whether the current guidance required revision based on recent experience.

METHODS

We searched the published literature for articles published from January 1, 1998 to January 1, 2010 reporting on measles in emergencies. As definitions and concepts of emergencies vary and have changed over time, we chose to consider any context where an application for either a Consolidated Appeals Process or a Flash Appeal to the UN Central Emergency Revolving Fund (CERF) occurred during the period examined. We included publications from countries irrespective of their progress in measles control as humanitarian emergencies may occur in any of these contexts and as such, guidance applies irrespective of measles control goals.

RESULTS

Of the few well-documented epidemic descriptions in humanitarian emergencies, the age range of cases is not limited to under 5 year olds. Combining all data, both from preventive and outbreak response interventions, about 59% of cases in reports with sufficient data reviewed here remain in children under 5, 18% in 5-15 and 2% above 15 years. In instances where interventions targeted a reduced age range, several reports concluded that the age range should have been extended to 15 years, given that a significant proportion of cases occurred beyond 5 years of age.

CONCLUSIONS

Measles outbreaks continue to occur in humanitarian emergencies due to low levels of pre-existing population immunity. According to available published information, cases continue to occur in children over age 5. Preventing cases in older age groups may prevent younger children from becoming infected and reduce mortality in both younger and older age groups.

Assessment of the epidemiology and burden of measles in Southern Mozambique

Measles has been a major killer among vaccine-preventable diseases in children < 5 years of age in developing countries. Despite progress in global efforts to reduce mortality, measles remains a public health problem. Hospital-based measles surveillance was conducted in Manhica, Mozambique (July 2001-September 2004). Suspected cases and community-based controls were enrolled, and blood was collected for immunoglobulin M (IgM) confirmation. Two hundred fifty-three suspected cases and 477 controls were enrolled, with 85% (216 of 253) cases reported during a measles outbreak. Measles-IgM confirmation was 30% among suspected cases and 5% in controls. Fifty-eight percent (14 of 24) of laboratory-confirmed cases had records indicating previous measles vaccination. Mortality was 3% (8 of 246) among cases and 1% among controls (6 of 426). Forty-five percent (33 of 74) of cases were < 24 months of age and 22% occurred in infants < 9 months of age and were associated with a high case-fatality rate (25%). Our data suggest that improved diagnostics, new tools to protect infants < 9 months of age, and a supplemental dose of measles vaccine could assist measles control.