Risk factors associated with nasopharyngeal carriage and density of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus in young children living in Indonesia

Prevalence, serotype distribution, and antimicrobial susceptibility profile of Streptococcus pneumoniae in Sea Nomad children under 5 years of age in Wakatobi, Southeast Sulawesi, Indonesia: A cross-sectional study

OBJECTIVE

Indonesia commenced the nationwide introduction of pneumococcal conjugate vaccine (PCV) in 2022. Pre-vaccine Streptococcus pneumoniae data from across the country could be critical to enable vaccine impact evaluation in the future. This study evaluates colonization prevalence, factors associated with colonization, serotype distribution, and the antimicrobial susceptibility profile of S. pneumoniae.

METHODS

Children under 5 years of age were enrolled from Bajau tribe settlements in Wakatobi, southeast Sulawesi, Indonesia, from October 2018 to February 2019. Nasopharyngeal swab specimens were analysed by culture, and isolates were serotyped using sequential multiplex polymerase chain reaction. Antibiotic susceptibility was performed by the disk diffusion method. Multivariable logistic regression was performed for risk factor analysis.

RESULTS

A total of 499 NP swab specimens were collected; 61.9% were colonized with S. pneumoniae and 48.9% of the isolates were of PCV13-vaccine type. The most common serotypes were 23F, 6B, 19F, and 6A at 13.2%, 9.8%, 8.9%, and 8.0%, respectively. Exposure to cigarette smoke in the household and runny nose were significant risk factors for colonization, with aORs of 1.6 (95% confidence interval: 1.1-2.3) and 2.1 (95% confidence interval: 1.4-3.3), respectively.

CONCLUSIONS

The findings of this study may contribute to baseline pre-vaccine data in Indonesia that would be critical for the impact evaluation of vaccines.

Nasopharyngeal Carriage of Streptococcus pneumoniae Serotypes Among Healthy Children in Northern India

Streptococcus pneumoniae (SP) infections cause morbidity and mortality among children worldwide. Hence India introduced 13-valent pneumococcal conjugate vaccine (PCV-13) in 2017 in a phased manner. The primary objective of this study was to assess the proportion of healthy children having nasopharyngeal colonization (NP) with SP. Secondary objective was to determine prevalent serotype of SP among the PCV13 vaccinated and non-vaccinated children. This cross-sectional study was conducted in 4 hospitals of Lucknow District, Northern India. Three hundred healthy children (2-59 months) were recruited between July and August 2019 from vaccination-clinics of hospitals. NP specimen was cultured using 5% sheep blood agar plate containing gentamicin. Pneumococcal isolates were identified by optochin sensitivity and bile-solubility tests. Serotyping was done using Quellung Method. Of the 300 healthy children, 56.7% (170/300) were males and 59.3% (181/300) had received at least one dose of PCV13 vaccine. The NP carriage rate of SP among healthy children was 37.7% (113/300). Vaccine serotypes were found in 33.3% (22/66) in PCV vaccinated children and 48.9% (23/47) in non-vaccinated children (p 0.09). Common vaccine serotypes that isolated were: 18C, 19A, 19F, 23F, 3, 4, 6A, 6B, 9 V. Thus more than one-third of healthy children had NP colonization with SP. Adjusting for age, there was a trend for significant reduction in vaccine serotypes in the NP with one doses versus two or more doses (ptrend = 0.04).

Household fuel use and its association with potential respiratory pathogens among healthy mothers and children in Ethiopia

Background

Over 90% of Ethiopians still rely on solid fuels for cooking food. The pollution from the burning process causes adverse respiratory outcomes including respiratory infections. This study aimed to assess the association of the pollution with nasopharyngeal occurrence of potential pathogens.

Methods

We conducted a comparative cross-sectional study in urban and rural settings in Ethiopia in 2016. Questionnaire-based data were collected from 168 mothers and 175 children aged below two years. Multiplex real-time PCR assays were performed on nasopharyngeal secretions for detection of bacteria and viruses and for the identification of pneumococcal serotypes/groups.

Results

High rates of bacteria and viruses in the nasopharynx were detected by PCR among both the children and the mothers. Among the detected viruses, enterovirus was more commonly detected among rural children than among children from urban areas. Streptococcus pneumoniae and Haemophilus influenzae were both more prevalent among children and mothers from rural areas compared with urban groups and among those using solid fuels compared with cleaner fuel users. Children from rural households using solid fuels and children whose mothers had educational status below high school had four times higher odds for detection of S. pneumoniae compared with those households using cleaner energy or those children having mothers with a higher educational status, respectively. One or more serotype/serogroup was identified in about 40% of the samples that were positive for pneumococci. Out of all identified serotypes/serogroups, 43% in the children and 45% in the mothers belonged to PCV13, indicating the larger majority of detected pneumococci being non-PCV13 serotypes.

Conclusion

This study presented a high carriage rate of S. pneumoniae and H. influenzae among both children and their mothers, especially in rural areas and among solid fuel users. Thus, interventions should target cleaner energy sources to the public and promote maternal education.

Co-carriage of Streptococcus pneumoniae and Moraxella catarrhalis among preschool children and its influencing factors

OBJECTIVES

To investigate the carriage status of Streptococcus pneumoniae (S.pneumoniae) and Moraxella catarrhalis (M. catarrhalis) in preschool children and the influencing factors for the carriage status.

METHODS

The stratified cluster sampling method was used to select 2 031 healthy children from seven kindergartens in Shunde District of Foshan in Guangdong, China. Nasal swabs were collected from all children for the isolation and identification of S. pneumoniae and M. catarrhalis. The carriage status of S. pneumoniae and M. catarrhalis was analyzed in terms of its association with demographic features and hospital- and community-related factors.

RESULTS

The carriage rates of S. pneumoniae and M. catarrhalis were 21.81% and 52.44%, respectively among the children. The co-carriage rate of S. pneumoniae and M. catarrhalis was 14.87%. The correspondence analysis showed that the factors such as lower grade, non-local registered residence, living in rural areas, small living area, history of respiratory tract infection but no history of antibiotic use, allergic skin diseases, and no hospital-related exposure history were significantly associated with the co-carriage of S. pneumoniae and M. catarrhalis among the children (P<0.05).

CONCLUSIONS

Co-carriage of S. pneumoniae and M. catarrhalis can be observed in preschool children. Young age, poor living environment, a history of respiratory tract infection but no history of antibiotic use, allergic skin diseases, and no hospital-related exposure history are important risk factors for the co-carriage of S. pneumoniae and M. catarrhalis in preschool children.

Differences in Bacterial Colonization and Mucosal Responses Between High and Low SES Children in Indonesia

BACKGROUND

Increased nasopharyngeal carriage of pathogenic bacteria is found in low socioeconomic status (SES) settings. How SES affects local immune responses, important for controlling colonization, is currently unknown.

OBJECTIVE

Examining bacterial colonization and cytokine response in the nasal mucosa of children from high and low SES.

METHODS

Nasosorption samples were collected in October 2019 from 48 high SES and 50 low SES schoolchildren, in a cross-sectional study in Makassar, Indonesia. Twenty-five cytokines were measured in nasal fluid. Quantitative polymerase chain reaction was performed to determine carriage and density of Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis and Staphylococcus aureus. Data were analyzed using multivariate regression.

RESULTS

H. influenzae and S. pneumoniae densities were increased in low SES settings compared to the high SES settings (P = 0.006, P = 0.026), with 6 and 67 times higher median densities, respectively. Densities of H. influenzae and S. pneumoniae were positively associated with levels of IL-1beta and IL-6. After correcting for bacterial density, IL-6 levels were higher in colonized children from high SES than low SES for H. influenzae and S. pneumoniae (both P = 0.039).

CONCLUSION

Increased densities of H. influenzae and S. pneumoniae were observed in low SES children, whereas IL-6 levels associated with colonization were reduced in these children, indicating that immune responses to bacterial colonization were altered by SES.

Unexpected and Sudden Death Due to Undiagnosed Moraxella catarrhalis Meningoencephalitis in a 40-day-old Infant: Case Report and Literature Review

Acute bacterial meningitis in infants and newborns represents a medical emergency and a significant cause of mortality and morbidity worldwide. Moraxella catarrhalis has been considered a microorganism with low pathogenic potential, and only in exceptional cases has it been found to cause meningitis in infants and immunocompetent people. We will now document an unusual case of an unexpected and sudden death of a 40-day-old infant due to acute meningitis from M. catarrhalis, apparently asymptomatic and subsequently diagnosed by an autopsy. According to our knowledge this is the first case of unexpected infant death due to undiagnosed M. catarrhalis meningitis.The suggested case, as well as for the rarity of such a fatal event, should be considered a caution to pediatrics and neonatologists for M. catarrhalis can cause paucisymptomatic meningoencephalitis in infants which can be potentially fatal.From a forensic point of view, an autopsy accompanied by a multidisciplinary assessment is always necessary in cases of unexpected infant deaths to identify the causes.

Streptococcus pneumoniae carriage and antibiotic susceptibility among Indonesian pilgrims during the Hajj pilgrimage in 2015

The Hajj is an annual pilgrimage to Mecca and one of the largest gathering of people in the world. Most Indonesian pilgrims are senior adults and elderly adults, who are more prone to acquire infections during the Hajj ritual. The aims of this study are to investigate the dynamics of Streptococcus pneumoniae colonization and to investigate antibiotic susceptibility of pneumococcal strains in Indonesian pilgrims. This was a prospective multi-site longitudinal study in Indonesian hajj pilgrims aged >18 years old in the year 2015. Nasopharyngeal swabs were collected from the same subject before departure and upon arrival at the airport. S. pneumoniae was identified using conventional and molecular approach, while antibiotic susceptibility was determined using a disk diffusion method. Among 813 Hajj pilgrims who were enrolled from five sites in this study, the prevalence of S. pneumoniae carriage rates before- and after-the Hajj were 8.6% (95% CI 6.7–10.5%) and 8.2% (95% CI 6.4–10.1%), (p value: 0.844) respectively. Serotype 16F, 6A/6B, 3, 18, and 23F were the five most prevalent serotypes before Hajj, whereas serotypes 3, 34, 13, 4, and 23F were the most prevalent serotypes after Hajj. Serotype 3 was identified as most acquired serotype during Hajj in Indonesian pilgrim. There was an increase in the percentage of isolates susceptible to co-trimoxazole after Hajj (42.9% versus 57.4%). The study provided an overview of the change of dynamics of S. pneumoniae serotype acquisition in Indonesian Hajj Pilgrims. Along with data of vaccination serotypes coverage and antimicrobial susceptibility, these findings may contribute to recommendation of vaccination and treatment policies in the future.

Pneumococcal nasopharyngeal carriage in Indonesia infants and toddlers post-PCV13 vaccination in a 2+1 schedule: A prospective cohort study

Background

The PCV13 immunization demonstration program began in October 2017 in Indonesia. The aim of this study is to assess the dynamic changes of pneumococcal serotype before and after PCV13 administration, with two primary and one booster doses.

Methods

The prospective cohort study was conducted as a follow up study measuring the impact of PCV13 demonstration program by the Indonesian Ministry of Health in Lombok Island, West Nusa Tenggara, Indonesia, from March 2018 to June 2019. The subjects were two-month-old healthy infants who were brought to the primary care facility for routine vaccination and followed until 18 months of age. We use convenience sampling method. There were 115 infants in the control group and 118 infants in the vaccine group, and the PCV immunization was given on a 2+1 schedule. Nasopharyngeal (NP) swabs were collected four times during the vaccination periods by trained medical staff. Specimens were analyzed by culture methods to detect S. pneumonia colonization and multiplex polymerase chain reaction (mPCR) to determine serotype. The most frequently detected serotypes will be named as dominant serotypes. Descriptive analysis of demographic characteristics, the prevalence of overall and serotype colonization, and the distribution of serotypes were performed. The prevalence of both cohort groups were compared using chi-square test. Statistical significance was set at p < 0.05.

Results

Two hundred and thirty three infants age two months old were recruited, with 48.9% of the subjects were male and 51.1% of the subjects were female. Sociodemographic data in both cohort groups were relatively equal. Nasopharyngeal pneumococcal colonization before PCV13 administration occurred in 19.1% of the control and 22.9% of the vaccine group. The prevalence increased with increasing age in both groups. The prevalence of VT serotypes in control groups aged 2 months, 4 months, 12 months, and 18 months was 40.9%, 44.2%, 53.8%, and 54.3%, respectively, and in the vaccine group, 25.9%, 40.4%, 38.0%, and 22.6%, respectively. The most common VT serotypes in both groups were 6A/6B, 19F, 23F, and 14. The prevalence of VT serotypes decreased significantly compared to non-vaccine type serotypes after three doses of the PCV13 vaccine (p < 0.001). Another notable change was the decline in prevalence of serotype 6A/6B after PCV13 administration using the 2+1 schedule.

Conclusions

This study shows lower prevalence of VT and 6A/6B serotypes in the nasopharynx among children who were PCV13 vaccinated compared with those who were unvaccinated. The result from this study will be the beginning of future vaccine evaluation in larger population and longer period of study.

Streptococcus pneumoniae Serotypes Carried by Young Children and Their Association With Acute Otitis Media During the Period 2016-2019

Background: Streptococcus pneumoniae (Sp) is a major cause of acute otitis media (AOM). Pneumococcal conjugate vaccine (PCV) programs have altered pneumococcal serotype epidemiology in disease and carriage. In this study, we used samples collected during a cross-sectional study to examine if the clinical picture of acute otitis media (AOM) in young children exposed to the PCV program in Belgium was related to the carried pneumococcal strains, and if their carriage profile differed from healthy children attending daycare centers. Material/Methods: In three collection periods from February 2016 to May 2018, nasopharyngeal swabs and background characteristics were collected from children aged 6-30 months either presenting at their physician with AOM (AOM-group) or healthy and attending day care (DCC-group). Clinical signs of AOM episodes and treatment schedule were registered by the physicians. Sp was detected, quantified, and characterized using both conventional culture analysis and real-time PCR analysis. Results: Among 3,264 collected samples, overall pneumococcal carriage and density were found at similar rates in both AOM and DCC. As expected non-vaccine serotypes were most frequent: 23B (AOM: 12.3%; DCC: 17.4%), 11A (AOM: 7.5%; DCC: 7.4%) and 15B (AOM: 7.5%; DCC: 7.1%). Serotypes 3, 6C, 7B, 9N, 12F, 17F, and 29 were more often found in AOM than in DCC (p-value < 0.05), whereas 23A and 23B were less often present in AOM (p-value < 0.05). Antibiotic non-susceptibility of Sp strains was similar in both groups. No predictors of AOM severity were identified. Conclusion: In the present study, overall carriage prevalence and density of S. pneumoniae were found similar in young children with AOM and in healthy children attending day-care centers in Belgium. Certain serotypes not currently included in the PCV vaccines were found to be carried more often in children with AOM than in DCC, a finding that might suggest a relationship between these serotypes and AOM.

Dynamics of Pneumococcal Carriage in Adults: A New Look at an Old Paradigm

BACKGROUND

Limited information is available on pneumococcal colonization among adults. We studied pneumococcal carriage dynamics in healthy adults using high-sensitivity approaches.

METHODS

Eighty-seven adults (25-50 years old) were followed for 6 months in Portugal. Nasopharyngeal, oropharyngeal, and saliva samples were obtained monthly; pneumococcal carriers were also sampled weekly. Carriage was investigated by quantitative polymerase chain reaction (targeting lytA and piaB) and culture. Positive samples were serotyped.

RESULTS

Approximately 20% of the adults were intermittent carriers; 10% were persistent carriers (>4 months). Pneumococcal acquisition and clearance rates were 16.5 (95% confidence interval [CI], 11.2-24.2) and 95.9 (95% CI, 62.3-145.0) cases/1000 person-weeks, respectively. Living with children increased pneumococcal acquisition (hazard ratio, 9.7 [95% CI, 2.6-20.5]; P < .001). Median duration of carriage was 7 weeks and did not depend on regular contact with children.

CONCLUSIONS

The pneumococcal carrier state in healthy adults is more dynamic than generally assumed: Acquisition is frequent and duration of carriage is often long. This suggests that some adults may act as reservoirs of pneumococci and hence, depending on the social structure of a community, the magnitude of herd effects potentially attainable through children vaccination may vary. These findings are important when designing strategies to prevent pneumococcal disease in adults.

Nasopharyngeal Pneumococcal Density during Asymptomatic Respiratory Virus Infection and Risk for Subsequent Acute Respiratory Illness

Increased nasopharyngeal pneumococcal (Streptococcus pneumoniae) colonization density has been associated with invasive pneumococcal disease, but factors that increase pneumococcal density are poorly understood. We evaluated pneumococcal densities in nasopharyngeal samples from asymptomatic young children from Peru and their association with subsequent acute respiratory illness (ARI). Total pneumococcal densities (encompassing all present serotypes) during asymptomatic periods were significantly higher when a respiratory virus was detected versus when no virus was detected (p<0.001). In adjusted analyses, increased pneumococcal density was significantly associated with the risk for a subsequent ARI (p<0.001), whereas asymptomatic viral detection alone was associated with lower risk for subsequent ARI. These findings suggest that interactions between viruses and pneumococci in the nasopharynx during asymptomatic periods might have a role in onset of subsequent ARI. The mechanisms for these interactions, along with other potentially associated host and environmental factors, and their role in ARI pathogenesis and pneumococcal transmission require further elucidation.

Factors associated with pneumococcal carriage and density in children and adults in Fiji, using four cross-sectional surveys

This study describes predictors of pneumococcal nasopharyngeal carriage and density in Fiji. We used data from four annual (2012-2015) cross-sectional surveys, pre- and post-introduction of ten-valent pneumococcal conjugate vaccine (PCV10) in October 2012. Infants (5-8 weeks), toddlers (12-23 months), children (2-6 years), and their caregivers participated. Pneumococci were detected and quantified using lytA qPCR, with molecular serotyping by microarray. Logistic and quantile regression were used to determine predictors of pneumococcal carriage and density, respectively. There were 8,109 participants. Pneumococcal carriage was negatively associated with years post-PCV10 introduction (global P<0.001), and positively associated with indigenous iTaukei ethnicity (aOR 2.74 [95% CI 2.17-3.45] P<0.001); young age (infant, toddler, and child compared with caregiver participant groups) (global P<0.001); urban residence (aOR 1.45 [95% CI 1.30-2.57] P<0.001); living with ≥2 children <5 years of age (aOR 1.42 [95% CI 1.27-1.59] P<0.001); low family income (aOR 1.44 [95% CI 1.28-1.62] P<0.001); and upper respiratory tract infection (URTI) symptoms (aOR 1.77 [95% CI 1.57-2.01] P<0.001). Predictors were similar for PCV10 and non-PCV10 carriage, except PCV10 carriage was negatively associated with PCV10 vaccination (0.58 [95% CI 0.41-0.82] P = 0.002) and positively associated with exposure to household cigarette smoke (aOR 1.21 [95% CI 1.02-1.43] P = 0.031), while there was no association between years post-PCV10 introduction and non-PCV10 carriage. Pneumococcal density was positively associated with URTI symptoms (adjusted median difference 0.28 [95% CI 0.16, 0.40] P<0.001) and toddler and child, compared with caregiver, participant groups (global P = 0.008). Predictors were similar for PCV10 and non-PCV10 density, except infant, toddler, and child participant groups were not associated with PCV10 density. PCV10 introduction was associated with reduced the odds of overall and PCV10 pneumococcal carriage in Fiji. However, after adjustment iTaukei ethnicity was positively associated with pneumococcal carriage compared with Fijians of Indian Descent, despite similar PCV10 coverage rates.

Factors associated with pneumococcal carriage and density in infants and young children in Laos PDR

Nasopharyngeal carriage of Streptococcus pneumoniae (the pneumococcus) is a precursor to pneumococcal disease. Several host and environmental factors have been associated with pneumococcal carriage, however few studies have examined the relationship between host factors and pneumococcal carriage density. We sought to identify risk factors for pneumococcal carriage and density using data from cross-sectional pneumococcal carriage surveys conducted in the Lao People's Democratic Republic before and after the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13). Nasopharyngeal swabs were collected infants from aged 5–8 weeks old (n = 999) and children aged 12–23 months (n = 1,010), pneumococci detected by quantitative PCR, and a risk factor questionnaire completed. Logistic and linear regression models were used to evaluate associations between participant characteristics and pneumococcal carriage and density. In infants aged 5–8 weeks, living in a household with two or more children under the age of five years (aOR 1.97; 95% CI 1.39–2.79) and low family income (aOR 1.64; 95% CI 0.99–2.72) were positively associated with pneumococcal carriage. For children aged 12–23 months, upper respiratory tract infection (URTI) symptoms (aOR 2.64; 95% CI 1.97–3.53), two or more children under five in the household (aOR 2.40; 95% CI 1.80–3.20), and rural residence (aOR 1.84, 95% CI 1.35–2.50) were positively associated with pneumococcal carriage. PCV13 vaccination was negatively associated with carriage of PCV13 serotypes (aOR 0.60; 95% CI 0.44–0.83). URTI symptoms (p < 0.001), current breastfeeding (p = 0.005), rural residence (p = 0.012), and delivery by Caesarean section (p = 0.035) were associated with higher mean pneumococcal density in pneumococcal carriers (both age groups combined). This study provides new data on pneumococcal carriage and density in a high disease burden setting in southeast Asia.

Associations between ethnicity, social contact, and pneumococcal carriage three years post-PCV10 in Fiji

BACKGROUND

Pneumococcal carriage is a prerequisite for pneumococcal disease. Little is known about whether social contact frequency and intensity are associated with pneumococcal carriage. In Fiji, indigenous iTaukei have higher prevalence of pneumococcal carriage compared with Fijians of Indian Descent (FID). We hypothesised that contact differences may contribute to ethnic differences in pneumococcal carriage prevalence and density.

METHODS

In 2015, young infants (5-8 weeks), toddlers (12-23 months), children (2-6 years), and caregivers from Suva and surrounding areas, participated in a cross-sectional survey (n = 2014), three years post pneumococcal conjugate vaccine introduction. Demographic and contact data, and nasopharyngeal swabs were collected. Pneumococci were detected, and quantified using quantitative real-time PCR, with molecular serotyping by microarray. Associations between ethnicity, contact, and pneumococcal carriage and density were estimated using multivariable generalised estimating equation regression models.

RESULTS

iTaukei participants had larger household sizes, higher pneumococcal carriage rates, more contacts, and more frequent contacts of longer duration, compared with FID. The odds of vaccine-type carriage increased by 28% (95% CI 8-53%) P < 0.01 in association with physical contact with 7-14 year old children. iTaukei ethnicity was associated with vaccine-type carriage (aOR) 1.73; 95% CI 1.06-2.82, P = 0.03) and non-vaccine type carriage (aOR 5.98; 95% CI 4.47-8.00, P < 0.01). Ethnicity and contact were not associated with pneumococcal density.

CONCLUSIONS

iTaukei had greater frequency and intensity of contact compared with FID. Physical contact was associated with pneumococcal carriage. Observed differences in pneumococcal nasopharyngeal carriage prevalence between iTaukei and FID were not explained by differences in social contact patterns by ethnicity.

Using pneumococcal carriage studies to monitor vaccine impact in low- and middle-income countries

Pneumococcal disease is a leading cause of childhood mortality, globally. The pneumococcal conjugate vaccine (PCV) has been introduced to many countries worldwide. However there are few studies evaluating PCV impacts in low- and middle-income countries (LMIC) because measuring the impact of PCV on pneumococcal disease in LMICs is challenging. We review the role of pneumococcal carriage studies for the evaluation of PCVs in LMICs and discuss optimal methods for conducting these studies. Fifteen carriage studies from 13 LMICs quantified the effects of PCV on carriage, and identified replacement carriage serotypes in the post-PCV era. Ten studies reported on the indirect effects of PCV on carriage. Results can be used to inform cost-effectiveness evaluations, guide policy decisions on dosing and product, and monitor equity in program implementation. Critically, we highlight gaps in our understanding of serotype replacement disease in LMICs and identify priorities for research to address this gap.