Impact of childhood 13-valent pneumococcal conjugate vaccine introduction on adult pneumonia hospitalisations in Mongolia: a time series analysis.

Background: Few studies have assessed the potential indirect effects of childhood pneumococcal conjugate vaccine (PCV) programs on the adult pneumonia burden in resource-limited settings. We evaluated the impact of childhood PCV13 immunisation on adult all-cause pneumonia following a phased program introduction from 2016. Methods: We conducted a time-series analysis to assess changes in pneumonia hospitalisation incidence at four district hospitals in Mongolia. Adults (≥18 years) that met the clinical case definition for all-cause pneumonia were enrolled. A negative binomial mixed-effects model was used to assess the impact of PCV13 introduction on monthly counts of pneumonia admissions from January 2015-February 2022. We also performed a restricted analysis excluding the COVID-19 pandemic period. All models were stratified by age and assessed separately. Additional analyses assessed the robustness of our findings. Findings: The average annual incidence of all-cause pneumonia hospitalisation was highest in adults 65+ years (62.81 per 10,000 population) and declined with decreasing age. After adjusting for the COVID-19 pandemic period, we found that rates of pneumonia hospitalisation remained largely unchanged over time. We did not observe a reduction in pneumonia hospitalisation in any age group. Results from restricted and sensitivity analyses were comparable to the primary results, finding limited evidence of a reduced pneumonia burden. Interpretation: We did not find evidence of indirect protection against all-cause pneumonia in adults following childhood PCV13 introduction. Direct pneumococcal vaccination and other interventions should be considered to reduce burden of pneumonia among older adults. Funding: Pfizer clinical research collaboration agreement (contract number: WI236621).

Survey-Based Assessment of Water, Sanitation, and Animal-Associated Risk Factors for Moderate-to-Severe Diarrhea in the Vaccine Impact on Diarrhea in Africa (VIDA) Study: The Gambia, Mali, and Kenya, 2015-2018.

BACKGROUND: Pediatric exposures to unsafe sources of water, unsafely managed sanitation, and animals are prevalent in low- and middle-income countries. In the Vaccine Impact on Diarrhea in Africa case-control study, we examined associations between these risk factors and moderate-to-severe diarrhea (MSD) in children <5 years old in The Gambia, Kenya, and Mali. METHODS: We enrolled children <5 years old seeking care for MSD at health centers; age-, sex-, and community-matched controls were enrolled at home. Conditional logistic regression models, adjusted for a priori confounders, were used to evaluate associations between MSD and survey-based assessments of water, sanitation, and animals living in the compound. RESULTS: From 2015 to 2018, 4840 cases and 6213 controls were enrolled. In pan-site analyses, children with drinking water sources below "safely managed" (onsite, continuously accessible sources of good water quality) had 1.5-2.0-fold higher odds of MSD (95% confidence intervals [CIs] ranging from 1.0 to 2.5), driven by rural site results (The Gambia and Kenya). In the urban site (Mali), children whose drinking water source was less available (several hours/day vs all the time) had higher odds of MSD (matched odds ratio [mOR]: 1.4, 95% CI: 1.1, 1.7). Associations between MSD and sanitation were site-specific. Goats were associated with slightly increased odds of MSD in pan-site analyses, whereas associations with cows and fowl varied by site. CONCLUSIONS: Poorer types and availability of drinking water sources were consistently associated with MSD, whereas the impacts of sanitation and household animals were context-specific. The association between MSD and access to safely managed drinking water sources post-rotavirus introduction calls for transformational changes in drinking water services to prevent acute child morbidity from MSD.

Exploring Survey-Based Water, Sanitation, and Animal Associations With Enteric Pathogen Carriage: Comparing Results in a Cohort of Cases With Moderate-to-Severe Diarrhea to Those in Controls in the Vaccine Impact on Diarrhea in Africa (VIDA) Study, 2015-2018.

BACKGROUND: The magnitude of pediatric enteric pathogen exposures in low-income settings necessitates substantive water and sanitation interventions, including animal feces management. We assessed associations between pediatric enteric pathogen detection and survey-based water, sanitation, and animal characteristics within the Vaccine Impact on Diarrhea in Africa case-control study. METHODS: In The Gambia, Kenya, and Mali, we assessed enteric pathogens in stool of children aged <5 years with moderate-to-severe diarrhea and their matched controls (diarrhea-free in prior 7 days) via the TaqMan Array Card and surveyed caregivers about household drinking water and sanitation conditions and animals living in the compound. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using modified Poisson regression models, stratified for cases and controls and adjusted for age, sex, site, and demographics. RESULTS: Bacterial (cases, 93%; controls, 72%), viral (63%, 56%), and protozoal (50%, 38%) pathogens were commonly detected (cycle threshold <35) in the 4840 cases and 6213 controls. In cases, unimproved sanitation (RR, 1.56; 95% CI, 1.12-2.17), as well as cows (RR, 1.61; 95% CI, 1.16-2.24) and sheep (RR, 1.48; 95% CI, 1.11-1.96) living in the compound, were associated with Shiga toxin-producing Escherichia coli. In controls, fowl (RR, 1.30; 95% CI, 1.15-1.47) were associated with Campylobacter spp. In controls, surface water sources were associated with Cryptosporidium spp., Shigella spp., heat-stable toxin-producing enterotoxigenic E. coli, and Giardia spp. CONCLUSIONS: Findings underscore the importance of enteric pathogen exposure risks from animals alongside more broadly recognized water and sanitation risk factors in children.

Programmatic Effectiveness of a Pediatric Typhoid Conjugate Vaccine Campaign in Navi Mumbai, India.

BACKGROUND: The World Health Organization recommends vaccines for prevention and control of typhoid fever, especially where antimicrobial-resistant typhoid circulates. In 2018, the Navi Mumbai Municipal Corporation (NMMC) implemented a typhoid conjugate vaccine (TCV) campaign. The campaign targeted all children aged 9 months through 14 years within NMMC boundaries (approximately 320 000 children) over 2 vaccination phases. The phase 1 campaign occurred from 14 July 2018 through 25 August 2018 (71% coverage, approximately 113 420 children). We evaluated the phase 1 campaign's programmatic effectiveness in reducing typhoid cases at the community level. METHODS: We established prospective, blood culture-based surveillance at 6 hospitals in Navi Mumbai and offered blood cultures to children who presented with fever ≥3 days. We used a cluster-randomized (by administrative boundary) test-negative design to estimate the effectiveness of the vaccination campaign on pediatric typhoid cases. We matched test-positive, culture-confirmed typhoid cases with up to 3 test-negative, culture-negative controls by age and date of blood culture and assessed community vaccine campaign phase as an exposure using conditional logistic regression. RESULTS: Between 1 September 2018 and 31 March 2021, we identified 81 typhoid cases and matched these with 238 controls. Cases were 0.44 times as likely to live in vaccine campaign communities (programmatic effectiveness, 56%; 95% confidence interval [CI], 25% to 74%; P = .002). Cases aged ≥5 years were 0.37 times as likely (95% CI, .19 to .70; P = .002) and cases during the first year of surveillance were 0.30 times as likely (95% CI, .14 to .64; P = .002) to live in vaccine campaign communities. CONCLUSIONS: Our findings support the use of TCV mass vaccination campaigns as effective population-based tools to combat typhoid fever.

Epidemiology of pneumonia in hospitalized adults ≥18 years old in four districts of Ulaanbaatar, Mongolia, 2015-2019.

Background: Community-acquired pneumonia is a leading cause of morbidity and mortality among children and adults worldwide. Adult pneumonia surveillance remains limited in many low- and middle-income settings, resulting in the disease burden being largely unknown. Methods: A retrospective cohort study was conducted by reviewing medical charts for respiratory admissions at four district hospitals in Ulaanbaatar during January 2015-February 2019. Characteristics of community-acquired pneumonia cases were summarized by disease severity and age. To explore factors associated with severe pneumonia, we ran univariable and age-adjusted logistic regression models. Incidence rates were calculated using population denominators. Results: In total, 4290 respiratory admissions met the case definition for clinical pneumonia, including 430 admissions of severe pneumonia. The highest proportion of severe pneumonia admissions occurred in adults >65 years (37.4%). After adjusting for age, there were increased odds of severe pneumonia in males (adjusted odds ratio [aOR]: 1.63; 95% confidence interval [CI]: 1.33-2.00) and those with ≥1 underlying medical condition (aOR: 1.46; 95% CI: 1.14-1.87). The incidence of hospitalized pneumonia in adults ≥18 years increased from 13.49 (95% CI: 12.58-14.44) in 2015 to 17.65 (95% CI: 16.63-18.71) in 2018 per 10,000 population. The incidence of severe pneumonia was highest in adults >65 years, ranging from 9.29 (95% CI: 6.17-13.43) in 2015 to 12.69 (95% CI: 9.22-17.04) in 2018 per 10,000 population. Interpretations: Vaccination and other strategies to reduce the risk of pneumonia, particularly among older adults and those with underlying medical conditions, should be prioritized. Funding: Pfizer clinical research collaboration agreement (contract number: WI236621).

Use, Acceptability, Performance, and Health Impact of Hollow Fiber Ultrafilters for Water Treatment in Rural Kenyan Households, 2009-2011.

Diarrheal illness remains a leading cause of morbidity and mortality in children < 5 years in developing countries, and contaminated water contributes to diarrhea risk. To address this problem, a novel hollow fiber ultrafilter (HFU) was developed for household water treatment. To test its impact on water quality and infant health, we conducted a cluster-randomized longitudinal evaluation in 10 intervention and 10 comparison villages in Kenya, attempting to enroll all households with infants (< 12 months old). We conducted a baseline survey, distributed HFUs to intervention households, made biweekly home visits for 1 year to assess water treatment practices and diarrhea in infants, and tested water samples from both groups every 2 months for Escherichia coli. We enrolled 92 infants from intervention households and 74 from comparison households. During the 1-year study period, 45.7% of intervention households and 97.3% of comparison households had at least one stored water sample test positive for E. coli. Compared with comparison households, the odds of E. coli contamination in stored water was lower for intervention households (odds ratio [OR]: 0.42, 95% CI: 0.24, 0.74), but there was no difference in the odds of reported diarrhea in infants, adjusting for covariates (OR: 1.19, 95% CI: 0.74, 1.90). Although nearly all water samples obtained from unprotected sources and filtered by the HFU were free of E. coli contamination, HFUs alone were not effective at reducing diarrhea in infants.

Impact of program transfer from a non-governmental organization to a district health office: Evaluation of a program integrating water treatment and hygiene kits into reproductive health and HIV services, Machinga District, Malawi, 2010-2012.

BACKGROUND: In September 2009, the Machinga Integrated Antenatal Water Hygiene Kit Program began addressing problems of unsafe water, high infant mortality, and low antenatal care (ANC) attendance in Machinga District, Malawi. In March 2011, the supporting international non-governmental organization transitioned management of the program to the Machinga District Health Office (DHO). We evaluated maternal and HIV service use before and after program transition to the DHO. METHODS: We compared pre- and post-transition periods by examining data recorded in ANC and maternal registries in 15 healthcare facilities (HCFs) by proportion z-tests. We classified HCFs by size, using the median monthly patient volumes as the split for large or small facilities. We used logistic regression to evaluate changes in the use of ANC, maternal, and HIV services and their interactions with HCF size. RESULTS: The percentage of women attending their first ANC visit during the first trimester was similar in the pre-and post-transition periods (9.3% vs 10.2%). Although the percentage of women with ≥4 ANC visits was similar from pre- to post-transition (26.0% vs 24.8%), the odds increased among women in small facilities (OR: 1.37, 95% CI: 1.24-1.51), and decreased among women in large facilities (OR: 0.80, 95% CI: 0.75-0.85). Although a similar percentages of pregnant women were diagnosed with HIV in all HCFs in the pre- and post-transitions periods (6.4% vs 4.8%), a substantially larger proportion of women were not tested for HIV in large HCFs (OR: 6.34, 95% CI: 5.88-6.84). A larger proportion of women gave birth at both small (OR: 1.30, 95% CI: 1.16-1.45) and large HCFs (OR: 1.55, 95% CI: 1.43-1.67) in the post-transition vs. the pre-transition period. CONCLUSIONS: The evaluation results suggest that many positive aspects of this donor-supported program continued following transition of program management from a non-governmental organization to a DHO.

A Randomized Controlled Trial to Assess the Impact of Ceramic Water Filters on Prevention of Diarrhea and Cryptosporidiosis in Infants and Young Children-Western Kenya, 2013.

Cryptosporidium is a leading cause of diarrhea among Kenyan infants. Ceramic water filters (CWFs) are used for household water treatment. We assessed the impact of CWFs on diarrhea, cryptosporidiosis prevention, and water quality in rural western Kenya. A randomized, controlled intervention trial was conducted in 240 households with infants 4-10 months old. Twenty-six weekly household surveys assessed infant diarrhea and health facility visits. Stool specimens from infants with diarrhea were examined for Cryptosporidium. Source water, filtered water, and filter retentate were tested for Cryptosporidium and/or microbial indicators. To estimate the effect of CWFs on health outcomes, logistic regression models using generalized estimating equations were performed; odds ratios (ORs) and 95% confidence intervals (CIs) are reported. Households reported using surface water (36%), public taps (29%), or rainwater (17%) as their primary drinking water sources, with no differences in treatment groups. Intervention households reported less diarrhea (7.6% versus 8.9%; OR: 0.86 [0.64-1.16]) and significantly fewer health facility visits for diarrhea (1.0% versus 1.9%; OR: 0.50 [0.30-0.83]). In total, 15% of intervention and 12% of control stools yielded Cryptosporidium (P = 0.26). Escherichia coli was detected in 93% of source water samples; 71% of filtered water samples met World Health Organization recommendations of < 1 E. coli/100 mL. Cryptosporidium was not detected in source water and was detected in just 2% of filter rinses following passage of large volumes of source water. Water quality was improved among CWF users; however, the short study duration and small sample size limited our ability to observe reductions in cryptosporidiosis.

Impact of the Integration of Water Treatment, Hygiene, Nutrition, and Clean Delivery Interventions on Maternal Health Service Use.

AbstractReducing barriers associated with maternal health service use, household water treatment, and improved hygiene is important for maternal and neonatal health outcomes. We surveyed a sample of 201 pregnant women who participated in a clinic-based intervention in Kenya to increase maternal health service use and improve household hygiene and nutrition through the distribution of water treatment products, soap, protein-fortified flour, and clean delivery kits. From multivariable logistic regression analyses, the adjusted odds of ≥ 4 antenatal care (ANC4+) visits (odds ratio [OR] = 3.0, 95% confidence interval [CI] = 1.9-4.5), health facility delivery (OR = 5.3, 95% CI = 3.4-8.3), and any postnatal care visit (OR = 2.8, 95% CI = 1.9-4.2) were higher at follow-up than at baseline, adjusting for demographic factors. Women who completed primary school had higher odds of ANC4+ visits (OR = 1.8, 95% CI = 1.1-2.9) and health facility delivery (OR = 4.2, 95% CI = 2.5-7.1) than women with less education. For women who lived ≤ 2.5 km from the health facility, the estimated odds of health facility delivery (OR = 2.4, 95% CI = 1.5-4.1) and postnatal care visit (OR = 1.6, 95% CI = 1.0-2.6) were higher than for those who lived > 2.5 km away. Compared with baseline, a higher percentage of survey participants at follow-up were able to demonstrate proper handwashing (P = 0.001); water treatment behavior did not change. This evaluation suggested that hygiene, nutritional, clean delivery incentives, higher education level, and geographical contiguity to health facility were associated with increased use of maternal health services by pregnant women.