Estimated reductions in hospitalizations and deaths from childhood diarrhea following implementation of rotavirus vaccination in Africa

Epidemiological trends of diarrheal viruses in central and western Kenya before and after Rotavirus vaccine introduction

BACKGROUND

Rotavirus, norovirus, adenovirus (type 40/41) and astrovirus are the most significant viral etiological agents of acute gastroenteritis in young children globally. Kenya introduced the rotavirus vaccine into her National Immunization Program in July 2014, which has led to a significant decline in the prevalence of rotavirus. We sought to assess the impact of rotavirus vaccination on the epidemiological trends of other diarrhea-associated enteric viruses across different regions in Kenya.

METHODOLOGY

Using conventional and multiplex RT-PCR, we analyzed a total of 716 fecal samples for adenovirus, astrovirus and norovirus from children aged below 5 years presenting with acute gastroenteritis but tested negative for rotavirus at Mbita Sub-County Referral Hospital in Western Kenya and Kiambu County Referral Hospital in Central Kenya before (2011-2013) and after (2019-2020) rotavirus vaccine introduction.

RESULTS

Following the rotavirus vaccine introduction, there was no significant difference in norovirus and astrovirus prevalence post-vaccine introduction in both Central (norovirus- 5.4% vs 5.9%; astrovirus- 2% vs 2.4%) and Western Kenya (norovirus- 2% vs 3%; astrovirus 3.3% vs 5.9%). Although the prevalence of adenovirus increased substantially in Western Kenya (9% vs 12.4%), there was a significant decrease in adenovirus in Central Kenya (17%, vs 6%, p = 0.007). Before the introduction of the rotavirus vaccine, a large proportion of adenovirus cases occurred at 6-8 months in Central Kenya and 12-23 months in Western Kenya, while norovirus prevalence was highest at 12-23 months in Central and 3-5 months in Western Kenya. Astrovirus infections in Central Kenya were predominantly among children aged 12-23 months, both before and after the vaccine. Following vaccine introduction, a large proportion of adenovirus cases occurred among children aged 12-23 months in both regions. Norovirus peaked at 12-23 months in Central Kenya and showed dual peaks at 3-5 and 9-11 months in Western Kenya. Astrovirus infections in Western Kenya shifted from peaks at 6-8 and 24-59 months pre-vaccine to 9-11 months post-vaccine.

CONCLUSION

Our data demonstrate the burden and changing epidemiology of enteric viruses in Western and Central Kenya and underscores the need for continued monitoring to guide the design and implementation of appropriate public health interventions.

Global burden of diarrhea disease in the older adult and its attributable risk factors from 1990 to 2021: a comprehensive analysis from the global burden of disease study 2021

Introduction

Diarrhea disease among the older adult is an underappreciated global health issue despite its substantial burden. This study provides a comprehensive analysis of the epidemiological trends of diarrhea in individuals over 65 years, examining incidence, prevalence, mortality, and disability-adjusted life-years (DALYs) from 1990 to 2021.

Methods

Utilizing data from the Global Burden of Diseases (GBD) 2021, this cross-sectional study assesses the older adult population across 204 countries and territories. The analysis includes metrics such as incidence, prevalence, mortality, DALYs, and estimated annual percentage changes (EAPCs), stratified by region, country, age, sex, and Sociodemographic Index (SDI).

Results

A nearly 200% increase in incidence and prevalence was observed worldwide, with the highest rise in those over 95 years. Mortality and DALYs have declined, especially in the 65-69 age group. High SDI regions showed the largest increase in incidence rates and are the only areas with increasing mortality and DALYs trends. Unsafe water sources emerged as the primary risk factor for diarrhea-related deaths among the older adult.

Discussion

The burden of diarrhea in the older adult has significantly increased, particularly in high-income regions, warranting targeted interventions. The positive correlation between EAPC and the Human Development Index underscores the need for improved water safety to mitigate the disease burden. This study's findings are crucial for shaping public health strategies and informing policy decisions regarding the older adult population.

Health seeking behaviour of caregivers of children under five and its determinants in Ho West and Adaklu districts, Volta Region, Ghana: a community-based cross-sectional study

BACKGROUND

Despite gains made in child survival, morbidity and mortality remain high in sub-Saharan Africa. Seeking healthcare at health facilities for sick children under-five within 24 h of onset of symptoms is key to mitigating severe morbidity and mortality. However, literature on this outcome is limited and poses challenges for monitoring caregivers' adherence to prompt health seeking behaviour. This study assessed the prevalence and determinants of prompt caregiver health seeking behaviour (HSB) for sick under-fives in two districts in the Volta Region of Ghana.

METHODS

The study was conducted among 770 caregivers/children in the Ho West and Adaklu districts of the Volta Region. Data on caregiver and child characteristics and knowledge of childhood illness symptoms/ signs among others were obtained. Summary statistics were presented as frequencies and percentages. Logistic regression was used to assess for association between prompt HSB and independent variables including caregiver and child socio-demographics. Odds ratios were presented with 95% confidence intervals at a statistical significance of p < 0.05 in the final model.

RESULTS

Almost 93% (714/770) of the caregivers were females while about three-quarters (559/767) were aged 20-39 years. The mean age of the study children was 24.1 months. Of caregivers who sought formal health care the last time their children fell ill, only about 59% (337/573) did so within 24 h of symptoms onset. Less than 10% (52/770) of caregivers had adequate knowledge of childhood danger signs while about 64% (492/770) had decision-making capacity regarding sending a sick child to a health facility. Male children had twice the odds of caregivers' prompt HSB compared to females [AOR 2.02 95% CI: 1.24, 3.27; p = 0.004]. Fourth-born or higher birth order children had 56% reduced odds of prompt HSB [AOR 0.44 95% CI: 0.26, 0.75; p = 0.003].

CONCLUSION

About 60% of those who sought formal care for their sick children did so promptly and this was influenced by the sex and birth order of the child. Public health managers in the study area must promote interventions to improve prompt caregiver HSB, especially for children of higher birth orders. Community education is needed to minimize 'discrimination' against the girl child as far as prompt HSB is concerned.

Prevalence and associated factors of immunization among under-five children in Somalia

BACKGROUND

Children worldwide can live lives free from various illnesses and disabilities due to vaccination. For instance, vaccination has eliminated smallpox, a deformative and frequently fatal illness that claimed an estimated 300 million lives in the twentieth century. However, due to a lack of access to immunization and other health services, 14.3 million infants in 2022 still did not receive their first dose of the Diphtheria-Tetanus-Pertussis (DTP) vaccine, and an additional 6.2 million received only a portion of the scheduled dose. This study aimed to assess prevalence and determinant factors of immunization among under-five children in Somalia using Somalia Health and Demographic Survey (SHDS) Data.

METHODS

The study design was cross-sectional, utilizing the SHDS 2020 data. A total of 3916 under-five children who fulfilled the inclusion criteria were included in this study. Count regression models were employed to explore factors associated with the number of vaccinations received per child.

RESULTS

In this study, 9.14% of children did not receive any vaccination during their childhood. Different candidate count regression models were compared. Using AIC and BIC, the Negative-binomial (NB) regression model was found to be the best fit. From this model, we found that women ages 20-24 (IRR = 1.192, 95% CI: 1.083, 1.313) and 25-29 (IRR = 1.180, 95% CI: 1.068, 1.305) had a higher number of vaccinations per child compared to women in the 15-19 age group. Women who attended primary education (IRR = 1.090, 95% CI: 1.034, 1.150) and secondary education (IRR = 1.157, 95% CI: 1.058, 1.266) had a higher number of vaccinations per child compared to uneducated women) also correlated with increased vaccination Parity (IRR = 1.090, 95% CI: 1.031-1.153), and wealth quantile (IRR = 1.110, 95% CI: 1.012, 1.217) positively influenced vaccination attendance. Regional disparities were also found to be significant, with Togdheer, Sool, Sanaag, Bari, Nugaal, Bay, Bakool, Mudug, Hiiraan and Galgaduud significantly different from Awdal region. In Negative-Binomial, age, region, residence, educational level, wealth quantile, child size at birth, parity and birth order emerged as key predictors, revealing complex determinants of vaccination utilization in Somalia.

CONCLUSIONS

A large proportion of children did not complete the full vaccination schedule. Socio-demographic factors, such as age, region, residence, educational level, wealth quantile, child size at birth, parity, and birth order, had a significant impact on the number of children vaccinated in Somalia. These findings underscore the importance of targeted interventions for addressing these factors. Implementing initiatives based on these conclusions has the potential to enhance vaccination coverage and child health outcomes.

Determinants of pneumococcal vaccination dropout among children aged 12-23 months in Ethiopia: a secondary analysis from the 2019 mini demographic and health survey

Background

Vaccination is a cost-effective public health program that helps reduce significant morbidity and mortality in children under the age of five. Worldwide, the number of vaccine-preventable causes of child death has significantly decreased since the Expanded Program of Immunization (EPI) was introduced. However, for a variety of reasons, 23 million children did not have adequate access to vaccines in 2020. Therefore, this study aimed to evaluate the determinants of pneumonia conjugate vaccine (PCV) dropout among children aged 12-23 months in Ethiopia.

Methods

The study analyzed cross-sectional data obtained from the 2019 mini Ethiopian demographic and health survey. Multilevel binary logistic regression analysis was utilized, and the best fit model was chosen using the Akaike Information Criteria. The study comprised a weighted sample of 989 children aged 12 to 23 months. The study presented the Adjusted Odds Ratio (AOR) along with a 95% Confidence Interval (CI) to identify the significant factors influencing PCV dropout.

Results

The PCV dropout rate was reported at 20.2% in this study. In the multilevel analysis, possession of a health card (AOR = 0.076, 95% CI: 0.019, 0.04), vaccination for PCV 2 (AOR =0.002, 95% CI: 0.023, 0.263), and region 7 (AOR = 6.98, 95% CI: 10.1, 48.31) were significantly associated with children's PCV dropout.

Conclusion

Having a health card, having received the PCV 2 vaccinations, and region were significant predictors of PCV dropout. Consequently, health education on immunization for all mothers and region-specific, customized public health interventions are needed to reduce the vaccination dropout rate.

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990-2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND

Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations.

METHODS

The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds.

FINDINGS

The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles.

INTERPRETATION

Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere.

FUNDING

Bill & Melinda Gates Foundation.

Antimicrobial resistance containment in Africa: Moving beyond surveillance

Worldwide, infections caused by drug-resistant pathogens constitute a significant challenge threatening therapeutic efforts. According to the World Health Organization (WHO), antimicrobial resistance (AMR) ranks among the top 10 global public health threats. Organisms with a high rate of multiple host adaptivity, significant genetic diversity (multiple lineages), high virulence factors, and genetic exchange have been isolated from various sources (humans, animals, and the environment) even without exposure to prior antibiotics. Till now, the source of AMR and how resistant clones are selected in the environment remain largely elusive, and potential anthropogenic transmission has been reported in different studies. Various drug-resistant pathogens, lineages, resistant clones, outbreak clusters, plasmid replicates, and genes that play a critical role in resistance dissemination have been identified. Maintenance of certain multidrug-resistant (MDR) determinants has also been shown to enhance or support the propagation of MDR. So far, significant advances have been made in understanding the burden of AMR. However, overcoming AMR requires a holistic approach, as there is no single approach with sufficient precision to curb the threat. While strengthening AMR surveillance efforts is essential, as we have shown, there is also a need to intensify efforts to strengthen therapeutic interventions, especially in priority regions such as Africa. Herein, we discussed the burden of AMR and the dissemination of AMR in humans, animals, and the environment (non-medical drivers). We further delved into the big questions on Africa and discussed how therapeutic interventions involving vaccines and other viable biomaterials could be pivotal in reducing the burden of AMR to the barest minimum.

Prevalence of Cryptosporidium and Giardia infections in under-five children with diarrhoea in Blantyre, Malawi

BACKGROUND

Diarrhoeal diseases are common among children in low- and middle-income countries and are major causes of morbidity and mortality. Cryptosporidium and Giardia are considered to be the main parasitic causes of diarrhoea in children. The aim of the present study was to determine the prevalence and associated factors of Cryptosporidium and Giardia infection in children under five years of age presenting at two health centres (Ndirande and Limbe) in Blantyre, Malawi.

METHODS

This cross-sectional study was performed from February to July 2019 and included 972 children under 5 years of age with diarrhoea. Stool samples were immediately tested after collection at enrolment with a rapid diagnostic test for Cryptosporidium and Giardia infection. Descriptive statistics were used to assess the prevalence of these protozoan parasitic infections, and differences in the basic demographic and anthroponotic variables (between children with diarrhoea and parasite infection, being either Cryptosporidium and Giardia or both versus children with diarrhoea but no RDT confirmed parasite infection) were assessed. Their association with Cryptosporidium and Giardia infection was analysed using simple logistic regressions.

RESULTS

Of the children recruited, 88 (9.1%) tested positive for Cryptosporidium and 184 (18.9%) for Giardia. Children with only a Giardia infection or a coinfection (of both parasites) were significantly older (mean age 24-26 months) compared to children with only a Cryptosporidium infection (mean age 13 months) or no parasitic infection (mean age 14 months). No significant differences were found with respect to gender, body temperature, stunting or wasting between the different groups of children with moderate to severe diarrhoea. Children attending the Ndirande health centre had almost two times higher odds of testing positive for both infections than those attending Limbe health centre.

CONCLUSION

Cryptosporidium and Giardia infections are highly prevalent in children < 5 years with moderate to severe diarrhoea attending the Limbe and Ndirande health centres in Blantyre, Malawi.

Clinical characteristics and influencing factors of infectious diarrhea in preschool children: An observational study

Infectious diarrhea is a common disease in preschool children, but the pathogenic species, origins, and influencing factors remain debatable. Therefore, more studies are required to solve these debatable topics. A number of 260 eligible preschool children diagnosed with infectious diarrhea in our hospital were enrolled in the infection group. Meanwhile, a number of 260 matched healthy children from the health center were enrolled in the control group. The pathogenic species and origins, the time of onset of infectious diarrhea in the infection group, demographic data, exposure history, hygiene habits, dietary habits, and other variables in both groups were initially collected from medical documents. In addition, a questionnaire was used to complete and confirm study variables through face-to-face or telephone interviews. Then, the univariate and multivariate regression analyses were used to screen the influencing factors of infectious diarrhea. Among 260 infected children, salmonella (15.77%), rotavirus (13.85%), shigella (11.54%), vibrio (10.38%), and norovirus (8.85%) were the top 5 common pathogens; January (13.85%), December (12.69%), August (12.31%), February (11.92%), and July (8.46%) were the top 5 frequent times of infectious diarrhea. The distribution of onset time for infectious diarrhea was commonly found in winter and summer, and the pathogens always originated from foods. The results of multivariate regression analysis showed that recent exposure to diarrhea, flies, and/or cockroaches indoors were the 2 risk factors for infectious diarrhea; Meanwhile, rotavirus vaccination, regular hand-washing, tableware disinfection, separate preparation of cooked and raw foods, and regular intake of lactobacillus products were the 5 protective factors for infectious diarrhea in preschool children. Infectious diarrhea has a diversity of pathogenic species, origins, and influencing factors in preschool children. Activities focusing on these influencing factors such as rotavirus vaccination, consumption of lactobacillus products, and other conventional factors would be beneficial to preschool children's health.

Genetic diversity and Genomic analysis of G3P[6] and equine-like G3P[8] in Children Under-five from Southern Highlands and Eastern Tanzania

Rotavirus group A genomic characterization is critical for understanding the mechanisms of rotavirus diversity, such as reassortment events and possible interspecies transmission. However, little is known about the genetic diversity and genomic relationship of the rotavirus group A strains circulating in Tanzania. The genetic and genomic relationship of RVA genotypes was investigated in children under the age of five. A total of 169 faecal samples were collected from under-five with diarrhea in Mbeya, Iringa and Morogoro regions of Tanzania. The RVA were screened in children under five with diarrhea using reverse transcription PCR for VP7 and VP4, and the G and P genotypes were determined using Sanger dideoxynucleotide cycle sequencing. Whole-genome sequencing was performed on selected genotypes. The overall RVA rate was 4.7% (8/169). The G genotypes were G3 (7/8) and G6 (1/8) among the 8 RVA positives, while the P genotypes were P[6] (4/8) and P[8] (2), and the other two were untypeable. G3P[6] and G3P[8] were the identified genotype combinations. The genomic analysis reveals that the circulating G3P[8] and G3P[6] isolates from children under the age of five with diarrhea had a DS-1-like genome configuration (I2-R2-C2-M2-Ax-N2-T2-E2-H2). The phylogenic analysis revealed that all 11 segments of G3P[6] were closely related to human G3P[6] identified in neighboring countries such as Uganda, Kenya, and other African countries, implying that G3P[6] strains descended from a common ancestor. Whereas, G3P[8] were closely related to previously identified equine-like G3P[P8] from Kenya, Japan, Thailand, Brazil, and Taiwan, implying that this strain was introduced rather than reassortment events. We discovered amino acid differences at antigenic epitopes and N-linked glycosylation sites between the wild type G3 and P[8] compared to vaccine strains, implying that further research into the impact of these differences on vaccine effectiveness is warranted. The phylogenic analysis of VP7 also identified a bovine-like G6. For the first time in Tanzania, we report the emergence of novel equine-like G3 and bovine-like G6 RVA strains, highlighting the importance of rotavirus genotype monitoring and genomic analysis of representative genotypes.

Genomic Analysis of G2P[4] Group A Rotaviruses in Zambia Reveals Positive Selection in Amino Acid Site 7 of Viral Protein 3

The G2P[4] genotype is among the rotavirus strains that circulate commonly in humans. Several countries have reported its immediate upsurge after the introduction of rotavirus vaccination, raising concern about sub-optimal vaccine effectiveness against this genotype in the long term. This study aimed to gain insight into the evolution of post-vaccine Zambian G2P[4] group A rotavirus (RVA) strains and their overall genetic make-up by analysis of sequence alignments at the amino acid (AA) level. Twenty-nine Zambian G2P[4] rotavirus strains were subjected to whole-genome sequencing using the Illumina MiSeq® platform. All the strains exhibited the typical DS-1-like genotype constellation, and the nucleotide sequences of the 11 genome segments showed high nucleotide similarities (>97%). Phylogenetic analyses together with representative global G2P[4] RVA showed that Zambian strains clustered into human lineages IV (for VP2, VP4, VP7, NSP1, and NSP5), V (for VP1, VP3, VP6, NSP2, and NSP3), and XXIII (for NSP4). The AA differences between the lineages where the study strains clustered and lineages of global reference strains were identified and analyzed. Selection pressure analysis revealed that AA site seven in the Viral Protein 3 (VP3) genome segment was under positive selection. This site occurs in the region of intrinsic disorder in the VP3 protein, and Zambian G2P[4] strains could potentially be utilizing this intrinsically disordered region to survive immune pressure. The Zambian G2P[4] strains from 2012 to 2016 comprised the G2P[4] strains that have been circulating globally since the early 2000s, highlighting the epidemiological fitness of these contemporary G2P[4] strains. Continuous whole-genome surveillance of G2P[4] strains remains imperative to understand their evolution during the post-vaccination period.

Determinants of immunization status among 12-24 months old children in Ethiopia: Using 2019 Ethiopian mini demographic and health survey data

BACKGROUND

Vaccination is a global success story, one of the most effective and successful health interventions for health and development, saving the lives of millions of children every year. In 2018, nearly 870,000 Ethiopian children did not receive the life-saving measles, diphtheria, and tetanus vaccines. This study aimed to determine what factors influence children's immunization status in Ethiopia.

METHODS

Immunization status was examined in a sample of 1843 children aged 12-24 months using data from the 2019 Ethiopian Mini Demographic and Health Survey 2019. The study used percentages to show the prevalence of immunization status among children. The marginal likelihood effect was used to determine the impact of each category of the explanatory variable on one response category of immunization status. Ordinal logistic regression models were constructed, and the best-fitting model was selected to identify significant immunization status variables.

RESULTS

The immunization prevalence among children was 72.2% (34.2% fully immunized and 38.0% partially immunized), while about 27.8% of children were non-immunized. The fitted partial proportional odds model revealed that child immunization status was significantly associated with region afar (OR = 7.90; CI: 4.78-11.92), family planning use (OR = 0.69; CI: 0.54-0.88), residence (OR = 2.22;CI: 1.60-3.09), antenatal visit (OR = 0.73;CI: 0.53-0.99), and delivery place (OR = 0.65;CI: 0.50-0.84).

CONCLUSIONS

Vaccinating children was a significant step forward in improving and protecting child health in Ethiopia, as the proportion of non-immunized children was about 27.8%. The study showed that the prevalence of non-immunization status among rural children was 33.6% and about 36.6% among children from non-educated mothers. As a result, it is agreeable that treatments are better to focus on targeting essential childhood vaccinations by promoting maternal education about family planning, antenatal visits, and maternal access to health care.

Estimated public health impact of human rotavirus vaccine (HRV) and pneumococcal polysaccharide protein D-conjugate vaccine (PHiD-CV) on child morbidity and mortality in Gavi-supported countries

Vaccine impact models against rotavirus disease (RD) and pneumococcal disease (PD) in low- and middle-income countries assume vaccine coverage based on other vaccines. We propose to assess the impact on severe disease cases and deaths avoided based on vaccine doses delivered by one manufacturer to Gavi-supported countries. From the number of human rotavirus vaccine (HRV) and pneumococcal polysaccharide protein D-conjugate vaccine (PHiD-CV) doses delivered, we estimated the averted burden of disease 1) in a specific year and 2) for all children vaccinated during the study period followed-up until 5 years (y) of age. Uncertainty of the estimated impact was assessed in a probabilistic sensitivity analysis using Monte-Carlo simulations to provide 95% confidence intervals. From 2009 to 2019, approximately 143 million children received HRV in 57 Gavi-supported countries, avoiding an estimated 18.7 million severe RD cases and 153,000, deaths. From 2011 to 2019, approximately 146 million children received PHiD-CV in 36 countries, avoiding an estimated 5.0 million severe PD cases and 587,000 deaths. The number of severe cases and deaths averted for all children vaccinated during the study period until 5 years of age were about 23.2 million and 190,000, respectively, for HRV, and 6.6 million and 749,000, respectively, for PHiD-CV. Models based on doses delivered help to assess the impact of vaccination, plan vaccination programs and understand public health benefits. In 2019, HRV and PHiD-CV doses delivered over a 5-y period may have, on average, averted nine severe disease cases every minute and one child death every 4 min.

Beyond coverage: Rural-urban disparities in the timeliness of childhood vaccinations in Tanzania

BACKGROUND

Timely vaccination maximizes efficacy for preventing infectious diseases. In the absence of national vaccination registries, representative sample survey data hold vital information on vaccination coverage and timeliness. This study characterizes vaccination coverage and timeliness in Tanzania and provides an analytic template to inform contextually relevant interventions and evaluate immunization programs.

METHODS

Cross-sectional data on 6,092 children under age 3 from the 2015-16 Tanzania Demographic and Health Survey were used to examine coverage and timeliness for 14 vaccine doses recommended in the first year of life. The Kaplan-Meier method was used to model time to vaccination. Cox proportional hazard models were used to examine factors associated with timely vaccination.

RESULTS

Substantial rural-urban disparities in vaccination coverage and timeliness were observed for all vaccines. Across 14 recommended doses, documented coverage ranged from 52 % to 79 %. Median vaccination delays lasted up to 35 days; gaps were larger among rural than urban children and for later doses in vaccine series. Among rural children, median delays exceeded 35 days for the 3rd doses of the polio, pentavalent, and pneumococcal vaccines. Median delays among urban children were < 21 days for all doses. Among rural and urban children, lower maternal education and delivery at home were associated with increased risk of delayed vaccination. In rural settings, less household wealth and greater distance to a health facility were also associated with increased risk of delayed vaccination.

DISCUSSION

This study highlights persistent gaps in uptake and timeliness of childhood vaccinations in Tanzania and substantial rural-urban disparities. While the results provide an informative situation assessment and outline strategies for identifying unvaccinated children, a national electronic registry is critical for comprehensive assessments of the performance of vaccination programs. The timeliness measure employed in this study-the amount of time children are un- or undervaccinated-may serve as a sensitive performance metric for these programs.

Partial vaccination and associated factors among children aged 12-23 months in eastern Ethiopia

BACKGROUND

Vaccine prevents about 2-3 million deaths from vaccine-preventable diseases each year. However, immunization coverage in Ethiopia is lower than the herd immunity level required to prevent the spread of all vaccine-preventable diseases. Thus, this study aimed to assess the partial immunization and associated factors among 12-23-month-old children in Eastern Ethiopia.

METHOD

A community-based cross-sectional study design was carried out among 874 randomly selected mothers/caregivers of children aged 12-23 months. A structured questionnaire was adapted and data were collected through face-to-face interviews and review of vaccination cards. Data were coded and analyzed using the Stata version 14 software. A binary logistic regression model was utilized to identify the determinant factors. The predictor of partial immunization was presented by an adjusted odds ratio with a 95% confidence interval. A p-value of < 0.05 was used to establish statistical significance.

RESULT

The prevalence of partial immunization was 31.4% (95% CI: 28-35). The dropout rate between the first and third pentavalent vaccine was 17%. Being female child [AOR = 0.73, 95% CI: 0.52-0.95], 18-20 month child [AOR = 1.6, 95% CI: 1.1- 2.4], the child born to mothers who heard about vaccination [AOR = 3.9, 95%CI: 1.92- 8.01], a child born to mother who did not receive immunization counselling [AOR = 1.65, 95%CI: 1.15-2.36], and child whose mother walk 15-30 min, 31-60 min, and > 60 min to reach nearby health facilities [AOR = 1.94, 95% CI: 1.1-3.45], [AOR = 4.5, 95% CI: 2.47-8.15], and [AOR = 3.45, 95% CI: 1.59- 7.48] respectively were factors significantly associated with partial vaccination.

CONCLUSIONS

The prevalence of partial immunization is high compared to other studies. As a result, to decrease the proportion of defaulters and to increase immunization coverage, maternal health care utilization like antenatal care follow-up and mother knowledge about the importance of the vaccine need to be sought cautiously.

Immunity to enteric viruses

Pathogenic enteric viruses are a major cause of morbidity and mortality, particularly among children in developing countries. The host response to enteric viruses occurs primarily within the mucosa, where the intestinal immune system must balance protection against pathogens with tissue protection and tolerance to harmless commensal bacteria and food. Here, we summarize current knowledge in natural immunity to enteric viruses, highlighting specialized features of the intestinal immune system. We further discuss how knowledge of intestinal anti-viral mechanisms can be translated into vaccine development with particular focus on immunization in the oral route. Research reveals that the intestine is a complex interface between enteric viruses and the host where environmental factors influence susceptibility and immunity to infection, while viral infections can have lasting implications for host health. A deeper mechanistic understanding of enteric anti-viral immunity with this broader context can ultimately lead to better vaccines for existing and emerging viruses.

Global Estimates of Rotavirus Hospitalizations Among Children Below 5 Years in 2019 and Current and Projected Impacts of Rotavirus Vaccination

BACKGROUND

Rotavirus vaccine impact on rotavirus hospitalizations is not well documented globally. We performed a systematic review to estimate the number of rotavirus hospitalizations that (1) occur annually, (2) are currently prevented by rotavirus vaccines, and (3) could be prevented with improved vaccine coverage and universal vaccine introduction.

METHODS

We systematically reviewed articles indexed in the PubMed database published from January 1, 2000, to December 31, 2019. We included all primary peer-reviewed studies with rotavirus hospitalization rates for children below 5 years that reported data prior to vaccine introduction, utilized at least one continuous year of data collection, and collected hospitalization data after 2000 using active surveillance. We grouped pre-vaccine country estimates by childhood mortality strata and calculated the median rate among each group. We then assigned the mortality stratum-specific hospitalization rates to each country and calculated the number of rotavirus hospitalizations by country, mortality strata, and World Health Organization region.

RESULTS

Our search strategy identified 4590 manuscripts, of which 32 were included in the final dataset. In 2019, an estimated 1 760 113 (interquartile range [IQR]: 1 422 645-2 925 372) rotavirus hospitalizations occurred globally, with 524 871 (IQR: 415 987-814 835) prevented by rotavirus vaccination. With universal introduction of rotavirus vaccines and increased vaccine coverage, we estimate that an additional 751 609 (IQR: 607 671-1 318 807) rotavirus hospitalizations can be prevented annually.

CONCLUSIONS

This analysis highlights the continued burden of rotavirus hospitalizations among children below 5 years. A large, preventable proportion of this burden could be eliminated by expanding introductions to new countries and increasing rotavirus vaccine coverage to levels seen with other childhood vaccinations.

Understanding Rotavirus Vaccine Efficacy and Effectiveness in Countries with High Child Mortality

Rotavirus claims thousands of lives of children globally every year with a disproportionately high burden in low- and lower-middle income countries where access to health care is limited. Oral, live-attenuated rotavirus vaccines have been evaluated in multiple settings in both low- and high-income populations and have been shown to be safe and efficacious. However, the vaccine efficacy observed in low-income settings with high rotavirus and diarrheal mortality was significantly lower than that seen in high-income populations where rotavirus mortality is less common. Rotavirus vaccines have been introduced and rolled out in more than 112 countries, providing the opportunity to assess effectiveness of the vaccines in these different settings. We provide an overview of the efficacy, effectiveness, and impact of rotavirus vaccines, focusing on high-mortality settings and identify the knowledge gaps for future research. Despite lower efficacy, rotavirus vaccines substantially reduce diarrheal disease and mortality and are cost-effective in countries with high burden. Continued evaluation of the effectiveness, impact, and cost-benefit of rotavirus vaccines, especially the new candidates that have been recently approved for global use, is a key factor for new vaccine introductions in countries, or for a switch of vaccine product in countries with limited resources.

Rotavirus research: 2014-2020

Rotaviruses are major causes of acute gastroenteritis in infants and young children worldwide and also cause disease in the young of many other mammalian and of avian species. During the recent 5-6 years rotavirus research has benefitted in a major way from the establishment of plasmid only-based reverse genetics systems, the creation of human and other mammalian intestinal enteroids, and from the wide application of structural biology (cryo-electron microscopy, cryo-EM tomography) and complementary biophysical approaches. All of these have permitted to gain new insights into structure-function relationships of rotaviruses and their interactions with the host. This review follows different stages of the viral replication cycle and summarizes highlights of structure-function studies of rotavirus-encoded proteins (both structural and non-structural), molecular mechanisms of viral replication including involvement of cellular proteins and lipids, the spectrum of viral genomic and antigenic diversity, progress in understanding of innate and acquired immune responses, and further developments of prevention of rotavirus-associated disease.

Life Course Approach to Vaccination in Bangladesh for meeting the SDG health and health related goals - a commentary

Bangladesh is entering from low-income to lower-middle-income status in 2020, and this will be completed in the next 5 years. With gross national income growing, vaccines will need to be procured through private market for the Expanded Program on Immunization. A cost-benefit analysis is needed to evaluate vaccine demand in different socioeconomic groups in the country, to inform this procurement. Moreover, disease burden studies and awareness of importance of specific vaccines are needed as we move forward. A life-course approach to vaccination may enable whole society to realize the full potential of vaccination and address most significant threats to its success over time.

Detection of diarrhoea associated rotavirus and co-infection with diarrhoeagenic pathogens in the Littoral region of Cameroon using ELISA, RT-PCR and Luminex xTAG GPP assays

Background

Despite the global roll-out of rotavirus vaccines (RotaTeq/Rotarix / ROTAVAC/Rotasiil), mortality and morbidity due to group A rotavirus (RVA) remains high in sub-Saharan Africa, causing 104,000 deaths and 600,000 hospitalizations yearly. In Cameroon, Rotarix™ was introduced in March 2014, but, routine laboratory diagnosis of rotavirus infection is not yet a common practice, and vaccine effectiveness studies to determine the impact of vaccine introduction have not been done. Thus, studies examining RVA prevalence post vaccine introduction are needed. The study aim was to determine RVA prevalence in severe diarrhoea cases in Littoral region, Cameroon and investigate the role of other diarrheagenic pathogens in RVA-positive cases.

Methods

We carried out a study among hospitalized children < 5 years of age, presenting with acute gastroenteritis in selected hospitals of the Littoral region of Cameroon, from May 2015 to April 2016. Diarrheic stool samples and socio-demographic data including immunization and breastfeeding status were collected from these participating children. Samples were screened by ELISA (ProSpecT™ Rotavirus) for detection of RVA antigen and by gel-based RT-PCR for detection of the VP6 gene. Co-infection was assessed by multiplexed molecular detection of diarrheal pathogens using the Luminex xTAG GPP assay.

Results

The ELISA assay detected RVA antigen in 54.6% (71/130) of specimens, with 45, positive by VP6 RT-PCR and 54, positive using Luminex xTAG GPP. Luminex GPP was able to detect all 45 VP6 RT-PCR positive samples. Co-infections were found in 63.0% (34/54) of Luminex positive RVA infections, with Shigella (35.3%; 12/34) and ETEC (29.4%; 10/34) detected frequently. Of the 71 ELISA positive RVA cases, 57.8% (41/71) were fully vaccinated, receiving two doses of Rotarix.

Conclusion

This study provides insight on RVA prevalence in Cameroon, which could be useful for post-vaccine epidemiological studies, highlights higher than expected RVA prevalence in vaccinated children hospitalized for diarrhoea and provides the trend of RVA co-infection with other enteric pathogens. RVA genotyping is needed to determine circulating rotavirus genotypes in Cameroon, including those causing disease in vaccinated children.

Impact of rotavirus vaccine introduction on rotavirus hospitalizations among children under 5 years of age - World Health Organization African Region, 2008-2018

BACKGROUND

Rotavirus is the leading cause of acute gastroenteritis (AGE) among children worldwide. Prior to rotavirus vaccine introduction, over one third of AGE hospitalizations in Africa were due to rotavirus. We describe the impact of rotavirus vaccines using data from the African Rotavirus Surveillance Network (ARSN).

METHODS

For descriptive analysis, we included all sites reporting to ARSN for any length of time between 2008-2018. For vaccine impact analysis, continuous surveillance throughout the year was required to minimize potential bias due to enrollment of partial seasons and sites had to report a minimum of 100 AGE cases per year. We report the proportion of rotavirus AGE cases by year relative to vaccine introduction, and the relative reduction in the proportion of rotavirus AGE cases reported following vaccine introduction.

RESULTS

From 2008-2018, 97,366 prospectively enrolled hospitalized children <5 years of age met the case definition for AGE, and 34.1% tested positive for rotavirus. Among countries that had introduced rotavirus vaccine, the proportion of hospitalized AGE cases positive for rotavirus declined from 39.2% in the pre-vaccine period to 25.3% in the post-vaccine period, a 35.5% (95% CI: 33.7-37.3) decline. No declines were observed among countries that had not introduced the vaccine over the 11-year period.

CONCLUSION

Rotavirus vaccine introduction led to large and consistent declines in the proportion of hospitalized AGE cases that are positive for rotavirus. To maximize the public health benefit of these vaccines, efforts to introduce rotavirus vaccines to the remaining countries in the region and improve coverage should continue.

Implementation of the World Health Organization recommendation on the use of rotavirus vaccine without age restriction by African countries

The World Health Organization (WHO) recommended the worldwide use of rotavirus vaccines initially in 2007 and 2009 applying a strict age restriction criterion due to the potential for age-related association with increased risk of intussusception in infants. The restriction was relaxed in the 2013 after detailed review of robust safety data generated in post-marketing surveillance studies. We assessed the status of the implementation of the 2013 recommendation to remove age restriction in the WHO African region (AFR). Of the approximately 75% (35/47) of countries that had introduced the vaccine by 2018, only 43% (15/35) removed age restriction, exclusively from South and East sub-region (78%, 14/18). Avoiding confusion at the health facilities and financial constraints particularly resources required for re-training the health workers, use of vaccine off-label were cited as the main reasons for not implementing the 2013 WHO recommendation on age restriction removal. The 2013 WHO recommendation has not been fully implemented by African countries, suggesting the need for technical advisory bodies to further guide the countries, continue monitoring the implementation status and impact on the rotavirus vaccine coverage and intussusception in the Africa region.

A decade of rotavirus vaccination in Africa - Saving lives and changing the face of diarrhoeal diseases: Report of the 12th African Rotavirus Symposium

The African Rotavirus Network organised the 12^th African Rotavirus Symposium (ARS) from 30 July to 1 August 2019 in Johannesburg, South Africa. The symposium theme "A decade of rotavirus vaccination in Africa - Saving lives and changing the face of diarrhoeal diseases", included sessions aimed at sharing ideas and expertise on prevention and control of diarrhoeal disease in Africa. Inter alia, the delegates reviewed global and regional epidemiological trends on rotavirus diarrhoea, progress and experiences on rotavirus vaccine introduction, including vaccine safety monitoring and impact in Africa, scientific advances in developing newer rotavirus vaccines, surveillance and research on other diarrhoeal pathogens, and providing an enabling environment for networking. Importantly, the 12^th ARS served to commemorate the 20^th anniversary of the African Rotavirus Network (AfrRN) coinciding with the 50th anniversary of the South African Medical Research Council. Four oral, live-attenuated rotavirus vaccines are currently prequalified by the WHO (Rotarix, RotaTeq, Rotavac and RotaSiil). African countries utilising rotavirus vaccines in routine national immunisation programmes are realising their effectiveness and impact on diarrhoeal disease morbidity. An ~40% reduction in hospitalisations of <5-year-olds with acute gastroenteritis following rotavirus vaccine introduction, was reported between 2006 and 2018 in 92,000 children from the WHO-coordinated African Rotavirus Surveillance Network (AfrRSN) comprising 33 Member States. This was corroborated by a meta-analysis of published data, sourced from January 2000 to August 2018 that reported substantial reductions in rotavirus hospitalisations in countries using rotavirus vaccines. However, it was highlighted that the transition of some countries from Gavi-eligibility and vaccine supply shortfalls present significant challenges to achieving the full impact of rotavirus immunization in Africa. The wide diversity of rotavirus genotypes continues in Africa, with variation observed both geographically and temporally. There is currently no evidence to suggest that the emergence of rotavirus strains not included in the current vaccines do escape vaccine-induced immunity.

Genetic characterization of G12P[6] and G12P[8] rotavirus strains collected in six African countries between 2010 and 2014

BACKGROUND

G12 rotaviruses were first observed in sub-Saharan Africa in 2004 and since then have continued to emerge and spread across the continent and are reported as a significant human rotavirus genotype in several African countries, both prior to and after rotavirus vaccine introduction. This study investigated the genetic variability of 15 G12 rotavirus strains associated with either P[6] or P[8] identified between 2010 and 2014 from Ethiopia, Kenya, Rwanda, Tanzania, Togo and Zambia.

METHODS

The investigation was carried out by comparing partial VP7 and partial VP4 sequences of the African G12P[6] and G12P[8] strains with the available GenBank sequences and exploring the recognized neutralization epitopes of these strains. Additionally, Bayesian evolutionary analysis was carried out using Markov Chain Monte Carlo (MCMC) implemented in BEAST to estimate the time to the most recent ancestor and evolutionary rate for these G12 rotavirus strains.

RESULTS

The findings suggested that the VP7 and VP4 nucleotide and amino acid sequences of the G12 strains circulating in African countries are closely related, irrespective of country of origin and year of detection, with the exception of the Ethiopian strains that clustered distinctly. Neutralization epitope analysis revealed that rotavirus VP4 P[8] genes associated with G12 had amino acid sequences similar to those reported globally including the vaccine strains in RotaTeq and Rotarix. The estimated evolutionary rate of the G12 strains was 1.016 × 10^- 3 substitutions/site/year and was comparable to what has been previously reported. Three sub-clusters formed within the current circulating lineage III shows the diversification of G12 from three independent ancestries within a similar time frame in the late 1990s.

CONCLUSIONS

At present it appears to be unlikely that widespread vaccine use has driven the molecular evolution and sustainability of G12 strains in Africa. Continuous monitoring of rotavirus genotypes is recommended to assess the long-term impact of rotavirus vaccination on the dynamic nature of rotavirus evolution on the continent.

Update on rotavirus vaccine underperformance in low- to middle-income countries and next-generation vaccines

In the decade since oral rotavirus vaccines (ORV) were recommended by the World Health Organization for universal inclusion in all national immunization programs, significant yet incomplete progress has been made toward reducing the burden of rotavirus in low- to middle-income countries (LMIC). ORVs continue to demonstrate effectiveness and impact in LMIC, yet numerous factors hinder optimal performance and evaluation of these vaccines. This review will provide an update on ORV performance in LMIC, the increasing body of literature regarding factors that affect ORV response, and the status of newer and next-generation rotavirus vaccines as of early 2020. Fully closing the gap in rotavirus prevention between LMIC and high-income countries will likely require a multifaceted approach accounting for biological and methodological challenges and evaluation and roll-out of newer and next-generation vaccines.

Effectiveness of Rotarix ® vaccine in Africa in the first decade of progressive introduction, 2009-2019: systematic review and meta-analysis

Background: Randomized controlled trials of licensed oral rotavirus group A (RVA) vaccines, indicated lower efficacy in developing countries compared to developed countries. We investigated the pooled effectiveness of Rotarix ^® in Africa in 2019, a decade since progressive introduction began in 2009.

Methods: A systematic search was conducted in PubMed to identify studies that investigated the effectiveness of routine RVA vaccination in an African country between 2009 and 2019. A meta-analysis was undertaken to estimate pooled effectiveness of the full-dose versus partial-dose of Rotarix ^® (RV1) vaccine and in different age groups. Pooled odds ratios were estimated using random effects model and the risk of bias assessed using Newcastle-Ottawa scale. The quality of the evidence was assessed using GRADE.

Results: By December 2019, 39 (72%) countries in Africa had introduced RVA vaccination, of which 34 were using RV1. Thirteen eligible studies from eight countries were included in meta-analysis for vaccine effectiveness (VE) of RVA by vaccine dosage (full or partial) and age categories. Pooled RV1 VE against RVA associated hospitalizations was 44% (95% confidence interval (CI) 28-57%) for partial dose versus 58% (95% CI 50-65%) for full dose. VE was 61% (95% CI 50-69%), 55% (95% CI 32-71%), 56% (95% CI 43-67%), and 61% (95% CI 42-73%) for children aged <12 months, 12-23 months, <24 months and 12-59 months, respectively.

Conclusion: RV1 vaccine use has resulted in a significant reduction in severe diarrhoea in African children and its VE is close to the efficacy findings observed in clinical trials. RV1 VE point estimate was higher for children who received full dose than those who received partial dose, and its protection lasted beyond the first year of life.

Next-generation rotavirus vaccine developers meeting: Summary of a meeting sponsored by PATH and the bill & melinda gates foundation (19-20 June 2019, Geneva)

Despite the contribution of currently licensed live, oral rotavirus vaccines (LORVs) to alleviating the burden of severe disease and death from rotavirus gastroenteritis, those vaccines have proven less efficacious in resource-limited settings than in high- and middle-income countries. It has been proposed that the residual burden of rotavirus disease might be overcome with parenterally administered vaccines, or next-generation rotavirus vaccines (NGRV). To better define the progress of development of these vaccines, a meeting of vaccine developers and manufacturers engaged in NGRV research and development was convened in Geneva in June 2019. Several NRGVs are in various stages of preclinical development, and two have already entered clinical testing. The vaccine platforms include subunit protein, inactivated whole virus, virus-like particle and RNA-based vaccines. Meeting participants included groups involved in NGRV development, scientists investigating correlates of protection of rotavirus vaccines, and representatives of international organizations with insight into considerations for vaccine introduction. This report summarizes the presentations shared at the meeting.

Whole Genome In-Silico Analysis of South African G1P[8] Rotavirus Strains Before and After Vaccine Introduction Over A Period of 14 Years

Rotavirus G1P[8] strains account for more than half of the group A rotavirus (RVA) infections in children under five years of age, globally. A total of 103 stool samples previously characterized as G1P[8] and collected seven years before and seven years after introducing the Rotarix® vaccine in South Africa were processed for whole-genome sequencing. All the strains analyzed had a Wa-like constellation (G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1). South African pre- and post-vaccine G1 strains were clustered in G1 lineage-I and II while the majority (84.2%) of the P[8] strains were grouped in P[8] lineage-III. Several amino acid sites across ten gene segments with the exception of VP7 were under positive selective pressure. Except for the N147D substitution in the antigenic site of eight post-vaccine G1 strains when compared to both Rotarix® and pre-vaccine strains, most of the amino acid substitutions in the antigenic regions of post-vaccine G1P[8] strains were already present during the pre-vaccine period. Therefore, Rotarix® did not appear to have an impact on the amino acid differences in the antigenic regions of South African post-vaccine G1P[8] strains. However, continued whole-genome surveillance of RVA strains to decipher genetic changes in the post-vaccine period remains imperative.

Diarrhea hospitalization costs among children <5 years old in Madagascar

BACKGROUND

Following a recommendation by the World Health Organization, Madagascar introduced rotavirus vaccine in 2014. Though national rotavirus vaccine coverage has remained <80%, rotavirus hospitalizations declined by 78%. Gavi, the Vaccine Alliance, has provided financial support for rotavirus vaccine, however the Malagasy government has increasing responsibility for the financial cost.

METHODS

In this evaluation, we describe the direct medical, direct non-medical, and indirect cost of illness due to diarrhea among children <5 years old at a public pediatric referral hospital. A 3-part structured questionnaire was administered during and following the hospitalization and the child's hospital record was reviewed.

RESULTS

In total, 96 children were included in this analysis. The median total cost of the illness was $156.00 (IQR: 104.00, 210.86) and the median direct medical cost was $107.22. Service delivery costs represented a median of 44% of the inpatient costs; medications and diagnostic tests represented a median of 28% and 20% of the total costs of the hospitalization, respectively. The median percentage of the total illness costs paid by the household was 67%. Among households with income of <$61/month, the median costs of the illness paid by the household were $78.55, representing a median of 168% of the household's monthly expenses. Among households earning >$303/month, the median costs paid by the household were $147.30, representing a median of 53% of the household's monthly expenses. Among all household income levels, caregivers commonly paid these bills from savings, borrowed money, and donations.

CONCLUSIONS

Our findings will be useful in assessing the cost-effectiveness of rotavirus vaccine by decisionmakers. These results may also help hospital administrators and healthcare providers better understand the financial constraints of families.

Cost of pediatric hospitalizations in Burkina Faso: A cross-sectional study of children aged <5 years enrolled through an acute gastroenteritis surveillance program

INTRODUCTION

Diarrheal illness is a leading cause of hospitalizations among children <5 years. We estimated the costs of inpatient care for rotavirus and all-cause acute gastroenteritis (AGE) in two Burkina Faso hospitals.

METHODS

We conducted a cross-sectional study among children <5 years from December 2017 to June 2018 in one urban and one rural pediatric hospital. Costs were ascertained through caregiver interview and chart abstraction. Direct medical, non-medical, and indirect costs per child incurred are reported. Costs were stratified by rotavirus results.

RESULTS

211 children <5 years were included. AGE hospitalizations cost 161USD (IQR 117-239); 180USD (IQR 121-242) at the urban and 154USD (IQR 116-235) at the rural site. Direct medical costs were higher in the urban compared to the rural site (140USD (IQR 102-182) vs. 90USD (IQR 71-108), respectively). Direct non-medical costs were higher at the rural versus urban site (15USD (IQR 10, 15) vs. 11USD (IQR 5-20), respectively). Indirect costs were higher at the rural versus urban site (35USD (IQR 8-91) vs. 0USD (IQR 0-26), respectively). Rotavirus hospitalizations incurred less direct medical costs as compared to non-rotavirus hospitalizations at the rural site (79USD (IQR 64-103) vs. 95USD (IQR 80-118)). No other differences by rotavirus testing status were observed. The total median cost of a hospitalization incurred by households was 24USD (IQR 12-49) compared to 75USD for government (IQR 59-97). Direct medical costs for households were higher in the urban site (median 49USD (IQR 31-81) versus rural (median 14USD (IQR 8-25)). Households in the lowest wealth quintiles at the urban site expended 149% of their monthly income on the child's hospitalization, compared to 96% at the rural site.

CONCLUSIONS

AGE hospitalization costs differed between the urban and rural hospitals and were most burdensome to the lowest income households. Rotavirus positivity was not associated with greater household costs.

Monovalent Rotavirus Vaccine Effectiveness Against Rotavirus Hospitalizations Among Children in Zimbabwe

BACKGROUND

Rotavirus is a leading cause of mortality among children <5 years old. We evaluated monovalent rotavirus vaccine effectiveness (VE) under conditions of routine use at 2 surveillance sites in Harare, Zimbabwe, after vaccine introduction in May 2014.

METHODS

Children aged <5 years hospitalized or treated in the accident and emergency department (A&E) for acute watery diarrhea were enrolled for routine surveillance. Copies of vaccination cards were collected to document vaccination status. Among children age-eligible to receive rotavirus vaccine, we estimated VE, calculated as 1 - odds ratio, using a test-negative case-control design.

RESULTS

We included 903 rotavirus-positive cases and 2685 rotavirus-negative controls in the analysis; 99% had verified vaccination status. Rotavirus-positive children had more severe diarrhea than rotavirus-negative children; 61% of cases and 46% of controls had a Vesikari score ≥11 (P < .01). Among cases and controls, 31% and 37%, respectively, were stunted for their age (P < .01). Among children 6-11 months old, adjusted 2-dose VE against hospitalization or treatment in A&E due to rotavirus of any severity was 61% (95% confidence interval [CI], 21%-81%) and 68% (95% CI, 13%-88%) against severe rotavirus disease. Stratified by nutritional status, adjusted VE was 45% (95% CI, -148% to 88%) among stunted infants and 71% (95% CI, 29%-88%) among infants with a normal height for age.

CONCLUSIONS

Monovalent rotavirus vaccine is effective in preventing hospitalizations due to severe rotavirus diarrhea among infants in Zimbabwe, providing additional evidence for countries considering rotavirus vaccine introduction that live, oral rotavirus vaccines are effective in high-child-mortality settings.

Otieno G, Maia M, N. Agoti C. Effectiveness of Rotarix® vaccine in Africa in the first decade of progressive introduction, 2009-2019: systematic review and meta-analysis

Background: Randomized controlled trials of licensed oral rotavirus group A (RVA) vaccines, indicated lower efficacy in developing countries compared to developed countries. We investigated the pooled effectiveness of Rotarix® in Africa in 2019, a decade since progressive introduction began in 2009. Methods: A systematic search was conducted in PubMed to identify studies that investigated the effectiveness of routine RVA vaccination in an African country between 2009 and 2019. A meta-analysis was undertaken to estimate pooled effectiveness of the full-dose versus partial-dose of Rotarix® (RV1) vaccine and in different age groups. Pooled odds ratios were estimated using random effects model and the risk of bias assessed using Newcastle-Ottawa scale. The quality of the evidence was assessed using GRADE. Results: By December 2019, 39 (72%) countries in Africa had introduced RVA vaccination, of which 34 were using RV1. Thirteen eligible studies from eight countries were included in meta-analysis for vaccine effectiveness (VE) of RVA by vaccine dosage (full or partial) and age categories. Pooled RV1 VE against RVA associated hospitalizations was 44% (95% confidence interval (CI) 28-57%) for partial dose versus 58% (95% CI 50-65%) for full dose. VE was 61% (95% CI 50-69%), 55% (95% CI 32-71%), 56% (95% CI 43-67%), and 61% (95% CI 42-73%) for children aged <12 months, 12-23 months, <24 months and 12-59 months, respectively. Conclusion: RV1 vaccine use has resulted in a significant reduction in severe diarrhoea in African children and its VE is close to the efficacy findings observed in clinical trials. RV1 VE point estimate was higher for children who received full dose than those who received partial dose, and its protection lasted beyond the first year of life.

Fifteen years of experience with the oral live-attenuated human rotavirus vaccine: reflections on lessons learned

INTRODUCTION

Rotavirus (RV) disease remains a prominent cause of disease burden in children <5 years of age worldwide. However, implementation of RV vaccination has led to significant reductions in RV mortality, compared to the pre-vaccination era. This review presents 15 years of real-world experience with the oral live-attenuated human RV vaccine (HRV; Rotarix). HRV is currently introduced in ≥80 national immunization programs (NIPs), as 2 doses starting from 6 weeks of age.

AREAS COVERED

The clinical development of HRV and post-marketing experience indicating the impact of HRV vaccination on RV disease was reviewed.

EXPERT OPINION

In clinical trials, HRV displayed an acceptable safety profile and efficacy against RV-gastroenteritis, providing broad protection against heterotypic RV strains by reducing the consequences of severe RV disease in infants. Real-world evidence shows substantial, rapid reduction in the number of RV infections and associated hospitalizations following introduction of HRV in NIPs, regardless of economic setting. Indirect effects against RV disease are also observed, such as herd protection, decrease in nosocomial infections incidence, and a reduction of disease-related societal/healthcare costs. However, not all countries have implemented RV vaccination. Coverage remains suboptimal and should be improved to maximize the benefits of RV vaccination.

Report of the 1st African Enteric Viruses Genome Initiative (AEVGI) Data and Bioinformatics Workshop on whole-genome analysis of some African rotavirus strains held in Bloemfontein, South Africa

The University of the Free State - Next Generation Sequencing (NGS) Unit, Bloemfontein, South Africa, hosted a data and bioinformatics workshop from 19 to 22 June 2018. The workshop was coordinated by the African Enteric Viruses Genome Initiative (AEVGI) with support from the Bill & Melinda Gates Foundation. The event introduced technologies in NGS and data analysis with focus on the rotavirus (RV) genome. The workshop fostered interactions and networking between professionals, scientific experts, technicians and students. The courses provided an overview of RV diarrhoea and its burden in Africa, while highlighting the key resources and methodologies in NGS and advanced bioinformatics in deciphering vaccine impact. It was concluded that, despite the reported significant decline in RV associated-diarrhoea mortality and morbidity in Africa due to RV vaccine impact, the need for continuous surveillance and genomic characterization to better understand the ever-changing dynamics of RV strains is imperative.

An overview of rotavirus vaccination programs in developing countries

INTRODUCTION

Rotavirus is the leading cause of acute diarrhea among children <5 years worldwide. As all children are equally susceptible to infection and disease development, rotavirus vaccination programs are the best upstream approach to preventing rotavirus disease, and the subsequent risk of hospitalization or death.

AREAS COVERED

We provide an overview of global rotavirus vaccine policy, summarize the burden of rotavirus disease in developing countries, review data on the effectiveness, impact, safety, and the cost-effectiveness of rotavirus vaccination programs, and identify areas for further research and improvement.

EXPERT OPINION

Rotavirus vaccines continue to be an effective, safe, and cost-effective solution to preventing rotavirus disease. As two new rotavirus vaccines enter the market (Rotasiil and Rotavac) and Asian countries continue to introduce rotavirus vaccines into their national immunization programs, documenting vaccine safety, effectiveness, and impact in these settings will be paramount.

Childhood diarrhoeal diseases in developing countries

Diarrhoeal diseases collectively constitute a serious public health challenge globally, especially as the leading cause of death in children (after respiratory diseases). Childhood diarrhoea affecting children under the age of five accounts for approximately 63% of the global burden. Accurate and timely detection of the aetiology of these diseases is very crucial; but conventional methods, apart from being laborious and time-consuming, often fail to identify difficult-to-culture pathogens. The aetiological agent of an average of up to 40% of cases of diarrhoea cannot be identified. This review gives an overview of the recent trends in the epidemiology and treatment of diarrhoea and aims at highlighting the potentials of metagenomics technique as a diagnostic method for enteric infections.

Fucosyltransferase Gene Polymorphisms and Lewisb-Negative Status Are Frequent in Swedish Newborns, With Implications for Infectious Disease Susceptibility and Personalized Medicine

BACKGROUND

Single-nucleotide polymorphisms (SNPs) in the fucosyltransferase genes FUT2 and FUT3 have been associated with susceptibility to various infectious and inflammatory disorders. FUT variations influence the expression of human histo-blood group antigens (HBGAs) (H-type 1 and Lewis), which are highly expressed in the gut and play an important role in microbial attachment, metabolism, colonization, and shaping of the microbiome. In particular, FUT polymorphisms confer susceptibility to specific rotavirus and norovirus genotypes, which has important global health implications.

METHODS

We designed a genotyping method using a nested polymerase chain reaction approach to determine the frequency of SNPs in FUT2 and FUT3, thereby inferring the prevalence of Lewisb-positive, Lewisb-negative, secretor, and nonsecretor phenotypes in 520 Swedish newborns.

RESULTS

There was an increased frequency of homozygotes for the minor allele for 1 SNP in FUT2 and 4 SNPs in FUT3. Overall, 37.3% of newborns were found to have Lewis b negative phenotypes (Le (a+b-) or Le (a-b-). Using our new, sensitive genotyping method, we were able to genetically define the Le (a-b-) individuals based on their secretor status and found that the frequency of Lewis b negative newborns in our cohort was 28%.

CONCLUSIONS

Given the high frequency of fucosyltransferase polymorphisms observed in our newborn cohort and the implications for disease susceptibility, FUT genotyping might play a future role in personalized health care, including recommendations for disease screening, therapy, and vaccination.

Rotavirus Burden, Genetic Diversity and Impact of Vaccine in Children under Five in Tanzania

In Tanzania, rotavirus infections are responsible for 72% of diarrhea deaths in children under five. The Rotarix vaccine was introduced in early 2013 to mitigate rotavirus infections. Understanding the disease burden and virus genotype trends over time is important for assessing the impact of rotavirus vaccine in Tanzania. When assessing the data for this review, we found that deaths of children under five declined after vaccine introduction, from 8171/11,391 (72% of diarrhea deaths) in 2008 to 2552/7087 (36% of diarrhea deaths) in 2013. Prior to vaccination, the prevalence of rotavirus infections in children under five was 18.1–43.4%, 9.8–51%, and 29–41% in Dar es Salaam, Mwanza and Tanga, respectively, and after the introduction of vaccines, these percentages declined to 17.4–23.5%, 16–19%, and 10–29%, respectively. Rotaviruses in Tanzania are highly diverse, and include genotypes of animal origin in children under five. Of the genotypes, 10%, 28%, and 7% of the strains are untypable in Dar es Salaam, Tanga, and Zanzibar, respectively. Mixed rotavirus genotype infection accounts for 31%, 29%, and 12% of genotypes in Mwanza, Tanga and Zanzibar, respectively. The vaccine effectiveness ranges between 53% and 75% in Mwanza, Manyara and Zanzibar. Rotavirus vaccination has successfully reduced the rotavirus burden in Tanzania; however, further studies are needed to better understand the relationship between the wildtype strain and the vaccine strain as well as the zoonotic potential of rotavirus in the post-vaccine era.

Sources of Health Care Among Under-5 Malawian Children With Diarrhea Episodes: An Analysis of the 2017 Demographic and Health Survey

Diarrhea is a leading cause of morbidity and mortality in the world but mostly in Sub-Saharan Africa. These could be prevented if universal coverage of current available interventions were implemented. The study aimed to identify factors associated with the choice of health care source among caretakers seeking treatment for under-5 children with diarrhea illness. Using women's questionnaire we extracted a subset of data of children aged 0 to 59 months from the 2017 Demographic & Health Survey. Questions regarding history of childhood diarrhea for the past 24 hours or last 2 weeks prior to the survey were key in data extraction. Caregivers were asked to report the place where they sought treatment. In this study, 4 types of health facilities were defined: public, private, pharmacies, and other unspecified sources. A multinomial logistic regression model was used to identify sources of health facility used and corresponding factors associated with the choice. Factors associated with choice of health care source included education (educated women were less likely to self-medicate their children [relative risk ration (RRR) = 0.46; 95% confidence interval (CI) = 0.22-0.94]), income (better income earning families were more likely to seek care from private facility such as pharmacy [RRR = 1.87; 95% CI = 1.14-3.09]), and rural living (those in rural areas were more likely to seek treatment from other unspecified sources [RRR = 7.33, 95% CI = 1.40-38.36]). Public health facilities (79.9%) were the main source of health care service; however, reducing under-5 mortality due to diarrhea illness would require significant efforts to address other inequalities in accessing and utilizing health care services.

Evidence of reduction of rotavirus diarrheal disease after rotavirus vaccine introduction in national immunization programs in the African countries: Report of the 11th African rotavirus symposium held in Lilongwe, Malawi

The 11th African Rotavirus Symposium was held in Lilongwe, Malawi from May 28th to 30th 2017. Over 270 delegates (73% from Africa) from 40 countries of which 30 (75%) were from African countries attended the symposium. Participants in this symposium included research scientists, clinicians, immunization managers, public health officials, policymakers and vaccine manufacturers. At the time of the symposium, 38 of the 54 (70%) countries in Africa had introduced rotavirus vaccines into their national immunization schedules. Delegates shared progress from rotavirus surveillance and vaccine impact monitoring, demonstrating the impact of the vaccine against rotavirus diarrheal hospitalizations. Data supported the beneficial effect and safety of WHO pre-qualified available vaccines up to 2017 (RotaTeq, Rotarix). This symposium highlighted the dramatic impact of the rotavirus vaccination, called for urgent adoption of these vaccines in remaining countries, particularly those with high disease burden and large birth cohorts (e.g. Nigeria, Democratic Republic of Congo) to attain the full public health benefits of rotavirus vaccination in Africa.

Rotavirus Infection and Vaccination: Knowledge, Beliefs, and Behaviors among Parents in Italy

This study was designed to investigate the knowledge, beliefs, and behaviors about rotavirus infection and its vaccination in a sample of parents in Naples, Italy. The survey was conducted between June and December 2018 among parents of children aged 3 months to 3 years. A total of 40.7% of the study subjects declared that they had heard about rotavirus infection and 60.8% and 59.2% were aware about the vaccination and of its availability in Italy. Parents with a child aged <1 year and those who reported the physicians as source of information were more likely to have heard about rotavirus infection and to know that the vaccination is available in Italy. More than half (56.4%) were worried that their children could have a rotavirus gastroenteritis and this was most likely to occur in those who have heard about rotavirus infection. Only 15.3% declared that they had immunized their children against rotavirus infection. Parents who considered it dangerous for their children to contract the rotavirus gastroenteritis, those who considered the rotavirus vaccine useful, and those who had received information by physicians were more likely to have vaccinated their children against the infection. More than half of the parents who did not immunize their children expressed their willingness to vaccinate them. Developing and implementing additional public education programs are needed for better knowledge toward rotavirus infection and vaccination and a high coverage among parents.

Reduction of hospitalizations with diarrhea among children aged 0-5 years in Nouakchott, Mauritania, following the introduction of rotavirus vaccine

INTRODUCTION

Rotavirus vaccine was introduced in Mauritania in December 2014. We investigated hospitalizations with diarrhea during pre and post-vaccination periods among children aged 0-5 years in Nouakchott, the capital of Mauritania.

METHODS

We conducted a retrospective review of hospital admission registries from November 1st 2012 through October 31th 2017 at all referral hospitals in Nouakchott. We described admissions of children aged 0-5 years by diagnosis, data of admission, age and sex, and compared the proportion of all childhood hospitalizations with diarrhea before and after rotavirus vaccine introduction.

RESULTS

In total, 6552 (19%) of all 34,329 hospitalizations in 0-5 year-olds had diarrhea. Of these, 3523/16,952 (20.7%) were recorded during the pre-vaccine period, 1373/6897 (19.9%) during the transition period (November 2014-October 2015), and 1656/10,480 (15.8%) during the post-vaccination period. The proportion of all childhood hospitalizations with diarrhea during the pre-vaccine period was 22.6% among males and 18.7% among females. Approximately one third (32.3%) of hospitalizations with diarrhea occurred in children aged 6-11 months. During the post-vaccination period, the proportion of hospitalizations with diarrhea declined by 24%, and the highest reduction (74%) was observed in children aged 2 to 5 years (P < 0.001).

CONCLUSIONS

The proportion of childhood hospitalizations with diarrhea in Nouakchott was reduced by about one fourth after introduction of rotavirus vaccination in Mauritania, indicating a major impact for public health for children in the capital city.

Experiences with rotavirus vaccines: can we improve rotavirus vaccine impact in developing countries?

Rotavirus vaccines have been introduced into over 95 countries globally and demonstrate substantial impact in reducing diarrheal mortality and diarrheal hospitalizations in young children. The vaccines are also considered by WHO as "very cost effective" interventions for young children, particularly in countries with high diarrheal disease burden. Yet the full potential impact of rotavirus immunization is yet to be realized. Large countries with big birth cohorts and where disease burden is high in Africa and Asia have not yet implemented rotavirus vaccines at all or at scale. Significant advances have been made demonstrating the impact of the vaccines in low- and lower-middle income countries, yet the modest effectiveness of the vaccines in these settings is challenging. Current research highlights these challenges and considers alternative strategies to overcome them, including alternative immunization schedules and host factors that may inform us of new opportunities.

Impact of rotavirus vaccines in Sub-Saharan African countries

By the end of 2017, 32 (68%) of 47 countries in the World Health Organization's African Region had introduced rotavirus vaccine into their national immunization programs, including 27 countries that received financial support from the Gavi, the Vaccine Alliance. Several early introducing African countries previously evaluated the impact, vaccine effectiveness, and/or cost effectiveness of their routine rotavirus vaccination programs and found that rotavirus vaccine was effective and resulted in substantial declines in hospitalizations due to rotavirus. This Special Issue of Vaccine provides additional rotavirus vaccine effectiveness and impact data from a broader range of African countries, describes the longer term impact and potential indirect benefits of rotavirus vaccination programs, describes trends in circulating genotypes in the pre- and post-vaccine introduction eras, and evaluates the cost-effectiveness of a rotavirus vaccination program in a post-introduction setting. As countries begin transitioning from Gavi support, the findings of these studies provide evidence of the impact and effectiveness of rotavirus vaccination programs under conditions of routine use.