Early impact of rotavirus vaccination in children less than five years of age in Mozambique

Diarrheal disease and associated factors among children aged 6 to 59 months in Oda Bultum District, Eastern Ethiopia: a community-based cross-sectional study

BACKGROUND

Diarrhea is a serious health problem in children under the age of five that is both preventable and treatable. In low-income countries like Ethiopia, children under the age five years frequently experience diarrhea. However, the burden and associated factors of these diarrheal diseases are understudied in Eastern Ethiopia, Thus, this study aimed to determine the factors associated with the prevalence of diarrheal diseases in Eastern Ethiopia from September 1-30, 2022.

METHODS

A cross-sectional study was conducted on the total of 602 children aged 6 to 59 months in Oda Bultum district in eastern Ethiopia. A multistage sampling method was used. Three kebeles were selected from nine kebeles by the lottery method. Data was entered into Epi data 4.0.2 and exported to SPSS version 21 for analysis. Descriptive analysis was used for frequency, mean, and standard deviations. In addition, bivariable, and multivariable Poisson regression model was used to identify predictors of diarrhea along with a 95% confidence interval. Finally, statistical significance was declared at a p-value of 0.05.

RESULT

A total of 602 children were included in this study. The prevalence of diarrhea 7.4% (47/602), 95% CI; 5.5-9.7%) among the children. Factors such as being unvaccinated for any vaccine (AOR = 10.82, 95%CI; 4.58-25.48) and born from a mother who had medium level of empowerment (AOR = 0.34, 95%CI; 0.11-0.88) in the household had statistically significant association with diarrhea among the children compared to their counterparts.

CONCLUSION

The study found that nearly one out of thirteen children aged 6 to 59 months had any form of diarrheal diseases in Oda Bultum District, Eastern Ethiopia. In addition, the study revealed that children who were vaccinated for their age developed diarrhea less likely compared to those who did not receive any form of vaccine for their age. Moreover, children with mothers who had a medium level of empowerment were less likely to get diarrhea than children with mothers who had a low level of empowerment.

Examining comorbidities in children with diarrhea across four provinces of Mozambique: A cross-sectional study (2015 to 2019)

Comorbidities are defined as the simultaneous occurrence of two or more diseases within the same individual. Comorbidities can delay a patient's recovery and increase the costs of treatment. Assessing comorbidities can provide local health care policy-makers with evidence of the most common multi-health impairments in children. This could aid in redirecting and integrating care and treatment services by increasing health facilities the awareness and readiness of health facilities. The present analysis aims to determine the frequency and associated factors of comorbidities in children with diarrhea in Mozambique. A cross-sectional hospital-based analysis was conducted between January 2015 and December 2019 in children up to 59 months of age who were admitted with diarrhea in six reference hospitals in Mozambique. These hospitals are distributed across the country's three regions, with at least one hospital in each province from each region. Sociodemographic and clinical data were obtained through semi-structured interviews and by reviewing the child clinical process. Descriptive statistics, and Mann-Whitney-U tests were used. Crude and adjusted logistics regression models were built. P-values < 0.05 were considered statistically significant. Comorbidities were observed in 55.5% of patients (389/701; 95%CI: 51.8-59.1). Wasting was the most common comorbidity (30.2%; 212/701) and pneumonia was the least common (1.7%; 12/701). Children born with a low birth weight were 2.420 times more likely to have comorbidities, adjusted odds ratio: 2.420 (95% CI: 1.339-4374). The median (interquartile range) duration of hospitalization was significantly higher in children with comorbidities than without comorbidities, 5 days (3-7) and 4 days (3-6), respectively (p-value < 0.001). One in every two children with diarrhea in Mozambique has an additional health impairment, and this increases the length of their hospital stay.

Enterovirus detection in stool samples from Mozambican children with acute gastroenteritis

Enteroviruses (EV) are predominantly enteric viruses, present in all parts of the world causing disease in humans with a broad spectrum of clinical presentations. The purpose of this study was to identify non-polio enteroviruses (NPEV) in stool samples collected from children with acute gastroenteritis (AGE) symptoms of unknown etiology in four provinces (Maputo, Nampula, Sofala and Zambézia) of Mozambique. From June 2014 to March 2018, 327 stool samples were collected from children hospitalized with AGE in health care units. NPEVs were detected in 52 samples (52/327; 15.9%) and were more frequent in children under 5 years of age. The age group from 12 to 23 months was the most affected and showed more severity of disease. We also identified 26 different EV-types with the following detection pattern EV-B>EV-C>EV-A. The major EV-types were EV-A119 (9/52; 17.3%) and EV-C99 (8/52; 15.4%), accounting for 32.7% of the total. In addition to EV-A119, other uncommon EV-types were also identified, such as EV-B75, EV-B97 and EV-C113. The current study shows a high heterogeneity of EV types circulating in children with AGE in Mozambique as well as the identification of rarely described enteroviruses.

Impact of rotavirus vaccination on diarrheal hospitalizations in children younger than 5 years of age in a rural southern Mozambique

BACKGROUND

Rotavirus vaccine(Rotarix®) was introduced in Mozambique through its Expanded Program of Immunization in September 2015. We assessed the impact of rotavirus vaccination on childhood gastroenteritis-associated hospitalizations post-vaccine introduction in a high HIV prevalence rural setting of southern Mozambique.

METHODS

We reviewed and compared the trend of hospitalizations (prevalence) and incidence rates of acute gastroenteritis (AGE), and rotavirus associated-diarrhea (laboratory confirmed rotavirus) in pre- (January 2008-August 2015) and post-rotavirus vaccine introduction periods (September 2015-December 2020), among children <5 years of age admitted to Manhiça District Hospital.

RESULTS

From January 2008 to December 2020, rotavirus vaccination was found to contribute to the decline of the prevalence of AGE from 19% (95% CI: 18.14-20.44) prior to the vaccine introduction to 10% (95% CI: 8.89-11.48) in the post-introduction period, preventing 40% (95 % IE: 38-42) and 84% (95 % IE: 80-87) of the expected AGE and laboratory confirmed rotavirus cases, respectively, among infants. Similarly, the overall incidence of rotavirus was 11.8-fold lower in the post-vaccine introduction period (0.4/1000 child-years-at-risk [CYAR]; 95% CI: 0.3-0.6) compared with the pre-vaccination period (4.7/1000 CYAR; 95% CI: 4.2-5.1) with the highest reduction being observed among infants (16.8-fold lower from the 15.1/1000 CYAR in the pre-vaccine to 0.9/1000 CYAR in the post-vaccine eras).

CONCLUSIONS

We documented a significant reduction in all-cause diarrhea hospitalizations and rotavirus positivity after vaccine introduction demonstrating the beneficial impact of rotavirus vaccination in a highly vulnerable population.

Norovirus Genetic Diversity in Children under Five Years Old with Acute Diarrhea in Mozambique (2014-2015)

Norovirus (NoV) is the second most important cause of viral diarrheal disease in children worldwide after rotavirus and is estimated to be responsible for 17% of acute diarrhea in low-income countries. This study aimed to identify and report NoV genotypes in Mozambican children under the age of five years with acute diarrhea. Between May 2014 and December 2015, stool specimens were collected within the Mozambique Diarrhea National Surveillance (ViNaDia) and tested for NoV genogroups I (GI) and II (GII) using conventional reverse transcriptase-polymerase chain reaction (RT-PCR). Partial capsid and RNA-dependent RNA polymerase (RdRp) nucleotide sequences were aligned using the Muscle tool, and phylogenetic analyses were performed using MEGA X. A total of 204 stool specimens were tested for NoV. The detection rate of NoV was 14.2% (29/204). The presence of NoV was confirmed, by real-time RT-PCR (RT-qPCR), in 24/29 (82.8%) specimens, and NoV GII predominated (70.8%; 17/24). NoV GII.4 Sydney 2012[P31] was the predominant genotype/P-type combination detected (30.4%; 7/23). This is the first study which highlights the high genetic diversity of NoV in Mozambican children and the need to establish a continuous NoV surveillance system.

Cost-effectiveness of rotavirus vaccination in Mozambique

Introduction

Rotavirus is one of the most common cause of severe gastroenteritis in children, with the largest mortality burden in low- and middle-income countries. To prevent rotavirus gastroenteritis, Mozambique introduced ROTARIX® vaccine in 2015, however, its cost-effectiveness has never been established in the country. In 2018, additional vaccines became available globally. This study estimates the cost-effectiveness of the recently introduced ROTARIX in Mozambique and compares the cost-effectiveness of ROTARIX®, ROTAVAC®, and ROTASIIL® to inform future use.

Methods

We used a decision-support model to calculate the potential cost-effectiveness of vaccination with ROTARIX compared to no vaccination over a five-year period (2016–2020) and to compare the cost-effectiveness of ROTARIX, ROTAVAC, and ROTASIIL to no vaccination and to each other over a ten-year period (2021–2030). The primary outcome was the incremental cost per disability-adjusted life-year (DALY) averted from a government perspective. We assessed uncertainty through sensitivity analyses.

Results

From 2016 to 2020, we estimate the vaccine program with ROTARIX cost US$12.3 million, prevented 4,628 deaths, and averted US$3.1 million in healthcare costs. The cost per DALY averted was US$70. From 2021 to 2030, we estimate all three vaccines could prevent 9,000 deaths and avert US$7.8 million in healthcare costs. With Global Alliance for Vaccines and Immunization (Gavi) support, ROTARIX would have the lowest vaccine program cost (US$31 million) and 98 % probability of being cost-effective at a willingness-to-pay threshold of 0.5x GDP per capita. Without Gavi support, ROTASIIL would have the lowest vaccine program cost (US$75.8 million) and 30 % probability of being cost-effective at the same threshold.

Conclusion

ROTARIX vaccination had a substantial public health impact in Mozambique between 2016 and 2020. ROTARIX is currently estimated to be the most cost-effective product, but the choice of vaccine should be re-evaluated as more evidence emerges on the price, incremental delivery cost, wastage, and impact associated with each of the different rotavirus vaccines.

Effectiveness of Monovalent Rotavirus Vaccine in Mozambique, a Country with a High Burden of Chronic Malnutrition

Mozambique introduced monovalent rotavirus vaccine (Rotarix®) in September 2015. We evaluated the effectiveness of Rotarix® under conditions of routine use in Mozambican children hospitalized with acute gastroenteritis (AGE). A test negative case-control analysis was performed on data collected during 2017−2019 from children <5 years old, admitted with AGE in seven sentinel hospital sites in Mozambique. Adjusted VE was calculated for ≥1 dose of vaccine vs. zero doses using unconditional logistic regression, where VE = (1 − aOR) × 100%. VE estimates were stratified by age group, AGE severity, malnutrition, and genotype. Among 689 children eligible for analysis, 23.7% were rotavirus positive (cases) and 76.3% were negative (controls). The adjusted VE of ≥1 dose in children aged 6−11 months was 52.0% (95% CI, −11, 79), and −24.0% (95% CI, −459, 62) among children aged 12−23 months. Estimated VE was lower in stunted than non-stunted children (14% (95% CI, −138, 66) vs. 59% (95% CI, −125, 91)). Rotavirus vaccination appeared moderately effective against rotavirus gastroenteritis hospitalization in young Mozambican children. VE point estimates were lower in older and stunted children, although confidence intervals were wide and overlapped across strata. These findings provide additional evidence for other high-mortality countries considering rotavirus vaccine introduction.

Characterizing Undernourished Children Under-Five Years Old with Diarrhoea in Mozambique: A Hospital Based Cross-Sectional Study, 2015-2019

Diarrhoea is associated with undernutrition and this association is related to increased morbidity and mortality in children under-five. In this analysis we aimed to assess the frequency and associated factors of undernutrition in children under-five with diarrhoea. A hospital-based cross-sectional study was conducted from January 2015 to December 2019 through a surveillance system in five sentinel hospitals in Mozambique. Sociodemographic and clinical information was collected, including anthropometry. A total of 963 children were analysed. The overall undernutrition frequency was 54.1% (95% CI: 50.9−57.2), with 32.5% (95% CI: 29.6−35.5) stunting, 26.6% (95% CI: 23.9−29.6) wasting and 24.7% (95% CI: 22.1−27.5) underweight. Children from Nampula province had 4.7 (p = 0.016) higher odds for stunting compared with children from Maputo. Children whose caregiver was illiterate had higher odds of being underweight 5.24 (p < 0.001), and the wet season was associated with higher odds 1.70 (p = 0.012) of being wasted. Children born under 2500 g of weight had 2.8 (p = 0.001), 2.7 (p < 0.001) and 2.6 (p = 0.010) higher odds for being underweighted, wasted and stunted, respectively. The HIV positive status of the children was associated with higher odds of being underweight 2.6 (p = 0.006), and stunted 3.4 (p = 0.004). The province, caregiver education level, wet season, child’s birthweight and HIV status were factors associated with undernutrition in children with diarrhoea. These findings emphasise the need for additional caregiver’s education on the child’s nutrition and associated infectious diseases. More studies are needed to better understand the social context in which a child with diarrhoea and undernutrition is inserted.

Paediatric emergency care at an academic referral hospital in Mozambique

Background

Improved emergency care of children with acute illness or injuries is needed for countries in Africa to continue to reduce childhood mortality rates. Quality improvement efforts will depend on robust baseline data, but little has been published on the breadth and severity of paediatric illness seen in Mozambique.

Methods

This was a retrospective review of routinely collected provider shift summary data from the Paediatric Emergency Department (PED) at Hospital Central de Maputo (HCM), the principal academic and referral hospital in the country. All children 0–14 years of age seen in the 12-month period from August 2018–July 2019 were included. Descriptive statistical analyses were performed.

Results

Data from 346 days and 64,966 patient encounters were analyzed. The large majority of patients (96.4%) presented directly to the PED without referral from a lower level facility. An average of 188 patients was seen per day, with significant seasonal variation peaking in March (292 patients/day). The most common diagnoses were upper respiratory infections (URI), gastroenteritis, asthma, and dermatologic problems. The highest acuity diagnoses were neurologic problems (59%), asthma (57%), and neonatal diagnoses (50%). Diagnoses with the largest proportion of admissions included neurologic problems, malaria, and neonatal diagnoses. Rapid malaria antigen tests were the most commonly ordered laboratory test across all diagnostic categories; full blood count (FBC) and chemistries were also commonly ordered. Urinalysis and HIV testing were rarely done in the PED.

Conclusion

This epidemiologic profile of illness seen in the HCM PED will allow for improved resource utilisation. We identified opportunities for evidence-based care algorithms for common diagnoses such as respiratory illness to improve patient care and flow. The PED may also be able to optimize laboratory and radiology evaluation for patients and develop standardized admission criteria by diagnosis.

Rotavirus A infection in pre- and post-vaccine period: Risk factors, genotypes distribution by vaccination status and age of children in Nampula Province, Northern Mozambique (2015-2019)

Mozambique introduced the monovalent rotavirus vaccine (Rotarix^®, GSK Biologicals, Rixensart, Belgium) in September 2015. Previous analysis, showed that Nampula province continues reporting a high frequency of Rotavirus A (RVA) infection and the emergence of G9P[6], G9P[4] and G3P[4] genotypes. This analysis aimed to determine the RVA frequency; risk factors; genotype distribution by vaccination status and age between pre- and post-vaccine periods in children under-five years old with diarrhea in Nampula. A cross-sectional, hospital-based surveillance study was conducted in the Hospital Central de Nampula in Mozambique. Socio-demographic and clinical data were collected to assess factors related to RVA infection in both periods. Stool specimens were screened to detect RVA by ELISA, and positive samples were genotyped. Between 2015 (pre-vaccine period) and 2016–2019 (post-vaccine period), 614 stool specimens were collected and tested for RVA in which 34.9% (67/192) were positive in pre-vaccine period and 21.8% (92/422) in post-vaccine (p = 0.001). In the post-vaccine period, age, year, and contact with different animal species (chicken, duck, or multiple animals) were associated with RVA infection. RVA infection was higher in children partially vaccinated (40.7%, 11/27) followed by the fully vaccinated (29.3%, 56/191) and the unvaccinated (15.3%, 21/137) (p = 0.002). G1P[8] and G9P[4] were common in vaccinated children less than 12 months. The present analysis showed that RVA infection reduced slightly in the post-vaccine period, with a high proportion of infection and genotype diversity in children, under 12 months of age, vaccinated. Further research on factors associated with RVA infection on vaccinated compared to unvaccinated children and vaccination optimization should be done.

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.

Rotavirus disease burden pre-vaccine introduction in young children in Rural Southern Mozambique, an area of high HIV prevalence

BACKGROUND

Rotavirus vaccines have been adopted in African countries since 2009, including Mozambique (2015). Disease burden data are needed to evaluate the impact of rotavirus vaccine. We report the burden of rotavirus-associated diarrhea in Mozambique from the Global Enteric Multicenter Study (GEMS) before vaccine introduction.

METHODS

A case-control study (GEMS), was conducted in Manhiça district, recruiting children aged 0-59 months with moderate-to-severe diarrhea (MSD) and less-severe-diarrhea (LSD) between December 2007 and November 2012; including 1-3 matched (age, sex and neighborhood) healthy community controls. Clinical and epidemiological data and stool samples (for laboratory investigation) were collected. Association of rotavirus with MSD or LSD was determined by conditional logistic regression and adjusted attributable fractions (AF) calculated, and risk factors for rotavirus diarrhea assessed.

RESULTS

Overall 915 cases and 1,977 controls for MSD, and 431 cases and 430 controls for LSD were enrolled. Rotavirus positivity was 44% (217/495) for cases and 15% (160/1046) of controls, with AF = 34.9% (95% CI: 32.85-37.06) and adjusted Odds Ratio (aOR) of 6.4 p< 0.0001 in infants with MSD compared to 30% (46/155) in cases and 14% (22/154) in controls yielding AF = 18.7%, (95% CI: 12.02-25.39) and aOR = 2.8, p = 0.0011 in infants with LSD. The proportion of children with rotavirus was 32% (21/66) among HIV-positive children and 23% (128/566) among HIV-negative ones for MSD. Presence of animals in the compound (OR = 1.9; p = 0.0151) and giving stored water to the child (OR = 2.0, p = 0.0483) were risk factors for MSD; while animals in the compound (OR = 2.37, p = 0.007); not having routine access to water on a daily basis (OR = 1.53, p = 0.015) and washing hands before cooking (OR = 1.76, p = 0.0197) were risk factors for LSD.

CONCLUSION

The implementation of vaccination against rotavirus may likely result in a significant reduction of rotavirus-associated diarrhea, suggesting the need for monitoring of vaccine impact.

Rotavirus A infection in children under five years old with a double health problem: undernutrition and diarrhoea - a cross-sectional study in four provinces of Mozambique

BACKGROUND

Mozambique has a high burden of group A rotavirus (RVA) infection and chronic undernutrition. This study aimed to determine the frequency and potential risk factors for RVA infection in undernourished children under 5 years old with diarrhoea in Mozambique.

METHODS

The analysis was conducted using data from March 2015 to December 2017, regarding children under 5 years old with at least one type of undernutrition. Anthropometric measures were used to calculate indices of weight-for-age, weight-for-height and height-for-age through the Z-Scores. RVA results were extracted from the National Diarrhoea Surveillance database. Descriptive statistics, chi-square test was used for qualitative variables and organized in contingency tables and 95% Confidence Intervals (CI) were considered for the calculation of RVA infection proportion and in the multiple logistic regression models to estimate the adjusted odds ratios (AOR).

RESULTS

Of the 842 undernourished children included in the analysis, 27.2% (95% CI: 24.3-30.3%) were positive for RVA. The rate of RVA infection was 42.7% (95% CI: 38.0-47.5%) in the pre-vaccine period, with great reduction to 12.2% (95% CI: 9.4-15.6%) in the post-vaccine period. Most of the RVA undernourished children had severe wasting (33.3%) and severe stunting (32.0%). The risk of infection was significantly high in children from 0 to 11 months (p-value < 0.001) when compared to the age group of 24-59 months. A higher proportion of RVA infection was detected in households with five or more members (p-value = 0.029). Similar proportions of RVA were observed in children fed only by breast milk (34.9%) and breast milk with formula (35.6%). A higher proportion of undernourished HIV-positive children co-infected with RVA (7.4%) was observed.

CONCLUSIONS

The frequency of RVA infection in undernourished children declined following the introduction of the vaccine in Mozambique. Beyond the temporal variation, Maputo province, age and crowded households were also associated to RVA infection. A high proportion of RVA infection was observed in children with severe wasting and a triple burden of disease: undernutrition, RVA and HIV, highlighting the need to conduct follow-up studies to understand the long-term impact of these conditions on children's development.

Whole Genome Characterization and Evolutionary Analysis of G1P[8] Rotavirus A Strains during the Pre- and Post-Vaccine Periods in Mozambique (2012-2017)

Mozambique introduced the Rotarix^® vaccine (GSK Biologicals, Rixensart, Belgium) into the National Immunization Program in September 2015. Although G1P[8] was one of the most prevalent genotypes between 2012 and 2017 in Mozambique, no complete genomes had been sequenced to date. Here we report whole genome sequence analysis for 36 G1P[8] strains using an Illumina MiSeq platform. All strains exhibited a Wa-like genetic backbone (G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1). Phylogenetic analysis showed that most of the Mozambican strains clustered closely together in a conserved clade for the entire genome. No distinct clustering for pre- and post-vaccine strains were observed. These findings may suggest no selective pressure by the introduction of the Rotarix^® vaccine in 2015. Two strains (HJM1646 and HGM0544) showed varied clustering for the entire genome, suggesting reassortment, whereas a further strain obtained from a rural area (MAN0033) clustered separately for all gene segments. Bayesian analysis for the VP7 and VP4 encoding gene segments supported the phylogenetic analysis and indicated a possible introduction from India around 2011.7 and 2013.0 for the main Mozambican clade. Continued monitoring of rotavirus strains in the post-vaccine period is required to fully understand the impact of vaccine introduction on the diversity and evolution of rotavirus strains.

40 years of immunization in Mozambique: a narrative review of literature, accomplishments, and perspectives

In Mozambique, the Expanded Program on Immunization (EPI) was implemented in 1979 with the objective of reducing child mortality and morbidity through the provision of immunization services. This study aims to describe the characteristics of the EPI and review the available information related to immunization service in Mozambique, its accomplishments and perspectives. A narrative review of the literature was carried out and the electronic databases accessed were VHL, Google Scholar, and PubMed between 1979 and 2019, using descriptors related to the theme. A total of 28 articles and other relevant sources have been consulted for the review. The national immunization coverage in Mozambique between 1997 (47%) and 2015 (66%) improved 19 percentual points; also immunization coverage of children under 12 months has increased from 44.3% (1997) to 57% (2015). The 2015 survey showed that out of the 11 provinces, only the southern and Cabo Delgado province could reach the 80% recommended goal at the provincial level. Zambézia, Nampula, and Tete provinces have been reporting low coverage over the years and Cabo Delgado presents coverage oscillation. The BCG, DPT3, Polio 3, and measles have reached 80% of coverage goal from 1997 to 2015. Our analysis have shown important improvements in national immunization, characterized by an overall increase in the national and provincial coverage and a decrease in the number of children that did not receive any vaccine. Despite these improvements, some provinces have lower coverages than expected and it is necessary to understand the determinants of dropout in children to retain them and provide timely and full immunization.

Molecular Epidemiology of Rotavirus A Strains Pre- and Post-Vaccine (Rotarix®) Introduction in Mozambique, 2012-2019: Emergence of Genotypes G3P[4] and G3P[8]

Group A rotavirus (RVA) remains the most important etiological agent associated with severe acute diarrhea in children. Rotarix^® monovalent vaccine was introduced into Mozambique’s Expanded Program on Immunization in September 2015. In the present study, we report the diversity and prevalence of rotavirus genotypes, pre- (2012–2015) and post-vaccine (2016–2019) introduction in Mozambique, among diarrheic children less than five years of age. Genotyping data were analyzed for five sentinel sites for the periods indicated. The primary sentinel site, Mavalane General Hospital (HGM), was analyzed for the period 2012–2019, and for all five sites (country-wide analyses), 2015–2019. During the pre-vaccine period, G9P[8] was the most predominant genotype for both HGM (28.5%) and the country-wide analysis (46.0%). However, in the post-vaccine period, G9P[8] was significantly reduced. Instead, G3P[8] was the most common genotype at HGM, while G1P[8] predominated country-wide. Genotypes G9P[4] and G9P[6] were detected for the first time, and the emergence of G3P[8] and G3P[4] genotypes were observed during the post-vaccine period. The distribution and prevalence of rotavirus genotypes were distinct in pre- and post-vaccination periods, while uncommon genotypes were also detected in the post-vaccine period. These observations support the need for continued country-wide surveillance to monitor changes in strain diversity, due to possible vaccine pressure, and consequently, the effect on vaccine effectiveness.

Intestinal protozoan infections among children 0-168 months with diarrhea in Mozambique: June 2014 - January 2018

BACKGROUND

Intestinal parasites such as Cryptosporidium spp., Giardia lamblia and Entamoeba histolytica can cause severe diarrhea, especially among children in developing countries. This study aims to determine the frequency of Cryptosporidium spp., Giardia lamblia and Entamoeba histolytica in children with diarrhea and identify risk factors for infection.

METHODOLOGY

We conducted a cross-sectional study in children aged 0-168 months hospitalized with diarrhea in three regions of Mozambique, from June 2014 to January 2018. Following consent, caretakers were interviewed and a single stool specimen was collected from each child to diagnose Cryptosporidium spp., G. lamblia and E. histolytica using commercial immune-enzymatic assay (TechLab, Inc, Blacksburg, VA, USA). Anthropometric data were collected from the clinical reports. Multivariable logistic regression models were built to identify risk factors for Cryptosporidium spp. and G. lamblia infection.

RESULTS

Twenty-one percent of all specimens (212/1008) presented at least one parasitic infection. Cryptosporidium spp. infection was the most common 12.0% (118/985), followed by G. lamblia 9.7% (95/983) and E. histolytica 2.0% (20/1004). Risk factors for infection by Cryptosporidium spp. were: provenience (children from Nampula province showed the highest risk, OR: 8.176; CI: 1.916-34.894; p-value < 0.01); animal contact (children with animal contact had a protective effect OR: 0.627; CI: 0.398-0.986; p-value < 0.05); underweight (children severely underweight showed a risk of 2.309; CI: 1.310-4.069; p-value < 0.05). Risk factors for infection by G. lamblia were: age (group with highest risk, 60-168 months (OR: 2.322; CI: 1.000-5.393, p-value > 0.05)); and living in a household with five or more members (OR: 2.141; CI: 1.286-3.565, p-value < 0.01).

CONCLUSIONS

Parasitic infection is common among children with diarrhea. Routine testing, standard treatment, and assessment for risk exposure of children with diarrhea should be implemented at health facilities in Mozambique.

Occurrence of Diarrhea and Feeding Practices among Children below Two Years of Age in Southwestern Saudi Arabia

Growing evidence suggests that feeding practices in early childhood play a major role in the occurrence of childhood diarrhea. However, there is a lack of information regarding feeding practices and its relationship with occurrences of diarrhea in young children from Saudi Arabia. The present study is aimed to measure the prevalence of diarrhea and assess its relationship with feeding practices among children between two months and two years of age in Saudi Arabia. A cross-sectional study was carried out in two large cities in the Aseer region in southwest Saudi Arabia. A total of 302 mothers attending well-baby clinics across six primary health centers were included. A structured questionnaire was used to collect data. Factors associated with diarrheal disease were identified by multivariable logistic regression analysis. The prevalence of diarrhea among children during the study period was 56.3% (95% CI: 50.7%–61.8%). Only 15.9% of children in our study were exclusively breastfed. The occurrence of diarrhea was significantly associated with age 7–12 months (aOR = 2.64, 95% CI: 1.42–4.91). We found that diarrhea was prevalent among children between two months and two years of age, and that exclusive breastfeeding was not a common practice in this region. Health education programs should be directed towards mothers to improve rates of breastfeeding, weaning practices, food hygiene, and childcare. Special attention and support should be provided for working mothers.

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.

Safety of a heat-stable rotavirus vaccine among children in Niger: Data from a phase 3, randomized, double-blind, placebo-controlled trial

BACKGROUND

Rotavirus remains a major cause of diarrhea among children under 5 years of age. The efficacy of RotaSIIL, a pentavalent rotavirus vaccine, was shown in an event-driven trial in Niger. We describe the two-year safety follow-up of this trial.

METHODS

Follow-up of safety outcomes began upon administration of the first dose of RotaSIIL or placebo. Adverse events were followed until 28 days after the third dose, and serious adverse events were followed until 2 years of age. Suspected cases of intussusception were evaluated at first point of contact and then referred to hospital for surgical evaluation. Causes of death were obtained by chart review and verbal autopsy. Passive surveillance was carried out in health centers. Community health workers carried out active surveillance in villages. Between-group differences were evaluated using the chi-squared test and Fisher's exact test.

RESULTS

A total of 4092 children were randomized, and 4086 received at least one dose of RotaSIIL or placebo, constituting the intention-to-treat population, who accrued a total of 7385 child-years of follow-up time. At two years of follow-up, 58 (2.8%) participants who received RotaSIIL and 49 (2.4%) participants who received placebo had died (p = 0.38). Most deaths were due to infectious causes common to the study area. One participant had confirmed intussusception, 542 days after receiving the third dose of RotaSIIL. A total of 395 (19.3%) participants receiving RotaSIIL and 419 (20.5%) participants receiving placebo experienced any serious adverse event (p = 0.36). Most serious adverse events were hospitalizations due to infection (malaria, lower respiratory tract infection and gastroenteritis) or marasmus. Overall, 1474 (72.1%) participants receiving RotaSIIL and 1456 (71.1%) participants receiving placebo had at least one adverse event (p = 0.49) in the follow-up period.

CONCLUSIONS

At two years of follow-up, RotaSIIL was found to be safe.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02145000.