Prevalence and Genetic Characterization of Rotavirus Infections Among Children Under Five Years in Mutaho Health District, Gitega Province and Bujumbura Municipality, Burundi

Rotavirus is the leading cause of severe diarrhea in children under five years worldwide. It is ranked as a priority for vaccine. In Burundi, vaccine against rotavirus was implemented in 2013. The impact of recent rotavirus vaccination on morbidities in Burundi is not well established. Moreover, no study has been carried out to document the genetic diversity of rotavirus strains circulating in Burundi. This cross-sectional health facility-based study aimed at determining the prevalence and molecular characteristics of rotavirus infections among children under five years of age in Mutaho Health District and the Municipality of Bujumbura, in Burundi. Stool specimens were collected from children presenting with acute diarrhea. These specimens were tested for rotavirus antigen using Diagnostar® rapid test kit.  Positive stool samples were confirmed at the Kenya Medical Research Institute (KEMRI) by ELISA. Positive confirmed samples underwent RT-PCR, G and P genotyping by multiplex semi-nested PCR using a cocktail of type specific primers or by sequencing. A total of 646 participants were enrolled in this study. The overall prevalence of rotavirus was 6.2% (40/646) with 4.0% (16/400) in Mutaho health district and 9.7% (24/246) in the Municipality of Bujumbura. Rotavirus detection rate tended to increase as the level of precipitation went down, showing a significant negative association between the two variables. (OR = 15.2; P = 0.0001). In addition, rotavirus detection rate was higher in Bujumbura Municipality than in Mutaho health district (OR = 2.6; P = 0.005). Two G genotypes were identified, G1 the predominating G genotype accounted for 53.8% (14/26) followed by G12 (46.2%, 12/26). The prevalence of the genotype G1 of Group A rotavirus was significantly higher in Bujumbura Municipality than in Mutaho health district while G12 predominated in Mutaho health district (OR = 7.33; P = 0.026). Rotavirus strains from pigs might have contributed to the high prevalence of human G12 rotavirus in that area. Three different P types were identified P[8] the most common, followed by P[6] and P[4]. The most common G/P combination genotype was G1P[8] which accounted for 45.5% of all rotavirus genotypes identified, followed by G12 P [8] (41.0%), G1P [6] (4.5%), G12 P [6] (4.5%) and G12 P [4] (4.5%). The emergence of G12 rotavirus strains which share neither G nor P genotypes with currently used rotavirus vaccines raises public health concerns as they have the potential to challenge their efficacy. Therefore, we recommend to initiate and maintain a continuous rotavirus strain surveillance in Burundi so as to monitor trends in the occurrence of these prevailing and potentially emerging new strains. Keywords: Rotavirus, diarrhea, genetic diversity, prevalence, Mutaho, Bujumbura, children DOI: 10.7176/JBAH/9-10-04 Publication date:May 31st 201

Prevalence and genetic diversity of rotavirus infection in children with acute gastroenteritis in a hospital setting, Nairobi Kenya in post vaccination era: a cross-sectional study

Introduction: Rotavirus is the leading cause of severe diarrhoea among infants and young children. Each year more than 611 000 children die from rotavirus gastroenteritis, and two million are hospitalized, worldwide. In Kenya, the impact of recent rotavirus vaccinations on morbidities has not been estimated. The study aimed at determining the prevalence and identity of rotavirus strains isolated from rotavirus-associated diarrhoea in vaccinated children presenting with acute gastroenteritis.Methods: Two hundred and ninety eight specimen from children presented at Gertrude Childrens’ Hospital from January to June 2012 were tested by EIA (Enzyme-linked Immunosorbent Assay) for rotavirus antigens. Molecular characterization was conducted on rotavirus-positive specimens. Extracted viral RNA was separated by polyacrylamide gel electrophoresis (PAGE) and the specific rotavirus VP4 (P-types) and VP7 (G-types) determined.Results: The prevalence rate of rotavirus was 31.5% (94/298). Of the rotavirus dsRNA, 57 (60.1%) gave visible RNA profiles, 38 (40.4%) assigned long electropherotypes while 19 (20.2%) were short electropherotypes. The strains among the vaccinated were G3P [4], G12P [6], G3P [6], G9P [4], G mixed G9/3P [4] and G1/3P [4]. Specifically, the G genotypes were G9/3 (5.3%), G9 (4.3%), G3 (4.3%), G12 (2.1%) and mixed G1/3 (1.1%). The P genotypes detected were P [4] (5.3%) and P [6] (5.3%). Conclusion: The present study demonstrates diversity in circulating genotypes with emergence of genotypes G3, G9, G12 and mixed genotypes G9/3 and recommends that vaccines should be formulated with a broad range of strains to include G9 and G12

Emergence and Characterization of Serotype G9 Rotavirus Strains from Africa

Serotype G9 strains have been detected sporadically and in localized outbreaks in various African countries, including South Africa, Botswana, Malawi, Kenya, Cameroon, Nigeria, Ghana, Guinea-Bissau, Libya, and Mauritius. Serotype G9 strains were analyzed to investigate genogroup characteristics, including subgroup specificity, electropherotype, and P and G genotypes. In addition, the antigenic composition of the South African G9 strains was assessed. African G9 strains were associated with both DS-1-like characteristics and Wa-like characteristics, indicating the predisposition of G9 strains to frequently reassort. Despite these reassortment events, serotype G9 strains appear to maintain antigenic character in the outer capsid protein, as evident with the reaction of the South African G9 strains with the G9-specific monoclonal antibody F45:1. Phylogenetic analysis clustered African G9 strains geographically, regardless of genogroup characteristics, into 1 lineage (IIId). Two groups of G9 strains, originating in India and Japan, were identified in this lineage. Continuous surveillance of circulating rotavirus strains in Africa is vital to prepare for future vaccine implementation on a continent that clearly needs such preventative medicine

A cost effectiveness and capacity analysis for the introduction of universal rotavirus vaccination in Kenya : comparison between Rotarix and RotaTeq vaccines

Background Diarrhoea is an important cause of death in the developing world, and rotavirus is the single most important cause of diarrhoea associated mortality. Two vaccines (Rotarix and RotaTeq) are available to prevent rotavirus disease. This analysis was undertaken to aid the decision in Kenya as to which vaccine to choose when introducing rotavirus vaccination. Methods Cost-effectiveness modelling, using national and sentinel surveillance data, and an impact assessment on the cold chain. Results The median estimated incidence of rotavirus disease in Kenya was 3015 outpatient visits, 279 hospitalisations and 65 deaths per 100,000 children under five years of age per year. Cumulated over the first five years of life vaccination was predicted to prevent 34% of the outpatient visits, 31% of the hospitalizations and 42% of the deaths. The estimated prevented costs accumulated over five years totalled US$1,782,761 (direct and indirect costs) with an associated 48,585 DALYs. From a societal perspective Rotarix had a cost-effectiveness ratio of US$142 per DALY (US$5 for the full course of two doses) and RotaTeq US$288 per DALY ($10.5 for the full course of three doses). RotaTeq will have a bigger impact on the cold chain compared to Rotarix. Conclusion Vaccination against rotavirus disease is cost-effective for Kenya irrespective of the vaccine. Of the two vaccines Rotarix was the preferred choice due to a better cost-effectiveness ratio, the presence of a vaccine vial monitor, the requirement of fewer doses and less storage space, and proven thermo-stability

Full genomic analysis of a simian SA11-like G3P[2] rotavirus strain isolated from an asymptomatic infant: Identification of novel VP1, VP6 and NSP4 genotypes

We report here the full genomic analysis of a simian SA11-like G3P[2] group A rotavirus (GAR) strain, B10, isolated from an asymptomatic infant in Kenya in 1987. By nucleotide sequence identities and phylogenetic analyses, the VP7–VP4–VP2–VP3–NSP1–NSP2–NSP3–NSP5 genes of strain B10 exhibited maximum genetic relatedness to those of the different isolates of simian strain SA11, and were assigned to the G3–P[2]–C5–M5–A5–N5–T5–H5 genotypes, respectively. On the other hand, the VP1, VP6 and NSP4 genes of strain B10 did not belong to any of the established GAR genotypes, and therefore, were assigned to new genotype numbers R8, I16 and E13, respectively, by the Rotavirus Classification Working Group. These observations suggested that strain B10 might have originated from reassortment event/s involving simian SA11-like strains and GAR strains from unknown animal host species (possibly other wild animals) preceding transmission to humans. Alternatively, considering the lack of data on simian GARs, it might be also possible that the VP1, VP6 and NSP4 genes of strain B10 are those of unknown simian strains, and that strain B10 might be a typical simian strain that was directly transmitted to humans. Therefore, either hypothesis pointed towards a rare instance of possible direct transmission of GARs from an animal host (possibly a monkey or some other wild animal) to humans. This was corroborated by the presence of different species of wild animals including non-human primates, and unhygienic conditions at the sampling site. To our knowledge, the present study is the first report on the detection of a simian SA11-like G3P[2] GAR strain in humans

Prevalence of Clostridium difficile infections among Kenyan children with diarrhea

Background: Diarrhea causes significant morbidity and mortality among children worldwide. Regions most affected by diarrhea include Sub-Saharan Africa and Southeast Asia, where antibiotics are in common use and can make children more vulnerable to Clostridium difficile and pathogens that are not affected by these drugs. Indeed, C. difficile is a major diarrhea-associated pathogen and poses a significant threat to vulnerable and immunocompromised populations. Yet, little is known about the role and epidemiology of C. difficile in diarrhea-associated illness among young children. As a result, C. difficile is often neglected in regions such as Sub-Saharan Africa that are most impacted by childhood diarrhea. The purpose of this study was to establish the frequency of C. difficile in young children (<5 years) with diarrhea. Methods: Children presenting with diarrhea at a national hospital in Kenya from 2015 to 2018 were enrolled consecutively. Following informed consent by a parent or legal guardian, stool samples were obtained from the children and demographic data were collected. The stools were examined for the presence of four common pathogens known to cause diarrhea: C. difficile, rotavirus, Cryptosporidium parvum, and Giardia lamblia. C. difficile was verified by toxigenic culture and PCR. The presence of C. parvum and/or G. lamblia was determined using the ImmunoCard STAT! Crypto/Giardia Rapid assay. Rotavirus was detected by ELISA. Results: The study population comprised 157 children; 62.4% were male and 37.6% were female and their average age was 12.4 months. Of the 157 stool specimens investigated, 37.6% were positive for C. difficile, 33.8% for rotavirus, 5.1% for Cryptosporidium, and 5.1% for Giardia. PCR analysis identified at least one of the C. difficile-specific - genes (tcdA, tcdB, or tcdC). Further, 57.6% of the stools had C. difficile colonies bearing a frame-shift deletion in the tcdC gene, a mutation associated with increased toxin production. The frequency of C. difficile was 32.6% in children ≤12 months old and increased to 46.6% in children 12–24 months old. Conclusions: In Kenyan children presenting with diarrhea, C. difficile is more prevalent than rotavirus or Cryptosporidium, two leading causes of childhood diarrhea. These findings underscore the need to better understand the role of C. difficile in children with diarrhea, especially in areas with antibiotic overuse. Understanding C. difficile epidemiology and its relationship to co-infecting pathogens among African children with diarrhea will help in devising ways of reducing diarrhea-associated illness. Keywords: Clostridium difficile infections in Africa, C. difficile pathogenesis, C. difficile epidemiology, CDI in young children, CDI in infants, C. difficile co-infectio

Molecular characterization of group A rotaviruses in Mukuru slums Kenya: detection of novel strains circulating in children below 5 years of age

Abstract Background Gastroenteritis is a public health concern due to high morbidity and mortality among children. Rotaviruses are the leading etiological agents of severe gastroenteritis in children and accounts for more than half a million deaths per year in Africa. The study aimed at investigating the rotavirus genotypes that were circulating in children aged 5 years and below in and around Mukuru slums in Nairobi County Kenya. Methods A purposive cross sectional sampling method was applied where 166 samples were collected from children below 5 years of age and taken to Kenya Medical Research Institute virology laboratory. Presence of rotaviruses was determined using reverse transcription polymerase chain reaction, while extraction was done using ZR Soil/Fecal RNA MicroPrep™ extraction kit. This was followed by reverse transcription and genotyping using various group A rotavirus primers. Results The G type was successfully determined in 37 (92.5%), while the P type was successfully determined in 35 (87.5%) of the 40 (24%) page positive samples. Type G1 was the most predominant of the G types (40.5%), and the incidences of G3 and G9 were 21.6 and 32.4% respectively. Mixed types G3/G9 were detected at 5.4%. Three P types existed in Mukuru slums, P[8] (60%), P[6] (22.9%), P[4] (11.4) and their relative incidence varied over the 15 months of this study. Conclusions The G types and P types detected in this study are important causes of acute gastroenteritis in Mukuru slums Nairobi Kenya. An indication that the prevalence of certain genotypes may change over a rotavirus season is significant and mirrors observations from studies in other tropical climates. Thus monitoring of the genotypic changes among circulating viruses should be encouraged over the coming years