Hospital-based surveillance for rotavirus gastroenteritis in children younger than 5 years of age in Ethiopia: 2007-2012

Genetic Profile of Rotavirus Type A in Children under 5 Years Old in Africa: A Systematic Review of Prevalence

Human type A rotavirus (RV-A) is world-recognized as the major pathogen causing viral gastroenteritis in children under 5 years of age. The literature indicates a substantial increase in the diversity of rotavirus strains across continents, especially in Africa, which can pose significant challenges including an increase of disease burden and a reduction of vaccines' effectiveness. However, few studies have mapped the variety of circulating virus strains in different regions, which may hamper decisions on epidemiological surveillance and preventive public health measures. Thus, our aim was to compile the most updated available evidence on the genetic profile of RV-A among children in Africa and determine the prevalence of different genotypes according to the geographical regions by means of a broad systematic review. Systematic searches were performed in PubMed, Scopus, Web of Science, and Scielo without language, time limits, or geographical restrictions within the African continent. We selected full-text peer-reviewed articles assessing the genetic profile (i.e., genotyping) of RV-A in children up to 5 years old in Africa. Overall, 682 records were retrieved, resulting in 75 studies included for evidence synthesis. These studies were published between 1999 and 2022, were conducted in 28 countries from the five African regions, and 48% of the studies were carried out for 24 months or more. Most studies (n = 55; 73.3%) evaluated RV-A cases before the introduction of the vaccines, while around 20% of studies (n = 13) presented data after the vaccine approval in each country. Only seven (9.3%) studies compared evidence from both periods (pre- and post-vaccine introduction). Genotyping methods to assess RV-A varied between RT-PCR, nested or multiplex RT-PCR, testing only the most common P and G-types. We observed G1 and P[8] to be the most prevalent strains in Africa, with values around 31% and 43%, respectively. Yet if all the genotypes with the following highest prevalence were added ((G1 + G2, G3, G9) and (P[8] + P[6], P[4])), these figures would represent 80% and 99% of the total prevalence. The combination G1P[8] was the most reported in the studies (around 22%). This review study demonstrated an increased strain diversity in the past two decades, which could represent a challenge to the efficacy of the current vaccine.

Molecular Detection of Enteric Viruses in Under-Five Children with Diarrhea in Debre Tabor, Northwest Ethiopia

Background

Viral gastroenteritis belongs to the major public health problems of infant and children worldwide. The largest proportion of morbidity and mortality occurs in Sub-Saharan Africa.

Purpose

Aimed to assess the burden and genetic diversity of enteric viruses among children with diarrhea.

Patients and Methods

A cross-sectional study was undertaken from December 2015 to April 2016 in Debre Tabor. A total of thirty-eight children, who presented with diarrhea at Debre Tabor health centers, were included. Fecal samples were collected and screened for enteric viruses by RT-PCR. Data were analyzed using SPSS software. Descriptive summary techniques were used to display the findings.

Results

Out of thirty-eight children screened, 52.6% were positive for at least one enteric virus. Six (30.0%) of the children had mixed enteric virus infections. Human adenovirus (HAdV) 7 (18.4%) was predominant followed by noroviruses (NoVs) 5 (13.2%), enterovirus (EV) 5 (13.2%), rotavirus A (RVA) 4 (10.5%), human astrovirus (HAstV) 2 (5.3%), and human parechovirus (HPeV) 1 (2.6%). Overall, nineteen different types of enteric virus genotypes were identified. Diverse adenovirus within species A (HAdV-12,-31), B (HAdV-3), C (HAdV-2), and F (HAdV-4) were detected. Norovirus II (GII.4 and GII.6) and norovirus I (GI.2, GI.3, and GI.5) genotypes were found. Sapovirus genotypes within genogroup II (GII.1, GII.5, and GII.6) were identified. Wild-type rotavirus G9 and P[8] genotypes were detected in one of the rotavirus positive samples. Non-polio enteroviruses within species A (coxsackie A virus (CAV) 5, CAV6, and CAV14) and C (enterovirus (EV-C) 99) were also identified. In two of the fecal samples classic HAstV-2 was detected.

Conclusion

Diverse enteric viruses were detected in fecal samples from under-five children with diarrhea. The detection of heterogeneous enteric viruses in this small data set highlights the need for extended multicenter studies to describe the burden and genetic diversity of enteric virus.

Prevalence and characteristics of rotavirus acute gastroenteritis among under-five children in ahmadu bello university teaching hospital, Zaria, Nigeria

Background:

Rotavirus infection is a significant cause of gastroenteritis in developing countries and, in severe cases even leads to death. The impact of rotavirus vaccine introduction in reducing the rotavirus disease burden in children was well known. The study was aimed to determine the prevalence and clinical characteristics of rotavirus gastroenteritis before the introduction of rotavirus vaccine into Nigeria's routine immunization program.

Materials and Methods:

We conducted a cross-sectional hospital-based study involving 735 children aged 0–59 months with acute gastroenteritis hospitalized at the Ahmadu Bello University Teaching Hospital Zaria from September 2017 to August 2020. Relevant sociodemographic and clinical data were obtained and entered into the World Health Organization standardized case investigation forms. Stool specimens were tested for rotavirus Group A antigen using the ProSpecT™ Rotavirus Microplate Assay by Thermoscientific Oxoid Microbiology UK.

Results:

One hundred and fifty-three stool samples tested positive for rotavirus giving a prevalence of 20.8%. One hundred and two (66.7%) children with rotavirus gastroenteritis were infants. There were 87 males and 66 females with M: F ratio of 1.3:1. Only 30 (19.6%) children with rotavirus-associated diarrhea presented with severe dehydration. The presence of vomiting was significantly associated with rotavirus diarrhea (P = 0.001). More cases of rotavirus diarrhea occurred in September through February. None of the studied children were vaccinated against rotavirus.

Conclusion:

The prevalence of rotavirus diarrhea remains high in this study. Infants were recognized as a high-risk group, and none of them were vaccinated against rotavirus and this underscores the urgent need for implementing the rotavirus vaccine in the national vaccination program to reduce the disease burden in the country.

Epidemiology of Group A Rotavirus Diarrhea among Children Hospitalized for Acute Gastroenteritis in Ondo State, Nigeria

Globally, infective group A rotavirus (RVA) enteric infection in children culminates in acute diarrheal disease, severe dehydration, and mortality in children under the age of 5 years, particularly in sub-Saharan Africa. This research sought to determine the prevalence of RVA diarrhea among children aged below 5 years in Ondo state, as one of the necessary frameworks before instituting a vaccine campaign, and to expand knowledge on the epidemiology of RVA diarrhea in Nigeria.

In a cross-sectional descriptive study between October 2012 and September 2014, convenience sampling was adopted to obtain demographic information, clinical details, and stool samples from accented under five children who sought treatment for acute gastroenteritis at designated hospitals in Akure and Owo, Nigeria. A total of 390 stool samples were collected from children with acute diarrhea and tested for VP6 RVA antigen using enzyme immunoassay. Data generated were analyzed using descriptive statistics and chi-square at α 0.05.

From the 390 children hospitalized for diarrhea, 240 samples (240/390; 61.5%) were from males, while 150 samples (150/390; 38.5%) were from females, representing a male:female ratio of 1.6:1. RVAs were found in 24.2% (58/240) males and 28% (42/150) females, giving a male-female ratio of 1:1.2 and total prevalence of 25.6% (100/390). RVA infection was inversely proportional to the age as a rate of 11.8% was observed in children aged above 36 months and 31.8% (35/110) in children 7 to 12 months, while the highest rate (45.7%) was among children ≤ 6 months old. No significant difference was found (chi-square = 0.712) in the induction of diarrhea in children from Akure and Owo, neither was there any significant difference in the rates of infection between the boys and girls in Akure (chi-square = 0.576) nor in Owo (chi-square = 0.333). Seasonal association (chi-square = 5.802) in RVA infection was observed in the rainy season of year 2013/2014 period.

RVA diarrhea occurred year-round at a prevalence of 25.6%, predominantly in females. A seasonal fluctuation was observed in the rainy and dry seasons of the 2-year period. RVA diarrhea occurred predominantly in children aged below 18 months of age, and may thus help in determining the optimal period/schedule of any immunization program.

Relationship between the number of pediatric patients with rotavirus and telephone triage for associated symptoms

BACKGROUND

Earlier syndromic surveillance may be effective in preventing the spread of infectious disease. However, there has been no research on syndromic surveillance for rotavirus. The study aimed to assess the relationship between the incidence of rotavirus infections and the number of telephone triages for associated symptoms in pediatric patients under 4 years old in Osaka prefecture, Japan.

METHODS

This was a retrospective observational study for which the study period was the 3 years between January 2015 and December 2017. We analyzed data on children under 4 years old who were triaged by telephone triage nurses using software. The primary endpoint was the number of rotavirus patients under 4 years triaged old per week. Using a linear regression model, we calculated the R square value of the regression model to assess the relationship between the number of patients with rotavirus and the number of telephone triages made for associated symptoms. Covariates in the linear regression model were the week number indicating seasonality and the weekly number of telephone triages related to rotavirus symptoms such as stomachache and vomiting.

RESULTS

During the study period, there were 102,336 patients with rotavirus, and the number of people triaged by telephone was 123,720. The highest correlation coefficient was 0.921 in the regression model with the number of telephone triages for "stomachache + nausea/vomiting" and "stomachache + diarrhea + nausea/vomiting".

CONCLUSION

The number of telephone triage symptoms was positively related to the incidence of pediatric patients with rotavirus in a large metropolitan area of Japan.

Prevalence and Genetic Diversity of Rotaviruses among under-Five Children in Ethiopia: A Systematic Review and Meta-Analysis

Rotavirus infection is the major cause of acute gastroenteritis among children globally. Sub-Saharan Africa including Ethiopia is disproportionally affected by the disease. The aims of this review were to determine the pooled prevalence of rotavirus infection among children under-five and to identify the dominant rotavirus genotypes in Ethiopia. Twelve studies were included to estimate the pooled prevalence of rotavirus acute gastroenteritis and five studies were used to determine predominantly circulating genotypes of rotavirus. The pooled prevalence of rotavirus infection was 23% (95% CI = 22%-24%). G3 (27.1%) and P[8] (49%) were the dominant G and P types, respectively. The G8 G-type uncommon in humans but highly prevalent in cattle was also reported accounting for 1% of all cases. The major G/P combinations were G12P[8] (15.4%), G3P[6] (14.2%), G1P[8] (13.6%) and G3P[8] (12.9%) collectively accounting for 56.1% of rotavirus strains. Similar to other parts of the world, the dominance of G1, G3, P[6] and P[8] genotypes was noted in Ethiopia. The increased prevalence of G12P[8] strains observed in Ethiopia was similar to observations in other geographic regions in the post-vaccine introduction period. Thus, further studies are required on the vaccine effectiveness, genotype distribution and inter-species transmission potential of rotaviruses in Ethiopia.

Full genome characterization of human G3P[6] and G3P[9] rotavirus strains in Lebanon

Rotaviruses are the most common infectious agents causing severe diarrheal diseases in young children globally. Three rare human rotavirus strains, two G3P[9] and one G3P[6], were detected in stool samples of children under 5 years of age hospitalized for gastroenteritis in Lebanon during the course of a surveillance study. Complete genomes of these strains were sequenced using VirCapSeq-VERT, a capture based high-throughput sequencing method. Genomic sequences were further characterized by using phylogenetic analyses with global RVA G3P[6]/P[9] strains, other vaccine and reference strains. Genetic analysis revealed that the G3P[6] strain emerged as a DS-1/Wa-like mono-reassortant strain with a potential Ethiopian origin. The two G3P[9] strains possessed a mixed DS-1/Wa/AU-1-like origin indicating that these may have evolved via multiple reassortment events involving feline, human and bovine rotaviruses. Furthermore, analysis of these strains revealed high antigenic variability compared to the vaccine strains. Additional studies are essential to fully understand the evolutionary dynamics of G3P[6]/P[9] strains spreading worldwide and their implications on vaccine effectiveness.

Rotavirus-associated acute diarrhea outbreak in West Shewa Zone of Oromia Regional State, Ethiopia, 2017

Introduction

Rotavirus causes severe-diarrheal diseases in infants. An estimation of 138 million rotavirus-associated diarrheal cases and 215,000 deaths occur every year globally. In December 2016, West-Shewa zone in Ethiopia reported unidentified gastrointestinal diarrhea outbreak. We investigated to identify the causative agent of the outbreak to support response operations.

Methods

Medical records were reviewed, and the daily line list was collected from health facilities. Descriptive data analysis was done by time, person and place. Stool specimens were first tested by antigen capture enzyme immunoassay (EIA) technique and further confirmed by reverse-transcription polymerase chain reaction (RT-PCR) as a gold standard. The product of RT-PCR was genotyped for each gene using G1-G4, G8-G9 and G12 primers for VP7 gene and P(4), P(6), P(8) and P(14) primers for VP4 gene.

Results

A total of 1,987 diarrheal cases (5.7 per 1000) and five deaths (case-fatality rate 0.25%) were identified and epidemiologically-linked to confirmed rotavirus from December 2016 to February 2017. Among the cases, 1,946 (98%) were < 5 children. Fourteen (74%) of the 19 tested stool specimens were positive for rotavirus by EIA and RT-PCR. Majority of strains detected were G12P(6) (25%) and G-negative P(8) (25%) followed by G9P(8) (19%), G1P(8) (13%) and G3/G2 P(8), G12P(8), and G-negative P(6) (6% each).

Conclusion

Diarrheal outbreak which occurred in West-Shewa zone of Ethiopia was associated with rotavirus and relatively more affected districts with low vaccination coverage. Routine rotavirus vaccination quality and coverage should be evaluated and the surveillance system needs to be strengthened to detect, prevent and control a similar outbreak.

Rates of hospitalization and death for all-cause and rotavirus acute gastroenteritis before rotavirus vaccine introduction in Kenya, 2010-2013

Background

Rotavirus vaccine was introduced in Kenya immunization program in July 2014. Pre-vaccine disease burden estimates are important for assessing vaccine impact.

Methods

Children with acute gastroenteritis (AGE) (≥3 loose stools and/or ≥ 1 episode of unexplained vomiting followed by loose stool within a 24-h period), hospitalized in Siaya County Referral Hospital (SCRH) from January 2010 through December 2013 were enrolled. Stool specimens were tested for rotavirus (RV) using an enzyme immunoassay (EIA). Hospitalization rates were calculated using person-years of observation (PYO) from the Health Demographic Surveillance System (HDSS) as a denominator, while adjusting for healthcare utilization at household level and proportion of stool specimen collected from patients who met the case definition at the surveillance hospital. Mortality rates were calculated using PYO as the denominator and number of deaths estimated using total deaths in the HDSS, proportion of deaths attributed to diarrhoea by verbal autopsy (VA) and percent positive for rotavirus AGE (RVAGE) hospitalizations.

Results

Of 7760 all-cause hospitalizations among children < 5 years of age, 3793 (49%) were included in the analysis. Of these, 21% (805) had AGE; RV was detected in 143 (26%) of 541 stools tested. Among children < 5 years, the estimated hospitalization rates per 100,000 PYO for AGE and RVAGE were 2413 and 429, respectively. Mortality rate associated with AGE and RVAGE were 176 and 45 per 100,000 PYO, respectively.

Conclusion

AGE and RVAGE caused substantial health care burden (hospitalizations and deaths) before rotavirus vaccine introduction in Kenya.

Exclusive breastfeeding and rotavirus vaccination are associated with decreased diarrheal morbidity among under-five children in Bahir Dar, northwest Ethiopia

BACKGROUND

More than one in every ten (14%) of under-five child deaths is associated with diarrheal morbidity in Ethiopia. Although Ethiopia has implemented different health interventions like its immunization program, childhood diarrhea morbidity, on which literature is limited, continues as a public health problem. Hence, the aim of this study was to assess the prevalence of diarrheal morbidity and associated factors among under-five children in Bahir Dar, northwest Ethiopia.

METHOD

A community based cross-sectional study was carried out from March 05 to April 03/2015 in Bahir Dar in which 553 mother-child pairs participated. A structured questionnaire was adapted from the World Health Organization (WHO) and the Ethiopian Demography and Health Survey (EDHS) to collect the data. Bivariate and multivariate logistic regression analyses were carried out to identify the independent predictors of diarrheal morbidity.

RESULT

The overall prevalence of diarrheal morbidity was 9.4% [95% Confidence Interval (CI): 4.8, 14.0%]. No receipt of Rotavirus vaccine dose 2 [AOR = 3.96, 95%CI; 2.13, 7.33], non-exclusive breastfeeding [AOR = 2.69, 95%CI; 1.39, 5.19], unavailability of solid waste disposal system [AOR = 2.62, 95%CI; 1.19, 5.77], employed and private business occupational status of mothers [AOR = 2.10, 95%CI; 1.02, 4.31)], and less than Ethiopia Birr (ETB) 600 household monthly income [AOR = 2.10, 95% CI; 1.2, 7.2] were independently associated with diarrheal morbidity.

CONCLUSION

In Bahir Dar, one in every ten of the under-five children surveyed suffered from diarrheal morbidity. Thus, implementing effective rotavirus vaccination programs, encouraging exclusive breastfeeding and emphasizing appropriate solid waste management would reduce childhood diarrheal morbidity in the region. In addition, the finding suggests that improved child care mechanisms, especially for mothers working outside the home, and efforts to increase household income should be intensified to reduce incidence of diarrhea.

Impact of rotavirus vaccine introduction and genotypic characteristics of rotavirus strains in children less than 5 years of age with gastroenteritis in Ethiopia: 2011-2016

INTRODUCTION

A monovalent rotavirus vaccine was introduced in the Ethiopian Expanded Program on Immunization from November 2013. We compared impact of rotavirus vaccine introduction on rotavirus associated acute diarrhea hospitalizations and genotypic characteristics of rotavirus strains pre-and post-vaccine introduction.

METHODS

Sentinel surveillance for diarrhea among children <5 years of age was conducted at 3 hospitals in Addis Ababa, Ethiopia from 2011 to 2017. Stool specimens were collected from enrolled children and tested using an antigen capture enzyme immunoassay. Rotavirus positive samples (156 from pre- and 141 from post-vaccination periods) were further characterized by rotavirus genotyping methods to identify the predominant G and P types circulating during the surveillance era.

RESULTS

A total of 788 children were enrolled during the pre- (July 2011-June 2013) and 815 children during the post-vaccination (July 2014-June 2017) periods. The proportion of diarrhea hospitalizations due to rotavirus among children <5 years of age declined by 17% from 24% (188/788) in the pre-vaccine period and to 20% (161/185) in post-vaccine introduction era. Similarly, a reduction of 18% in proportion of diarrhea hospitalizations due to rotavirus in children <12 months of age in the post (27%) vs pre-vaccine (33%) periods was observed. Seasonal peaks of rotavirus declined following rotavirus vaccine introduction. The most prevalent circulating strains were G12P[8] in 2011 (36%) and in 2012 (27%), G2P[4] (35%) in 2013, G9P[8] (19%) in 2014, G3P[6] and G2P[4] (19% each) in 2015, and G3P[8] (29%) in 2016.

DISCUSSION

Following rotavirus vaccine introduction in Ethiopia, a reduction in rotavirus associated hospitalizations was seen in all age groups with the greatest burden in children <12 months of age. A wide variety of rotavirus strains circulated in the pre- and post-vaccine introduction periods.

Molecular epidemiology of rotaviruses in Northwest Ethiopia after national vaccine introduction

BACKGROUND

Rotaviruses mortality among infants and young children is high in Sub-Saharan Africa. Recently, Ethiopia introduced the monovalent rotavirus vaccine in its national immunization program to decrease the burden of rotavirus disease and mortality. Rotavirus surveillance in Ethiopia is based largely on data provided by sentinel hospitals in its capital Addis Ababa.

OBJECTIVE

To assess rotavirus abundancy and diversity in outpatient infants and children outside of Addis Ababa in the early post-introduction period.

METHOD

Fecal samples were obtained from children aged less than five years presenting with diarrhea at outpatient health institutions in two cities in Northwest Ethiopia, Gondar and Bahir Dar, from November 2015 to April 2016. Basic demographic data were assessed. Real-time RT-PCR was used to detect rotavirus A RNA. Based on sequences of VP4 and VP7 gene segments phylogenetic analysis was performed.

RESULTS

Rotavirus wildtype positivity was 25% (113/450). Rotavirus infection was less common in infants below 6 months than in children of all other age-groups. Rotavirus genotype distributions were distinct between Bahir Dar and Gondar. In total, wildtype G3P[8], G2P[4], G9P[8], G12P[8], and G3P[6] rotaviruses were detected in 68 (60.2%), 21 (18.6%), 13 (11.5%), 9 (8.0%), and 2 (1.8%) of the positive samples, respectively. Wildtype G1P[8] strains were absent. The phylogenetic analysis revealed close relatedness of current rotaviruses with Ethiopian strains of the pre-vaccination period.

CONCLUSION

In the early period after the introduction of vaccination, rotaviruses in Northwestern Ethiopia were frequent in children of 6-59 months and diverse. High phylogenetic relatedness with strains of the pre-vaccine era, indicate absence of early vaccine-induced strain replacement. Future surveillance studies should be carried out throughout the country to gain comprehensive data on rotavirus strain diversity and to monitor the effect of the ongoing vaccine program on the disease burden and eventual rotavirus strain replacement.

Diversity of rotavirus strains circulating in children under five years of age who presented with acute gastroenteritis before and after rotavirus vaccine introduction, University Teaching Hospital, Lusaka, Zambia, 2008-2015

BACKGROUND

Following the introduction of rotavirus vaccine into the routine immunization schedule, the burden of rotavirus disease has significantly reduced in Zambia. Although rotavirus vaccines appear to confer good cross-protection against both vaccine and non-vaccine strains, concerns about strain replacement following vaccine implementation remain. We describe the diversity of the circulating rotavirus strains before and after the Rotarix® vaccine was introduced in Lusaka from January 2012.

METHODS

Under five children were enrolled through active surveillance at University Teaching Hospital using a standardized WHO case investigation form. Stool samples were collected from children who presented with ≥3 loose stool in 24 h and were admitted to the hospital for acute gastroenteritis as a primary illness. Samples were tested for group A rotavirus antigen enzyme-linked immunosorbent assay. Randomly selected rotavirus positive samples were analysed by reverse transcription polymerase chain reaction for G and P genotyping and and Nucleotide sequencing was used to confirm some mixed infections.

RESULTS

A total of 4150 cases were enrolled and stool samples were collected from 4066 (98%) children between 2008 and 2011, before the vaccine was introduced. Rotavirus antigen was detected in 1561/4066 (38%). After vaccine introduction (2012 to 2015), 3168 cases were enrolled, 3092 (98%) samples were collected, and 977/3092 (32%) were positive for rotavirus. The most common G and P genotype combinations before vaccine introduction were G1P[8] (49%) in 2008; G12P[6] (24%) and G9P[8] (22%) in 2009; mixed rotavirus infections (32%) and G9P[8] (20%) in 2010, and G1P[6] (46%), G9P[6] (16%) and mixed infections (20%) in 2011. The predominant strains after vaccine introduction were G1P[8] (25%), G2P[4] (28%) and G2P[6] (23%) in 2012; G2P[4] (36%) and G2P[6] (44%) in 2013; G1P[8] (43%), G2P[4] (9%), and G2P[6] (24%) in 2014, while G2P[4] (54%) and G2P[6] (20%) continued to circulate in 2015.

CONCLUSION

These continual changes in the predominant strains suggest natural secular variation in circulating rotavirus strains post-vaccine introduction. These findings highlight the need for ongoing surveillance to continue monitoring how vaccine use affects strain evolution over a longer period of time and assess any normal seasonal fluctuations of the rotavirus strains.

Drug therapy combined with systematic nursing for children with rotavirus enteritis: Therapeutic effect and impact on serum cytokines

AIM

To investigate the therapeutic effect of drug therapy combined with systematic nursing in children with rotavirus enteritis and the effect on serum cytokines.

METHODS

A total of 90 children with rotavirus enteritis treated at our hospital from July 2015 to August 2017 were selected and equally divided into either an observation group (Saccharomyces boulardii sachets + systematic nursing) or a control group (Saccharomyces boulardii sachets). After 3 d of treatment, the clinical efficacy of the two groups was evaluated, time to remission of clinical symptoms and the hospitalization time were recorded, and the levels of serum interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α were measured.

RESULTS

The total effective rate was significantly higher in the observation group than in the control group (93.33% vs 77.78%, P < 0.05). The time to remission of fever, dehydration, and diarrhea and hospitalization time were significantly shorter in the observation group than in the control group (3.02 d ± 0.97 d vs 4.57 d ± 1.04 d, 3.36 d ±1.67 d vs 5.84 d ± 1.49 d, 5.32 d ± 1.13 d vs 6.28 d ± 1.25 d, 5.98 d ± 2.11 d vs 7.83 d ±2.16 d; P < 0.05). After treatment, serum levels of IL-6, IL-10, and TNF-αin both groups significantly decreased (P < 0.05), and the decrease was significantly greater in the observation group than in the control group (70.21 pg/mL ± 16.84 pg/mL vs 78.58 pg/mL ± 18.63 pg/mL, 12.18 pg/mL ± 8.97 pg/mL vs 16.86 pg/mL ± 9.14 pg/mL, 3.48 pg/mL ± 1.08 pg/mL vs 4.39 pg/mL ± 1.13 pg/mL; P < 0.05).

CONCLUSION

Saccharomyces boulardii sachets combined with systematic nursing is an effective way to shorten the time to remission of clinical symptoms and hospitalization time and lower the levels of IL-6, IL-10, and TNF-α in children with rotavirus enteritis.

Impact of rotavirus vaccine on rotavirus diarrhoea in countries of East and Southern Africa

BACKGROUND

Established in 2006 with four countries conducting hospital-based rotavirus surveillance, the African rotavirus surveillance network has expanded over subsequent years. By 2015, 14 countries in the World Health Organization (WHO) East and Southern Africa sub-region (Eritrea, Ethiopia, Kenya, Lesotho, Madagascar, Mauritius, Namibia, Rwanda, Seychelles, Swaziland, Tanzania, Uganda, Zambia and Zimbabwe) were participating in the rotavirus surveillance network coordinated by WHO. We monitored the proportion of rotavirus diarrhoea among children under five years of age who were hospitalized for diarrhoea in the sentinel hospitals from 2010 to 2015 among countries that introduced rotavirus vaccine during or before 2013 (Rwanda, Tanzania, Zambia and Ethiopia) and compared with the other countries in the network.

METHODS

Children under the age of five years hospitalized due to acute diarrhoea were enrolled into the sentinel surveillance system and had stool samples collected and tested for rotavirus antigens by enzyme immunoassay. We described trends in rotavirus positivity among tested stool samples before and after rotavirus vaccine introduction.

RESULTS

In countries that introduced rotavirus vaccine by 2013 (Rwanda, Tanzania, Zambia and Ethiopia), average rotavirus vaccine coverage from 2010 to 2015 improved from 0% in 2010 and 2011, 13% in 2012, 46% in 2013, 83% in 2014 to 90% in 2015. Annual average rotavirus positivity from 2010 to 2015 was 35%, 33%, 38%, 28%, 27%, and 19%, respectively. In countries that introduced rotavirus vaccine after 2013 or had not introduced by 2015, average rotavirus vaccine coverage was 0% in 2010-2013, 13% in 2014 and 51% in 2015. In these countries, rotavirus positivity was 44% in 2010, 32% in 2011, 33% in 2012, 41% in 2013, 40% in 2014 and 25% in 2015.

CONCLUSION

Countries that introduced rotavirus vaccine by 2013 had a lower proportion of rotavirus positive hospitalizations in 2013-2015 as compared to those that had not introduced rotavirus vaccine by 2013. The decrease in rotavirus positivity was inversely related to increase in rotavirus vaccine coverage showing impact of rotavirus vaccines.

Group A rotaviruses circulating prior to a national immunization programme in Nigeria: Clinical manifestations, high G12P[8] frequency, intra-genotypic divergence of VP4 and VP7

Nigeria having approximately 50 000 Rotavirus A (RVA) deaths annually is yet to introduce RVA vaccine into routine national immunization; therefore surveillance of RVA strains circulating before vaccine introduction is essential in evaluating impact of the intervention. Stool samples and sociodemographic data of diarrhoeic children, <5 years were collected between August 2012 and December 2013. While a high prevalence of RVA infection (47.6%; 49/103) was observed by quantitative reverse transcription real time PCR, only 25% (26/103) had high RVA genome concentrations and were antigen positive. G and P types were obtained for 31 and 37 samples respectively. G12P[8] strains were predominant (30.6%; 16/31); Other genotypes found included G9, G3, G2 and P[4], P[6], P[8]. A G12 + G2/P[8] + P[6] mixed infection was detected. The P[8] genotype showed divergence with strains distributed in lineage III and IV. Compared to the vaccines, changes in antigenic sites of VP8* and VP7 were found. The finding of the G2P[6] genotype combination and emergence of G12 strains support observations in most of the recent RVA studies from Africa. P[6] is common in many African countries, in contrast to countries in Europe and the Americas. In conclusion, this study shows the circulation of other RVA genotypes compared to the common RVA genotypes in Nigeria. PCR results should be interpreted with caution to avoid significant bias from samples with low RVA genome concentrations. These findings provide important information on the detection and molecular epidemiology of RVA prior to vaccination and contribute as a baseline for future evaluations after possible vaccine introduction.

Early impact of rotavirus vaccine in under 5year old children hospitalized due to diarrhea, Swaziland

BACKGROUND

Swaziland introduced rotavirus vaccine in the National Immunization Program, in May 2015, with the objective of reducing the burden of rotavirus diarrheal disease. We monitored the early impact of the vaccine in reducing rotavirus diarrhea.

METHODS

We conducted sentinel rotavirus surveillance from January 2013 to December 2016 in children under five years of age admitted due to diarrhea attending Mbabane Government Referral Hospital in the Hhohho Region and Raleigh Fitkin Memorial Hospital in the Manzini Region. All cases had stool samples collected and tested for rotavirus antigen by enzyme immunoassay.

RESULTS

Between 2013 and 2016, 596 samples were collected and tested. Rotavirus positivity reduced from average of 50.8% (172/338) (in 2013-2014 (pre vaccine period)) to 29% (24/82) in 2016, post-vaccine introduction. The median age of children with rotavirus infection increased from average of 10months in 2013-2014 to 13.7months in 2016. The peak season for all-cause diarrhea and rotavirus-specific hospitalizations among children under five years of age was June-August in all years with a blunting of the peak season in 2016. Rotavirus positivity among children 0-11months reduced from an average of 49% in 2013-2014 (116/236) to 33% (15/45) in 2016, a 33% reduction following rotavirus vaccine introduction.

CONCLUSION

There has been a rapid reduction of all-cause diarrhea and rotavirus hospitalizations in Swaziland, particularly in young children and during the rotavirus season, after the introduction rotavirus vaccine. Continued surveillance is needed to monitor the long-term impact of rotavirus vaccine introduction.

Epidemiology, Seasonality and Factors Associated with Rotavirus Infection among Children with Moderate-to-Severe Diarrhea in Rural Western Kenya, 2008-2012: The Global Enteric Multicenter Study (GEMS)

Objective

To evaluate factors associated with rotavirus diarrhea and to describe severity of illness among children <5 years old with non-dysenteric, moderate-to-severe diarrhea (MSD) in rural western Kenya.

Methods

We analyzed data from children <5 years old with non-dysenteric MSD enrolled as cases in the Global Enteric Multicenter Study (GEMS) in Kenya. A non-dysenteric MSD case was defined as a child with ≥3 loose stools in 24 hrs. and one or more of the following: sunken eyes, skin tenting, intravenous rehydration, or hospitalization, who sought care at a sentinel health center within 7 days of illness onset. Rotavirus antigens in stool samples were detected by ELISA. Demographic and clinical information was collected at enrollment and during a single follow-up home visit at approximately 60 days. We analyzed diarrhea severity using a GEMS 17 point numerical scoring system adapted from the Vesikari score. We used logistic regression to evaluate factors associated with rotavirus infection.

Results

From January 31, 2008 to September 30, 2012, among 1,637 (92%) non-dysenteric MSD cases, rotavirus was detected in stools of 245 (15.0%). Rotavirus-positive compared with negative cases were: younger (median age, 8 vs. 13 months; p<0.0001), had more severe illness (median severity score, 9 vs 8; p<0.0001) and had to be hospitalized more frequently (37/245 [15.1%] vs. 134/1,392 [9.6%]), p <0.013). Independent factors associated with rotavirus infection included age 0–11 months old (aOR = 5.29, 95% CI 3.14–8.89) and presenting with vomiting ≥3 times/24hrs (aOR = 2.58, 95% CI [1.91–3.48]). Rotavirus was detected more commonly in warm and dry months than in the cool and rainy months (142/691 [20%] vs 70/673 [10%]) p<0.0001).

Conclusions

Diarrhea caused by rotavirus is associated with severe symptoms leading to hospitalization. Consistent with other settings, infants had the greatest burden of disease.

Population-Based Incidence Rates of Diarrheal Disease Associated with Norovirus, Sapovirus, and Astrovirus in Kenya

Background

Diarrheal diseases remain a major cause of mortality in Africa and worldwide. While the burden of rotavirus is well described, population-based rates of disease caused by norovirus, sapovirus, and astrovirus are lacking, particularly in developing countries.

Methods

Data on diarrhea cases were collected through a population-based surveillance platform including healthcare encounters and household visits in Kenya. We analyzed data from June 2007 to October 2008 in Lwak, a rural site in western Kenya, and from October 2006 to February 2009 in Kibera, an urban slum. Stool specimens from diarrhea cases of all ages who visited study clinics were tested for norovirus, sapovirus, and astrovirus by RT-PCR.

Results

Of 334 stool specimens from Lwak and 524 from Kibera, 85 (25%) and 159 (30%) were positive for norovirus, 13 (4%) and 31 (6%) for sapovirus, and 28 (8%) and 18 (3%) for astrovirus, respectively. Among norovirus-positive specimens, genogroup II predominated in both sites, detected in 74 (87%) in Lwak and 140 (88%) in Kibera. The adjusted community incidence per 100,000 person-years was the highest for norovirus (Lwak: 9,635; Kibera: 4,116), followed by astrovirus (Lwak: 3,051; Kibera: 440) and sapovirus (Lwak: 1,445; Kibera: 879). For all viruses, the adjusted incidence was higher among children aged <5 years (norovirus: 22,225 in Lwak and 17,511 in Kibera; sapovirus: 5,556 in Lwak and 4,378 in Kibera; astrovirus: 11,113 in Lwak and 2,814 in Kibera) compared to cases aged ≥5 years.

Conclusion

Although limited by a lack of controls, this is the first study to estimate the outpatient and community incidence rates of norovirus, sapovirus, and astrovirus across the age spectrum in Kenya, suggesting a substantial disease burden imposed by these viruses. By applying adjusted rates, we estimate approximately 2.8–3.3 million, 0.45–0.54 million, and 0.77–0.95 million people become ill with norovirus, sapovirus, and astrovirus, respectively, every year in Kenya.

High prevalence of G12P[8] rotavirus strains in Rio Branco, Acre, Western Amazon, in the post-rotavirus vaccine introduction period

The present study aimed to provide a molecular characterization of circulating rotavirus (RVA) strains in Rio Branco, Acre, in the post-rotavirus vaccination period, particularly with regard to the emerging, increasingly prevalent G12P[8] genotype. A total of 488 fecal specimens from diarrheic and non-diarrheic children were obtained between January and December 2012. RVA detection was initially performed using enzyme-linked immunosorbent assay (ELISA) method, followed by reverse-transcription polymerase chain reaction (RT-PCR) using specific primers. RVA was detected in 18.3% (44/241) of the children with acute diarrhea and in 1.2% (3/247) of the non-diarrheic children (P < 0.001), with overall RVA-positivity of 9.6% (47/488). The most common genotype was G2P[4] with 43.2% (19/44) of the diarrheic cases, followed by G12P[8] (27.3%, 12/44), G3P[6] (18.2%, 8/44), G3P[8] (4.5%, 2/44), and G12P[6] (2.3%, 1/44). G12 samples belonged to lineage III and were from children aged 4-52 months. All of these children had acute diarrhea associated with fever (83.3%, 10/12) and vomiting (66.7%, 8/12). Most of the cases occurred in August (58.3%, 7/12), 75% (9/12) of which having received the full vaccination scheme with Rotarix™. For the first time G12 was reported at relative high prevalence in Brazil. Our findings warrant further monitoring studies on the molecular characterization of circulating RVA strains after rotavirus vaccine introduction in Brazil and elsewhere, since the occurrence of either unusual our emerging genotypes may pose a challenge to vaccination strategies.

Whole genome detection of rotavirus mixed infections in human, porcine and bovine samples co-infected with various rotavirus strains collected from sub-Saharan Africa

Group A rotaviruses (RVA) are among the main global causes of severe diarrhea in children under the age of 5years. Strain diversity, mixed infections and untypeable RVA strains are frequently reported in Africa. We analysed rotavirus-positive human stool samples (n=13) obtained from hospitalised children under the age of 5years who presented with acute gastroenteritis at sentinel hospital sites in six African countries, as well as bovine and porcine stool samples (n=1 each), to gain insights into rotavirus diversity and evolution. Polyacrylamide gel electrophoresis (PAGE) analysis and genotyping with G-(VP7) and P-specific (VP4) typing primers suggested that 13 of the 15 samples contained more than 11 segments and/or mixed G/P genotypes. Full-length amplicons for each segment were generated using RVA-specific primers and sequenced using the Ion Torrent and/or Illumina MiSeq next-generation sequencing platforms. Sequencing detected at least one segment in each sample for which duplicate sequences, often having distinct genotypes, existed. This supported and extended the PAGE and RT-PCR genotyping findings that suggested these samples were collected from individuals that had mixed rotavirus infections. The study reports the first porcine (MRC-DPRU1567) and bovine (MRC-DPRU3010) mixed infections. We also report a unique genome segment 9 (VP7), whose G9 genotype belongs to lineage VI and clusters with porcine reference strains. Previously, African G9 strains have all been in lineage III. Furthermore, additional RVA segments isolated from humans have a clear evolutionary relationship with porcine, bovine and ovine rotavirus sequences, indicating relatively recent interspecies transmission and reassortment. Thus, multiple RVA strains from sub-Saharan Africa are infecting mammalian hosts with unpredictable variations in their gene segment combinations. Whole-genome sequence analyses of mixed RVA strains underscore the considerable diversity of rotavirus sequences and genome segment combinations that result from a complex evolutionary history involving multiple host species.

Incidence of rotavirus and circulating genotypes in Northeast Brazil during 7 years of national rotavirus vaccination

Background and Aims

Rotavirus causes severe diarrhoea and Brazil introduced the Rotarix G1P[8] vaccine in 2006. We aimed to describe changes in rotavirus incidence and diarrhoea epidemiology before and after vaccine introduction.

Methods

Design: (i) hospital-based survey of children with diarrhoea (2006–2012); (ii) diarrhea-mortality and hospitalization surveillance (1999–2012).

Setting

(i) Aracaju and (ii) state and national level.

Results

1841 children were enrolled and 231 (12.5%) had rotavirus. Rotavirus was less frequent from January-June than from July-December (9.4% versus 20.9%, p<0.01), but the seasonal variation was less defined after 2009. Very few rotavirus cases (8–3.9%) were detected in 2011, with an increase in 2012 (13–18.5%). In 2006, unvaccinated children were more likely to have rotavirus, but thereafter unvaccinated and vaccinated children had equally low incidence. Older children and those with rotavirus were more likely to have severe diarrhea episodes. The most frequent genotype from 2006 to 2010 was G2P[4]; except in 2009, when most cases were G1P[8]. Very few G2P[4] were detected from 2011 and 50% cases in 2012 were G8P[4]. Diarrhoea-hospitalizations decreased nationally from 89,934 (2003) to 53,705 (2012; 40.3% reduction) and in the state from 1729 to 748 (56.7% reduction). Diarrhoea-deaths decreased nationally from 4368 in 1999 to 697 in 2012 (84% reduction, p<0.001) and in the state from 132 to 18 (86% reduction). These changes were much larger after vaccine introduction.

Conclusions

The vaccine was associated with substantial reductions in rotavirus incidence and diarrhoea-hospitalizations and deaths. The G2P[4] genotype predominance disappeared over time and may be replaced by other heterotypic genotypes.

Review of global rotavirus strain prevalence data from six years post vaccine licensure surveillance: is there evidence of strain selection from vaccine pressure?

Comprehensive reviews of pre licensure rotavirus strain prevalence data indicated the global importance of six rotavirus genotypes, G1P[8], G2P[4], G3P[8], G4P[8], G9P[8] and G12P[8]. Since 2006, two vaccines, the monovalent Rotarix (RV1) and the pentavalent RotaTeq (RV5) have been available in over 100 countries worldwide. Of these, 60 countries have already introduced either RV1 or RV5 in their national immunization programs. Post licensure vaccine effectiveness is closely monitored worldwide. This review aimed at describing the global changes in rotavirus strain prevalence over time. The genotype distribution of the nearly 47,000 strains that were characterized during 2007-2012 showed similar picture to that seen in the preceding period. An intriguing finding was the transient predominance of heterotypic strains, mainly in countries using RV1. Unusual and novel antigen combinations continue to emerge, including some causing local outbreaks, even in vaccinated populations. In addition, vaccine strains have been found in both vaccinated infants and their contacts and there is evidence for genetic interaction between vaccine and wild-type strains. In conclusion, the post-vaccine introduction strain prevalence data do not show any consistent pattern indicative of selection pressure resulting from vaccine use, although the increased detection rate of heterotypic G2P[4] strains in some countries following RV1 vaccination is unusual and this issue requires further monitoring.