Hera Nirwati

Maternal antibodies to rotavirus: could they interfere with live rotavirus vaccines in developing countries?

INTRODUCTION Past experience with live oral vaccines including licensed rotavirus vaccines demonstrates a trend towards reduced vaccine efficacy in developing countries compared with developed countries. The reasons behind this disparity are not well understood. Transplacental transfer of maternal antibodies and breast milk ingestion may attenuate vaccine responses in infants in developing countries where rotavirus infections are endemic, and maternal antibody levels are high. We examined the prevalence and level of rotavirus antibody in maternal and cord serum, colostrum and breast milk in a developing country setting. METHODS 100 mother-infant pairs were prospectively recruited from December 2008 to February 2009 at Dr. Sardjito Hospital, Yogyakarta, Indonesia. Maternal and cord sera were collected during delivery. Colostrum and transitional breast milk were collected between day 0-3 and day 7-10 postpartum respectively. Rotavirus-specific IgA and IgG were estimated for all specimens and virus neutralization assays were conducted on a subset of milk specimens. RESULTS All maternal and cord serum samples were positive for rotavirus-specific IgG antibodies with a strong correlation between levels of rotavirus-specific IgG in mothers and levels transferred to infants in cord blood (r=0.86; p=0.001). 78% of colostrum and 67% of transitional breast milk specimens were positive for rotavirus-specific IgA. There was a median 4-fold decrease in rotavirus-specific IgA from colostrum to transitional breast milk. Neutralizing antibodies were present in 56% of colostrum specimens assayed (19/34) and in 41% of transitional milk specimens assayed (14/34). CONCLUSIONS Maternal serum and breast milk antibodies to rotavirus are highly prevalent in a developing country setting. Evaluation of the impact of maternal anti-rotavirus serum and breast milk antibody upon vaccine immunogenicity would help to inform rotavirus vaccination strategies, especially in developing settings.

Identification of Rotavirus Strains Causing Diarrhoea in Children under Five Years of Age in Yogyakarta, Indonesian

BACKGROUND Rotavirus is an important cause of severe diarrhoea in children. The aims of this study were to identify the rotavirus strains that cause diarrhoea in children in Yogyakarta and to determine the association between rotavirus positivity and its clinical manifestations. METHODS Clinical data and stool samples were collected from children hospitalised at Kodya Yogyakarta Hospital, Indonesia. Rotavirus was detected in stool samples using an enzyme immunoassay (EIA), which was followed by genotyping using reverse transcriptase polymerase chain reaction (RT-PCR). Electropherotyping was performed for the rotavirus-positive samples. RESULTS In total, 104 cases were included in the study, 57 (54.8%) of which were rotavirus-positive. Based on a multiple logistic regression analysis, age group, vomiting and stool mucous were associated with rotavirus positivity. Most of the 56 samples subjected to genotyping were classified as G1 (80.36%) and P[8] (69.64%) genotypes. The genotype combination G1P[8] was identified as the most prevalent strain (66.07%). Of the 19 samples subjected to electropherotyping, 17 G1 isolates and 1 G3 isolate had long patterns, and 1 G1 isolate had a short pattern. CONCLUSION G1P[8] was the most dominant strain of rotavirus causing diarrhoea in children in Yogyakarta. Age group, vomiting and stool mucous were associated with rotavirus positivity.

Significance of continuous rotavirus and norovirus surveillance in Indonesia

BackgroundDiarrhea significantly contributes to the global burden of diseases, particularly in developing countries. Rotavirus and norovirus are the most dominant viral agents responsible for diarrheal disease globally. The aim of this review was to conduct a comprehensive assessment of rotavirus and norovirus study in Indonesia.Data sourcesArticles about rotavirus and norovirus surveillance in Indonesia were collected from databases, including PubMed and Google Scholar. Manual searching was performed to identify additional studies. Furthermore, relevant articles about norovirus diseases were included.ResultsA national surveillance of rotavirus-associated gastroenteritis has been conducted for years, resulting in substantial evidence about the high burden of the diseases in Indonesia. In contrast, norovirus infection received relatively lower attention and very limited data are available about the incidence and circulating genotypes. Norovirus causes sporadic and epidemic gastroenteritis globally. It is also emerging as a health problem in immunocompromised individuals. During post-rotavirus vaccination era, norovirus potentially emerges as the most frequent cause of diarrheal diseases.ConclusionsOur review identifies knowledge gaps in Indonesia about the burden of norovirus diseases and the circulating genotypes. Therefore, there is a pressing need to conduct national surveillance to raise awareness of the community and national health authority about the actual burden of norovirus disease in Indonesia. Continuing rotavirus surveillance is also important to assess vaccine effectiveness and to continue tracking any substantial changes of circulating rotavirus genotypes.

Molecular characterisation of rotavirus strains detected during a clinical trial of the human neonatal rotavirus vaccine (RV3-BB) in Indonesia

Highlights • Equine-like G3P[8] the major cause of gastroenteritis during RV3-BB efficacy trial.• The Indonesian equine-like G3P[8] strain was genetically similar to Hungarian and Spanish strains.• Equine-like G3P[8] strain is an emerging cause of gastroenteritis in Indonesia.

Diarrhea among hospitalized children under five: A call for inclusion of rotavirus vaccine to the national immunization program in Indonesia

CONTEXT Rotavirus diarrhea is a common disease worldwide which mostly affects children under five years old. Rotavirus infection causes severe diarrhea and leads to substantial health care costs. In Indonesia the rotavirus vaccine has been available since 2011, however it has not been included into the National Immunization Program. This study aims to describe the proportion of rotavirus in children under 5 in Indonesia, the clinical characteristics of rotavirus infections, and the rotavirus strains circulating in the country during 2010-2015. METHODS Children under five years of age with acute watery diarrhea were prospectively identified and enrolled through the active diarrhea surveillance system in 5 sites in four provinces in Indonesia during 2010-2015. The rotavirus specimens were tested using Enzyme Immunoassay. Bivariate logistic regression tests were performed to compare rotavirus positive and negative results with respect to the collected demographic and clinical variables. RESULTS From January 2010 to December 2015, the average annual rotavirus prevalence among children hospitalized with acute watery diarrhea in four provinces in Indonesia was 47.5%. Rotavirus diarrhea occurred mostly in children under 2 years of age. Of all age groups, children aged 6-11 and 12-23 months had the highest prevalence of rotavirus diarrhea in all years (54.2% and 50.6%, respectively). This study found that the most prevalent of G and P genotypes were G1P8 in 2010 (63.2%), 2011 (64.1%) and 2012 (74.6%) and G3P8 in 2013 (49.7%), 2014 (82.5%) and 2015 (84.4%) CONCLUSIONS: This study demonstrates that rotavirus is a major cause of diarrhea in hospitalized children in Indonesia. These findings highlight the need for inclusion of the rotavirus vaccine to the National Immunization Program in Indonesia.

Quality of Symptom-Based Diagnosis of Rotavirus Infection Based on Mathematical Modeling

Rotavirus is the leading cause of severe childhood gastroenteritis worldwide. The laboratory diagnosis requires testing of fecal specimens with commercial assays that often are not available in low resource settings. Therefore, estimation of rotavirus presence based on clinical symptoms is expected to improve the disease management without laboratory verification.