Acute diarrhea and rotavirus infection in newborn babies and children in Yogyakarta, Indonesia, from June 1978 to June 1979

Complete genome analyses of G12P[8] rotavirus strains from hospitalized children in Surabaya, Indonesia, 2017-2018

Rotavirus A (RVA) is a major viral cause of acute gastroenteritis (AGE) worldwide. G12 RVA strains have emerged globally since 2007. There has been no report of the whole genome sequences of G12 RVAs in Indonesia. We performed the complete genome analysis by the next-generation sequencing of five G12 strains from hospitalized children with AGE in Surabaya from 2017 to 2018. All five G12 strains were Wa-like strains (G12-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1) and were clustered into lineage-III of VP7 gene phylogenetic tree. STM430 sample was observed as a mixed-infection between G12 and G1 strains: G12/G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. A phylogenetic tree analysis revealed that all five Indonesian G12 strains (SOEP379, STM371, STM413, STM430, and STM433) were genetically close to each other in all 11 genome segments with 98.0%-100% nucleotide identities, except VP3 and NSP4 of STM430, suggesting that these strains have originated from a similar ancestral G12 RVA. The VP3 and NSP4 genome segments of STM430-G12P[8] were separated phylogenetically from those of the other four G12 strains, probably due to intra-genotype reassortment between the G12 and G1 Wa-like strains. The change from G12P[6] lineage-II in 2007 to G12P[8] lineage-III 2017-2018 suggests the evolution and diversity of G12 RVAs in Indonesia over the past approximately 10 years.

Molecular Epidemiology and Clinical Features of Rotavirus Infection Among Pediatric Patients in East Java, Indonesia During 2015-2018: Dynamic Changes in Rotavirus Genotypes From Equine-Like G3 to Typical Human G1/G3

Group A rotavirus (RVA) is the most important cause of severe gastroenteritis among children worldwide, and effective RVA vaccines have been introduced in many countries. Here we performed a molecular epidemiological analysis of RVA infection among pediatric patients in East Java, Indonesia, during 2015-2018. A total of 432 stool samples were collected from hospitalized pediatric patients with acute gastroenteritis. None of the patients in this cohort had been immunized with an RVA vaccine. The overall prevalence of RVA infection was 31.7% (137/432), and RVA infection was significantly more prevalent in the 6- to 11-month age group than in the other age groups (P < 0.05). Multiplex reverse transcription-PCR (RT-PCR) revealed that the most common G-P combination was equine-like G3P[8] (70.8%), followed by equine-like G3P[6] (12.4%), human G1P[8] (8.8%), G3P[6] (1.5%), and G1P[6] (0.7%). Interestingly, the equine-like strains were exclusively detected until May 2017, but in July 2017 they were completely replaced by a typical human genotype (G1 and G3), suggesting that the dynamic changes in RVA genotypes from equine-like G3 to typical human G1/G3 in Indonesia can occur even in the country with low RVA vaccine coverage rate. The mechanism of the dynamic changes in RVA genotypes needs to be explored. Infants and children with RVA-associated gastroenteritis presented more frequently with some dehydration, vomiting, and watery diarrhea, indicating a greater severity of RVA infection compared to those with non-RVA gastroenteritis. In conclusion, a dynamic change was found in the RVA genotype from equine-like G3 to a typical human genotype. Since severe cases of RVA infection were prevalent, especially in children aged 6 to 11 months or more generally in those less than 2 years old, RVA vaccination should be included in Indonesia's national immunization program.

Significance of continuous rotavirus and norovirus surveillance in Indonesia

BACKGROUND

Diarrhea 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 SOURCES

Articles 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.

RESULTS

A 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.

CONCLUSIONS

Our 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.

Untangling the Impacts of Climate Change on Waterborne Diseases: a Systematic Review of Relationships between Diarrheal Diseases and Temperature, Rainfall, Flooding, and Drought

Global climate change is expected to affect waterborne enteric diseases, yet to date there has been no comprehensive, systematic review of the epidemiological literature examining the relationship between meteorological conditions and diarrheal diseases. We searched PubMed, Embase, Web of Science, and the Cochrane Collection for studies describing the relationship between diarrheal diseases and four meteorological conditions that are expected to increase with climate change: ambient temperature, heavy rainfall, drought, and flooding. We synthesized key areas of agreement and evaluated the biological plausibility of these findings, drawing from a diverse, multidisciplinary evidence base. We identified 141 articles that met our inclusion criteria. Key areas of agreement include a positive association between ambient temperature and diarrheal diseases, with the exception of viral diarrhea and an increase in diarrheal disease following heavy rainfall and flooding events. Insufficient evidence was available to evaluate the effects of drought on diarrhea. There is evidence to support the biological plausibility of these associations, but publication bias is an ongoing concern. Future research evaluating whether interventions, such as improved water and sanitation access, modify risk would further our understanding of the potential impacts of climate change on diarrheal diseases and aid in the prioritization of adaptation measures.

Introduction of pentavalent vaccine in Indonesia: a policy analysis

The introduction of pentavalent vaccine containing Haemophilus influenzae type b antigen in Indonesia's National Immunization Program occurred nearly three decades after the vaccine was first available in the United States and 16 years after Indonesia added hepatitis B vaccine into the program. In this study, we analyzed the process that led to the decision to introduce pentavalent vaccine in Indonesia. Using process tracing and case comparison, we used qualitative data gathered through interviews with key informants and data extracted from written sources to identify four distinct but interrelated processes that were involved in the decision making: (a) pentavalent vaccine use policy process, (b) financing process, (c) domestic vaccine development process and (d) political process. We hypothesized that each process is associated with four necessary conditions that are jointly sufficient for the successful introduction of pentavalent vaccine in Indonesia, namely (a) an evidence-based vaccine use recommendation, (b) sufficient domestic financing capacity, (c) sufficient domestic vaccine manufacturing capacity and (d) political support for introduction. This analysis of four processes that led to the decision to introduce a new vaccine in Indonesia may help policy makers and other stakeholders understand and manage activities that can accelerate vaccine introduction in the future.

Detection of group A rotavirus strains circulating among children with acute diarrhea in Indonesia

Rotavirus is the major cause of severe diarrhea in children under 5 years old in developed and developing countries. Since improvements in sanitation and hygiene have limited impact on reducing the incidence of rotavirus diarrhea, implementation of a vaccine will be a better solution. We conducted an observational study to determine the disease burden and to identify the genotype of circulating rotavirus in Indonesia. Hospitalized children due to acute diarrhea were enrolled from four teaching hospitals in Indonesia. Stool samples were collected based on WHO protocol and were tested for the presence of group A rotavirus using enzyme immunoassay. Then, rotavirus positive samples were genotyped using RT-PCR. Fisher’s Exact tests, Chi square tests and logistic regression were performed to determine differences across hospital and year in rotavirus prevalence and genotype distribution. There were 4235 samples from hospitalized children with diarrhea during 2006, 2009 and 2010. Among them, the rotavirus positive were 2220 samples (52.42 %) and incidence rates varied between hospitals. The G1P[8], G1P[6], and G2P[4] were recognized as the dominant genotypes circulating strains in Indonesia and the proportion of predominant strains changed by year. Our study showed the high incidence of rotavirus infection in Indonesia with G1P[8], G1P[6], and G2P[4] as the dominant strains circulating in Indonesia. These results reinforce the need for a continuing surveillance of rotavirus strain in Indonesia.

Conquering rotavirus: from discovery to global vaccine implementation

Rotavirus, the commonest cause of severe dehydrating gastroenteritis world-wide, was discovered less than 50 years ago. It causes about 450,000 deaths per year in children <5 years of age and hospitalises millions more. Rotavirus vaccines have been shown to have a major impact on hospital admissions due to rotavirus gastroenteritis and all-cause gastroenteritis and reduce mortality in developing countries. In Australia, there has been a 71% decrease in rotavirus hospitalisations in children 0-5 years of age. From the discovery of rotavirus as the major causative agent for severe gastroenteritis, through vaccine development and vaccine post-marketing surveillance activities, Australian scientists and clinicians have played a significant role in the global effort to reduce the burden of rotavirus infection.

Molecular characteristics of rotavirus isolated from a diarrhea outbreak in october 2008 in bintuni bay, papua, indonesia

BACKGROUND

Viral diarrhea continues to be a health problem in Indonesia that often causes outbreaks; in particular, acute viral diarrhea in young children. Rotavirus is the leading cause of severe diarrhea in children under two years of age. This study aimed to determine the genotypes of rotavirus in Bintuni Bay, Papua.

METHODS

Stool specimens from 15 patients were collected and analyzed for rotavirus using an enzyme immunosorbent assay (EIA) and reverse transcriptase-polymerase chain reaction (RT-PCR). Subsequently, we sequenced the genetic material of rotavirus positive samples by RT-PCR and analyzed the results using Mega-4 software.

RESULTS

Two rotavirus serotypes were identified from the diarrhea outbreak in Bintuni, Papua in October 2008: serotype G1 with G1P[6] (50%) and G1P[8] (16.7%) strains, and serotype G2 with G2P[4] (23.3%) strain. Phylogenetic tree analyses of VP7 protein showed that rotavirus-infected diarrhea in Bintuni Bay, Papua at that time was dominated by the G1 serotype (83%).

CONCLUSION

The laboratory results showed that G1 serotype rotavirus was a cause of the outbreak of diarrhea in October 2008 in Bintuni, Papua.

Rotavirus surveillance to determine disease burden and epidemiology in Java, Indonesia, August 2001 through April 2004

This study estimates rotavirus disease burden in children under age 3 years presenting with acute gastroenteritis to hospitals in Purworejo district and Yogyakarta city from August 2001 to April 2004. Among a total of 8929 hospitalized children, 1397 (16%) presented with acute gastroenteritis and of the 1321 stool samples tested, 705 (53%) were positive for rotavirus. Rotavirus infections were most common among children aged 7-23 months and rotavirus was more common during the dry season (June through August). Logistic regression analysis showed no differences in socioeconomic indicators between the rotavirus positive and negative admissions. Rotavirus vaccination may prevent a large proportion of all hospitalizations of young children under 3 years of age presenting with acute gastroenteritis.

Discovery of rotavirus: Implications for child health

For centuries, acute diarrhea has been a major worldwide cause of death in young children, and until 1973, no infectious agents could be identified in about 80% of patients admitted to hospital with severe dehydrating diarrhea. In 1973 Ruth Bishop, Geoffrey Davidson, Ian Holmes, and Brian Ruck identified abundant particles of a 'new' virus (rotavirus) in the cytoplasm of mature epithelial cells lining duodenal villi and in feces, from such children admitted to the Royal Children's Hospital, Melbourne. Rotaviruses have now been shown to cause 40-50% of severe acute diarrhea in young children worldwide in both developing and developed countries, and > 600 000 young children die annually from rotavirus disease, predominantly in South-East Asia and sub-Saharan Africa. Longitudinal surveillance studies following primary infection in young children have shown that rotavirus reinfections are common. However the immune response that develops after primary infection is protective against severe symptoms on reinfection. This observation became the basis for development of live oral rotavirus vaccines. Two safe and effective vaccines are now licensed in 100 countries and in use in 17 countries (including Australia). Rotarix (GSK) is a single attenuated human rotavirus, representative of the most common serotype identified worldwide (G1P[8]). RotaTeq (Merck) is a pentavalent mixture of naturally attenuated bovine/human rotavirus reassortants representing G1, G2, G3, G4, and P(8) serotypes. Preliminary surveillance of the numbers of children requiring hospitalization for severe diarrhea, in USA, Brazil, and Australia, after introduction of these vaccines, encourages the hope that rotavirus infection need no longer be a threat to young children worldwide.

Seasonality of rotavirus disease in the tropics: a systematic review and meta-analysis

BACKGROUND

To date little conclusive evidence exists on the seasonality of rotavirus incidence in the tropics. We present a systematic review and meta-analysis on the seasonal epidemiology of rotavirus in the tropics, including 26 studies reporting continuous monthly rotavirus incidence for which corresponding climatological data was available.

METHODS

Using linear regression models that account for serial correlation between months, monthly rotavirus incidence was significantly negatively correlated with temperature, rainfall and relative humidity in 65%, 55% and 60% of studies, respectively. We carried out pooled analyses using a generalized estimating equation (GEE) that accounts for correlation from between-study variation and serial correlation between months within a given study.

RESULTS

For every 1 degrees C (1.8 degrees F) increase in mean temperature, 1 cm (0.39 in.) increase in mean monthly rainfall, and 1% increase in relative humidity (22%) this analysis showed reductions in rotavirus incidence of 10% (95% CI: 6-13%), 1% (95% CI: 0-1%), and 3% (95% CI:0-5%), respectively.

CONCLUSIONS

On the basis of the evidence, we conclude that rotavirus responds to changes in climate in the tropics, with the highest number of infections found at the colder and drier times of the year.

Rotavirus infection among infants with diarrhea in Pakistan

Rotavirus was examined in 818 diarrheal stool samples collected in Karachi, Pakistan, from 1990 to 1997. Rotavirus was detected in 112 samples (13.7%). The predominant serotypes were G1 and G4 and G3 was not detected. The predominant type changed between years. Rotavirus was found in all seasons and most infections were found in children aged less than 2 years.

Seroepidemiology of human group C rotavirus in the UK

The gene coding for the major inner capsid protein VP6 of human group C rotavirus was cloned into baculovirus using the pBlueBac2 vector and expressed in insect cells. When cultured in High Five cells, VP6 was expressed at a high level and exported to the cell culture medium. Purified VP6 was used to immunise rabbits. Hyperimmune rabbit serum, which reacted with native human group C rotavirus in infected cells, was used to develop and optimise an EIA for the detection of antibodies to group C rotavirus using the recombinant VP6 as a source of antigen. In a local epidemiological survey of 1000 sera grouped by age, an average of 43% of samples were found to have antibodies to human group C rotavirus with the highest proportion (66%) in the 71-75 year age group. In comparison, 97% of adults and 85% of children had antibodies to recombinant VP6 from the bovine RF strain of group A rotavirus. These results suggest that infection with human group C rotavirus is a common occurrence despite the apparent rarity of reports of human group C rotavirus in clinical samples from patients with gastroenteritis.

Typing of human group A rotavirus with alkaline phosphatase-labeled oligonucleotide probes or a monoclonal enzyme immunoassay in unfrozen stools of children with diarrhea in Bangkok

In developed countries, serotypes (or G types) have been identified in > 70% of group A rotavirus using monoclonal enzyme immunoassays (MEIAs); however, these assays have identified < 50% of rotavirus G types from developing countries presumably because the VP7 antigens were damaged by freezing and thawing during transportation of specimens. The VP7 (G) serotypes of rotavirus in unfrozen stool collected from children with acute diarrhea in Bangkok were determined using MEIA and compared to hybridization with alkaline phosphatase-labeled oligonucleotide probes. Reverse transcription of dsRNA coding for VP7 followed by polymerase chain reaction amplification of cDNA was used as an additional step prior to hybridization for 98 specimens that did not hybridize with the oligonucleotide probes. Of 251 rotavirus specimens, 208 (83%; 99% Cl = 76-89%) hybridized with G type specific oligonucleotides compared to 146 (58%; 99% Cl = 50-66%) that were typeable by MEIA. Forty-five (82%) of 55 stools containing G type 1, 80 of 84 (95%) containing G type 2, 0 of 3 containing G type 3, and 2 of 4 (50%) containing G type 4 as identified by MEIA hybridized with G type specific oligonucleotides. Differences in nucleotide sequences coding for VP7, in addition to destruction of the VP7 antigen by freezing and thawing of the specimen, may explain why not all rotavirus hybridized with G type specific probes.

Electrophoretic typing of nosocomial rotavirus infection in a general paediatric unit showing the continual introduction of community strains

During 1989 stool specimens from hospitalised children with gastroenteritis at Ga-Rankuwa Hospital in South Africa were examined for the presence of rotaviruses. Overall 16% of the children were positive for rotavirus. However, 43% of the rotavirus positive patients were infected in the hospital. Further characterisation of the rotavirus strains was performed by electrophoresis of the RNA genome and hybridisation analysis of the VP7 and VP4 genes present. The strains associated with nosocomial infection were similar to those strains acquired in the community. The majority of the strains, both community- or hospital-acquired, were associated with a serotype 1 strain with a long electrophoretype and bearing the Wa-like VP4 gene. Three minor rotavirus strains with a long electrophoretype were also observed to be circulating bearing serotype 1 or 4 VP7 genes and the Wa-like VP4 gene. Interestingly, a serotype 4 strain bearing the M37-like VP4 gene was identified to occur almost exclusively in neonates although the gene was associated with diarrhoea in these cases. Two strains with differing short RNA electrophoretypes were also observed, members of which hybridised to VP7 serotype 2 and VP4 DS-1 type probes.

Typing of human rotavirus VP4 by an enzyme immunoassay using monoclonal antibodies

Two different neutralization specificities exist on the outer capsid of group A rotaviruses. At least seven VP7 (G) antigenic types are distinguishable among human rotaviruses. Four distinct antigenic (P) types of human rotavirus VP4 corresponding to separate rotavirus gene 4 groups have been described. The aim of this study was to identify P types in clinical specimens by developing an enzyme immunoassay, using P-type-specific neutralizing monoclonal antibodies (N-MAbs). Three N-MAbs primarily or solely recognizing each of P types 4, 6, and 8 and binding to VP4 or its subunit VP5* were derived. These N-MAbs served as detector antibodies in an enzyme immunoassay P-typing system similar to that in use for G typing. P-type specificity was highest when the G-type specificity of the capture antiserum was matched to the G type of the rotavirus in the test sample. The method correctly identified the P types of 13 well-characterized, cell culture-adapted human rotaviruses and was used to classify a further six strains. P typing of 118 rotavirus-positive stools gave results consistent with the P type inferred from the G type for 98 (83%) samples. Twelve (10%) of the stools showed no reaction with any N-MAb and eight (7%) samples were untypeable because of cross-reactivity between N-MAbs or high background readings. This P-typing enzyme immunoassay system is economical and amenable to large-scale use in epidemiological studies. Its use will facilitate assessment of the distribution of P types worldwide and of the role of VP4 in eliciting protective immune responses.

[Epidemiology of rotavirus infections in the Federal District, Brazil]

Rotavirus testing was performed on fecal samples of 607 infants and young children aging from 0 to 6 years with acute diarrhoea between May 1986 and April 1990. Samples were analyzed by polyacrylamide gel electrophoresis (PAGE). Rotaviruses were detected in 123 samples (20.27%); from those, 107 (87.00%) were classified as subgroup II (long profile). Rotaviruses were not detected in the control group of healthy children, but it were present in 7.80% of the children hospitalized for other causes but acute diarrhoea. Most of the children with rotavirus infection ranged from 6 to 24 months of age (73.98%). The mean of positive cases during the rainy months (October to April) was of 9.60% and during the dry period was of 34.48%. The highest values were 53.17 and 73.27% in June and July, the coldest months of the year.

Rotavirus studies in Indian (Asian) South African infants with acute gastro-enteritis: I. Microbiological and epidemiological aspects

This study, which is the first one documenting rotavirus (RV) diarrhoea in Asian infants in South Africa, describes the virological and epidemiological aspects of this disease in this population. Fifty-five per cent of 1142 hospitalized cases investigated over a 31-month period showed a positive stool ELISA for RV. Most of these children stopped shedding RV by days 4-6 of hospital admission, though prolonged excretion was recorded in some acute cases for up to 13 days. Mixed RV-bacterial infections occurred in 7% of the total gastro-enteritis (GE) patients, while 8.6% had pure bacterial gastro-enteritis. Sixteen per cent of 188 GE patients had serum anti-RV complement-fixing (CF) antibodies on admission. Rotavirus diarrhoea occurred in half of the seropositive infants. Seroconversion occurred in only two-thirds of the initially seronegative children who had RV diarrhoea. In 5.6% of the RV diarrhoea patients the infection was acquired nosocomially whilst in the hospital for other illnesses. The age-groups mainly affected were between 3 and 14 months, with a peak at 9-11 months; 3% of the RVGE patients were neonates. Both the RVGE and the total GE admissions showed well-marked winter peaks, with an inverse relationship between RV prevalence and both temperature and humidity. It is concluded that RV is the most important cause of infantile GE in this population, whereas pure bacterial infections play a relatively minor role. Circulating anti-RV antibodies do not necessarily afford protection against RV diarrhoea, probably owing to serotypic differences.

Aetiological factors of infantile diarrhoea: a community-based study

A community-based study was undertaken to compare the organisms responsible for diarrhoea in children living in formal housing with indoor water supply and sanitation with those from a deprived environment. The role of "home remedies" was also assessed. Among 373 children with diarrhoea, rotavirus was detected in 15% (in 371 symptom-free controls, 9%), and proved to be the single most common causative agent. Bacterial pathogens were found in 20% of patients, with enteropathogenic Escherichia coli (EPEC) being isolated most frequently (9%; controls 3%), followed by Shigella species (4%; controls 1%), Campylobacter jejuni (4%; controls 1%), Salmonella species (2%; controls 1%) and enterotoxigenic E. coli (ETEC) (2%; controls 1%). Giardia lamblia and cryptosporidium were detected in 6% (controls 6%) and 3% (controls 1%) of patients, respectively; 7% (controls 1%) harboured more than one enteropathogen and no pathogens were detected in 58% (controls 78%). The vast majority (greater than 90%) of both patients and controls received some form of "home remedy" which included disinfectants and traditional herbs. The findings of this study therefore confirm the extremely complex nature of diarrhoea in developing communities and indicate that environmental factors are compounded by other issues.

Evaluation of end-point titration, single dilution and capture enzyme immunoassays for measurement of antirotaviral IgA and IgM in infantile secretions and serum

In order to facilitate measurement of antirotaviral IgA in large collections of faeces and secretions, adaptations of enzyme immunoassay methods for estimating antirotaviral IgA and IgM in duodenal fluid, saliva, faeces and serum were studied. To quantitate specific IgA, a single dilution of each sample was assayed. Results were expressed as antirotaviral IgA units derived from a standard curve. Units were calculated by log-logit analysis on computer. There was strong correlation between antirotaviral IgA units and end-point titres in 257 faecal samples (correlation coefficient r = 0.92) and in 182 duodenal fluids and salivary samples (correlation coefficient r = 0.74). The assay was validated using acute and convalescent faeces from children with or without rotavirus infection. Immune conversions in IgA were detected in 33 (75%) of the children by units and 34 (77%) by titres. None of nine children with gastroenteritis due to other infectious agents showed immune conversions to rotavirus. A monoclonal capture IgM assay showed similar end-point titres and numbers of immune conversions when compared with a direct assay for antirotaviral IgM in serum and secretions. Use of the capture method eliminated false-positive reactions with the cell control. The assay for antirotaviral IgA units in secretions is simple, rapid, reproducible and reliable, and has proven of value in longitudinal epidemiological studies of rotavirus coproIgA profiles. Both the capture IgM technique and the single dilution IgA method permit analysis of large numbers of specimens and are appropriate for examination of immune responses to natural rotavirus infection or during vaccine trials.

Rotavirus serotypes causing acute diarrhoea in hospitalized children in Yogyakarta, Indonesia during 1978-1979

Rotavirus strains in stool specimens from 111 children aged 3-24 months admitted to hospital in Yogyakarta, Indonesia for treatment of acute diarrhoea were serotyped using VP7 serotype specific monoclonal antibodies in a double sandwich enzyme immunoassay. A serotype could be assigned to 59 of 111 specimens (53%). Inability to assign a serotype to 47% of specimens was probably due to loss of the outer capsid during transport of specimens from Indonesia to Australia. All four major human rotavirus serotypes were detected during the 15 month survey from June 1978 to August 1979, including one serotype 1, 5 serotype 2, 31 serotype 3, and 21 serotype 4 strains. One additional strain reacted with serotype 3 and 4 Mabs. Serotype 3 strains showed intratypic variation. The relative frequency of serotypes 2, 3, and 4 varied during the 15 months and appeared to be influenced by climatic changes associated with dry and wet seasons. Vaccine strategies must take account of comparatively rapid changes of predominant serotypes in a community and are only likely to be successful if comprehensive immunity can be established simultaneously against the four major human serotypes.

The VP7 gene of a new G serotype of human rotavirus (B37) is similar to G3 proteins in the antigenic c region

The human rotavirus isolate B37 has a characteristic "super-short" RNA electropherotype and has been shown to represent a new VP7 serotype (M. J. Albert, L. E. Unicomb, and R. F. Bishop, 1987, J. Clin. Microbiol. 25, 183-185). The VP7 gene was cloned, and its nucleotide and predicted amino acid sequences were compared to other published VP7 gene sequences. Consistent with the serological evidence, two major antigenic regions of the B37 VP7 (i.e., regions A and B) differ in sequence from those of other G serotypes. Unexpectedly, the C antigenic region shows close similarity to G3 rotaviruses, but we were unable to detect a serological relationship using serotype 3 monoclonal antibodies.

Human viral gastroenteritis

During the last 15 years, several different groups of fastidious viruses that are responsible for a large proportion of acute viral gastroenteritis cases have been discovered by the electron microscopic examination of stool specimens. This disease is one of the most prevalent and serious clinical syndromes seen around the world, especially in children. Rotaviruses, in the family Reoviridae, and fastidious fecal adenoviruses account for much of the viral gastroenteritis in infants and young children, whereas the small caliciviruses and unclassified astroviruses, and possibly enteric coronaviruses, are responsible for significantly fewer cases overall. In addition to electron microscopy, enzyme immunoassays and other rapid antigen detection systems have been developed to detect rotaviruses and fastidious fecal adenoviruses in the stool specimens of both nonhospitalized patients and those hospitalized for dehydration and electrolyte imbalance. Experimental rotavirus vaccines have also been developed, due to the prevalence and seriousness of rotavirus infection. The small, unclassified Norwalk virus and morphologically similar viruses are responsible for large and small outbreaks of acute gastroenteritis in older children, adolescents, and adults. Hospitalization of older patients infected with these viruses is usually not required, and their laboratory diagnoses have been limited primarily to research laboratories.

Characterization of a human rotavirus strain which is possibly a naturally-occurring reassortant virus

We investigated the antigenic and genetic characters of one of two human rotavirus strains 69M and 57M isolated in Indonesia, both of which showed a "super-short" RNA electrophoretic pattern (A. Hasegawa et al., Microbiol. Immunol. 28, 719-722, 1984). By an enzyme-linked immunosorbent assay with subgroup-specific monoclonal antibodies, one virus, strain 57M, was found to have subgroup II antigenicity. The cross-reaction of this strain, in a plaque neutralization test, with a serotype 4 strain was high whereas that of strain 69M was low. When radiolabeled RNA probes prepared from this virus were hybridized with RNAs from reference strains of different serotypes, treated with S-1 nuclease and then subjected to polyacrylamide gel electrophoresis, we found that (i) RNA segment 10 (the super-short segment) hybridized with that of another super-short pattern virus, strain 69M; (ii) segment 7, coding for a neutralization antigen, hybridized with that of the serotype 4 virus; (iii) segment 6, coding for a major inner-shell protein, hybridized with that of a serotype 1 virus; and (iv), some other segments hybridized with those of the reference viruses of serotypes other than 2 and 3. We suspect that this strain is possibly a naturally-occurring reassortant virus whose genetic segments are derived from different human rotaviruses.

Non-neutralizing monoclonal antibodies to a trypsin-sensitive site on the major glycoprotein of rotavirus which discriminate between virus serotypes

Monoclonal antibodies were derived to a human rotavirus purified from stools. Three of the antibodies immunoprecipitated the rotavirus outer capsid glycoprotein gp 34 and were non-neutralizing. These antibodies reacted by enzyme immunoassay with cultivable rotaviruses showing the "long" RNA electropherotype but were inefficient as detectors of "long" RNA pattern rotaviruses in stools. Treatment of SA 11 rotavirus with 7.5 micrograms/ml porcine trypsin for 30 minutes at 37 degrees C irreversibly reduced binding of the antibodies to SA 11 rotavirus in enzyme immunoassays by 50 per cent. Binding was abolished in the presence of rotavirus-negative faecal extracts. These results indicate that non-neutralizing sites on gp 34 of rotaviruses can vary with RNA electropherotype and serotype, and that levels of trypsin currently in use to assist growth of rotaviruses in cell culture may alter the serological profile of the viruses.

Molecular epidemiology of rotavirus in black infants in South Africa

The molecular epidemiology of rotavirus infections in black infants in Ga-Rankuwa, South Africa, was investigated by polyacrylamide gel electrophoresis. Between 1983 and 1986, 14 different RNA electrophoretic patterns were observed for children with acute gastroenteritis. These electrophoretypes showed a sequential pattern of appearance, with a limited number being present at any one time. In contrast, for neonates only one RNA electrophoretype was detected, which persisted for at least 3 years.

Acute gastroenteritis in children attending day-care centres with special reference to rotavirus infections. I. Aetiology and epidemiologic aspects

Acute gastroenteritis (GE) among 214 children (aged 6 months-7 years) attending day-care centres (DDCs) in the Copenhagen County was studied during a 12-month period. A total of 197 cases of GE was observed in 109 children (i.e. 51% of the participants). The aetiology was as follows: rotavirus (n = 48) (24%), pathogenic bacteria (n = 11) (6%), Giardia lamblia (n = 3) (2%), while the aetiology of 68% remains unknown. The pathogenic bacteria included Yersinia enterocolitica, thermophilic Campylobacter, Clostridium difficile (+/- toxin) and enteropathogenic E. coli. In 4% of the GE the infections were multiple and Cryptosporidium was seen in one of these cases. The rate of GE declined with age from 1.35 GE per child per year (age group 1.0- less than 2.0 years) to 0.36 (6.0- less than 8.0 years). Serum sampled at the start of the study period showed that the frequency of detectable rotavirus IgG increased with age from 48% in the 6 months- less than 1.0 year group to 96% in the 4.0- less than 7.0 year group. The highest rates of rotavirus GE occurred from January to April (i.e. the rotavirus season). Moreover, rotavirus GE was almost absent after the age of 4. Hence, the rates of rotavirus GE per rotavirus season per child were 0.80 (age group 6 months-less than 1.0 year), 0.32 (1.0-less than 2.0), 0.14 (2.0-less than 3.0), 0.16 (3.0-less than 4.0), 0.06 (4.0-less than 5.0) and 0.04 (5.0-less than 6.0). Only 2 out of the 48 rotavirus GE were reinfections.(ABSTRACT TRUNCATED AT 250 WORDS)

Variation in neutralization epitopes of human rotaviruses in relation to genomic RNA polymorphism

Fecal rotaviruses collected from October 1983 to September 1984 from outpatients and inpatients attending the Royal Children's Hospital, Melbourne, Australia, with acute gastroenteritis were serotyped by enzyme immunoassay using rotavirus-neutralizing mouse monoclonal antibodies specific for serotypes 1 to 4. Application of three different serotype 1-neutralizing antibodies indicated variations in neutralization epitopes between serotype 1 rotaviruses on the major outer capsid glycoprotein, including a site shared with serotype 3 rotaviruses. The three different binding patterns observed were termed "monotypes." Comparison of monotype and serotype with genomic RNA profiles generated by gel electrophoresis of ds viral RNA indicated that each RNA electropherotype corresponded to only one monotype (1a, 1b, 1c) or serotype (3, 4). However, serotypes 1 (a and c) and 4 contained multiple electropherotypes. Greater numbers of RNA segment variations, including alteration in mobility of gene segments 7, 8, and 9, were evident between rotaviruses of different serotype or monotype than within those groups. Within limits of time and location, rotavirus neutralization epitope variations appear to correlate with RNA polymorphism. Where rotavirus epidemiology has been analyzed by year using RNA electropherotypes, only limited numbers of each RNA pattern need to be serotyped to ascertain the major serotypes in circulation.

Cold-adaptation of human rotavirus

A human rotavirus strain was cold-adapted for possible future use as a live vaccine. The original strain was isolated in 1980 in primary cynomolgus monkey kidney cells and has a serotype I and subgroup II antigenicity. The virus was serially passaged in African green monkey kidney cells; it was cultivated at 37 degrees C at the first stage of passages, and the cultivation temperature was then shifted down stepwise by 3 degrees C per each 10 passages. Finally the virus was passaged 10 times at 25 degrees C (total passage number of 55). The virus formed small-size plaques with irregular shaped borders at 31 degrees C. Growth at 25 degrees C of the cold-adapted virus was higher than that of the original virus. There was no difference between the migration patterns of 11 dsRNA segments in polyacrylamide gel electrophoresis of the original and the cold-adapted viruses.

Simple and specific enzyme immunoassay using monoclonal antibodies for serotyping human rotaviruses

An enzyme immunoassay for serotyping human rotaviruses in stools and in cell culture was developed. Hyperimmune rabbit antisera to rotaviruses were used as capture antibodies, and rotavirus-neutralizing mouse monoclonal antibodies specific for serotypes 1, 2, 3, and 4 were used as detection reagents. Partial purification of monoclonal antibodies and inclusion of skim milk powder in antibody diluents contributed to assay specificity. The sensitivity of this assay was greater than that of a direct enzyme immunoassay in which rotaviruses of the appropriate serotype were adsorbed directly to the solid phase. When fecal extracts were concentrated threefold, this serotyping enzyme immunoassay was of equal specificity and approached the sensitivity of electron microscopy for rotavirus detection. This assay is simple and rapid and is suitable for serotyping the large numbers of isolates obtained from epidemiological studies and vaccine trials.

An eight-year study of the viral agents of acute gastroenteritis in humans: ultrastructural observations and seasonal distribution with a major emphasis on coronavirus-like particles

During an 8-yr period, 862 stool specimens from patients with gastroenteritis were examined by electron microscopy after negative staining with 2% phosphotungstic acid (pH 6.5). Forty-one percent of the specimens submitted over an 8-yr period were determined to be positive for virus or viruslike particles belonging to one or more of seven morphologically distinct viral groups. Coronavirus-like particles (CVLPs) were present in 69.8% of the positive stool specimens. Membranous profiles containing "complement-type" holes (10 nm in diameter) were identified in some preparations containing CVLPs. The second most prevalent viral agent found in stool specimens was the rotavirus (17% of all positive stools). The incidence of other viruses identified in the survey were as follows: adenovirus 4.5%, picorna/parvovirus agents 2.9%, Norwalk-like agent 2.9%, astrovirus 1.9%, and calicivirus 0.5%. Unclassified small round viruses (approximately 25-30 nm in diameter) represented 0.5%. It was also determined that there was a seasonal distribution in excretion of all viruses except for CVLPs. A greater number of viruses were identified in the cooler, drier months of the year.

Molecular epidemiology of human rotavirus

The epidemiology of human rotavirus (HRV) in north-east Scotland was investigated between 1982 and 1984. During this period 708 HRV infections were recorded. The majority (83%) of the infections were in children less than 5 years of age although some were recorded in adults. The peak incidence occurred in the winter months although a high number of HRV infections was reported during the summer of 1983. A total of 840 faecal specimens containing rotavirus were screened for HRV genome RNA by polyacrylamide gel electrophoresis. Seven hundred (83%) specimens gave RNA profiles suitable for establishing the HRV electrophoretype. Twenty-five different electrophoretypes were identified, of which 21 had 'long' RNA profiles and four had 'short' RNA profiles. There was extensive co-circulation of distinct electrophoretypes although during any one epidemic period the majority of viruses belonged to a relatively small number of types. Comparison of viruses collected from hospitalized and non-hospitalized patients showed no differences in electrophoretype distribution. HRV was identified in faecal specimens from a wide age group and no correlation was demonstrated between age of patient and electrophoretype of the infecting virus.

Characterization of rotaviruses and subgroup F adenoviruses from acute summer gastroenteritis in South Africa

Six hundred and sixteen specimens were collected from black children hospitalised with acute gastroenteritis during the summer and autumn of 1982-1983 (October to May). Eighty-five children (13.8%) shed rotavirus and at least 40 (6.5%) shed adenovirus (Ad) type 40 or 41 belonging to subgroup F. The highest monthly prevalence of shedding subgroup F adenoviruses (10.1%) coincided with a peak in admissions in midsummer, whereas the highest monthly prevalence of shedding rotaviruses (41.9%) coincided with a peak in admissions in autumn. There were at least five genome types of rotavirus, at least three genome types of Ad40, and at least five genome types of Ad41 circulating in the Johannesburg-Soweto area during the study period. The high rate of rotavirus shedding in autumn could not be attributed to an upsurge in infections by any particular rotavirus strain.

Detection of rotavirus-specific IgG antibodies by immunoperoxidase assay and enzyme-linked immunosorbent assay

An indirect immunoperoxidase assay (IPA) has been developed for determination of IgG antibodies to rotavirus. The technique employed as antigen, SA-11 infected MA 104 cells, which were air-dried on glass slides and acetone-fixed. In parallel, rota-specific IgG antibodies were determined by enzyme-linked immunosorbent assay (ELISA). Specific IgG antibodies to rotavirus were determined in sera of healthy children and in sera of patients suffering from gastroenteritis. A good correlation (r = 0.92) and (r = 0.98) for healthy children and patients, respectively, was found between IPA and ELISA techniques. The IPA technique is rapid and simple and positive results, because of the intensive staining, are easily read by low-power light microscope. The potential application of IPA and ELISA methods in serodiagnosis of rotavirus infections is discussed.

Human-enteric-coronaviruslike particles (CVLP) with different epidemiological characteristics

One hundred fifty-six diarrheic and 115 control stools collected throughout a year from nonhospitalized children were examined by electron microscopy in Haut-Ogooué, Gabon; 65.2% of the controls and 38.5% of the diarrheics were found to contain coronavirus particles (CVLP). In both diarrheic and control groups the CVLP prevalences showed a seasonal variation whereas significant variation of prevalence with age was observed only in the controls. Thus, the CVLP in controls were significantly more abundant in children over 2 years old (76% vs 48%, P less than .01) and more frequently observed during the months of rainy seasons (75% vs 54%, P less than .02). On the other hand, the higher prevalence of CVLP in diarrheics over 2 years old was not significant (48% vs 36%, P = .20), whereas a significantly lower prevalence of CVLP during the months of rainy seasons was observed in this group (27% vs 50%, P less than .01). Studies of the climatological factors in this equatorial climate showed a parallel cyclical variation of parameters representing rainfall, temperature, as well as relative humidity. We were not able to distinguish which of these factors was influencing more directly the prevalence of CVLP.

Serotypic characterization of rotaviruses derived from asymptomatic human neonatal infections

Nineteen rotavirus strains derived from asymptomatic neonates (seven from England, five from Australia, two from Venezuela, and five from Sweden) were successfully cultivated in primary African green monkey kidney cell cultures, serotyped by plaque reduction neutralization tests, subgrouped by indirect enzyme-linked immunosorbent assay, and electropherotyped by polyacrylamide gel electrophoresis. All 19 strains were shown to fall into one of the four known human serotypes; serotype 1 (all Venezuelan strains), serotype 2 (all Swedish strains), serotype 3 (all Australian strains), or serotype 4 (all English strains). Hyperimmune guinea pig serum raised against the Venezuelan strain (M37) neutralized not only serotype 1 (strain Wa) but also serotype 4 (strain St. Thomas no. 3) viruses to a similar degree. The English, Australian, and Venezuelan isolates were found to belong to subgroup 2, and the Swedish strains were subgroup 1 viruses. The potential importance of these rotaviruses obtained from neonates as possible vaccine candidates is discussed.

Acute diarrhoea and rotavirus infections in young children in Kuwait

The role of rotavirus infections in acute diarrhoea in young children was studied over a period of one year. Rotavirus was detected by electron microscopy and enzyme immunoassay methods in 40.2% of faecal specimens from 343 children with acute diarrhoea and in 4.7% of 86 controls. The infections were most common in children aged 2-12 months (42.3%). Twelve per cent of the rotavirus infected children were also infected with bacterial enteropathogens (Salmonellae, Shigellae and enteropathogenic Escherichia coli). The incidence of rotavirus infections was not related to sex, socio-economic or nutritional status of children. Rotavirus-associated diarrhoea differed in several clinical parameters from bacterial associated and nonspecific diarrhoea. Rotavirus was detected throughout the year but was most frequent during months with little rainfall and low humidity (March-May). Our results suggest that in Kuwait, rotavirus infection is a major cause of childhood diarrhoea.

Rotavirus shedding by newborn children

We studied the shedding of rotavirus by newborn children in the nurseries of a large maternity hospital in Caracas, Venezuela, throughout the year 1982. Sixty-two (57%) of 108 children examined shed the virus within the first few days of life. Four (6%) of the 62 children who shed rotavirus had diarrhea but only one of them required oral rehydration therapy. The rotavirus specimens were identified as subgroup 2 in an ELISA subgrouping assay that employs monoclonal antibodies. Analysis of the RNA extracted from 52 of the samples by electrophoresis revealed a similar migration pattern in all the specimens; their identity was confirmed by crosshybridization analyses which revealed a strong degree of genomic homology among the strains studied.

Role of rotavirus as the cause of acute paediatric diarrhoea in Calcutta

Of the 245 acute paediatric diarrhoea cases admitted to the Infectious Diseases Hospital, Calcutta between July, 1979 and June, 1981, rotavirus was detected in the faeces of 55 (22.4%) patients either as the sole aetiological agent or in association with other enteropathogens. Children aged six months to two years were most commonly infected. The virus was detected throughout the year with higher incidence during the winter months of both years. The frequency of detection of major enteropathogens other than rotavirus was Vibrio cholerae biotype El Tor (31.0%), enteropathogenic Escherichia coli (8.2%) and enterotoxigenic E. coli (6.5%).

Bacteria, parasitic agents and rotaviruses associated with acute diarrhoea in hospital in-patient Indonesian children

Faeces from children (aged from one month to 12 years) with acute diarrhoea admitted to hospital in Yogyakarta, Indonesia, from June 1978 to June 1979, were examined for the presence of enteric pathogens. One or more recognized enteropathogens were identified in 56% of children. Rotaviruses were identified in 38% of all children. Toxigenic coliforms (predominantly Escherichia coli) were isolated from 12% of children. Salmonella sp. (6%), Shigella sp. (4%) and enteropathogenic parasites (predominantly Trichuris trichiura) from 3.5% of children. Mixed infections with two or more enteric pathogens were found in 7.6% of children. The incidence rate of each pathogen was correlated with age of the child, socio-economic level of the family and duration of breast feeding. Toxigenic coliforms were equally common in all age groups from both well-to-do and poor families. Enteropathogenic parasites appeared in increasing frequency with age. They were more common in artificially fed children and in children from families of low socio-economic level. The occurrence of multiple infection with mixtures of enteric pathogens increased with increasing age. Mixtures of parasites and other enteric pathogens only occurred in children with acute diarrhoea. These results provide baseline data about the relative importance of different enteropathogens in Indonesian children.

Epidemiology of rotavirus diarrhea in Yogyakarta, Indonesia, as revealed by electrophoresis of genome RNA

Nine different electropherotypes of rotaviruses occurred among 85 children with rotavirus diarrhea in Yogyakarta, Indonesia. Eighty percent of the electropherotypes had a "long" RNA pattern characteristic of human subgroup 2.

The effects of relative humidity and temperature on the survival of human rotavirus in faeces

The effects of relative humidity and temperature on the survival of human rotavirus in a thin layer of faeces on an impervious surface and on absorbent material was investigated using the indirect immunofluorescence technique in LLC-MK2 cells to titrate infectivity. Rotavirus was found to be very stable at low and high relative humidities but not in the medium range of relative humidity. Rotavirus infectivity was lost more rapidly under all humidities at 37 degrees C than at 4 degrees or 20 degrees C.

Rotavirus gastroenteritis and weather

During 5.5 years of a study in Washington, D.C., hospitalizations of children for rotavirus gastroenteritis tended to be more common after a month of cold or dry weather than after a corresponding calendar month of warm or wet weather. Overall, there were 84% more (178 versus 97) inpatients with rotavirus gastroenteritis after a set of relatively colder individual months taken as a group than after an equal number of warmer corresponding calendar months taken as a group. Comparable differences were not seen with nonrotavirus gastroenteritis patients. There also were 45% more rotavirus hospitalizations after the set of months with the least depth of precipitation compared with the set of corresponding calendar months with the greatest depth of precipitation. Rotavirus infection in young infants, the children least likely to be directly exposed to outdoor conditions, showed some of the most marked weather-associated effects. These findings suggest that weather-related low indoor relative humidity and indoor crowding may be key factors in the epidemiology of rotavirus disease.

Isolation of human rotaviruses in primary cultures of monkey kidney cells

We succeeded in isolating human rotaviruses from the feces of gastroenteritis patients by using roller cultures of primary cynomolgus monkey kidney cells with trypsin in the maintenance medium but without concentration and trypsin treatment of the inocula at each passage level. These cells were found to be more sensitive than MA-104 cells (derived from fetal rhesus monkey kidney) for the propagation of human rotaviruses. Polyacrylamide gel electrophoresis of the genome RNA revealed that there were small differences in the migration pattern of the segments among all the strains isolated from 1976 to 1981. The cultivation of human rotaviruses in primary cell cultures might aid in developing a liver rotavirus vaccine.

Variance in rotavirus infection rates in different urban population groups in South Africa

Rotavirus infection in black infants contrasts markedly with that of white infants in being much less common and showing no seasonal variation. In this multicentre study in Johannesburg, the aetiology of winter infantile gastroenteritis in black, coloured, and white infants was investigated. Stools were examined by electron microscopy and also by enzyme-immunoassay to detect subparticular antigen which may be missed by electron microscopy in patients presenting late in the course of the illness. Stools were also examined bacteriologically by conventional techniques. Rotavirus was the most common pathogen in all three population groups with bacteria playing a relatively minor role. Striking differences were observed in the rotavirus rates between the three groups. Infection in the whites was five times more common than in the blacks (60% versus 12%) with the coloureds intermediate at 40%. The hypothesis was put forward that the relative protection of the black population may be due to a greater degree of colonization of neonates, thus inducing protection against symptomatic infection at the target age of 6 to 24 months. This may well have important implications in immunoprophylaxis. The reason for the lack of seasonal variation in the black population is still unclear.