Enteric adenovirus infection among infants with diarrhea in rural Bangladesh

Detection and complete genome sequence analysis of human adenovirus in children with acute diarrhea in Yunnan, China, 2015-2021

The aims of this study were to determine the distribution and prevalence of gastroenteritis caused by human adenovirus (HAdV) in children in Yunnan province, China, in 2015-2021 and to identify preventive measures that can be taken to reduce morbidity and mortality in children.HAdV is a significant agent of diarrhea in children, but limited data are available regarding the epidemiology and genetic diversity of HAdV in children with diarrhea in Yunnan province, China. A total of 1754 fecal samples were subjected to real-time RT-PCR to detect and quantify HAdV. Positive samples were further analyzed using next-generation sequencing (NGS), and epidemiological data were analyzed as well.1754 patients with diarrhea were enrolled, of which 1041 were male and 713 were female (M:F ratio: 1.46). Seventy-two stool samples out of 1754 (4.10%) were positive for HAdV. The detection rates of all age groups varied from 2.50-4.78%. The highest incidence of HAdV was observed in children under 2 years of age, especially in children 12-24 months-old. From 2015-2021, the annual detection rate ranged from 1.62-12.26%. HAdV was detected throughout the year, but with marked seasonality. Children were most likely to be positive for HAdV in June and November. We detected HAdV in 15.53% (16/103) of samples collected in June and in 8.19% (14/171) of those collected in November. The entire viral genome was successfully sequenced for 13 of the 72 HAdV-positive samples, and 76.92% (10/13) of these were classified as genotype F41 and 23.08% (3/13) were classified as genotype C2.ConclusionsIn Yunnan province, children of all ages are susceptible to HAdV infection, but there has been marked variation in the yearly prevalence. The highest rate of HAdV detection was in June, followed by November. Priority should be given to disease prevention over the development of targeted antiviral therapies, and effective vaccines for preventing HAdV diarrhea are needed. It is also important to establish a surveillance system to collect relevant clinical and epidemiological data quickly in order to assess the potential risk of HAdV infection in children and to identify epidemic strains for the development of effective vaccines.

Molecular analysis of adenovirus strains responsible for gastroenteritis in children, under five, in Tunisia

Purpose of work

Enteric Adenovirus (EAdV) is recognized as one of the most commonly identified agents responsible for severe acute gastroenteritis (AGEs) in the stools of infants.We sought to determine the rate of human adenovirus (HAdV) infections, and the genotypic characterization of circulating strains of HAdV in children under 5 years of age with AGEs in university and regional hospitals, located in the Center-East of Tunisia, from January 2014 to December 2016.

Methods

A classic PCR was performed on 582 stool samples taken within 5 days of the onset of symptoms. Chosen positive samples were sequenced, and some of the results were confirmed by the Next Generation Sequencing technique (NGS). Partial nucleotide sequences of the Hexon gene obtained in this study were compared with the NCBI GenBank database using BLAST. Multiple sequence alignment and phylogenetic analysis were conducted using MEGA6 software. The phylogenetic tree was generated using the maximum-likelihood method and bootstrap analysis was performed with 1000 replications.

Results

Out of 582 samples, 52 (8.93 %) cases were positive for HAdV, with a male predominance (57.4 %). Phylogenetic analyses showed that Tunisian HAdV strains clustered into five HAdV lineages corresponding to serotypes F41 (14/28), C2 (9/28), C5 (3/28), E4 (1/28), and A18 (1/28). HAdV was more frequent in children aged up to 12 months, as compared to the other age groups. The HAdV activity was noted in almost all the months of the year with a peak in autumn, in 2014 and 2015, and in winter in 2016.

Conclusion

This study showed that infections with HAdV species were frequent in children suffering from AGE with the predominance of HAdV F41 and C2. This result underlines the importance of regular monitoring of circulating genotypes, and it could be useful for future epidemiological research.

Epidemiology of Human Adenovirus in Pakistani Children Hospitalized with Community-Acquired Gastroenteritis under the Age of Five Years

Acute gastroenteritis is the major cause of morbidity and mortality among infants and children around the globe. Along with other enteropathogens, human adenovirus (HadV) is a major etiological agent associated with diarrhea in young children. However, information about the epidemiology of Adenoviruses in Pakistan is limited or has not been reported. A total of 1082 stool samples were collected from patients with acute gastroenteritis under the age of five years with symptoms of diarrhea, vomiting, nausea, and abdominal cramps who visited Benazir Bhutto Hospital Rawalpindi and Children's hospital in Lahore of Punjab Province in Pakistan. Of this, 384 cases with no blood in their stool, negative for Rotavirus, and under the age of five years were recruited in this study. Human Adenoviruses were isolated in the human epithelial HEp-2 cell line. Furthermore, adenovirus antigen detection was carried out by an enzyme-linked immunosorbent assay (ELISA), and then all positive and negative samples were confirmed by nested PCR. After inoculating a clear stool supernatant on HEp-2 cell lines, we observed a positive cytopathic effect in 65 (16%) cases. Using an enzyme-linked immunosorbent assay, HAdV antigens were detected in 54 (14.06%) of the clear supernatant from gastroenteritis cases. However, HAdV hexon coding regions were amplified in 57 (14.80%) fecal samples, mainly from patients ≤24 months of age. The findings of this study suggest that adenovirus circulates significantly in the children population under the age of five years and may be the potential etiological factor of acute gastroenteritis in the mentioned cities. This study provides baseline data about the possible role of adenovirus in causing viral diarrhea in children. Further large-scale epidemiological surveys are recommended to better understand disease burden, etiological agents, and its clinical impact across the country.

Burden, clinical characteristics, risk factors, and seasonality of adenovirus 40/41 diarrhea in children in eight low-resource settings

Background

The application of molecular diagnostics has identified enteric group adenovirus serotypes 40 and 41 as important causes of diarrhea in children. However, many aspects of the epidemiology of adenovirus 40/41 diarrhea have not been described.

Methods

We used data from the 8-site Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project birth cohort study to describe site- and age-specific incidence, risk factors, clinical characteristics, and seasonality.

Results

The incidence of adenovirus 40/41 diarrhea was substantially higher by quantitative polymerase chain reaction than enzyme immunoassay and peaked at ∼30 episodes per 100 child-years in children aged 7–15 months, with substantial variation in incidence between sites. A significant burden was also seen in children 0–6 months of age, higher than other viral etiologies with the exception of rotavirus. Children with adenovirus 40/41 diarrhea were more likely to have a fever than children with norovirus, sapovirus, and astrovirus (adjusted odds ratio [aOR], 1.62; 95% CI, 1.16–2.26) but less likely than children with rotavirus (aOR, 0.66; 95% CI, 0.49–0.91). Exclusive breastfeeding was strongly protective against adenovirus 40/41 diarrhea (hazard ratio, 0.64; 95% CI, 0.48–0.85), but no other risk factors were identified. The seasonality of adenovirus 40/41 diarrhea varied substantially between sites and did not have clear associations with seasonal variations in temperature or rainfall.

Conclusions

This study supports the situation of adenovirus 40/41 as a pathogen of substantial importance, especially in infants. Fever was a distinguishing characteristic in comparison to other nonrotavirus viral etiologies, and promotion of exclusive breastfeeding may reduce the high observed burden in the first 6 months of life.

Prevalence of enteric adenovirus and co-infection with rotavirus in children under 15 years of age with gastroenteritis in Qom, Iran

AIM

The current study is the first performed in Qom to determine the prevalence of adenovirus and co-infections with rotavirus in children aged <15 years with gastroenteritis symptoms.

BACKGROUND

Gastroenteritis-associated viral infections are a cause of death among young children worldwide, especially in developing countries. The Adenovirus species F (40 and 41) are responsible for a range of acute diarrhea cases among infants and children.

METHODS

Over a period of 9 months, a total of 130 children suffering from intestinal problems who referred to the infectious ward of Children's Hospital were enrolled in the current study. After clinical examination and collection of demographic information, fecal samples were obtained from the patients. Viral genomes were extracted with a commercial kit and amplified and typed by adenovirus-specific PCR assay. Adenovirus-positive samples were also evaluated for co-infection with rotavirus.

RESULTS

Patients had a mean±SD age of 2.66±2.72 years; 63.1% of patients were male and 36.9% were female. Adenovirus infection was identified in 23 cases (17.7%), 21 (91.0%) and 2 (9.0%) of which were type 41 and type 40, respectively. Fever was the most common clinical manifestation among adenovirus-positive patients. No significant difference was observed between adenovirus infection and clinical symptoms, seasonal pattern, or serum laboratory results. Co-infection was found in only 5 cases (21.7%).

CONCLUSION

This study was the first to demonstrate adenovirus infection with a relatively high prevalence among children, especially infants, in Qom. The findings further revealed co-infection with rotavirus, indicating a health problem in this region.

Enteric adenovirus epidemiology from historical fecal samples in Brazil (1998-2005): Pre-rotavirus vaccine era

Human adenovirus (HAdV) is recognized as frequent cause of acute gastroenteritis and enteric viruses can be preserved in frozen stored feces for long periods of times. The purpose of the present study was to investigate enteric HAdV genotypic diversity in archival fecal specimens stored from 1998 to 2005 in order to understand the natural history of HAdV in diarrheal patients in Brazil before rotavirus vaccine introduction. A total of 3346 specimens were tested for HAdV using conventional PCR. Genotypes were identified by sequencing. HAdV was detected in 6.8% (228/3346). Positivity was higher in children ≤ 5 years and males (p < 0.05). HAdV was most frequently observed during winter and spring seasons (p < 0.05). HAdV-F41 was the most prevalent genotype (59.2%;135/228), followed by HAdV-F40 (16.2%;37/228), HAdV-C1 (5.2%;12/228), HAdV-C2 (5.2%;12/228), HAdV-C5 (3.1%;7/228), HAdV-A12 (1.3%;3/228), HAdV-E4 (0.9%;2/228), HAdV-B3 (0.9%;2/228) and HAdV-B21 (0.4%;1/228). In 7.6% (17/228) only species D could be defined. HAdV-E4 strains were phylogenetic analyzed and classified as lineage (a)-like PG II. HAdV prevalence remained stable in Brazilian population, regardless rotavirus vaccine introduction. The predominant HAdV genotypes detected did not change over time, highlighting a high diversity of circulating strains in the country throughout decades. Due to the historical lack of HAdV genotyping surveillance in Brazil, HAdV-E4 epidemiology is virtually unknown in the country. The present study contributed significantly to the understanding of the natural history of HAdV in diarrheal patients in Brazil. The acquired data are important for clinical diagnosis, particularly for studies investigating enteric viruses' prevalence and molecular epidemiology of archival clinical specimens.

Genetic characterization and phylogenetic variations of human adenovirus-F strains circulating in eastern India during 2017-2020

Human adenovirus-F (HAdV-F) (genotype 40/41) is the second-most leading cause of pediatric gastroenteritis after rotavirus, worldwide, accounting for 2.8%-11.8% of infantile diarrheal cases. Earlier studies across eastern India revealed a shift in the predominance of genotypes from HAdV41 in 2007-09 to HAdV40 in 2013-14. Thus, the surveillance for HAdV-F genotypes in this geographical setting was undertaken over 2017-2020 to analyze the viral evolutionary dynamics. A total of 3882 stool samples collected from children (≤5 years) were screened for HAdV-F positivity by conventional PCR. The hypervariable regions of the hexon and the partial shaft region of long fiber genes were amplified, sequenced, and phylogenetically analyzed with respect to the prototype strains. A marginal decrease in enteric HAdV prevalence was observed (9.04%, n = 351/3882) compared to the previous report (11.8%) in this endemic setting. Children <2 years were found most vulnerable to enteric HAdV infection. Reduction in adenovirus-rotavirus co-infection was evident compared to the sole adenovirus infection. HAdV-F genotypes 40 and 41 were found to co-circulate, but HAdV41 was predominant. HAdV40 strains were genetically conserved, whereas HAdV41 strains accumulated new mutations. On the basis of a different set of mutations in their genome, HAdV41 strains segregated into 2 genome type clusters (GTCs). Circulating HAdV41 strains clustered with GTC1 of the fiber gene, for the first time during this study period. This study will provide much-needed baseline data on the emergence and circulation of HAdV40/41 strains for future vaccine development.

Molecular analysis of human adenoviruses in hospitalized children <5 years old with acute gastroenteritis in Tehran, Iran

Human adenoviruses (HAdVs), especially AdV-40 and 41, are common causes of nonbacterial sporadic and outbreak gastroenteritis in children. The present study aimed to describe the frequency and genetic analysis of HAdVs in hospitalized children <5 years old with acute gastroenteritis. A total of 376 stool samples obtained from June 2015 to December 2017 were investigated for the presence of HAdVs by polymerase chain reaction. The HAdV DNA was detected in 16 (4.3%) out of 376 stool samples. Based on the hexon hypervariable region (HVR), B, C, and F HADV species including five types HAdV-1, 2, 3, 6, and 41 were identified, among which enteric AdV species F (EAdV-41) was the most dominant. Moreover, our findings showed the presence of genomic type cluster 1 (GTC1) pattern in Iranian type 41 strains, which was closely similar to the D1 prototype strain (Tak) and D28. In this regard, a recombination was found in AdV-41 strains presenting the hexon sequence that belonged to GTC1, while fiber sequence clustered with GTC2.

Detection of enteric- and non-enteric adenoviruses in gastroenteritis patients, Bangladesh, 2012-2015

Human adenoviruses (HAdVs) are common cause of nonbacterial acute gastroenteritis worldwide. Limited data exist on HAdVs molecular epidemiology associated with acute gastroenteritis in Bangladesh. We describe the genetic diversity and epidemiology of HAdVs among hospitalized diarrhea patients, including HAdV genotypes, clinical symptoms, and co-infecting enteric pathogens. Stool samples were collected from ongoing diarrhea surveillance during 2012-2015. HAdV was detected using PCR and genotyped by sequencing and phylogenetic analysis. Detailed socio-demographic and clinical information regarding each individual was recorded such as duration of diarrhea, dehydration status, vomiting, abdominal pain, fever, and severity. Of 871 fecal specimens, HAdV DNA was detected in 93 (10.7%). Among them 56% were co-infected with other known enteric viral and bacterial pathogens and 31.6% had severe gastroenteritis. The majority (55%) of HAdV positives were children <5 years of age. Two main clinical symptoms in HAdV infected patients were diarrhea and vomiting. HAdVs were detected throughout the year with low prevalence in winter (November-January). Five HAdV species (A, B, C, D, and F) including 17 different genotypes were identified during the study period, with enteric HAdV species F (HAdV-40/41) being the most dominant. However, non-enteric HAdV were also detected in substantial proportion of specimens (15% species C, 15% species D, 10.8% species A, and 4.3% species B). Our study demonstrates high genetic diversity of HAdVs including enteric and non-enteric HAdVs among diarrhea patients and provides a foundation for further clarification of the role of non-enteric HAdVs in diarrheal diseases.

Molecular characterization of enteric adenovirus genotypes 40 and 41 identified in children with acute gastroenteritis in Kolkata, India during 2013-2014

Human enteric adenovirus (HAdV) belonging to species F is one of the most common pathogens responsible for infantile gastroenteritis worldwide. This study was initiated to estimate prevalence and types of HAdV among children below 5 years of age seeking health care facility for treatment of diarrhea in Kolkata, Eastern India. A total of 1,562 stool specimens were tested during 2013-2014 and among them, 185 (11.8%) were positive for enteric HAdV. Maximum number of positive cases were observed among children between 6 and 12 months of age (13.9%). HAdV infection occurred at a low frequency throughout the year, with an increased incidence in the month of March-July in both the years. Among HAdV positive samples (n = 185), 44.8% showed coinfection with rotavirus. Genotyping based on hypervariable region of hexon and partial shaft region of fiber genes, revealed prevalence of HAdV-40 over HAdV-41 genotype during this study period. Nucleotide sequence analysis of HAdV-40 strains exhibited more than 99% similarity among themselves and 98.5% with the prototype strain Dugan. Sequence analysis of six hypervariable regions (HVRs) of hexon genes from all the HAdV-41 strains revealed co-circulation of both genome type cluster 1(GTC1) and GTC2. The presence of both types of GTCs reflects accumulation of amino acid (aa) mutations in HVR of hexon gene. A recombination event was evident in a subset of HAdV-41 strains where hexon gene belonged to GTC1 whereas, fiber gene clustered with GTC2. Sequence analysis of fiber gene shaft region of HAdV-41 strains revealed 15 aa deletion from the 15th repeat motif. J. Med. Virol. 89:606-614, 2017. © 2016 Wiley Periodicals, Inc.

Prevalence of Nosocomial Diarrhea Due to Adenoviruses 40 and 41 in a Paediatric Ward in Iran

BACKGROUND

Enteric adenoviruses 40 (Ad40) and adenovirus 41 (Ad41) have been shown to be a significant cause of paediatric gastroenteritis worldwide, but no data are available for nosocomial diarrhea due to adenovirus in Iran.

AIM

The present study was performed to determine the incidence of Ad40 and Ad41 in children less than five years with nosocomial diarrhea in Shahrekord, southwest Iran.

MATERIALS AND METHODS

Adenovirus was detected by polymerase chain reaction (PCR) in stool samples collected during one year (2010-2011) from children less than five years with nosocomial diarrhea admitted to a paediatric center in Shahrekord, Iran. Nosocomial diarrhea was defined as those occurring more than 72 hours after admission to hospital for non-diarrheal causes. PCR technique was used for investigation of Ad40 and Ad41.

RESULTS

In total of 100 samples, Ad40 and Ad41 DNA was found to be positive in 14/100 (14%), and 8/100 (8%) of diarrheic patients less than five years, respectively.

CONCLUSION

Ad40 and Ad41 are important causes of nosocomial diarrhea in less than five-year, hospitalized Iranian children.

Molecular Epidemiology of Enteric Adenovirus Gastroenteritis in under-Five-Year-Old Children in Iran

Background. Acute gastroenteritis is one of the major sources of morbidity and mortality among young children in developed and developing countries. The aim of this study was to determine the prevalence of human adenovirus- (HAdV-) 40 and HAdV-41 in children hospitalized with gastroenteritis in five different health centers of Iran. Methods. In a cross-sectional epidemiological study, we studied 2682 fecal specimens that were collected from children under the age of 5 years in five educational and therapeutic pediatric centers in Iran from February 2012 to February 2013. Samples were tested for HAdV-40 and HAdV-41, using a specific pair of primers in polymerase chain reaction (PCR) method. Results. HAdV-40 and HAdV-41 were detected in 132 (5.18%) of the patients with diarrhea. A significantly higher prevalence of HAdV-40 and HAdV-41 (58.3%) was observed in children under 12 months of age, compared to other age groups. The male to female ratio was 1.7. Conclusion. The results of this study demonstrated that HAdV-40 and HAdV-41 could be considered etiological agents for acute gastroenteritis among children in Iran. The PCR as a rapid test may increase the chance for a relatively mild course of the disease followed by a complete recovery and avoiding administration of unnecessary antibiotics.

Characteristics of rotavirus diarrhea in hospitalized children in kosovo

BACKGROUND

Diarrhea is a leading cause of child mortality worldwide. Rotavirus is one of the most common causes of severe diarrhea and dehydration in children. Authors reviewed epidemiological and clinical data of the rotavirus diarrhea in Kosovo.

METHODS

This is a prospective study carried between January 1st and December 31st 2011. All data, comprising demographics, nutrition, clinical presentation, laboratory findings, management and outcome of the rotavirus diarrhea are collected on the specially designed form.

RESULTS

116 children with rotavirus diarrhea are included in the study. The majority boys (74.4%) and children aged 0 - 12 months (82.75%). Mean age of children in the study was 16.38 months. Almost every third child in the study was hypotrophic (29.2%). More than half of the infants (55.2%) were on mixed food, somewhat more than every third was breast feeding (36.45%), and every twelfth (8.33%) was on artificial milk (animal or formula). Apart from diarrhea, present in all patients, vomiting (97.41%) and fever (43.96%) were characteristics of the clinical presentation of the diarrhea. Two thirds of the children had mild grade dehydration (70.7%). All patients recovered with no sequels.

CONCLUSION

Rotavirus continues to be responsible for a significant portion of acute diarrhea in Kosovo. Clinical features, epidemiological data and the agglutination test are safe enough to establish the diagnosis. Treated correctly rotavirus diarrhea has a favorable outcome.

Waterborne Viral Gastroenteritis: An Introduction to Common Agents

Acute gastroenteritis is among the most common illnesses of human beings, and its associated morbidity and mortality are greatest among those at the extremes of age; children and elderly. During the 1970s, several viruses were associated with this syndrome, which are now known to be caused mainly by viruses belonging to four distinct families—rotaviruses, caliciviruses, astroviruses, and adenoviruses. Other viruses, such as the toroviruses, picobirnaviruses, coronavirus, and enterovirus 22, may play a role as well. Transmission by food or water has been documented for astroviruses, caliciviruses, rotaviruses, and norovirus. In developing countries, gastroenteritis is a common cause of death in children <5 years, while deaths from diarrhea are less common, much illness leads to hospitalization or doctor visits. Laboratory confirmation of waterborne illness is based on demonstration of virus particles or antigen in stool, detection of viral nucleic acid in stool, or demonstration of a rise in specific antibody to the virus. Newer methods for syndrome surveillance of acute viral gastroenteritis are being developed like multiplex real-time reverse transcriptase PCRs. Application of these more sensitive methods to detect and characterize individual agents is just beginning, but has already opened up new avenues to reassess their disease burden, examine their molecular epidemiology, and consider new directions for their prevention and control through vaccination, improvements in water quality, and sanitary practices.

Molecular Epidemiology of Adenovirus Infection among Pediatric Population with Diarrhea in Asia

A total of 3,577 fecal specimens from infants and children with acute gastroenteritis in Japan, Korea and Vietnam during 1998 and 2001 were tested for adenovirus by the ELISA method. Of these, adenovirus was detected in 158 (4.4%). The detection rate of adenovirus was highest in Korea (8.7%, 20/231) followed by 5.0% (100/1,991) in Japan and 2.8% (38/1,355) in Vietnam. All adenoviruses were further serotyped by PCR-RFLP. The diversity of adenovirus serotypes including Ad2, 3, 5, 8, 31, 40 and 41 was demonstrated. Worth of note was a decrease in the rate of isolation of Ad40 (7.6%, 12/158) and a concomitant increase of Ad41 (63.9%, 101/158) to become the predominant serotype. Another interesting feature of the study was the presence of Ad3 (4.0% and 30%) and Ad8 (8.0% and 20%) in Japan and Korea, respectively, which is mainly associated with keratoconjunctivitis worldwide. Our result underscored the importance of adenovirus in association with acute gastroenteritis in Asian countries.

Detection and molecular characterization of adenoviruses in Korean children hospitalized with acute gastroenteritis

Human adenoviruses (HAdVs) are an important cause of acute gastroenteritis in children. However, few studies on the epidemiology or types of HAdVs associated with acute gastroenteritis have been conducted in Korea. Therefore, in the present study, the incidence of HAdV in 2064 stool samples from Korean children hospitalized with acute gastroenteritis (2004-2006) was assessed and the types of viruses present determined. Polymerase chain reaction, sequencing, and phylogenic analyses revealed that 113 samples (5.5%) were HAdV-positive. While HAdVs were mainly detected during July to October, no seasonal difference between the enteric and non-enteric viruses in the incidence of HAdV was observed. HAdV-41 and HAdV-40 were found in 54 (47.8%) and 3 (2.6%) HAdV-positive samples, respectively. HAdV-3, HAdV-7, HAdV-2, HAdV-31, HAdV-4, and HAdV-37 were detected in 11 (9.7%), 5 (4.4%), 2 (1.7%), 2 (1.7%), 1 (0.8%), and 1 (0.8%) of sample(s), respectively. Thus, not only enteric, but also non-enteric, HAdVs may play an important role in acute gastroenteritis in Korean children.

Circulation of a novel pattern of infections by enteric adenovirus serotype 41 among children below 5 years of age in Kolkata, India

Human adenovirus of strains subgenus F (AdV F) are the most common strains detected in acute gastroenteritis cases in developing countries. Subgenus F is represented by AdV serotype 40 (AdV-40) and AdV-41. Most of the reports have described the predominance of AdV-41 in acute gastroenteritis cases. To gain insight into the epidemiology and genetic variation of AdV-41 strains, we analyzed 1,053 stool specimens from children with diarrhea. Among them, 42 (4.0%) and 56 (5.3%) were positive for enteric adenovirus 40/41 by enzyme-linked immunosorbent assay (ELISA) and PCR, respectively. For 1,305 asymptomatic children, 9 (0.7%) and 22 (1.7%) samples were positive for enteric adenovirus 40/40 by ELISA and PCR, respectively. The age distribution revealed a higher frequency (90%) in children <24 months of age. AdV F infection was observed at a low frequency throughout the year, with an increased incidence occurring during February and March. Sequence analysis of one to three hypervariable regions (HVRs) of the hexon genes of 16 representative AdV-41 strains in this study confirmed circulation of a unique strain with genomic type cluster 1 (GTC1)/GTC2. However, sequence analysis of the fiber genes of these strains confirmed 15 amino acid deletions from the 15th repeat motif of the shaft region. The existence of two GTCs reflects the accumulation of amino acid mutations in the HVR of the hexon gene. The novel AdV-41 strain might follow the same infection pattern as AdV-40. There is no significant variation in the sequences of hexon and fiber genes among strains from symptomatic and asymptomatic children. Our data confirm the circulation of an AdV-41 strain with a novel pattern in Kolkata, India, among children below 5 years of age.

Molecular epidemiology of human astrovirus and adenovirus serotypes 40/41 strains related to acute diarrhea in Tunisian children

Human astrovirus (AstV) and adenovirus types 40 and 41 (AdV 40/41) are responsible for epidemic and endemic acute gastroenteritis in children and adults. The present study was designed to evaluate the prevalence and genetic diversity of enteric viruses in children in Tunisia. A total of 788 fecal samples were collected during a 4-year period in the region of Monastir, from children under 12 years old, hospitalized or presenting in dispensaries with symptoms of acute gastroenteritis. AstV and AdV40/41 were detected by immunoenzymatic methods and confirmed by PCR/RT-PCR and sequence analysis. Phylogenetic analyses were performed for nucleotide homology with reference strains. AstV and AdV40/41 were characterized as a causative agent in 28 (3.6%) and 18 (2.3%) of the fecal samples, respectively. Phylogenetic analysis showed that the AstVs belonged to the serotypes 3 (n = 4; 14.3%) and 1 (n = 24; 85.7%), and the enteric AdVs to the serotypes 40 (n = 1; 5.6%) and 41 (n = 17; 94.4%). This is the first report that describes the molecular epidemiology of AstV and AdV40/41 in Tunisian children. Their respective detection rate was very low, far below that of rotavirus and norovirus. The genetic diversity among these two viruses is relatively limited and varies depending on the area.

Maternal experiences of intimate partner violence and child morbidity in Bangladesh: evidence from a national Bangladeshi sample

OBJECTIVE

To provide an estimate of the risk of recent acute respiratory tract infection (ARI) and diarrhea among children 5 years and younger based on recent violence against their mothers.

DESIGN

The 2004 Bangladesh Demographic Health Survey, conducted from January 1 to May 31, 2004.

SETTING

Selected urban and rural areas of Bangladesh.

PARTICIPANTS

A total of 1592 women currently married, with at least 1 child 5 years of age or younger, each living with her husband and child(ren). Main Exposure Intimate partner violence (IPV) against women. Outcomes Measures The prevalence of past-year IPV was calculated. The risk of ARI and diarrhea within the past 2 weeks among young children was determined based on maternal experiences of IPV within the past year via analyses adjusted for demographics and environmental risks.

RESULTS

More than 2 of 5 married Bangladeshi mothers (42.4%) with children aged 5 years and younger experienced IPV from their husbands in the past year. Mothers who experienced IPV were more likely to report recent ARI (adjusted odds ratio, 1.37; 95% confidence interval, 1.03-1.83) and diarrhea (adjusted odds ratio, 1.65; 95% confidence interval, 1.15-2.38) among their young children compared with those who did not experience IPV.

CONCLUSIONS

Large numbers of married Bangladeshi women with young children experience IPV. Associations of maternal experiences of IPV with 2 leading causes of childhood mortality strongly suggest that such abuse threatens not only the health of women but also that of their children. Prevention of IPV perpetration by men may be critical to the improvement of maternal and child health.

Aetiology of acute gastro-enteritis in children at Saint Camille Medical Centre, Ouagadougou, Burkina Faso

The present study aims at identifying the infectious agents responsible for child Acute GastroEnteritis (AGE) in Ouagadougou. From May 5 2006 to June 22 2008, 648 children aged from 2 to 41 months, with at least an average of 3 loose stools per day have been enrolled for coproculture, parasitology and virology test. Among them, 34 (5.25%) were HIV seropositive. A single sample of faeces from each child was used to identify enteropathogens. An infectious aetiology was identified in 41.20% of cases. The pathogenic agents detected as responsible for the AGE are: Rotavirus 21.1%; Adenovirus 1.9%; Giardia 7.6% Entamoeba; 1.08%; entero-pathogenic E. coli 41.7%; Salmonella 3.40%; Shigella 1.85% and Yersinia 1.70%.

CONCLUSION

Therefore, these AGE etiologic agents constitute a problem of public health in Burkina Faso. Their control for the child would require: (1) a regular paediatric and clinical follow up; (2) health education of the population for food hygiene and (3) in case of absence of HIV infection in the mother, a promotion of exclusive breast-feeding up to the age of 4 months.

Age and gender specific prevalence of HTLV-1

BACKGROUND

The seroprevalence of Human T-cell Leukemia Virus Type 1 (HTLV-1) is female predominant despite the higher incidence of Adult T-cell Leukemia (ATL) in males. If the mother-to-child transmission of HTLV-1 is more common for male infants than in female infants, longer exposure to the virus for males may explain the paradoxically higher incidence of ATL.

OBJECTIVES

To test the hypothesis that the seroprevalence of HTLV-1 is male predominant during adolescence.

STUDY DESIGN

The presence of HTLV-1 antibody in 272,043 blood samples donated to a regional blood bank in an HTLV-1 high-endemic region was assessed.

RESULTS

The entire population of female donors had a significantly higher seroprevalence compared to males (2.05% and 1.80%, respectively, p<0.0001). However, compared with male donors, the carrier rate for female donors was lower for the youngest subgroup (16-19 years, p=0.0011); was similar for the next two age subgroups (20-29 years and 30-39 years); and was significantly higher for the last two age subgroups (40-49 years and over 50-64 years, both p<0.0001). In general, older age subgroups led to higher seroprevalence in both genders.

CONCLUSIONS

HTLV-1 infection is more common for males until after age 20, when male to female sexual transmission becomes likely. This suggests that mother-to-child transmission is more common for males.

Molecular epidemiology of adenovirus infection among infants and children with acute gastroenteritis in Dhaka City, Bangladesh

A total of 917 fecal specimens collected from infants and children with acute gastroenteritis in Dhaka City, Bangladesh during 2004-2005 were examined for the presence of adenoviruses by PCR. Adenoviruses were identified in 17 of 917 (1.9%) specimens. Detected adenoviruses were subjected to molecular genetic analysis by sequencing method. Adenoviruses detected in this study were classified into three serotypes, namely Ad9, Ad10 and Ad40. Of these, Ad40 was predominant, followed by Ad9 and accounted for 42% (7 of 17) and 36% (6 of 17), respectively. This is the first report of acute gastroenteritis attributed to Ad9 and Ad10 in Dhaka City, Bangladesh. Another interesting feature of the study was absence of Ad41 serotype. Our results clearly indicated that adenovirus infections were most commonly observed in winter season (October 2004 through January 2005) and in rainy season (May 2005 through July 2005) in Dhaka City. The most common clinical symptoms of adenovirus-infected patients were dehydration (94%), abdominal pain (59%) and vomiting (30%). To our knowledge, this is the first 1-year molecular epidemiological research of adenovirus infection in Bangladesh.

Prevalence of rotavirus, adenovirus and enteric parasites among pediatric patients attending Saint Camille Medical Centre in Ouagadougou

The present study carried out in the Saint Camille Medical Centre of Ouagadougou and related to the prevalence of Rotaviruses, Adenoviruses and enteric parasites infections among HIV-seropositive and HIV-seronegative children allowed to include 66 children aged from 2 to 60 months presenting acute diarrhea. The results revealed that 10.60% were infected by HIV. Stool samples analysis by direct microscopy and immunochromatographic tests (Rota-strip and Adeno-strip) showed 42.42% of global infections, among these, 18.18% parasitic infections and 24.24% viral infections, predominantly rotaviruses (22.73 and 1.52% for Rotaviruses and Adenoviruses, respectively). Among parasitic infections, Protozoan were most common than Helminthes (12.12% versus 6.06%). According to present results, Rotaviruses appeared as the major etiological agents in children aged from 2 to 11 months. However high rate of protozoan and helminthes was found in children aged from 12 to 60 months. Thus, virus, particularly Rotavirus must be painstaking as the principal etiologic agent of infant diarrhea in our country.

Adenoviruses associated with acute gastroenteritis in hospitalized and community children up to 5 years old in Rio de Janeiro and Salvador, Brazil

Acute gastroenteritis is a major source of morbidity and mortality among young children in developed and developing countries. Human adenoviruses (HAdVs), and in particular species F, are related to childhood diarrhoea worldwide. This study presents the results obtained during an investigation of HAdVs causing acute gastroenteritis in children hospitalized in Rio de Janeiro, RJ, Brazil, from April 1996 to September 2003, as well as in children with diarrhoea living in the slums of Salvador, BA, Brazil, from October 2001 to September 2003. A total of 3060 stool samples was analysed by an enzyme immunoassay for rotavirus and adenovirus (EIARA) and 61 (2%) were found to be positive. HAdV presented with low prevalence throughout the year, with a slight but not significant increase in incidence in late summer and early autumn. Children up to 2 years of age were the most frequently affected (79% of all positive samples). All positive samples were analysed further by generic and species-specific HAdV PCR protocols, confirming 100% specificity of this rapid and inexpensive EIARA. Species F was the most prevalent (65%), despite the occurrence of species A (12%), C, D and co-infection F/D (5% each) and species B and co-infections F/A, F/C and B/D (2% each). In order to type the species F strains as HAdV-40 or -41, generic PCR and a HinfI restriction digest were performed. HAdV-40 and -41 were found to represent 62% (23/37) and 38% (14/37), respectively. These results demonstrated that a combination of generic and species-specific PCRs is useful and reliable for HAdV species and type identification directly from faecal specimens. The results confirmed the endemism of human adenoviruses, mainly species F, in children as aetiological agents of diarrhoea, although the limited sensitivity of EIARA as a screening method may have underestimated their prevalence.

An outbreak of adenovirus serotype 41 infection in infants and children with acute gastroenteritis in Maizuru City, Japan

A total of 337 fecal specimens were collected from infants and children with acute gastroenteritis in Maizuru City, Japan from July 2004 to June 2005 and tested for the presence of rotavirus, norovirus, sapovirus, astrovirus, and adenovirus by RT-multiplex PCR. Among diarrheal viruses detected, norovirus was the most prevalent (13.6%, 46 of 337), followed by adenovirus (8%, 27 of 337), group A rotavirus (5%, 17 of 337), astrovirus (1.8%, 6 of 337), and sapovirus (1.8%, 6 of 337), respectively. Adenovirus was subjected to molecular genetic analysis by sequencing. Adenovirus detected in this study was classified into five serotypes, namely Ad1, Ad2, Ad3, Ad5, and Ad41. Of these, Ad41 was the most predominant serotype that accounted for 85.2% (23 of 27). It was noteworthy to point out that Ad41 infection was apparently confined only to the period of 4 months (October 2004 through January 2005). This pattern of infection implied the outbreak of Ad41 in these subjects, which was the first outbreak of acute gastroenteritis attributed to adenovirus in Maizuru City, Japan. Another interesting feature of the study was the existence of two Ad41 subtypes co-circulating in this outbreak. This report confirmed the presence of adenovirus as one of an important cause of acute gastroenteritis among Japanese infants and children.

Prevalence and characterization of enteric adenoviruses in the South of Ireland

Enteric adenoviruses have been shown to be a substantial cause of pediatric gastroenteritis in various parts of the world, and are considered to be the second most common cause of viral gastroenteritis, next to rotavirus in young children. Genetic characterization of 95 adenovirus isolates obtained from patients with acute gastroenteritis between 2002 and 2007 from the southern regions of Ireland, were characterized by PCR analysis, restriction endonuclease (RE) analysis and sequencing analysis. All isolates were found to be of adenovirus type 41 origin. Genetic analysis of seven hypervariable regions (HVRs) located within the hexon gene has revealed a high level of amino acid sequence homology in samples over the course of this study, with a very close relationship to the D22 genome type. The D22 genome type has been detected in several other countries, thus suggesting Irish isolates have common genome types with other stains worldwide. This is the first such study undertaken in the south of Ireland, to type and genetically characterize adenoviral gastroenteritis isolates, and has revealed a high level of conservation within the isolated analyzed.

Molecular epidemiology of subgenus F adenoviruses associated with pediatric gastroenteritis during eight years in Hiroshima Prefecture as a limited area

We have studied the prevalence of the subgenus F adenoviruses and the molecular characteristics of adenovirus type 41 in Hiroshima Prefecture, Japan, as a limited area during the period of 1997-2004. Subgenus F adenoviruses were detected in 30 (3.4%) of 892 fecal specimens by enzyme immunoassay (EIA), and 80.0% (24 of 30) of positive patients were <36 months old. One (3.3%) and 29 (96.7%) of the 30 EIA-positive specimens were adenoviruses type 40 (Ad40) and 41 (Ad41), respectively. The genomes of Ad41 strains amplified by PCR were divided into two genomic type clusters (GTC1 and GTC2) based on the hexon gene as described by Li et al. (J Clin Microbiol 42: 4032-4039, 2004.). Twenty-one (95.5%) of 22 Ad41 strains detected between 2000 and 2004 belonged to GTC1, whereas all seven strains detected between 1997 and 1999 belonged to GTC2. These genomic typings were the same for the hexon and fiber genes except for one strain. This strain contained a hexon gene belonging to GTC1 and a fiber gene belonging to GTC2 and was considered to be a recombinant between adenoviruses of these types.

Characterizations of adenovirus type 41 isolates from children with acute gastroenteritis in Japan, Vietnam, and Korea

Genetic and antigenic characterizations of 70 strains of adenovirus type 41 (Ad41), isolated between 1998 and 2001 from children in Japan, Vietnam, and Korea, were done by DNA restriction enzyme (RE) analysis, sequencing analysis, and monoclonal antibody (MAb)-based enzyme-linked immunosorbent assay (ELISA). Eight genome types were observed in the present study, among which D25, D26, D27, and D28 were novel genome types. These eight genome types were divided into two genome-type clusters (GTCs) based on phylogenetic analysis of the hypervariable regions (HVRs) of the hexon. GTC1 includes D1, D25, D26, D27, and D28, and the GTC2 contains D4, D12, and D22. The amino acid homologies among the members within a GTC were 97 to 100%, whereas between the members of different GTCs the homologies were 92 to 94%. The specificity of the GTC classification was confirmed by ELISA with MAb 1F, which was selected by the Ad41 prototype Tak strain. It was found that only the isolates of GTC1 but not of GTC2 reacted with MAb 1F. These results suggest that Ad41 isolates from the three countries should be classified into two subtypes. The accumulation of amino acid mutations located in HVRs of hexon are indicative for the classification of Ad41 subtype.

Viruses causing gastroenteritis

Acute gastroenteritis is one of the most common diseases in humans worldwide. Viruses are recognized as important causes of this disease, particularly in children. Since the Norwalk virus was identified as a cause of gastroenteritis, the number of viral agents associated with diarrheal disease in humans has steadily increased. Rotavirus is the most common cause of severe diarrhea in children under 5 years of age. Astrovirus, calicivirus and enteric adenovirus are also important etiologic agents of acute gastroenteritis. Other viruses, such as toroviruses, coronaviruses, picobirnaviruses and pestiviruses, are increasingly being identified as causative agents of diarrhea. In recent years, the availability of diagnostic tests, mainly immunoassays or molecular biology techniques, has increased our understanding of this group of viruses. The future development of a safe and highly effective vaccine against rotavirus could prevent, at least, cases of severe diarrhea and reduce mortality from this disease.

Enteropathogens associated with acute diarrhea in community and hospital patients in Jakarta, Indonesia

The prevalence of bacteria, parasite and viral pathogens in 3875 patients with diarrhea in community and hospital settings from March 1997 through August 1999 in Jakarta, Indonesia was determined using routine bacteriology and molecular assay techniques. Bacterial pathogens isolated from hospital patients were, in decreasing frequency, Vibrio cholerae O1, Shigella flexneri, Salmonella spp. and Campylobacter jejuni, while S. flexneri, V. cholerae O1, Salmonella spp. and C. jejuni were isolated from the community patients. V. cholerae O1 was isolated more frequently (P<0.005) from the hospital patients than the community patients. Overall, bacterial pathogens were isolated from 538 of 3875 (14%) enrolled cases of diarrhea. Enterotoxigenic Escherichia coli were detected in 218 (18%) of 1244 rectal swabs. A small percentage of enterohemorrhagic E. coli (1%) and of Clostridium difficile (1.3%) was detected. Parasitic examination of 389 samples resulted in 43 (11%) positives comprising Ascaris lumbricoides (1.5%), Blastocystis hominis (5.7%), Giardia lamblia (0.8%), Trichuris trichiura (2.1%) and Endolimax nana (0.5%). Rotavirus (37.5%), adenovirus (3.3%) and Norwalk-like virus (17.6%) were also detected. Antimicrobial resistance was observed among some isolates. Bacterial isolates were susceptible to quinolones, with the exception of some isolates of C. jejuni which were resistant to ciprofloxacin, nalidixic acid and norfloxacin. Data obtained from this community- and hospital-based study will enable the Indonesian Ministry of Health to plan relevant studies on diarrheal diseases in the archipelago.

Incidence of enteric adenovirus gastroenteritis in Iranian children

BACKGROUND

Enteric adenoviruses, i.e. adenovirus 40 (Ad40) and adenovirus 41 (Ad41), have been shown to be a substantial cause of pediatric gastroenteritis in various parts of the world, but no data are available for Iran.

OBJECTIVE

The present study was performed to determine the incidence of enteric adenoviruses in children presenting to the Children's Medical Center with gastroenteritis in Iran.

STUDY DESIGN

Stool specimens from 872 children less than 7 years of age attending the Children's Medical Center in Tehran, Iran, with gastroenteritis were tested for the presence of Ad40, Ad41, and adenovirus-genus by a monoclonal antibody-based enzyme immunoassay.

RESULTS AND CONCLUSION

6.7% of stool specimens contained enteric adenoviruses (3.3% Ad40 and 3.4% Ad41) and 2.0% nonenteric adenoviruses. Mean ages of Ad40, Ad41 and NEAd-positive children were 21, 19 and 29 months, respectively. Among the adenovirus-positive patients, 53.9% were male and 46.1% female. Watery diarrhea was present in 86.4% of children infected by adenoviruses. In conclusion, for the first time, we demonstrated the presence of enteric and nonenteric adenoviruses in a considerable proportion of stool samples from Iranian children with gastroenteritis.

Prevalence of enteric adenoviruses among children with diarrhea in four Brazilian cities

BACKGROUND

Enteric adenoviruses are related to child diarrhea and appear to be spread worldwide.

OBJECTIVES

The aim of the present study was to determine the prevalence of enteric adenovirus infection among children in four Brazilian cities.

STUDY DESIGN

stool specimens were collected from children under 5 years of age with acute diarrhea.

RESULTS AND CONCLUSIONS

Enteric adenoviruses were detected in 1.55% (n=1420) of the samples analyzed indicating the circulation of these viruses among Brazilian children in association to diarrheal disease. These agents were isolated throughout the year demonstrating no specific seasonal distribution. Also, no pattern of serotype distribution between the cities was observed.

Case-control study of enteropathogens associated with childhood diarrhea in Dhaka, Bangladesh

The International Centre for Diarrhoeal Disease Research, Bangladesh, is a major center for research into diarrheal diseases. The center treats more than 100,000 patients a year. To obtain useful information representative of all patients, a surveillance system in which a 4% systematic sample of all patients is studied in detail, including etiological agents of diarrhea, was installed in October 1979. The first paper on etiology for the surveillance patients was published in 1982, which identified a potential enteric pathogen in 66% of patients. In subsequent years, several new agents of diarrhea have been identified. To assess the importance of a broader spectrum of diarrheal agents including the ones identified relatively recently, we studied 814 children with diarrhea. The children were up to 5 years of age and were part of the surveillance system. They were matched with an equal number of community controls without diarrhea. The study was conducted from February 1993 to June 1994. A potential enteric pathogen was isolated from 74.8% of diarrheal children and 43.9% of control children (P = 0.0001). Even though the first study was not a case-control study, it identified rotavirus, Campylobacter jejuni, enterotoxigenic Escherichia coli, Shigella spp. , and Vibrio cholerae O1 as major pathogens. The present study identified these pathogens as being significantly associated with diarrhea. In addition, the study also identified six additional agents, including enteropathogenic E. coli, Aeromonas spp., V. cholerae O139, enterotoxigenic Bacteroides fragilis, Clostridium difficile, and Cryptosporidium parvum, as being significantly associated with diarrhea. Plesiomonas shigelloides, Salmonella spp., diffusely adherent E. coli, enteroaggregative E. coli, Entamoeba histolytica, and Giardia lamblia were not significantly associated with diarrhea. Enteroinvasive E. coli, enterohemorrhagic E. coli, and Cyclospora cayetanensis were not detected in any of the children. The major burden of diseases due to most pathogens occurred in the first year of life. As in the previous study, seasonal patterns were seen for diarrhea associated with rotavirus, V. cholerae, and enterotoxigenic E. coli, and infections with multiple pathogens were common. With a few exceptions, these findings are in agreement with those from other developing countries. This knowledge of a broader spectrum of etiological agents of diarrhea in the surveillance patients will help us plan studies into various aspects of diarrheal diseases in this population.

Astrovirus infection in association with acute, persistent and nosocomial diarrhea in Bangladesh

BACKGROUND

Diarrhea is an important public health concern in developing countries such as Bangladesh. Diarrhea in children that persists for 14 days or more occurs in 7% of patients in Bangladesh and frequently results in death. Astrovirus has been demonstrated as a cause of acute and nosocomial diarrhea and can be excreted for prolonged periods, yet its importance as a cause of diarrhea among children in a developing country like Bangladesh has not been investigated.

METHODS

We tested 629 stool specimens from patients with acute diarrhea, 153 from patients with persistent diarrhea, 175 specimens from 76 patients hospitalized for diarrhea who were sampled repeatedly to detect nosocomial infection and 428 from nonhospitalized healthy children (controls). All children enrolled in the study were <5 years of age. Astrovirus was detected by enzyme immunoassay and other enteropathogens were detected by standard techniques.

RESULTS

The detection of astrovirus increased significantly with the duration of diarrhea. Astrovirus was found in 23 (15%) specimens from patients with persistent diarrhea, 26 (4%) patients with acute diarrhea, but only 8 (2%) healthy controls. This trend remained when we limited our analysis to infants <12 months of age and to episodes in which astrovirus was the sole pathogen. Among patients with nosocomial diarrhea, 16% of postadmission specimens were positive for astrovirus when the admission specimen was negative.

CONCLUSION

The observation that astrovirus is detected more frequently with diarrhea of increasing duration suggests the need for further studies to determine whether astrovirus plays a causative role in persistent diarrhea or is a secondary agent.

Non-seasonal viral and bacterial episode of diarrhoea in the Jordan Valley, West of Jordan

A non-seasonal diarrhoeal episode in the Jordan Valley occurred over a 2-month period, during which no traditional enteropathogens were detected by the health authority laboratories. A total of 17 diarrhoeal stool specimens from infants, young children and adults were randomly collected and delivered to our laboratories to investigate the presence of unusual aetiological agents. Stools were examined for parasites, ova, viruses and cultured for bacterial pathogens. A multiplex polymerase chain reaction was developed to investigate the involvement of diarrhoeagenic Escherichia coli in this episode. Recognised pathogenic organisms were detected in 8 out of 17 of the diarrhoeatic patients, one patient of whom had a mixed infection with two agents. Rotavirus, enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC) were found to be associated with the diarrhoea. EIEC was the most common enteropathogen detected (4 out of 17) followed by rotavirus (3 out of 17). One of the EIEC isolates detected in one patient was associated with rotavirus. The clinical features of the diarrhoeatic patients were remarkably similar, regardless of aetiology. This study reveals the identity of pathogenic agents that are not detected by traditional methods employed by the health authority laboratories, which emphasise the urgent need for developing the current diagnostic techniques.

The molecular epidemiological study on enteric adenovirus in stool specimens collected from Wuhan area by using digoxigenin labeled DNA probes

A summer-autumn (1994) molecular epidemiological study of enteric adenoviruses (EAds) in stool specimens collected in Wuhan area was conducted by using Digoxigenin-labelled DNA probes specific to EAd40 and EAd41 respectively. 44 of 602 specimens were positive, among which 23 cases were identified as EAd40, 14 were EAd41 infection and 7 were dual infection. The ratio of males to females for the positive specimens was 1. 44. The infection rate of EAd40 and EAd41 each displayed no marked difference in seasons (summer and autumn) and similar age distribution was found between them. All of the two types of EAds infections predominated in patients with diarrhea under 3 years old. The results indicated that the Digoxigenin probe could detect DNA quantities as low as 1 pg with satisfactory specificity and the technique can be used for both clinical and experimental purposes.

Detection of enteric adenoviruses 40 and 41 in stool specimens by monoclonal antibody-based enzyme immunoassays

To examine the role of enteric adenoviruses (Ad40 and Ad41) in children with acute gastroenteritis, we evaluated 273 children with diarrhoea and 137 without enteric symptoms in Palermo, Italy, during an 8-month period. Stools were tested by two home-made monoclonal-based ELISAs to detected genus-specific adenovirus antigen and to type Ad40 and Ad41. Twenty-five samples (6.1%) were found to contain adenovirus, 18 of which were grown in Graham 293 and in HEp-2 cells. Ad40 and Ad41 were detected in 2.6% of children with diarrhoea and in none in the control group, while non-enteric adenoviruses were obtained from both patients (3.2%) and controls (6.5%). Samples containing Ad40 and Ad41 were positive by the virus isolation procedure in Graham and in HEp-2 cells, showing no distinct growth pattern in these cell lines. The evaluation of a latex agglutination test (Adenolex) and of a commercial ELISA (Adenoclone), respectively available for the detection of genus adenovirus antigen and for the typing of Ad40 and Ad41 suggests that both tests enable the identification of enteric adenoviruses in stool specimens, giving results comparable to our ELISAs.

Demonstration of a lack of synergistic effect of rotavirus with other diarrheal pathogens on severity of diarrhea in children

The severity of group A rotavirus (RV) diarrhea was compared with that of mixed infections of RV with diarrheagenic Escherichia coli, Vibrio cholerae O1, and Shigella species by a scoring system. The severity of mixed infections of RV and E. coli was the same as that of infections with RV alone. RV infections mixed with V. cholerae and Shigella species mimicked cholera and shigellosis, respectively.

Previous enteric adenovirus infection does not protect against subsequent symptomatic infection: longitudinal follow-up of eight infants

Eight infants followed longitudinally were found to have enteric adenovirus (EAdv) infections: in 5 infants with diarrhea and in 3 with no accompanying diarrhea. Sequential stool samples prior to EAdv infections were tested for adenovirus antigen, anti-adenoviral IgA and neutralizing antibodies to serotypes 40, 41 and 2 in order to ascertain whether protection from symptoms was due to prior infection. No difference was found in the number of adenoviral infections among infants prior to their EAdv infections with or without accompanying diarrhea. However, in 3 of the 5 infants in whom EAdv infection was accompanied by diarrhea and 2 of 3 control infants, previous EAdv infections had occurred as detected by serotype-specific antibody rises.

Structural features unique to enteric adenoviruses

Enteric adenoviruses are important agents of pediatric gastroenteritis. Characterization of monoclonal antibodies against human adenovirus 41 (h-41) identified an epitope of interest on protein VI, an internal virion protein. The epitope is common to enteric adenoviruses (subgenus A: h-12, h-18, h-31 and subgenus F: h-40, h-41) but is not shared by non-enteric serotypes (subgenera B, C, D or E). By expressing random oligonucleotide fragments of the protein VI gene as T7 gene 10 fusion proteins in the pTope vector (Novagen), the epitope was mapped within the central domain of protein VI, to the region corresponding to aa 114-125 of the Ad2 protein. Identification of this epitope reflects the close evolutionary relationship of subgenus A and subgenus F adenoviruses and draws attention to structural features of enteric adenoviruses as potential determinants of tropism. Furthermore, this epitope may be valuable for identification of enteric adenoviruses in clinical specimens.

Adenovirus genome types isolated from stools of children with gastroenteritis in São Paulo, Brazil

In a prospective one-year study of acute gastroenteritis in hospitalized children less than 2 years of age, in São Paulo (Brazil), adenoviruses were detected by specific enzyme immunoassay (El-ARA) in 7 of 67 (10%) ill children and in 9 of 79 (11.4%) controls. They were the sole recognizable agent of diarrhea in 6 ill children. In another child these viruses were detected in a dual infection with astrovirus. Enteric adenoviruses (Ad40/41) were the most common serotypes detected in children with diarrhea (3/7) and Ad7 the serotype most detected in the controls (5/9), associated with lower respiratory tract infection. Thirteen adenovirus strains, isolated in HEp2 or HEK-293 cells, were characterized by seroneutralization and restriction enzyme analysis. The established adenoviruses were typed as AV-7-D5 (five associated to lower respiratory tract infection and one to diarrhea), AV-1-D10 (one diarrhea case), AV-31-D2 (two controls with respiratory infection), and two isolates as AV-12-D7, a new genome type. One subgenus D isolate, serotype 28, with restriction patterns different from those of the prototype, remained untyped. Only one enteric adenovirus could be typed. The restriction patterns of this isolated were similar to those of the prototype AV-41-D1. The genome type of the other three enteric adenoviruses could not be determined.

Patients with enteric adenovirus gastroenteritis admitted to an Australian pediatric teaching hospital from 1981 to 1992

During the period 1981 to 1992, 4,473 fecal specimens collected from children hospitalized with acute gastroenteritis at the Royal Children's Hospital, Melbourne, Australia, were examined by electron microscopy. A monoclonal antibody enzyme immunoassay for enteric adenovirus (EAd) types 40 (Ad40) and 41 (Ad41) was used when adenoviruses were visualized. Fecal samples were positive for adenovirus by both electron microscopy and enzyme immunoassay in 138 patients (3.1%). Ad40 was identified in 19 children (14%), and Ad41 was identified in 119 children (86%). These EAd were identified during each of the 12 years surveyed. EAd were present year-round, but the annual number of hospitalizations was not constant. Yearly prevalence varied from 0.7% (1981) to 6.5% (1985). This was associated with monthly fluctuations in Ad41 activity, with overall peak monthly prevalence in May (late autumn). By contrast, Ad40 numbers remained low and constant year-round. The frequency of Ad41 relative to Ad40 increased from 25% in 1981 to exceed 75% after 1983. Children admitted with EAd infection were more likely to have diarrhea for more than 5 days (P < 0.001) but less likely to be febrile or dehydrated (P < 0.05) than children with rotavirus infection. EAd are responsible for enteric symptoms of only a fraction of hospitalized children with infectious diarrhea but result in a more-protracted illness than rotavirus. Their relationship to persistent diarrhea requires further investigation.

Identification of adenoviruses in faeces from patients with diarrhoea at the Hospitals for Sick Children, London, 1989-1992

Faecal samples from 137 patients that had been shown to contain adenoviruses by electron microscopy were identified in a series of enzyme immunoassays (EIA) using a single monoclonal antibody (Mab) to adenovirus 40 and four different Mabs to adenovirus 41. Adenoviruses were partially characterised by restriction enzyme analysis (REA) of DNA extracts using SmaI. Samples were also run in a commercial EIA (Adenovirus IDEIA; Dako, Ltd.) which detects group antigen. The majority (84%) of adenoviruses were subgenus F: adenovirus type 41, 87 (64%) and adenovirus type 40, 28 (20.4%). Subgenus A viruses were identified in ten, (7%) patients, eight were type 31, and two type 12. The adeno IDEIA test was sensitive and specific, detecting 127 of 131 positives and giving no false-positive results with other enteric viruses. Use of monoclonal-based EIAs showed significant differences depending on which adeno 41 Mab was used, although the restriction patterns obtained using SmaI appeared to be identical for 66 of 69 samples that produced recognisable bands. The Mab that performed best, M 4.3.1, was raised against strains obtained from children in England and detected 83 of 84 (99%) of the adenovirus 41 samples tested. In contrast Mab JH/41 raised against the prototype strain of adenovirus 41 (Tak) detected only 69 of 87 (79%).