Adenovirus infection in children with diarrhea disease in Northwestern Nigeria

Severe lower respiratory tract infections are associated with human adenovirus in hospitalised children in a high HIV prevalence area

Background

Viral causes of lower respiratory tract infections (LRTIs) are associated with increased mortality in children aged <5 years (U5). Human adenovirus (HAdV) has been associated with severe LRTI; however, its relationship with HIV and malnutrition in South Africa (SA) is not understood.

Objectives

To identify the prevalence of and factors associated with HAdV LRTIs in hospitalised U5 childen.

Methods

Clinical and viral data on U5 children hospitalised with severe LRTI from January 2018 to June 2020 at King Edward VIII Hospital, Durban, SA, including results of a multiplex polymerase chain reaction (PCR) panel assay for respiratory viruses, were retrieved from inpatient files and laboratory databases and retrospectively analysed. Standard descriptive statistics and Pearson's χ², Fisher's exact and Mann-Whitney tests were used to determine significant associations with HAdV LRTI.

Results

Among the 206 viral assays analysed (15.6% of all LRTI admissions), HAdV was the most common virus identified. The cohort had a median (interquartile range) age of 5 (2 - 13) months, 47.3% had perinatal HIV exposure, and 34.5% had severe acute malnutrition (SAM). No seasonal pattern with HAdV could be demonstrated. SAM and prematurity were significant risk factors for readmission, and perinatal HIV exposure was a significant risk factor for presence of multiple viruses on analysis of a respiratory specimen. Detection of HAdV was not associated with an increased risk of requiring oxygen or ventilatory support.

Conclusion

HAdV was the most common virus found on analysis of multiplex PCR panel results in children hospitalised with severe LRTI in SA, where high rates of HIV exposure may result in increased susceptibility to viral co-infections. The role of HAdV as a cause of severe LRTI in SA infants, who have high rates of HIV exposure, requires greater scrutiny.

Study synopsis

What the study adds. This study provides retrospective data identifying human adenovirus (HAdV) as the most common cause of severe lower respiratory tract infection (LRTI) in children aged <5 years (U5). The impact of respiratory syncytial virus as a common pathogen in children is well established. The study confirms anecdotal evidence that HAdV is an important disease-causing pathogen associated with LRTI. Children with perinatal HIV exposure and severe acute malnutrition (SAM) may be particularly susceptible.Implications of the findings. HAdV must be considered a major cause of severe LRTI in U5 children. Children with LRTI who had perinatal HIV exposure and those with SAM need to be tested for HAdV and to be monitored for severe disease.

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.

Pathogenetic characteristics of infectious diarrhea in Yantai City, Shandong Province, 2018-2019

Background

Analysis of the pathogenic spectrum, epidemiological characteristics and molecular epidemiological features of important pathogens of infectious diarrhea in Yantai City, Shandong Province, 2018-2019, were analyzed to provide a reference basis for the prevention and control of infectious diarrhea.

Methods

A total of 1514 stool specimens were collected within 3 days of the onset of diarrhea in secondary or higher hospitals in Yantai from 2018-2019, and all specimens were tested for the presence of seven major viruses and three major bacteria by employing reverse transcription ploymeraer chain reaction (RT-PCR). Population and seasonal analyses were also performed on positive samples for infectious diarrhea. The top two ranked rotavirus and norovirus were focused on genotyping and analysis of geographical distribution.

Results

The study showed that the high prevalence of infectious diarrhea in Yantai, Shandong Province, for two consecutive years in 2018 and 2019 was in young children aged 1-5 years, accounting for 48.6% of the total number of cases. Viral diarrhea was distributed throughout the year with no obvious seasonal distribution, while bacterial diarrhea was predominant in summer. Of 1514 stool specimens, the total positive rate of specimens was 43.92% (665/1514). One pathogen was detected in 507 specimens, two pathogens in 107 specimens, and three pathogens in 44 specimens, with mixed infections accounting for 22.71% of positive specimens (151/665). Viral diarrheal pathogens accounted for 93.23% (620/665) of positive samples. The percentages of positive samples for Rotavirus (RV), Norovirus GI, Norovirus GII, Enterovirus universal (EV), Enteroadenovirus (EAdV), Sapovirus (SaV), Astrovirus (Astv), Salmonella (SE), Listeria monocytogenes (LiMo), and Vibrio parahaemolyticus (VP) were 48.57%, 3.61%, 15.34%, and 10.68% of the total positive samples.

Conclusions

This study analyzed in detail the composition of infectious diarrhea pathogen spectrum, pathogen alternation pattern, seasonal distribution and population distribution of pathogens in Yantai City, Shandong Province, 2018-2019, to provide a basis for improving relevant local preventive measures and reducing the disease burden.

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.

Testosterone Promotes the Intestinal Replication and Dissemination of Coxsackievirus B3 in an Oral Inoculation Mouse Model

Enteroviruses initiate infection in the gastrointestinal tract, and sex is often a biological variable that impacts pathogenesis. Previous data suggest that sex hormones can influence the intestinal replication of Coxsackievirus B3 (CVB3), an enterovirus in the Picornaviridae family. However, the specific sex hormone(s) that regulates intestinal CVB3 replication is poorly understood. To determine if testosterone promotes intestinal CVB3 replication, we orally inoculated male and female Ifnar^-/- mice that were treated with either placebo or testosterone-filled capsules. Following oral inoculation, we found that the testosterone-treated male and female mice shed significantly more CVB3 in their feces than did the placebo-treated mice, indicating that testosterone enhances intestinal replication. Similarly, testosterone enhanced viral dissemination in both sexes, as we observed higher viral loads in peripheral tissues following infection. Further, the testosterone-treated male mice also had a higher mortality rate than did the testosterone-depleted male mice. Finally, we observed that testosterone significantly affected the immune response to CVB3. We found that testosterone broadly increased proinflammatory cytokines and chemokines while decreasing the number of splenic B cells and dendritic cells following CVB3 infection. Moreover, while testosterone did not affect the early CD4 T cell response to CVB3, testosterone reduced the activation of CD8 T cells. These data indicate that testosterone can promote intestinal CVB3 replication and dissemination while also impacting the subsequent viral immune response. IMPORTANCE Biological sex plays a significant role in the outcomes of various infections and diseases. The impact of sex hormones on the intestinal replication and dissemination of Coxsackievirus B3 remains poorly understood. Using an oral inoculation model, we found that testosterone enhances CVB3 shedding and dissemination in male and female mice. Further, testosterone can alter the immune response to CVB3. This work highlights the role of testosterone in CVB3 pathogenesis and suggests that sex hormones can impact the replication and dissemination of enteric viruses.

Seroprevalence and molecular characterization of human respiratory syncytial virus and human adenovirus among children in Ado-Ekiti, Nigeria

In children, the respiratory syncytial virus and adenovirus majorly cause acute respiratory infections. The study evaluated the seroprevalence and conducted the molecular characterization of human respiratory syncytial virus (HRSV) and human adenovirus (HAdV) among children. Venous blood, nasopharyngeal, and oropharyngeal swabs were collected from children presenting with acute respiratory infections in a tertiary health facility in Ado-Ekiti, Nigeria. A serological investigation was carried out on the sera samples for the detection of anti-HRSV immunoglobulin M (IgM), anti-HRSV IgG, anti-HAdV IgM, and anti-HAdV IgG using ELISA (enzyme-linked immunosorbent assay) kits. The amplification and sequencing of HRSV and HAdV were carried out using specific primer pairs that targeted the glycoprotein (G) gene of HRSV and the hexon gene of HAdV, respectively. The seroprevalence of HRSV IgG and IgM was 73% and 7.5%, respectively, while the seroprevalence of HAdV IgG and IgM was 98.5% and 8.5%, respectively. The age of enrolled children, presence of fever, and cough were associated (p < 0.05) with the infection. HRSV subtype B (HRSV-B) (13.3%), and species of HAdV (Mastadenovirus B and C) (11.7%) were detected among the studied population. There was no viral coinfection with both HRSV and HAdV. In infancy and early childhood, HRSV-B, HAdV species B and C are common etiologic agents of respiratory infections as reported in this study. Further studies on molecular characterization of respiratory tract viruses including circulating respiratory syncytial virus and adenovirus are hereby advocated.

Adenovirus Infection Is Predicted by Prolonged Duration of Diarrhea among Rotavirus-Vaccinated Children below Five Years of Age in Mwanza, Tanzania

Diarrhea is the commonest cause of morbidity and mortality in many resource-limited countries including Tanzania among children below five years of age. A significant number of diarrhea cases associated with severe dehydration are still being reported among children despite five years of rotavirus vaccine implementation in Tanzania necessitating the need to investigate other causes of diarrhea in this population. This study is aimed at determining the prevalence of human adenovirus infection and associated factors among rotavirus-vaccinated children with acute diarrhea in Mwanza, Tanzania. A cross-sectional study was conducted from June to August 2017 involving 137 children less than two years of age admitted with acute diarrhea in the health facilities located in Mwanza, Tanzania. Sociodemographic and other relevant information were collected using standardized rotavirus surveillance tool adopted from WHO. Stool specimens were collected and tested for human adenovirus antigen using immunochromatographic tests. Data were analyzed by using STATA version 13. The median age of enrolled children was 12 (IQR 8-17) months. The prevalence of human adenovirus was found to be 46 (33.6%, 95% CI: 25-41). By multivariable logistic regression analysis, only prolonged duration of diarrhea (OR: 1.619, 95% CI: 1.142-2.295, p = 0.007) was found to predict human adenovirus infection among rotavirus-vaccinated children with acute diarrhea. A significant proportion of rotavirus-vaccinated children with prolonged acute diarrhea have adenovirus infection. There is a need to consider other viral pathogens as potential cause of diarrhea especially in this postrotavirus vaccination period.

Molecular detection of human adenovirus in urban wastewater in Egypt and among children suffering from acute gastroenteritis

Incidence of enteric viruses in sewage, the efficacy of wastewater treatment plants to remove these viruses, and health effects from their release into the surface water are very important environmental issues in the microbiology field. One of the most pathogenic enteric viruses is adenovirus which can cause a serious disease such as gastroenteritis with low grade fever and mild dehydration in humans. In this study we performed qualitative polymerase chain reaction (PCR) analysis of HAdV on 60 stool samples from children with acute gastroenteritis admitted to Abu-Rish hospital and 96 environmental samples (32 raw sewage, 32 treated sewage, 32 sewage sludge) collected from Zenin wastewater treatment plant (WWTP). HAdV were detected in 17 (28.3%) of stool, 27 (84.4%) of raw sewage, 16 (50%) of treated sewage and 25 (78%) of sludge samples. The viral concentrations were in the range of 2.02 × 10⁶-7.23 × 10⁶, 8.7 × 10⁵-4.3 × 10⁶, 1.22 × 10⁴-3.7 × 10⁶ and 1.48 × 10⁶-1.77 × 10⁷ GC/mL in stool, raw sewage, treated sewage, and sludge, respectively. HAdV was detected throughout the whole year of sample collection. Moreover, our results suggested that males were more susceptible to adenovirus infections than females. The results indicate that the high incidence of HAdV in the treated sewage may cause adverse health effects.

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.

Delivery strategies to enhance oral vaccination against enteric infections

While the majority of human pathogens infect the body through mucosal sites, most licensed vaccines are injectable. In fact the only mucosal vaccine that has been widely used globally for infant and childhood vaccination programs is the oral polio vaccine (OPV) developed by Albert Sabin in the 1950s. While oral vaccines against Cholera, rotavirus and Salmonella typhi have also been licensed, the development of additional non-living oral vaccines against these and other enteric pathogens has been slow and challenging. Mucosal vaccines can elicit protective immunity at the gut mucosa, in part via antigen-specific secretory immunoglobulin A (SIgA). However, despite their advantages over the injectable route, oral vaccines face many hurdles. A key challenge lies in design of delivery strategies that can protect antigens from degradation in the stomach and intestine, incorporate appropriate immune-stimulatory adjuvants and control release at the appropriate gastrointestinal site. A number of systems including micro and nanoparticles, lipid-based strategies and enteric capsules have significant potential either alone or in advanced combined formulations to enhance intestinal immune responses. In this review we will outline the opportunities, challenges and potential delivery solutions to facilitate the development of improved oral vaccines for infectious enteric diseases.

Viral Agents of Diarrhea in Young Children in Two Primary Health Centers in Edo State, Nigeria

Enteric viruses have been shown to be responsible for diarrhea among children during their early childhood. This study was carried out to determine the prevalence of rotavirus, adenovirus, and norovirus infection in young children with diarrhea in two primary health centers in Edo State, Nigeria. A total of 223 stool specimens were collected from children aged 0–36 months with clinical signs of diarrhea and 59 apparently healthy age-matched children as control. These specimens were investigated for three viral agents using immunochromatographic technique (ICT). The overall results showed that at least one viral agent was detected in 95/223 (42.6%) of the children with diarrhea while the control had none. The prevalence of rotavirus was 28.3%, adenovirus 19.3%, and norovirus 3.6%. There was a significant association between age group and infection (P < 0.0001). Seasonal pattern of enteric viruses was not statistically significant (P = 0.17). The overall coinfection rate was 7.6% and rotavirus-adenovirus coinfection had the highest with 5.4%. Rotavirus was the most prevalent viral agent. Coinfections are not uncommon among the population studied. The most commonly associated clinical symptom of viral diarrhea in this study was vomiting. Viral diagnostic tests are advocated for primary health care facilities in this locality.

Prevalence and molecular characterisation of human adenovirus in diarrhoeic children in Tanzania; a case control study

BACKGROUND

Human adenovirus (HAdV) causes acute diarrhoea sporadically, as well as in outbreaks. Understanding the prevalence and types of HAdV in diarrhoea is important for control and preventive measures, especially in the African region where there is a high burden of diarrhoeal disease. The present study assessed the prevalence, molecular characteristics, seasonality and associated clinical features of HAdV infection Tanzanian children below two years of age with and without diarrhoea between 2010-2011.

METHODS

Stool specimens, demographic and clinical information were collected in 690 cases and 545 controls. All stool samples were screened for HAdV-antigen using ELISA. Positive samples subsequently underwent real-time PCR and sequencing for molecular typing.

RESULTS

HAdV was detected in 37 children, corresponding to a prevalence of 3.5% (24/690) in diarrhoeic and 2.4% (13/545) in non-diarrhoeic children (P > 0.05). Among HAdV-infected children, the median age was significantly lower in diarrhoeic than in non-diarrhoeic children (10 vs. 14 months, P˂0.001). More than half of HAdV infected (54.2%) were dehydrated as compared to diarrhoeic children without HAdV (45.8%, P = 0.01). The proportion of the enteric HAdV type 40/41 in diarrhoeic and non-diarrhoeic children was (50.0%, 12/24) and (46.2%, 6/13) respectively. Other HAdV types detected were; 1, 2, 7, 18, 19 and 31. The prevalence of adenovirus was not significantly different between rainy and dry seasons. HAdV was not detected in the 33 known HIV positive children. There was no significant association between HAdV infection and gender, nutritional status of the child and parent educational level.

CONCLUSION

The present study provides further evidence of the contribution of adenovirus in causing gastroenteritis in young children, with symptomatic infection being significantly more prevalent in children below one year. We found similar prevalence of adenovirus in non-diarrhoeic children and in diarrhoeic children. This first report on molecular epidemiology of human adenovirus in Tanzania observed diversity of HAdV types that circulate the study setting. The study findings suggest that HAdV is not an important cause of diarrhoea in young HIV-positive children.

Prevalence of adenovirus respiratory tract and hiv co-infections in patients attending the University of Ilorin, teaching hospital, Ilorin, Nigeria

BACKGROUND

Adenovirus co-infections in HIV patients cause wide-spread morbidity in sub-Saharan Africa, but little research has documented the burden and distribution of these pathogens. This study was conducted between December, 2010 and March, 2011 to investigate the prevalence of Adenovirus Respiratory Tract and HIV co-infections in Patients attending the University of Ilorin Teaching Hospital Ilorin, Nigeria.

METHOD

One Hundred and Eighty Four (184) patients were recruited with confirmed HIV positive status. Investigation was done by serology using the Human Adenovirus IgG ELISA Kit to test for the presence of the Immunoglobulin G (antibody) against the virus. This was conducted and juxtaposed simultaneously with responses received from the questionnaires provided to each participant to correlate the relationship of the co-infections to their socio-demographic factors (Age, Gender, Occupation and location of residence), risk factors (Average hours of exposure per day (time spent outdoor daily), proximity of their apartments to livestock settlements), recent occurrence of respiratory tract infections/conjunctivitis and their ART status.

RESULTS

This study recorded a prevalent rate of 38% (70 patients) to the co-infections. Nevertheless, 62% (114 patients) tested negative to the co-infections.

CONCLUSION

There was statistical significance between the ages of HIV patients and Adenovirus co-infection (p<0.05). However, there was no significance with respect to gender of the subjects (p>0.05). The findings also showed that there were statistical significance for all the risk factors; Occupation, Location and Proximity to Livestock settlement, recent respiratory tract infection/conjunctivitis, and ART status in relation to Adenovirus and HIV co-infections (p<0.05).

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.