Molecular and epidemiological characterization of human adenoviruses infection among children with acute diarrhea in Shandong Province, China.

BACKGROUND: Human adenovirus (HAdV) had been recognized as one of the most common enteric viruses associated with acute diarrhea in children. The present study was carried out to demonstrate the molecular and epidemiological characterization of HAdV Infections among children in Shandong province in China between July 2017 and June 2018. METHODS: Fecal specimens were collected from children under 5 years old with acute diarrhea. DNA was extracted from the stool specimens and adenovirus DNA was detected by PCR amplification with specific primers. The amplification products were subjected to electrophoresis and visualized on a UV transilluminator. All positive RT-PCR amplification products were sequenced and the obtained sequences analyzed by MEGA (version 7.0). Demographic information and clinical manifestation data were also analyzed. RESULTS: In total, 656 fecal specimens were collected and the overall positive rate of HAdV was 7.47%. HAdV infections were detected in all age groups, in which children aged 13-24 months presented the highest positive rate. Seasonal pattern could be observed with a peak in December, January and February. Diarrhea, vomiting, dehydration and fever were the main clinical manifestations, in which vomiting was the most common accompanied symptom. By phylogenetic analysis, four species (A, B, C, and F) were detected and seven different serotypes were identified. HAdV-41 (48.98%, 24/49) was the most common serotype followed by HAdV-3 (18.37%, 9/49), HAdV-31 (14.29%, 7/49), HAdV-7 (8.16%, 4/49), HAdV-40 (4.08%, 2/49), HAdV-1 (4.08%, 2/49) and HAdV-2 (2.04%, 1/49). CONCLUSION: This study indicated that HAdV infection was an important cause of acute diarrhea among children under 5 years old in Shandong province. The results will contribute to (a) increase understanding of the role of HAdV in diarrheal children and enhance identification of the predominant diarrhea pathogen for diagnosis; (b) avoid abuse of antibiotics; (c) monitor the change of prevalent HAdV serotypes and promote vaccine development and vaccination.

Clinical and molecular epidemiological characterization of rotavirus infections in children under five years old in Shandong province, China.

Rotaviruses are important causative agents of acute gastroenteritis in children. In China, rotavirus infection has a prevalence rate of 30% and is therefore considered a serious public health problem. This study was carried out to investigate the clinical and molecular epidemiological characteristics of rotavirus infections in children under 5 years old with acute diarrhea in Shandong province, China. From July 2017 to June 2018, a total of 1211 fecal specimens were tested, and the prevalence of rotavirus infection was 32.12%. The mean age of the infected children was 12.2 ± 10.9 months, and the highest infection rate was observed in children aged 7-12 months, with a rate of 41.64%. G9P[8] (76.61%) was the most prevalent genotype combination, followed by G2P[4] (7.20%), G3P[8] (3.60%), and G9P[4] (2.06%). In addition to diarrhea, vomiting, fever, and dehydration were the most common clinical signs. In general, there was no significant difference in clinical manifestations among different age groups. However, the clinical manifestations differed significantly between vaccinated and unvaccinated children. Vaccinated children showed lower incidence and frequency of vomiting, lower incidence and degree of dehydration, and lower incidence of severe cases than unvaccinated children. These findings suggest that it is necessary to continuously monitor changes in the characteristics of rotavirus infections. Moreover, the introduction of vaccines into the national immunization program to prevent and control rotavirus infection is needed in China.

Molecular and clinical epidemiological features of human astrovirus infections in children with acute gastroenteritis in Shandong province, China.

Human astrovirus (HAstV) is one of the most common causative agents of acute gastroenteritis in children with an infection rate estimated to range from 2% to 9% worldwide. This study was aimed at investigating the molecular and clinical epidemiological features of human astrovirus infections in children under 5 years old with acute gastroenteritis in Shandong province, China from July 2017 to June 2018. In total, 376 fecal samples and the corresponding clinical information were collected and analyzed. HAstV infections were detected in all age groups with an overall positive rate of 8.51%. In addition to acute diarrhea, the main clinical manifestations were fever, abdominal pain, vomiting, and dehydration, in which fever was the most common complication. Infections could be seen throughout the year with a peak in the colder season. Four genotypes were detected in which HAstV-1 was the most prevalent genotype with a prevalence of 78.12%, followed by HAstV-5 (9.38%), MLB-1 (9.38%), and MLB-2 (3.12%). HAstV-1 strains were classified as lineage 1a, 1b, and 1d, in which lineage 1a strains were the most prevalent followed by lineage 1b and lineage 1d strains. All HAstV-5 strains were classified as lineage 5b and no other lineages were detected. The results showed that HAstV infection was an important cause of acute gastroenteritis among children under 5 years old in Shandong province. Given that their disease spectrum had been broadened, HAstVs should be paid more attention, not only as a causative agent of acute gastroenteritis but also as a potential pathogen of unexpected diseases.