G6P[8] Rotavirus a Possessing a Wa-like VP3 Gene from a Child with Acute Gastroenteritis Living in the Northwest Amazon Region.

The introduction of rotavirus A (RVA) vaccines has considerably reduced the RVA-associated mortality among children under 5 years of age worldwide. The ability of RVA to reassort gives rise to different combinations of surface proteins G (glycoprotein, VP7) and P (protease sensitive, VP4) RVA types infecting children. During the epidemiological surveillance of RVA in the Northwest Amazon region, an unusual rotavirus genotype G6P[8] was detected in feces of a 2-year-old child with acute gastroenteritis (AGE) that had been vaccinated with one dose of Rotarix® (RV1). The G6P[8] sample had a DS-1-like constellation with a Wa-like VP3 gene mono-reassortment similar to equine-like G3P[8] that has been frequently detected in Brazil previously. The results presented here reinforce the evolutionary dynamics of RVA and the importance of constant molecular surveillance.

Epidemiology of enteric virus infections in children living in the Amazon region.

OBJECTIVES: To verify the frequency of viruses causing acute gastroenteritis (AGE) in association with the histo-blood group antigen (HBGA) and Rotarix™ vaccination coverage in children from the Amazon region. DESIGN: Fecal and saliva samples were collected from children with AGE (n = 485) and acute respiratory infection (ARI) (n = 249) clinical symptoms. Rotavirus A (RVA), norovirus, human adenovirus (HAdV), and sapovirus (SaV) were verified in feces by molecular detection. Saliva samples were used for HBGA phenotyping/FUT3 genotyping. Blood group types, clinical aspects and Rotarix™ RVA vaccination data were recorded. RESULTS: Norovirus remained the most prevalently detected cause of AGE (38%, 184/485 and ARI 21.3%, 53/249). High HAdV frequencies were observed in AGE children (28.6%, 139/485) and ARI children (37.3%, 93/249). RVA was the third most prevalent virus causing AGE (22.7%, 110/485 and ARI 19.3%, 48/249) and a low RV1 coverage (61%, 448/734) was verified. The SaV frequencies were lower (7.2%, 35/485 for AGE and 6.8%, 17/249 for ARI). Secretor children were HBGA susceptible to HAdV infection (OR 1.5, 95% CI 1.0-2.3; P = 0.04) but not to RVA, norovirus or SaV infection. CONCLUSIONS: Norovirus could be considered the main etiological agent of AGE. No association was verified for HBGA susceptibility to RVA, norovirus and SaV. Secretor children showed a slight susceptibility to HAdV infection and the Le (a-b-) heterogeneous SNPs on the FUT3 gene.

First report of human astrovirus MLB2 in Brazil detected in feces of children with acute gastroenteritis living in the state of Roraima, Northern Brazil.

Human astrovirus (HAstV) 1-8 and highly divergent HAstVMLB1-3 genotypes have been detected in children both with and without acute gastroenteritis (AGE). One hundred and seventy fecal samples from children (≤5 years old) living in the Amazon region were evaluated for the presence of HAstV1-8, HAstV MLB1-3 and HAstVVA1-3, using an usual RT-PCR protocol and a new protocol with specific primers designed to detect HAstVMLB1-3. HAstVMLB1 and HAstV MLB2, as well as the HAstV3 and 5 genotypes were detected. HAstVMLB1-2 genotype was detected for the first time in Brazil at a frequency of 3.5% (6/170).

Human Bocavirus genotypes 1 and 2 detected in younger Amazonian children with acute gastroenteritis or respiratory infections, respectively.

OBJECTIVES: This study aimed to verify the frequency, genotypes, and etiological role of Human Bocavirus (HBoV) in younger Amazonian children with either acute gastroenteritis (AGE) or respiratory infections (ARI). The influence of Rotarix™ vaccination and co-infection status was also investigated. DESIGN: HBoV quantitative polymerase chain reaction (qPCR) testing was done on both fecal and saliva (1468 samples) from 734 children < 5 months old living in the Amazon (Brazil, Guyana, and Venezuela). High and median HBoV viral load samples were used for extraction, nested PCR amplification, and sequencing for genotyping. HBoV mRNA detection was done by reverse transcription following DNA amplification. RESULTS: The overall HBoV frequencies were 14.2% (69/485; AGE) and 14.1% (35/249; ARI) (p = 0.83). HBoV exclusively infected 4.5% (22/485; AGE) and 4% (10/249) of the Amazonian children (Odds ratios 1.13, 95% confidence interval= 2.42-0.52). HBoV 1 was mainly detected in feces and saliva from AGE children; and HBoV2, from ARI children. HBoV mRNA was detected only in feces. The Rotarix™ vaccination status did not affect the HBoV frequencies. CONCLUSIONS: We suggest that, after entry into the air/oral pathways, HBoV1 continues infecting toward the intestinal tract causing AGE. HBoV2 can be a causative agent of AGE and ARI in younger Amazonian children.