Molecular analysis of norovirus in specimens from children enrolled in a 1982‐1986 study in Belém, Brazil: A community‐based longitudinal study

Abstract

Fecal specimens were collected during a longitudinal, community-based study in the city of Belém, North Brazil, that was conducted over 3 years (October 1982 to March 1986), in which 20 children were included from birth to 3 years of age. A total of 229 fecal samples were screened by real time RT-PCR targeting the junction region (ORF 1/2) of the norovirus (NoV) genome. NoV-positive samples were subjected to PCR and sequencing of the viral polymerase (ORF1) and viral protein 1 (VP1) genes (ORF2). The junction region was also sequenced to assess for recombination when ORF1 and ORF2 genotyping results were dissimilar. Samples classified as GII.P4/GII.4 were further characterized by sequencing the P2 subdomain of the viral capsid to determine possible alterations. An overall positivity of 16.1% (37/229) was observed, including GI (16.2%-6/37) and GII (83.8%-31/37) genogroups. Cases of NoV reinfection in at least 2-month intervals were observed, and 12 children developed at least one case of asymptomatic NoV infection. In total, 48.6% (18/37) NoV-positive samples were subjected to nucleotide sequencing analysis targeting the following polymerase genes: GI.P3 (n = 1), GII.Pa (n = 1), GII.Pc (n = 1), GII.P4 (n = 5), GII.P6 (n = 5), GII.P7 (n = 3), GII.P12 (n = 1), and GII.P22 (n = 1). For the VP1 gene, characterization was performed in 14 (77.8%) samples: GI.3 (n = 1), GII.2 (n = 1), GII.4 (n = 4), GII.6 (n = 4), GII.7 (n = 1), GII.12 (n = 1), GII.14 (n = 1), and GII.23 (n = 1). Recombination events were confirmed in three cases (GII.P12/GII.2, GII.P7/GII.14, and GII.Pa/GII.12), and four samples genotyped as GII.P4/GII.4 were analyzed to identify variants. None had contemporary counterparts. Three children developed consecutive NoV infections by different genotypes. The present report documents the importance of NoV as a cause of childhood infection during a longitudinal study conducted more than 30 years ago.

Epidemiological and molecular investigation of norovirus and astrovirus infections in Rio Branco, Acre, Northern Brazil: A retrospective study

“…The overall NoV positivity observed in the present study (12.3%) was lower than that observed in other studies conducted in the Amazon Region, such as the study from 1982 to 2011 in Belém city (16.9%) and that in Manaus city from 2010 to 2011 (35.2%) . This difference may be explained by the fact that the samples in this study were collected in UPAs and ambulatory care centers, not from hospitalized children, so the symptoms were normally mild.…”

“…Asymptomatic infections by HAstV and NoV have already been described, and are probably related to the circulation of antibodies that give protection to the person, but the virus is still excreted in the feces . Regarding NoV, there is evidence of short‐term immunity after infection; however, some individuals remain susceptible to developing clinical symptoms, while others will not develop symptoms even after direct contact with the virus . Consequently, the data obtained in the present study reinforce the presence of these viruses in asymptomatic patients, which facilitates the spread of infections, recombination events, and may even lead to outbreaks and epidemics.…”

Genetic Diversity of Norovirus in Children with Acute Gastroenteritis in Southwest Nigeria, 2015–2017

“…However, dual NoV and HAdV infection and mixed NoV, RVA, and HAdV infection have been reported in Edo State, Nigeria [ 19 ], and Kenya [ 34 ]. Elsewhere, a study in Brazil [ 35 ] also reported dual NoV and HAstV infection. The number of viruses analyzed, sample size, and diagnostic methods may account for the disparity.…”

Genotypic diversity and long‐term impact of human bocavirus on diarrheal disease: Insights from historical fecal samples in Brazil

“…The organic debris in the clinical matrix, such as vomit or feces, where the virus is shed, protects the viral integrity and provides defense against environmental damage 17 . In Brazil, there are fewer studies on the impact of long‐term storage on the detection and molecular characterization of viruses in fecal samples 16,18 . Like other enteric viruses transmitted through fecal‐oral contact, food, or water, HBoV is expected to remain infective for a reasonable period outside the human host, especially when protected by organic material like feces and stored at low temperatures.…”

“…Clinical specimens are typically stored for short periods (days to weeks) before viral DNA/RNA extraction and detection. However, research on archival stool samples reveals that viral genomes can still be detected even after being frozen for decades 16–18 . The organic debris in the clinical matrix, such as vomit or feces, where the virus is shed, protects the viral integrity and provides defense against environmental damage 17 .…”