Norovirus Epidemiology and Genotype Circulation during the COVID-19 Pandemic in Brazil, 2019-2022

Norovirus stands out as a leading cause of acute gastroenteritis (AGE) worldwide, affecting all age groups. In the present study, we investigated fecal samples from medically attended AGE patients received from nine Brazilian states, from 2019 to 2022, including the COVID-19 pandemic period. Norovirus GI and GII were detected and quantified using RT-qPCR, and norovirus-positive samples underwent genotyping through sequencing the ORF1/2 junction region. During the four-year period, norovirus prevalence was 37.2%, varying from 20.1% in 2020 to 55.4% in 2021. GII genotypes dominated, being detected in 92.9% of samples. GII-infected patients had significantly higher viral concentrations compared to GI-infected patients (median of 3.8 × 107 GC/g and 6.7 × 105 GC/g, respectively); and patients aged >12-24 months showed a higher median viral load (8 × 107 GC/g) compared to other age groups. Norovirus sequencing revealed 20 genotypes by phylogenetic analysis of RdRp and VP1 partial regions. GII.4 Sydney[P16] was the dominant genotype (57.3%), especially in 2019 and 2021, followed by GII.2[P16] (14.8%) and GII.6[P7] (6.3%). The intergenogroup recombinant genotype, GIX.1[GII.P15], was detected in five samples. Our study is the first to explore norovirus epidemiology and genotype distribution in Brazil during COVID-19, and contributes to understanding the epidemiological dynamics of norovirus and highlighting the importance of continuing to follow norovirus surveillance programs in Brazil.

Acute gastroenteritis outbreak associated with multiple and rare norovirus genotypes after storm events in Santa Catarina, Brazil

Norovirus is a major cause of acute diarrheal disease (ADD) outbreaks worldwide. In the present study, we investigated an ADD outbreak caused by norovirus in several municipalities of Santa Catarina state during the summer season, southern Brazil in 2023. As of the 10th epidemiological week of 2023, approximately 87 000 ADD cases were reported, with the capital, Florianópolis, recording the highest number of cases throughout the weeks. By using RT-qPCR and sequencing, we detected 10 different genotypes, from both genogroups (G) I and II. Some rare genotypes were also identified. Additionally, rotavirus and human adenovirus were sporadically detected among the ADD cases. Several features of the outbreak suggest that sewage-contaminated water could played a role in the surge of ADD cases. Storm events in Santa Catarina state that preceded the outbreak likely increased the discharge of contaminated wastewater and stormwater into water bodies, such as rivers and beaches during a high touristic season in the state. Climate change-induced extreme weather events, including intensified rainfall and frequent floods, can disturb healthcare and sanitation systems. Implementing public policies for effective sanitation, particularly during peak times, is crucial to maintain environmental equilibrium and counter marine pollution.

Simultaneous enterovirus EV-D68 and CVA6 infections causing acute respiratory distress syndrome and hand, foot and mouth disease

Background

Although most enterovirus (EV) infections can be asymptomatic, these viral agents can cause serious conditions associated with central nervous system, respiratory disease and uncommon manifestations of hand, foot and mouth disease (HFMD). EV-coinfections have been rarely reported with development of complications and severe clinical outcome. An atypical case of a child presenting HFMD and severe acute respiratory syndrome, co-infected with EV-D68 and CVA6, is reported herein.

Case presentation

A 3-year-old boy was admitted in the emergency department unit showing fever, abdominal pain and tachycardia. Twenty-four hours after hospitalization the child developed severe clinical symptoms associated with HFMD and was discharged after recovery. Two days later, the child was readmitted with fever, cough and respiratory distress. RT-PCR and Sanger sequencing confirmed positivity for EV-D68 and CVA6 in oro and nasopharynges swabs and vesicles fluid, respectively. Phylogenetic analysis based on VP1 gene sequences suggested that CVA6 was closely related with HFMD viruses circulating in Turkey, while EV-D68 was genetically related to a Chinese strain.

Conclusions

To the best of our knowledge, this case is the first report of a double infection caused by CVA6 and EV-D68, which shed light on the pathogenesis of enterovirus infections. Further studies must be conducted to ascertain the role and clinical significance of EV co-infections, as well as a potential synergistic pathway between these viruses.

Detection and characterization of a coxsackievirus B2 strain associated with acute meningoencephalitis, Brazil, 2018

Although different etiological agents can cause acute meningoencephalitis, this syndrome is usually associated with viruses. Among these, enteroviruses play a significant role. Here, we describe a fatal case of meningoencephalitis in a previously healthy teenager. Real-time RT-PCR and cell culture assays were performed with serum and cerebrospinal fluid (CSF) from a clinically diagnosed meningoencephalitis case that occurred in Rio de Janeiro State, Brazil. Coxsackievirus B2 (CVB2) was identified. Phylogenetic analysis revealed that the identified CVB2 was genetically related to strains known to cause neurological diseases. This case highlights the importance of continuous laboratory surveillance of central nervous system infections.

Hepatitis E virus is not detected in association with neurological disorders among Brazilian children

Hepatitis E virus is increasingly being associated with idiopathic neurological disease. We tested 325 stool samples from Brazilian children presenting acute flaccid paralysis or Guillain-Barré syndrome using a broadly reactive and sensitive Reverse-transcription Polymerase chain reaction. Hepatitis E genome was not detected in any of the samples tested. Our results suggest that hepatitis E virus does not seem to be associated as the etiologic agent of acute flaccid paralysis and Guillain-Barré syndrome cases occurred in Brazilian children during the period of investigation (2010-2012).

Echovirus 30 detection in an outbreak of acute myalgia and rhabdomyolysis, Brazil 2016-2017

OBJECTIVES

To describe an outbreak of acute myalgia accompanied by elevated levels of muscle enzymes that occurred in the northeast region of Brazil from December 2016 through to May 2017.

METHODS

Clinical data were analysed and laboratory tests were performed in 86 specimens obtained from 52 individuals with suspected acute myalgia. A broader reactive enterovirus real-time RT-PCR followed by a semi-nested PCR amplification of partial VP1 gene were performed to identify the causative agent.

RESULTS

Eighty-six clinical samples were received in our laboratory during the myalgia outbreak. Median age of individuals was 39 years. Sudden acute myalgia and dark urine were the most common symptoms. Creatine phosphokinase levels were elevated with mean value ∼16 893 U/L. Human enterovirus was detected in 67% (58/86) of the patient's specimens (urine, serum, faeces and rectal swab). The enterovirus positivity per patient was 82.7% (43/52). Echovirus 30 (E-30) (82% of the typed specimens, 18/22; 76.4% (13/17) of the typed specimens per patient) was the main enterovirus identified. In addition to E-30, CV-A16 (1/22) and E-6 (3/22) were detected in 4% and 14% of the typed specimens, respectively. No deaths occurred.

CONCLUSION

The 2016-2017 outbreak of acute myalgia that occurred in the northeast region of Brazil can be associated with E-30. Despite the clinical manifestations, a favourable outcome was observed for all patients.

A RT-PCR method for selective amplification and phenotypic characterization of all three serotypes of Sabin-related polioviruses from viral mixtures

Outbreaks caused by vaccine-derived polioviruses are challenging the final eradication of paralytic poliomyelitis. Therefore, the surveillance of the acute flaccid paralysis cases based on poliovirus isolation and characterization remains an essential activity. Due to the use of trivalent oral poliovirus vaccine (OPV), mixtures containing more than one serotype of Sabin-related polioviruses are frequently isolated from clinical samples. Because each poliovirus isolate needs to be individually analyzed, we designed polymerase chain reaction primers that can selectively distinguish and amplify a genomic segment of the three Sabin-related poliovirus serotypes present in mixtures, thus, optimizing the diagnosis and providing prompt information to support epidemiologic actions.

Molecular characterization and phylogenetic study of coxsackievirus A24v causing outbreaks of acute hemorrhagic conjunctivitis (AHC) in Brazil

BACKGROUND

Coxsackievirus A24 variant (CA24v) is the most prevalent viral pathogen associated with acute hemorrhagic conjunctivitis (AHC) outbreaks. Sixteen years after its first outbreak in Brazil, this agent reemerged in 2003 in Brazil, spread to nearly all states and caused outbreaks until 2005. In 2009, a new outbreak occurred in the northeast region of the country. In this study, we performed a viral isolation in cell culture and characterized clinical samples collected from patients presenting symptoms during the outbreak of 2005 in Vitória, Espírito Santo State (ES) and the outbreak of 2009 in Recife, Pernambuco State (PE). We also performed a phylogenetic analysis of worldwide strains and all meaningful Brazilian isolates since 2003.

METHODS AND FINDINGS

Sterile cotton swabs were used to collect eye discharges, and all 210 clinical samples were used to inoculate cell cultures. Cytopathic effects in HEp-2 cells were seen in 58 of 180 (32%) samples from Vitória and 3 of 30 (10%) samples from Recife. Phylogenetic analysis based on a fragment of the VP1 and 3C gene revealed that the CA24v causing outbreaks in Brazil during the years 2003, 2004 and 2005 evolved from Asian isolates that had caused the South Korean outbreak of AHC during the summer of 2002. However, the 2009 outbreak of AHC in Pernambuco was originated from the reintroduction of a new CA24v strain that was circulating during 2007 in Asia, where CA24v outbreaks has been continuously reported since 1970.

CONCLUSIONS

This study is the first phylogenetic analysis of AHC outbreaks caused by CA24v in Brazil. The results showed that Asian strains of CA24v were responsible for the outbreaks since 1987 and were independently introduced to Brazil in 2003 and 2009. Phylogenetic analysis of complete VP1 gene is a useful tool for studying the epidemiology of enteroviruses associated with outbreaks.

Inhibition of Mayaro virus replication by prostaglandin A(1) in Vero cells

Prostaglandins exhibit antiviral activity against a wide variety of RNA and DNA viruses. In the present report, we describe the effect of cyclopentenone prostaglandin A(1) (PGA(1)) on Mayaro virus replication in Vero cells. Virus yield was significantly reduced at nontoxic concentrations which did not suppress DNA, RNA or protein synthesis in uninfected or infected cells. Antiviral action decreased if PGA(1) was added at later times after infection. In Mayaro virus-infected cells, PGA(1) inhibited the synthesis of virus proteins. This effect is accompanied by the induction of heat shock proteins (HSPs). Actinomycin D treatment not only inhibited the induction of HSPs but also partially prevented PGA(1) antiviral activity.