Genotypes of Epstein-Barr virus (EBV1/EBV2) in individuals with infectious mononucleosis in the metropolitan area of Belém, Brazil, between 2005 and 2016

Abstract Two types of Epstein Barr virus (EBV1/EBV2) have been shown to infect humans. Although their genomes are similar, the regions containing the EBNA genes differ. This study aimed to characterize the EBV genotypes of infectious mononucleosis (IM) cases in the metropolitan region of Belém, Brazil, from 2005 to 2016. A total of 8295 suspected cases with symptoms/signs of IM were investigated by infectious disease physicians at Evandro Chagas Institute, Health Care Service, from January 2005 to December 2016. Out of the total, 1645 (19.8%) samples had positive results for EBV by enzyme immunoassay and 251 (15.3%) were submitted to polymerase chain reaction (PCR) technique, using the EBNA3C region, in order to determine the type of EBV. Biochemical testing involving aspartate aminotransferase, alanine aminotransferase and gamma-glutamyl transferase were also performed. EBV type was identified by PCR in 30.3% (76/251) of individuals; of those, 71.1% (54/76) were classified as EBV1, 17.1% (13/76) as EBV2, and 11.8% (9/76) as EBV1+EBV2. The main symptoms/signs observed with EBV1 infection were cervical lymphadenopathy (64.8%, 35/54), fever (63%, 34/54), headache (20.4%, 11/54), arthralgia (20.4%, 11/54), and exanthema (18.5%, 10/54). EBV2 infection was detected in all but two age groups, with an average age of 24 years. The most common signs/symptoms of EBV2 were fever (76.9%, 10/13), average duration of 18 days, and lymphadenopathy (69.2%, 9/13). In contrast, EBV1+EBV2 coinfections were more frequent in those aged five years or less (20.0%, 2/10). The symptoms of EBV1+EBV2 coinfection included fever (66.7%, 6/9), and cervical lymphadenopathy and headache (33.3%, 3/9) each. The mean values of hepatic enzymes according to type of EBV was significantly different (p<0.05) in those EBV1 infected over 14 years of age. Thus, this pioneering study, using molecular methods, identified the EBV genotypes in 30.3% of the samples, with circulation of EBV1, EBV2, and EBV1+EBV2 co-infection in cases of infectious mononucleosis in the northern region of Brazil.

Detection and genotyping of human adenovirus and sapovirus in children with acute gastroenteritis in Belém, Pará, between 1990 and 1992: first detection of GI. 7 and GV. 2 sapoviruses in Brazil

Abstract INTRODUCTION: Acute gastroenteritis (AGE) is one of the most common causes of morbidity and mortality, especially among children from developing countries. Human adenovirus (HAdV) and sapovirus (SaV) are among the agents that cause AGE. The present study aimed to detect and genotype HAdV and SaV in 172 fecal samples from children with AGE, collected during a surveillance study carried out in a low-income community in Belém, Pará, between 1990 and 1992. METHODS: HAdV was detected by nested PCR, using primers Hex1deg/Hex2deg and NeHex3deg/NeHex4deg. SaV was assayed by reverse transcription PCR (RT-PCR), nested PCR, and quantitative PCR. The nucleotide sequence was determined by direct cycle sequencing. RESULTS: Overall, 43% (74/172) of samples were positive for HAdV, of which 70.3% (52/74) were sequenced and classified as belonging to five different species, mostly A and F. For SaV, positivity was 5.2% (9/172) and genotypes GI.1, GI.7, GII.1, and GV.2 were detected. CONCLUSIONS: The present results reinforce the need for further studies to obtain epidemiological data about the circulation of these viruses in Brazil, especially in the Amazon Region, where data from the early 1990's are scarce. Furthermore, the study describes for the first time the detection of SaV genotypes GI.7 and GV.2 in Brazil, showing that these types circulated in the region more than 25 years ago.

High prevalence of norovirus in children with sporadic acute gastroenteritis in Manaus, Amazon Region, northern Brazil

BACKGROUND Norovirus (NoV) is a major cause of acute gastroenteritis (AGE) worldwide, especially in children under five years. Studies involving the detection and molecular characterisation of NoV have been performed in Brazil, demonstrating its importance as an etiological agent of AGE. OBJECTIVES The objectives of this study were to investigate the frequency of human NoV and to genotype the strains isolated from 0-14-year-old patients of AGE in Manaus, Brazil, over a period of two years. METHODS A total of 426 faecal samples were collected between January 2010 and December 2011. All samples were tested for the presence of NoV antigens using a commercial enzyme immunoassay kit. RNA was extracted from all faecal suspensions and reverse transcription-polymerase chain reaction (RT-PCR) for the NoV-polymerase partial region was performed as a trial test. Positive samples were then subjected to PCR with specific primers for partial capsid genes, which were then sequenced. FINDINGS NoV was detected in 150 (35.2%) faecal samples, for at least one of the two techniques used. NoV was detected in children from all age groups, with the highest positivity observed among the group of 1-2 years old. Clinically, fever was verified in 43% of the positive cases and 46.3% of the negative cases, and vomiting was observed in 75.8% and 70.8% cases in these groups, respectively. Monthly distribution showed that the highest positivity was observed in January 2010 (81.2%), followed by February and April 2010 and March 2011, when the positivity rate reached almost 50%. Phylogenetic analyses performed with 65 positive strains demonstrated that 58 (89.2%) cases of NoV belonged to genotype GII.4, five (7.7%) to GII.6, and one (1.5%) each to GII.7 and GII.3. MAIN CONCLUSIONS This research revealed a high circulation of NoV GII.4 in Manaus and contributed to the understanding of the importance of this virus in the aetiology of AGE cases, especially in a region with such few studies available.

Caliciviruses in hospitalized children, São Luís, Maranhão, 1997-1999: detection of norovirus GII. 12

ABSTRACT Gastroenteritis is one of the most common diseases during childhood, with norovirus (NoV) and sapovirus (SaV) being two of its main causes. This study reports for the first time the incidence of these viruses in hospitalized children with and without gastroenteritis in São Luís, Maranhão. A total of 136 fecal samples were tested by enzyme immunoassays (EIA) for the detection of NoV and by reverse transcription-polymerase chain reaction (RT-PCR) for detection of both NoV and SaV. Positive samples for both agents were subjected to sequencing. The overall frequency of NoV as detected by EIA and RT-PCR was 17.6% (24/136) and 32.6% (15/46), respectively in diarrheic patients and 10.0% (9/90) in non-diarrheic patients (p < 0.01). Of the diarrheic patients, 17% had fever, vomiting and anorexia, and 13% developed fever, vomiting and abdominal pain. Of the 24 NoV-positive samples, 50% (12/24) were sequenced and classified as genotypes GII.3 (n = 1), GII.4 (6), GII.5 (1), GII.7 (2), GII.12 (1) and GII.16 (1). SaV frequency was 9.8% (11/112), with 22.6% (7/31) in diarrheic patients and 4.9% (4/81) in nondiarrheic (p = 0.04) ones. In diarrheic cases, 27.3% had fever, vomiting and anorexia, whereas 18.2% had fever, anorexia and abdominal pain. One SaV-positive sample was sequenced and classified as GII.1. These results show a high genetic diversity of NoV and higher prevalence of NoV compared to SaV. Our data highlight the importance of NoV and SaV as enteropathogens in São Luís, Maranhão.

Group A rotavirus and norovirus display sharply distinct seasonal profiles in Belém, northern Brazil

Several viruses have been associated with acute gastroenteritis (AGE), and group A rotavirus (RVA) and nor-ovirus (NoV) are the most prevalent. This study aimed to assess their prevalence among children hospitalised for diarrhoea during a three-year surveillance study. From May 2008-April 2011, overall positivity rates of 21.6% (628/2904) and 35.4% (171/483) were observed for RVA and NoV, respectively. The seasonality observed indicated distinct patterns when both viruses were compared. This finding may explain why hospitalisation for AGE remains constant throughout the year. Continuous AGE monitoring is needed to better assess the patterns of infection.