Objective: To determine the safety, immunogenicity and efficacy of two doses of rotavirus vaccine in healthy Brazilian infants. Methods: A randomized, multicenter, double-blind, placebo-controlled trial was conducted in Brazil, Mexico and Venezuela. Infants received two oral doses of vaccine or placebo at 2 and 4 months of age, concurrently with routine immunizations, except for oral poliomyelitis vaccine (OPV). This paper reports results from Belém, Brazil, where the number of subjects per group and the viral vaccine titers were: 194 (10 4.7 focus forming units-FFU), 196 (10 5.2 FFU), 194 (10 5.8 FFU) and 194 (placebo). Anti-rotavirus (anti-RV) antibody response was assessed in 307 subjects. Clinical severity of gastroenteritis episodes was measured using a 20-point scoring system with a score of ≥ 11 defined as severe GE. Results: The rates of solicited general symptoms were similar in vaccine and placebo recipients. At 2 months after the second dose, a serum IgA response to RV occurred in 54.7 to 74.4% of vaccinees. No interference was seen in the immunogenicity of routine vaccines. Vaccine efficacy against any rotavirus gastroenteritis (RVGE) was 63.5% (95%CI 20.8-84.4) for the highest concentration (10 5.8 FFU). Efficacy was 81.5% (95%CI 44.5-95.4) against severe RVGE. At its highest concentration (10 5.8 FFU), RIX4414 provided 79.8% (95%CI 26.4-96.3) protection against severe RVGE by G9 strain. Conclusions: RIX4414 was highly immunogenic with a low reactogenicity profile and did not interfere with seroresponse to diptheria, tetanus, pertussis, hepatitis B and Hib antigens. Two doses of RIX4414 provided significant protection against severe GE caused by RV. J Pediatr (Rio J). 2007;83(3):217-224: Rotavirus, gastroenteritis, vaccine, efficacy.

Resumo Estudou-se a prevalência do papilomavírus humano (HPV)

Worldwide human astroviruses (HAstV) have increasingly been recognized as causative agents of viral gastroenteritis, mainly in infants and young children. The aim of this study was to assess the epidemiology and genotype diversity of HAstVs detected in children who participated in a trial in Belém, Brazil with the rhesus human reassortant rotavirus vaccine tetravalent (RRV-TV). From April/1990 to August/1992, 624 diarrheic stool samples were tested by enzyme immunoassay (EIA) for HAstV, with a positive rate of 4.0%. Reverse transcription-polymerase chain reaction (RT-PCR) was done in 129 samples (25 positive and 104 with twice the optical density (OD) value of negative control by EIA) being 33 positive. The overall positivity yielded by both methods was 5.4% (34/624). Genotyping of the 33 positive samples was done by type-specific RT-PCR and confirmed by sequence analysis. Phylogenetic analysis was performed using a 348-bp fragment of the ORF2 region of the capsid gene. HAstV-1 was the most prevalent, accounting for 45.5% of the isolates, followed by HAstV-2 (27.3%), HAstV-3 (12.1%), HAstV-4 (12.1%), and HAstV-6 (3.0%). The monthly distribution showed that HAstV-1 was predominant in the first year of study (May/1990 to May/1991) with highest prevalence in January/1991. HAstV-2 was predominant from July to November/1991 and HAstV-4 from September to October/1990. At 24 months of age, 30.6% of children had been infected by HAstV. The clinical symptoms registered during HAstV associated-diarrhea were usually mild. These data highlight the circulation of the different HAstV genotypes in Belém during the study period.

From November 1992 to November 1994 stool samples were obtained from 237 children admitted to a public hospital in Belém. Rotaviruses were detected in 19.3 per cent (60/310) of faecal samples. Of these, 32.1 per cent (18/56), 20.9 per cent (38/181), and 5.4 per cent (4/73) were recorded in cases of nosocomial diarrhoea, community-acquired diarrhoea, and controls, respectively. Fifty-two (86.7 per cent) of the 60 rotavirus-positive specimens were subgrouped and the G serotypes of 55 (91.7 per cent) of them were determined. Subgroups I and II were detected in 50 per cent each of the 52 subgrouped strains. G type 2 was present in 46 (83.6 per cent) of the 55 serotyped samples; serotypes G1 and (mixed) G1 and G4 were found in 14.5 per cent and 1.8 per cent, respectively, of these specimens. Viral RNA electrophoresis showed 14 distinct patterns, including 56.7 per cent (34/60) and 43.3 per cent (26/60) of long and short profiles, respectively. In 40 (66.6 per cent) of the 60 rotavirus-positive faecal samples no enteropathogens other than rotavirus were detected. There was an increased incidence of rotavirus infection from July 1993 to February 1994. The rotavirus-related episodes of diarrhoea were more severe than those of other aetiology and greater clinical severity was not related to a specific G type, subgroup, or electrophoretype.

This study showed that laboratory markers of recent infection by dengue, Zika or chikungunya arboviruses were detected in the biological samples of approximately one-third of patients with encephalitis, myelitis, encephalomyelitis or Guillain-Barré syndrome, in a surveillance programme in Piauí state, Brazil, between 2015-2016. Fever and myalgia had been associated with these cases. Since in non-tropical countries most infections or parainfectious diseases associated with the nervous system are attributed to herpesviruses, enteroviruses, and Campylobacter jejuni, the present findings indicate that in tropical countries, arboviruses may now play a more important role and reinforce the need for their surveillance and systematic investigation in the tropics.