Acute gastroenteritis in a pediatric hospital in rio de janeiro in pre- and post-rotavirus vaccination settings.

A 4(1/2)-year hospital-based survey was conducted in Rio de Janeiro to determine baseline rates of gastroenteritis-related cases, hospitalizations, and deaths; to examine the prevalence of rotavirus strains causing admissions; and to assess the immediate impact of the nationwide rotavirus immunization program launched in March 2006. From August 2002 to May 2007, 14,473 (10.4%) of the 139,747 consultations had AGE as primary diagnosis, 491 (3.4%) children required hospitalization and two (0.4%) dehydrated children died. Gastroenteritis contribution to hospitalizations varied from ~2.3% in 2004 and 2006 to 6.4% in 2005, being roughly half of them rotavirus-related cases. A gradual decrease in rotavirus strain diversity was observed from 2002 to 2005 when a single G9P[8] prevailed until April 2006. Then only short profile G9P[4] and G2P[4] strains were detected. Gastroenteritis cases were distributed year-round in a trimodal pattern with major winter peaks. Local climate apparently affected the incidence of gastroenteritis: reduction in dry years (2004 and 2007) and explosive outbreaks caused by multiple agents during the heavy rainfalls and recurrent floods of the 2005-early 2006 period. Besides rotavirus, adenovirus and calicivirus were major gastroenteritis agents of these seemingly waterborne outbreaks. In conclusion, rotavirus vaccination impacted marginally, if at all, on the incidence of childhood gastroenteritis, as favorable results obtained by comparing data from the post-vaccine period to the preceding unusual 2005 year all but disappeared when comparing to previous pre-vaccination periods, and the shift towards G2P[4] rotavirus strains may be a global trend unrelated to vaccination.

Changing distribution of human rotavirus serotypes during two epidemic outbreaks of gastroenteritis in Campinas, São Paulo, Brazil, 2003-2004: detection of G6 strains.

BACKGROUND: Rotavirus serotypes G1-G4 and G9 are the most important agents of severe diarrhea in children worldwide. OBJECTIVE: To characterize rotavirus serotypes/genotypes causing two large outbreaks of diarrhea in Campinas, São Paulo, during 2003-2004. STUDY: Rotavirus infection was investigated in 328 stool specimens collected from children and adults with diarrhea by PAGE and RT-PCR and further characterized by semi-nested PCR-typing assays. RESULTS: G3P[8] (26.1%), G9P[8] (18.7%) and G1P[8] (17.9%) were the most frequently detected serotypes/genotypes. G1P[8] was predominant in 2003, but significantly decreased the following year when G3P[8] and G9P[8] prevailed. G5P[8] was identified in about 9% of the typed specimens from each year consistent with its endemic nature in Brazil for over two decades. The other globally common serotypes (G4P[8] and G2P[4]), uncommon G-P combinations, and multiple G serotypes were also found. Rarely found in humans, and not previously reported in Brazil, serotype G6 was identified in three specimens obtained from children in 2004. CONCLUSION: Multiple rotavirus serotypes were observed co-circulating in the city with serotype predominance changing between the two-year study. This study provides pre-vaccine baseline information on locally endemic strains that might help analysis of post-vaccine data.

Changing epidemiology of rotavirus-related hospitalizations in rio de janeiro, Brazil, from 2002 to 2006.

A prospective hospital-based sentinel study conducted in Rio de Janeiro identified a shift in the pattern (long to short electropherotype and P(8) to P(4) genotype) of rotavirus strains recovered from children with severe diarrhea a few months after the far-reaching Brazilian rotavirus immunization program was launched, posing new interesting challenges.

Cloning, expression, and purification of recombinant bovine rotavirus hemagglutinin, VP8*, in Escherichia coli.

Rotavirus VP8* subunit is the minor trypsin cleavage product of the spike protein VP4, which is the major determinant of the viral infectivity and neutralization. To study the structure-function relationship of this fragment and to obtain type-specific reagents, substantial amounts of this protein are needed. Thus, full-length VP8* cDNA, including the entire trypsin cleavage-encoding region in gene 4, was synthesized and amplified by RT-PCR from total RNA purified from bovine rotavirus strain C486 propagated in MA104 cell culture. The extended VP8* cDNA (VP8ext) was cloned into the pGEM-T Easy plasmid and subcloned into the Escherichia coli expression plasmid pET28a(+). The correspondent 30 kDa protein was overexpressed in E. coli BL21(DE3)pLysS cells under the control of the T7 promoter. The identity and the antigenicity of VP8ext were confirmed on Western blots using anti-His and anti-rotavirus antibodies. Immobilized Ni-ion affinity chromatography was used to purify the expressed protein resulting in a yield of 4 mg of VP8ext per liter of induced E. coli culture. Our results indicate that VP8ext maintained its native antigenicity and specificity, providing a good source of antigen for the production of P type-specific immune reagents. Detailed structural analysis of pure recombinant VP8 subunit should allow a better understanding of its role in cell attachment and rotavirus tropism. Application of similar procedure to distinct rotavirus P serotypes should provide valuable P serotype-specific immune reagents for rotavirus diagnostics and epidemiologic surveys.

Strong association between genotype F and hepatitis B virus (HBV) e antigen-negative variants among HBV-infected argentinean blood donors.

A number of reports have indicated an increased risk of cirrhosis and hepatocellular carcinoma in hepatitis B virus (HBV)-infected individuals carrying HBV e antigen (HBeAg)-negative variants. Although distinct core promoter and precore mutations distributed according to geographical locality and viral genotype have been reported, epidemiological data from South America are still scarce. The prevalences of HBV genotypes and core promoter and precore polymorphisms in 75 HBeAg-negative Argentinean blood donors were surveyed. The observed frequencies of HBV genotypes were 64.0% for genotype F, 17.3% each for genotypes A and D, and 1.3% for genotype C. Genotype F strains were widely distributed and significantly more prevalent in the northern region of the country (P < 0.001). An overall high proportion of a stop codon mutation (UAG) at precore codon 28 (66.7%) was observed. Wild-type codon 28 (UGG) was present in 29.3% of the samples, and the remaining 4.0% of samples had mixed variants. The combination of A at nucleotide (nt) 1762 and G at nt 1764 of the core promoter was found in 58.7% of the samples. The variant profiles--T at nt 1762 and A at nt 1764 or A at nt 1762 and A at nt 1764--were detected in 28.0 and 1.3% of the samples, respectively. The observed core promoter polymorphisms could not be related to the ratio of HBeAg to anti-HBeAg antibody, HBV genotype, or precore codon 28 status. Nevertheless, a clear association of genotype F and a precore stop codon mutation was found (P < 0.05). In conclusion, HBV genotype F and mutant codon 28 strains predominated and were strongly associated in a geographically broad Argentinean blood donor population.

A comparison of simian rotavirus SA11 preparations maintained in different laboratories

Preparaçöes da amostra SA11 de rotavírus símio mantidas em diferentes laboratórios foram comparadas entre si por eletroforese do genoma viral em gel de poliacrilamida. Diferenças na migraçäo dos segmentos genômicos 4,5 e 7 permitiram a classificaçäo de oito preparaçöes virais em quatro tipos eletroforéticos