An atypical rotavirus detected in a child with gastroenteritis in Rio de Janeiro, Brazil

Particles morphologically identical to rotaviruses were found in the faeces of a nine week-old child with gastroenteritis. Analysis of the viral RNA genome by polyacrylamine gel electrophoresis revealed 10 bands (probably 11 segments) some of wich differed in migration rate from those of the great majority of rotaviruses infecting man and other animal hosts. The virus was not detected by a highly sensitive enzyme immunoassay (ELISA) and therefore probably lacked the crossreactive antigen(s) shared by the majority rotaviruses. This was the only strain with such behaviour among 230 rotaviruses of human origin examined in this laboratory since 1979. The implications of the existence of non-crossreactive rotaviruses are discussed.

Atypical rotavirus among diarrhoeic children living in Belém, Brazil

Atypical rotaviruses were detected in faeces from two diarrhoeic children living in Belém, Pará, Brazil. Rotavirus particles were detected by electron microscopy and the RNA electrophoresis showed patterns which were compatible with group C rotaviruses. Tests for the presence of group A antigen by enzyme-linked-immunosorbent assay (ELISA) were negative. The two children had three successive rotavirus infection and in both cases the atypical strains were excreted at the time of the third infection, causing a mild and short-lasting disease.

Group A rotavirus genotypes and the ongoing Brazilian experience: a review

Brazil was the first Latin American country to introduce universal group A rotavirus (RV-A) vaccination in March 2006, resulting in a unique epidemiological scenario. Since RV-A first identification in Brazil, 2,691 RV-A-positive stool samples, collected between 1982- 2007, were typed by independent research groups throughout the country. In the pre-vaccination era, 2,492 RV-A-positive samples collected from 1982-2005 were successfully typed, while 199 samples were analyzed from 2006-2007. According to the reviewed studies, there were two important times in the pre-vaccination era: (i) the period from 1982-1995, during which the detection of G5P[8] RV-A, in addition to the classical genotypes G1-4, challenged vaccine development programs; and (ii) the period from 1996-2005, during which genotype G9P[8] emerged, following a global trend. The rate of G2P[4] RV-A detection decreased from 26% (173/653) during 1982-1995 to 2% (43/1,839) during 1996-2005. The overall detection rate of RV-A genotypes from 1982-2005 was as follows: 43% (n = 1,079) G1P[8]/G1P[not typed (NT)]; 20% (n = 488) G9P[8]/G9P[NT]; 9% (n = 216) G2P[4]/G2P[NT]; 6% (n = 151) G3P[8]/G3P[NT]; 4% (n = 103) G4P[8]/G4P[NT]; and 4% (n = 94) G5P[8]/G5P[NT]. Mixed infections accounted for 189 (7%) of the positive samples, while atypical G/P combinations or other genotypes, including G6, G8, G10 and G12, were identified in 172 (7%) samples. The initial surveillance studies carried out in several Brazilian states with RV-A-positive samples collected in 2006 and 2007 show a predominance of G2P[4] strains (148/199 or 74%). Herein, we review RV-A typing studies carried out since the 1980s in Brazil, highlighting the dynamics of RV-A strain circulation profiles before and early after universal use of RV-A vaccine in Brazil.

Identificação por contraimunoeletroforese de rotavirus em casos de diarréia infantil

Os resultados obtidos na identificação de rotavirus, usando a técnica da contraimunoeletroforese, com 162 amostras de feses de crianças com quadros diarréicos agudos, mostram uma distribuição percentual de positividade de 72,7%, 77,7% e 66,6% em diferentes grupos etários de 6 a 8 meses até um ano de idade.

Detection of Astrovirus-like in diarrhoeic stool and its coexistence with Rotavirus

A clinical case is described in this paper in that a 5-month old baby girl severely malnourished and dehydrated presented a prolonged acute diarrhoea. No enteropathogenic bacteria or parasites were demonstrated. Virological study by electron microscopy (EM) showed that the patient shed both astrovirus-like and rotavirus in the watery stool as long as 12 days after the onset. Immune electron microscopy (IEM) performed with the patient serum revealed clumps of both viruses. It is suggest that this may be a case of mixed infection due to astrovirus-like and rotavirus.

Reinfections and rotavirus serotypes in Belém, Brazil

Repeated infections involving different rotavirus serotypes were detected in four children living in Belém, who were followed up since birth to three years of age. In one child (Reg. 23.983) three successive symptomatic infections (one of them associated with serotype 2) were noted: the first, at four months of age, the second at 20 months and the third at 27 months. Another child had two subsequent infections, the first one by rotavirus serotype 1, and the second by a not identified rotavirus serotype. In this case two episodes of rotavirus-related diarrhoea were recorded, occurring eight months apart. Apparent infections were detected on two occasions involving the same child (Reg. 24.004), the first being associated with serotype 1, and the second with serotype 2. The fourth child (Reg. 24.097) had two successive infections by not determined rotavirus serotypes, without clinical manifestations; the first occurred at 24 months and the second at 28 months.

Immunofluorescent antibody to rotavirus and antigen excretion in infantile acute diarrhoea

A serological study was carried out to evaluate the causal relationship of acute diarrhoea and rotavirus in children under five years of age. The rotaviral infection was demonstrated in paired sera by determining the antibody titers by immunofluorescence test (IF). Bovine rotavirus-infected MA-104 cell culture was used as substratum for IF. Out of 80 paired sera it was shown that 23 (28.75%) presented seroconversion, 19 (23.75%) samples showed a twofold increase in their titers and 38 (47.5%) had no increase in rotavirus antibody. This result is discussed on the light of previously obtained results on viral antigen detection by counterimmunoelectrosmophoresis (CIEOP).

A serological investigation of rotavirus infections in a shanty town population in Rio de Janeiro

The presence of antibodies against rotavirus was investigated by enzyme immunosorbent assay (ELISA) in two distinct groups of children living in a shanty town in Rio de Janeiro. One hundred and thirty six plasma samples were randomly collected from children of 0 to 33 months (first group) and 255 serum samples were collected from other 85 children at ages of 2, 6 and 9 months (second group). A high percentage of antibodies were found in the newborn children and this rate decreased progressively until the age of 11 months, after which it increased again. At the age of 7 months, geometric mean antibody titers increased indicating that infection had occurred.

Incidência de escherichia coli enterotoxigênica (ETEC), rotavirus e Clostridium perfringens de casos de diarréia em crianças, na região de Campinas, SP, Brasil

Foi realizada uma pesquisa na região de Campinas, SP, Brasil, sobre a presença de Escherichia coli enterotoxigênica (ETEC), rotavírus e Clostridium perfringens enterotoxigênico em fezes diarréicas de crianças com até 2 anos de idade. Dos 132 espécimens fecais examinados quanto à presença de ETEC 27 (20,45%) foram positivos. Destes foram isoladas 41 amostras de ETEC, das quais 40 produziram apenas a enterotoxina termolábil (LT) detectada pelo teste de imuno hemólise radial modifi cado. Entre as 183 amostras de fezes examinadas para rotavírus, 29 (15,84%) foram positivas pelas técnicas de eletroforese em gel de poliacrilamida (PAGE) e ensaio imunoenzimático (EIE), sendo que destas, 15 (51,7% ) foram provenientes de materiais coletados nos meses de inverno. Todas as amostras pertenciam ao grupo A e, através da técnica de PAGE, pode-se observar que o tipo eletroforético mais freqüente (9 amostras) foi designado Ib, IIc, Illb, IVa, de acordo com a classificação por nós adotada. Apenas 113 amostras de fezes foram examinadas para a presença de C. perfringens enterotoxigênico. Para a detecção da enterotoxina nos sobrenadantes das culturas foram utilizadas as técnicas de hemaglutinação passiva reversa e inoculação intravenosa em camundongos, sendo encontradas 12 (10,61%) amostras entero-toxigênicas. Diante destes resultados é chamada a atenção sobre o valor apenas relativo de uma coprocultura convencional para fins de diagnóstico, ressaltando-se a importância da criação de métodos simplificados que favoreçam a detecção e identificação dos grupos de agentes enteropatogênicos estudados na presente pesquisa.

Rotavirus associated diarrhoea during infancy in the city of S. Luís (MA), Brazil: a two-year longitudinal study

A total of 479 diarrhoeic children and 337 children without diarrhoea (controls) less than 5 years old were investigated in a two-year study in the city of S. Luís (MA), with the purpose to determine the incidence, the age distribution and the seasonality of rotaviruses, as well as to establish the severity of the disease in this region between the North and the Northeast of Brazil. rotavirus incidence was highest in children of the 1st. year of life, showing an average of 25% per year among the diarrhoeic patients attending the two main hospitals and three health units at the periphery of the city. It was shown that rotaviruses are significant enteropathogens in children less than 18 months old. Frequency of rotaviruses droped in diarrhoeic patients 18 to 23 months old to only 4%, the same percentage observed in children of the control group. A typical seasonal distribution of rotaviruses was not seen during the two years of study. There was a peak in the incidence of rotaviruses in 1986, during the rainy season, and two peaks in 1987, one in the rainy season and one in the dry season. It was also shown that severity of diarrhoea in rotavirus positive cases was higher than in the negative cases. Rotavirus diarrhoeic patients had more loose stools per day, and higher frequencies of vomiting and fever, resulting more often (> 2 times) in moderate or severe dehydration. Finally, it is concluded that the introduction of immunoprophylaxis may reduce significantly the high mortality rates in early childhood observed in S. Luís.

Rotavirus e adenovirus em crianças de 0-5 anos hospitalizadas com ou sem gastrenterite em Goiânia - GO., Brasil

De junho/1987 a julho/1990 foram estudadas 557 amostras fecais de crianças hospitalizadas de 0-5 anos de idade, na cidade de Goiânia-GO., para detecção de rotavírus e adenovírus. Destas, 291 provinham de crianças diarréicas e 266 de não diarréicas. Das amostras não diarréicas, 64 eram provenientes de crianças de berçário. Das 557 amostras, 261 foram analisadas pela imunomicroscopia eletrônica (IME), eletroforese em gel de poliacrilamida (EGPA-SDS) e ensaio imunoenzimático para rotavírus e adenovírus (EIARA) e as demais apenas pela EGPA e EIARA. Rotavírus e adenovírus mostraram positividade de 17,2% e 2,1% respectivamente, e na condição de diarréia ou não, observou-se percentuais de 29,2% e 4,1% respectivamente para rotavírus (p<0,05) e 2,4% e 1,5% para adenovírus. Rotavírus foram mais prevalentes entre as crianças de 1-11 meses de idade e não foram vistos em nenhum recém-nato de berçário. Os adenovírus ocorreram na faixa de 1-3 anos. Rotavírus apresentaram maior circulação entre os meses de maio a agosto (p<0,05), não sendo encontrados de dezembro a fevereiro.

Difficulties in diagnosing atypical primary HIV-1 infection

Several cases of primary HIV-1 infection are not identified, either because the diagnosis is not suspected or because they test negative for HIV-1 antibody. This work presents an uncommon case of primary HIV-1 infection in an young parenteral drug abuser man, who presented symptoms of acute hepatitis. During the initial acute phase the serum sample of the patient tested negative for the presence of antibodies against several viruses, including HIV-1. Nevertheless, the diagnosis of primary HIV-1 infection was suspected by using an alternative method for"in vitro" induced antibody production (IVIAP), and confirmed by p24 antigen serum positivity and seroconversion in serial plasma samples of the patient. The authors suggest the use of the IVIAP and others complementary assays to help the diagnosis of acute HIV-1 infection in persons at high risk conditions.

Concomitant rotavirus serotypes 1 and 4 infections in a diarrhoeic child from Belém, Brazil

Concomitant serotypes 1 and 4 infections were detected in a 15-month old female child with community-acquired diarrhoea which lasted 7 days and coursed with moderate dehydration. The evidence for dual rotavirus infection was offered by the following findings: a) enzyme-linked immunosorbent assay (ELISA) positive reactions to both 1 and 4 serotypes; and b) extra-migrating bands at electro-phoresis of RNA in polyacrylamide gel (PAGE). These results suggest that children living under poor sanitation conditions are heavily exposed to rotavirus infections; in addition, the co-circulation of different serotypes in the same setting sustains the current concept that a rotavirus vaccine should be rnultivalent, in order to protect children against the four epidemiologically important rotavirus G serotypes.

Characterization of rotavirus P genotypes circulating among paediatric inpatients in Northern Brazil

Between November 1992 and August 1993, twenty-eight rotavirus-positive stool samples obtained from paediatric inpatients in Belém, Brazil, aged less than four years, were tested by RT-PCR to determine the P genotype specificities. With the exception of 7 non-diarrhoeic children, all patients were either diarrhoeic at admission or developed diarrhoea while in hospital. Rotavirus strains with the gene 4 alleles corresponding to P1B[4] and P1A[8] types (both of which bearing G2 specificity) predominated, accounting for 78.6% of the strains. While only one P2A[6] type strain - with (mixed) G1 and 4 type specificities - was detected, the gene 4 allele could not be identified in 4 (14.3%) of the strains. Most (81%) of the specimens were obtained from children during their first 18 months of life. Rotavirus strains bearing single P1B[4] type-specificity were identified in both diarrhoeic (either nosocomial, 28.6% or community-acquired diarrhoea, 28.6%) and non-diarrhoeic (42.8%) children. P1A[8] gene 4 allele, on the other hand, was detected only among diarrhoeic children, at rates of 57.1% and 42.9% for nosocomial- and- community acquired diarrhoea, respectively. Mixed P1A[8],1B[4] type infection was identified in only one case of community-acquired diarrhoea.

Atypical disseminated cutaneous histoplasmosis in an immunocompetent child, caused by an "aberrant" variant of Histoplasma capsulatum var. capsulatum

A case of atypical disseminated cutaneous histoplasmosis in a five-year old, otherwise healthy child, native and resident in São Paulo metropolitan area is reported. Cutaneous lesions were clinically atypical. Histologic examination disclosed a granulomatous reaction but no fungal structures could be demonstrated by specific staining nor by immunohistochemical reaction. The fungus was isolated from biopsy material on two different occasions, confirming diagnosis of an unusual fungal infection. The fungus, originally thought to be a Sepedonium sp. due to the large sized, hyaline or brownish colored tuberculated macroconidia and to lack of dimorphism (yeast form at 37 °C) produce H and M antigens, visualized by the immunodiffusion with rabbit anti-Histoplasma capsulatum hyperimmune serum. Patient’s serum sample was non reactive with H. capsulatum antigen by immunodiffusion, counterimmunoelectrophoresis and complement fixation tests, and immunoenzymatic assay failed to detect the specific circulating antigen. This serum was tested negative by double immunodiffusion when antigen obtained from one of the isolated samples was used. Both cultures were sent to Dr. Leo Kaufman, Ph.D. (Mycoses Immunodiagnostic Laboratory, CDC-Atlanta/USA), who identified them as H. capsulatum by the exoantigen and gen-probe tests. Both clinic and mycologic characteristics of the present case were atypical, suggesting the fungus isolated is an “aberrant variant” of H. capsulatum var. capsulatum, as described by SUTTON et al. in 199719. Treatment with itraconazole 100 mg/day led to cure within 90 days