Serologic studies on the behaviour of influenza virus type A in persons of greater São Paulo during 1976, 1978 and 1979

Sera of persons of different age groups collected in 1976, 1978 and 1979 were tested for the presence of HI antibodies against various strains of the H3N2 and H1N1 subtypes of influenza virus. The occurrence of infection by H3N2 subtype was recorded during the 1976-1978 period but in 1979, circulation of this subtype of virus was limited. The prevalence of antibody against A/São Paulo/1/78 (H1N1) was significantly higher than that of antibody to A/USSB/90/77 (HIND in 1978. However in 1979 the predominant strain was A/USSR/90/77 (HIND. Persons under 20 years of age were the most affected by H1N1 subtype. Antibodies to H1N1 subtype were detected in sera of individuals older than 20 years in 1976, before the re-emergence of this strain. Serological results indicate that infections by H3N2 subtype in 1978 occurred in 65.4% of young children (0-4 year group). About 47.0% of children from the 0-4 year group had antibodies to H1N1 subtype in 1979. Antibodies to swine influenza virus were detected in 60% of 60+ year old people.

Human disease in ribeira valley, brazil caused by caraparu, a group c arbovirus - Report of a case

The clinical and laboratory data of a disease in a resident of Ribeira Valley, São Paulo State, southeastern Brazil, caused by an agent close or identical to Caraparu, a Group C arbovirus, was described. Although there is evidence of an intensive circulation of several arboviruses in the area, no diagnosis of human disease by these agents has been made, except the encephalitis cases caused by Rocio virus during an epidemic in 1975-1977. An antigenic difference between Caraparu strains isolated in São Paulo and in Pará States and a close antigenic relationship between Caraparu strain from São Paulo and Bruconha virus were suggested by the serological tests.

Mediastinal and pulmonary entomophthoromycosis with superior vena cava syndrome: case report

The first case of mediastinal and pulmonary entomophthoromycosis with supe rior vena cava syndrome is reported. The patient presented with a history of edema of the face, neck and upper limbs as well as collateral circulation in the anterior wall of the chest. Histological examination of tissue from mediastinum revealed a granulomatous reaction with microabscesses surrounded by eosinophilic amorphous material and with broad hyphae in the center. Culture was not performed because a preliminary diagnosis of nonHodgkin's malignant lymphoma was made. Surgical correction of the obstructed area was performed and the patient was sucessfully treated with potassium iodide. The authors propose that mediastinal entomoph thoromycosis must be considered in the differential diagnosis of diseases causing superior vena cava syndrome in tropical and sub-tropical regions. This case enlarges the spectrum of clinical manifestations of the zigomycosis caused by Entomoph-thoraceae.

Evaluation of the double diffusion, enzyme immunoassay and immunoblotting techniques, for the diagnosis of human hydatid disease in tropical areas

Hydatid disease in tropical areas poses a serious diagnostic problem due to the high frequence of cross-reactivity with other endemic helminthic infections. The enzyme-linked-immunosorbent assay (ELISA) and the double diffusion arc 5 showed respectively a sensitivity of 73% and 57% and a specificity of 84-95% and 100%. However, the specificity of ELISA was greatly increased by using ovine serum and phosphorylcholine in the diluent buffer. The hydatic antigen obtained from ovine cyst fluid showed three main protein bands of 64,58 and 30 KDa using SDS PAGE and immunoblotting. Sera from patients with onchocerciasis, cysticercosis, toxocariasis and Strongyloides infection cross-reacted with the 64 and 58 KDa bands by immunoblotting. However, none of the analyzed sera recognized the 30 KDa band, that seems to be specific in this assay. The immunoblotting showed a sensitivity of 80% and a specificity of 100% when used to recognize the 30 KDa band.

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.

VISCERAL LARVA MIGRANS AND TROPICAL PYOMYOSITIS: A CASE REPORT

We report a case of tropical pyomyositis in a boy who presented with a severe febrile illness associated with diffuse erythema, and swelling in many areas of the body which revealed on operation extensive necrotic areas of various muscles that required repeated débridement. The patient gave a history of contact with dogs, and an ELISA test for Toxocara canis was positive. He also presented eosinophilia and high serum IgE levels. Staphylococcus aureus was the sole bacteria isolated from the muscles affected. We suggest that tropical pyomyositis may be caused by the presence of migrating larvae of this or other parasites in the muscles. The immunologic and structural alterations caused by the larvae, in the presence of concomitant bacteremia, would favour seeding of the bacteria and the development of pyomyositis.

An indirect immunofluorescence assay to detect antibodies against St. Louis Encephalitis virus

An in house indirect immmunofluorescence assay ( IFA ) in relation to neutralization (NT) reference test, was assessed as a fast and cheap method to carry out serological surveys for St. Louis Encephalitis virus (SLE). Sera obtained from 213 blood donors were analyzed by both tests. The prevalence of seropositivity obtained with IFA was lower than (30.98%) that observed on NT (41.78%). The relative specificity rate of IFA was 96.77% whereas its relative sensitivity rate was 69.66%. Kappa index showed a good correlation between both tests. The results indicate that neutralization assay is still the serological test with the highest sensitivity and specificity relative rates for detecting antibodies against SLE virus. Nevertheless, the IFA could be useful as an alternative test in order to learn the circulation of the Flavivirus genus in a certain area.

Molecular typing of dengue virus type 2 in Brazil

Strain typing is a critical tool for molecular epidemiological analysis and can provide important information about the spread of dengue viruses. Here, we performed a molecular characterization of DEN-2 viruses isolated in Brazil during 1990-2000 from geographically and temporally distinct areas in order to investigate the genetic distribution of this serotype circulating in the country. Restriction site-specific polymerase chain reaction (RSS)-PCR presented the same pattern for all 52 Brazilian samples, showing the circulation of just one DEN-2 variant. Phylogenetic analysis using progressive pairwise alignments from 240-nucleotide sequences of the E/NS1 junction in 15 isolates showed that they belong to genotype III (Jamaica genotype).