Human parvovirus B19 infections among exanthematic diseases notified as measles

Abstract

A total of 1397 sera collected from 1095 cases of exanthematic disease notified as measles in ES and RJ states during July 1992 to December 1994 were investigated. These sera were first tested for measles and rubella specific IgM. When they proved negative, they were tested for B19 specific IgM by an enzyme immunoassay. B19 infection was confirmed in 27 (2.5%) of these cases. Sera from 194 negative cases for measles and rubella IgM received from other Brazilian states were also investigated and B19 infection was confirmed for 11 of them. Sera from these 38 IgM positive cases for B19, were tested for anti-B19 IgG by an enzyme immunoassay and for B19 DNA by dot blot hybridization. Anti-B19 IgG antibodies were detected in most of the acute sera. B19 DNA was detected in the acute serum of one patient that had been splenectomized before. As the exanthem caused by human parvovirus infection may be clinically diagnosed as rubella, it could be important to diagnose B19 infection in Brazil since it is becoming prevalent as the cause of rash in countries where rubella is controlled by vaccination.<br>Um total de 1397 soros colhidos de 1095 casos de exantema notificados como sarampo, nos estados do ES e RJ, no período de julho de 1992 a dezembro de 1994, foram investigados. Estes soros foram inicialmente testados para sarampo e rubéola por detecção de IgM específica. Os casos negativos foram então testados para a presença de IgM específca anti-B19 por um ensaio imunoenzimático. A infecção pelo B19 foi confirmada em 27 (2,5%) destes casos. Soros de 194 casos negativos para sarampo e rubéola provenientes de outros estados brasileiros foram também investigados, e a infecção pelo B19 pode ser confirmada em 11 destes casos. Os soros dos 38 casos IgM positivos para B19 foram testados para a presença de IgG específica anti-B19 por um ensaio imunoenzimático, e para a presença do ADN viral por hibridização em "dots" (dot blot). IgG específica anti-B19 pode ser detectada na maioria dos soros de fase aguda, e o ADN viral foi detectado no soro de fase aguda de um paciente esplenectomizado. Como o exantema causado pela infecção pelo parvovírus humano pode ser clinicamente diagnosticado como rubéola, seria importante realizar o diagnóstico desta virose no Brasil, já que um aumento no número de casos de exantema por B19 tem sido relatado nos países onde a rubéola é controlada por vacinação

Clinical and epidemiological aspects of human parvovirus B19 infection in an urban area in Brazil (Niterói city area, State of Rio de Janeiro, Brazil)

“…Outbreaks of parvovirus B19 infection in temperate climates are more common in late winter and spring months, though cases may be recorded in any month (Cohen 1995). In our study, 92.4% of the cases were recorded during this season, similar to the report by Cubel et al (1997) for other regions of Brazil. However, different findings were reported in the Amazon region by Miranda et al (1989), who described higher incidence of the disease during the first half of the year, a season of heavy rainfall and high humidity in the North of our country.…”

“…Moreover, parvovirus B19 infection shares the seasonal pattern with rubella and measles, i.e., late winter and spring, which makes clinical diagnosis even more difficult. In Brazil, because of the reduction in measles and rubella incidence rates after the introduction of national mass vaccination campaigns, parvovirus B19 infection has increased its relative importance in the surveillance of rash diseases (Cubel et al 1997, Ministério da Saúde 1999, Oliveira et al 2001a). However, without the aid of laboratory methods, the public health relevance is likely to be unnoticed.…”

Assessment of Immunoglobulin M Enzyme Immunoassays for Diagnosis of Measles

“…It has been shown that false-positive measles IgM results can occur, particularly with parvovirus B19 and rubella virus, which have similar clinical presentations (3,6,8). In addition, it has been shown that reactivation of IgM responses to multiple viruses (including measles and rubella viruses and parvovirus B19) can occur in response to infection by one of the viruses (14).…”

Anti-VP1 and anti-VP2 antibodies detected by immunofluorescence assays in patients with acute human parvovirus B19 infection

“…Compared to EIA (Cubel et al 1997) the sensitivity of IFA with VP1 was 100% and with VP2, 98.7%; the specificity with VP1 was 86.6% and with VP2, 93.3%. The 2 sera IgG negative by EIA and positive by VP1 IFA, were confirmed as B19 IgG positive by a sensitive and specific anti-VP1 Western-blotting assay (Pinheiro et al 1997), so the anti-VP1 IgG IFA could be considered 100% sensitive and specific.…”

“…The sera had previously been tested for anti-B19 IgM by MACEIA using the native virus as antigen (Cubel et al 1994) and for anti-B19 IgG using baculovirus recombinant capsids (Kajigaya et al1991) containing VP2 (70%) and VP1 (30%) in a indirect enzyme immunoassay (EIA) (Cubel et al 1997). All sera were now tested for anti-B19 IgM and IgG using Sf9 cells expressing both VP1 and VP2 by immunofluorescence assay (IFA) as described bellow.…”