Human herpesvirus-7 as a cause of exanthematous ilnesses in Belém, Pará, Brazil.
We screened sera from 370 patients suffering from exanthematous illnesses in Belém, North Brazil, for the presence of human herpesvirus-7 (HHV-7) IgM and IgG antibodies. Samples were obtained from January 1996 to December 2002 and were processed by a HHV-7-specific indirect immunofluorescence assay (IFA). HHV-7-specific IgM and/or IgG antibodies were found in 190 (51.4%) of these patients, with similar prevalence rates (IgM+ and IgG+ subgroups taken together) for female and male subjects: 52.5% and 50.3%, respectively. Serological status as defined by IgG was identified in 135 (36.5%) patients. In 55 (14.9%) of the patients HHV-7 IgM antibodies were detected. HHV-7 IgM- and- IgG antibody rates were similar (p > 0.05) when male and female subjects are compared: 14.4% versus 15.3% and 38.1% versus 35.0%, respectively. Statistically significant difference (p = 0.003) was noted when HHV-7-IgM-positive female and male patients aged 5-8 months are compared. Prevalence rates ranging from 4.6% (female, 5-8 months of age) to 93.3% (female, > 10 years of age) and 12.2% (male, 5-8 months) to 80.0% (male, 8-10 years of age) were noted in the IgG- positive subgroups. A subgroup (n = 131) of patients with IgM or IgG HHV-7 antibodies were examined for the presence of DNA using a polymerase chain reaction/nested PCR. Recent/active HHV-7 infection occurred at a rate of 11.0% (6/55) among patients whose samples presented IgM+ specific antibodies. In a subgroup (n = 76) of patients with high HHV-7-IgG antibody levels (titre > 1:160) DNA could not be detected in sera examined by PCR/nested PCR. Of the six recent/active infections, four subjects with less than 1 year and two with 3 and 6 years of age, presented typical exanthem subitum (E.S), as defined by higher fever (> 38.0 degrees C) with duration of 24 to 72 hours, followed by a maculopapular skin rash. Our results underscore the need for searching HHV-7 infection in patients with exanthematous diseases, particularly those presenting with typical E.S. HHV-7 appears therefore to emerge as a newly recognized pathogen of exanthem in our region.
Freitas
Ronaldo B
RB
Seção de Virologia, Instituto Evandro Chagas, Secretaria de Vigilância em Saúde, Ministério da Saúde, Belém, Para, Brazil. ronaldofreitas@iec.pa.gov.br
Freitas
Maria R
MR
Oliveira
Consuelo S
CS
Linhares
Alexandre C
AC
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood*; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005076:Exanthema / Q000453:epidemiology / Q000821:virology*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D016199:Herpesvirus 7, Human / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D008297:Male; D008875:Middle Aged; D019349:Roseolovirus Infections / Q000453:epidemiology / Q000821:virology*; D016036:Seroepidemiologic Studies; D017678:Sex Distribution
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M