Human herpesvirus-7 as a cause of exanthematous ilnesses in Belém, Pará, Brazil

Abstract

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.

Non-CMV Viral Infections Following Solid-Organ Transplantation – Focus on Human T-Cell Lymphotropic Virus Type-1 and Human Herpesviruses-6,-7 and -8

“…Infection due to HHV-7 occurs in early childhood but tends to occur later than HHV-6B [93]. The clinical manifestations of primary HHV-7 infection are not as well-defined but it has been described as a cause of exanthem subitum and febrile illness with seizures [94,95]. Primary HHV-7 infection is followed by the establishment life-long latency in host-peripheral blood mononuclear cells [96].…”

Beyond arboviruses: A multicenter study to evaluate differential diagnosis of rash diseases and acute febrile illness cases in Rio de Janeiro, Brazil

“…In Brazil, the epidemiological scenario of B19V was recently reviewed [18], and we observed that the period of study was from 1987 to 2016 in specific states of the country and varied from 2% (Para ´state in 1987) to 63.2% (São Paulo state in 2013-2014). In relation to herpesviruses, the seroprevalence of EBV, CMV, HHV-6 and HHV-7 has been evaluated in some studies with groups of patients with rash diseases of unknown etiology [19][20][21][22][23], and we observed that the period of study was from 1996 to 2011 in specific states of the country and varied from 2.0% (Para ´state in 1997) to 3.1% (São Paulo state in [2003][2004] for EBV, 17.0% (São Paulo state in 2000-2004) to 63.8% (Para ´state in 1997) for HHV-6, and 8.0% (São Paulo state in 1992-1993) to 51.4% (Para ´state in 1996-2002) for HHV-7. Therefore, there have been no epidemiological efforts to present the real dynamics of this infection in Brazil in recent years.…”

Development of an enzyme-linked immunosorbent assay for diagnosis of human herpesvirus-7 infection

“…The HHV-7 virus is ubiquitous and has a seroprevalence rate of 93.3% in northern Brazil 2 . HHV-7 infections in early childhood lead to common febrile infectious syndromes, known as exanthema subitum and roseola.…”