Molecular detection of human Parvovirus B19 in serum samples collected from 1998–2011 in Manaus, Amazonas State, Brazil

Parvovirus B19 (B19V) belongs to the Parvoviridae family and Erythrovirus genus and is predominantly transmitted by respiratory secretions. It is responsible for many diseases, such as infectious erythema, acute or chronic arthropathy in adults, transient aplastic crisis, anemia in immunodeficient or immunocompromised patients, and fetal hydrops in pregnant women. However, most infections are asymptomatic or manifest only nonspecific symptoms, such as fever, headache, arthralgia, rash and coryza and can therefore be easily confused with other viral infections. The first case of laboratory-proven B19V infection in Amazonas was reported in 2005. IgM antibodies against B19V were detected in serum samples collected from 1999 to 2003 from pediatric patients suspected of suffering from dengue fever. This study presents the first molecular detection of B19V in samples collected from 1998 to 2011 from Manaus, Amazonas. 177 serum samples collected during the acute phase (0–6 days) negative for dengue and stored at -80 °C were subjected to viral DNA extraction and nested PCR according to the protocol for B19V DNA detection. 92 samples (51.9%) tested positive for B19V, with the highest positivity in those from 2002. The youngest patient was 2 months old and the oldest was 76 years old, and the largest number of samples belonged to the 20–59 age group. Both genders were equally infected, with symptoms being similar to those of dengue. These results confirm the presence of autochthone of B19V in DENV samples since 1998 and the underreporting in Manaus, highlighting the importance of differential diagnosis during epidemics.