Inapparent dengue virus infection among students in Mandalay, Myanmar

BACKGROUND: A school conducted to find out the burden of inapparent dengue virus (DENV) infection in Mandalay where DENV is endemic and there is circulation of all four DENV serotypes. METHODS: A total of 420 students who had no history of fever and visited the hospital within 6 months were recruited from three monastic schools. Serum samples were collected and the DENV genome was checked by conventional one-step RT-PCR and anti-DENV IgM and IgG antibodies were determined. Inapparent dengue (DEN) infection is defined as individuals who were either RT-PCR-positive or anti-DENV IgM-positive with no clinical manifestations or mild symptoms, and which are not linked to a visit to a healthcare provider. RESULTS: Among 420 students, 38 students (9.0%, 95% CI, 6.4 to 12.2) were confirmed as recent inapparent DEN infection. The DENV serotype-1 was detected in six students. Thirty-one out of 38 (81.6%) laboratory-confirmed inapparent DEN-infected students had primary infections and seven (18.4%) had secondary infections. CONCLUSION: This study explored the prevalence of inapparent DEN infection rate in urban monastic schools in Mandalay and showed that the rate of primary infection among inapparent DENV-infected children was high.