Seroprevalence of Mycoplasma pneumoniae Specific IgM and IgG Antibodies in Asymptomatic Preschool Aged Children of Tehran, Iran, 2010

Background: Respiratory tract diseases in children are one of the two leading causes of death worldwide and Mycoplasma pneumonia is the most important etiologic agent of respiratory tract infections. Objectives: This study aimed at determining the seroprevalence of Mycoplasma pneumoniae specific IgM and IgG antibodies in asymptomatic 5- to 6-year-old children in Tehran, Iran. Methods: This cross sectional studywasconducted duringsummerseason of year 2010 in Tehran, North of Iran. Overall, 291 children were enrolled in the study in a sequential method. Blood samples were obtained from each child and the serum was separated and stored frozen at -70°C for later antibody assay. Detection of IgM and IgG antibodies against M. pneumoniae was performed using commercial qualitative Enzyme Linked Immunosorbent Assay (ELISA) kits. Results: Of the 291 participants in the present study, 156 (53.6%) were female and 135 (46.4%) were male. Overall, 73 (25.1%) serum samples had positive results for M. pneumoniae specific IgG. The frequency of positivity and mean of titers for M. pneumoniae specific IgG antibody amongmales and females was 31 (23%), 17.45.5 U/mL (95% CI 16.77 - 18.03) (ranged from 12.2 to 33 U/mL), and 42 (26.9%); 17.1 4.4 U/mL (95% CI 16.6 - 17.6) (ranged from 12 to 28 U/mL), respectively. Moreover, all tested serum samples for M. pneumoniaespecific IgM were negative. Conclusions: In summary, our findings present the frequency of recent and previous exposure to M. pneumoniae infection among asymptomatic children aged from 5 to 6 years old in our region. Moreover, findings of such surveillance studies could provide useful insight to compare our situation with others.