Mycoplasma pneumoniae is increasingly recognized as a common and important pathogen in community settings, and is responsible for various pulmonary and extrapulmonary conditions in the normal population. However, the seroepidemiology of acute M. pneumoniae infection in HIV-infected individuals is still unclear worldwide. This study examined the seroprevalence of antibodies to M. pneumoniae in HIV-infected patients admitted with respiratory complaints at a tertiary AIDS care centre in Chennai, India. A commercial gelatin microparticle agglutination test (Serodia-Myco II, Fujirebio) was used for the determination of antibodies against M. pneumoniae in acute serum specimens. Of the 200 HIV-infected patients with underlying pulmonary conditions tested, 34 (17 % positivity; 95 % CI 12-23 %) had antibodies specific to M. pneumoniae, while among the 40 patients with no underlying pulmonary symptoms, five (12?5 % positivity; 95 % CI 4-27 %) had evidence of anti-M. pneumoniae antibody. This shows that the incidence of M. pneumoniae seropositivity is greater in patients with underlying pulmonary complaints. Most positive titres were found in the age group 28-37 years in the symptomatic and symptom-free groups (64?7 and 60 %, respectively). The positive titres ranged from 40 to >20 480. High titres (¢320) were found in 10 out of the 39 patients (25?6 %). This seroprevalence study reports a 16?2 % prevalence of M. pneumoniae infections in HIV-infected patients by a particle agglutination test.
INTRODUCTIONMycoplasma pneumoniae is an important cause of upper and lower respiratory tract infections, including pharyngitis, tracheobronchitis and pneumonia, in children and adults of all ages (Cassell et al., 1981;Maniloff et al., 1992). Laboratory diagnosis of M. pneumoniae infection has relied mainly on serologic tests, because the organism is difficult to isolate (Chamberlein et al., 1983;Cimolai et al., 1996;Fedorko et al., 1995;Karppelin et al., 1993;Tully et al., 1979). A reliable and sensitive serologic test is needed for use in the early phase of infection by M. pneumoniae to confirm the infection and to ensure that the appropriate antibiotic is used for treatment. The detection of specific IgM, which appears 7-10 days after infection and approximately 2 weeks before IgG, has been shown to indicate a recent or current M. pneumoniae infection (Jacobs, 1993;Matas et al., 1998;Sherman et al., 1993;Sillis, 1990). However, the presence of IgM in adult serum does not always indicate a current infection, because in some cases IgM has been shown to persist for up to a year after infection. In addition, the IgM response is minimal or undetectable in some cases of adult reinfection with M. pneumoniae (Chamberlein et al., 1983;Jacobs, 1993;Sherman et al., 1993; Vikerfors et al., 1988). Therefore, reliance on the detection of specific IgM alone, especially in an adult population, could allow some infections to be missed. In a previous study (Vikerfors et al., 1988), approximately 20 % of adults did not mount an IgM response after in...