IgM ELISA: A Better Choice for the Detection of Active Chlamydia trachomatis Infection among HIV Patients 34-37
Dr. Padma Krishnan
Asst Professor, Dept of Microbiology,
Dr. ALM Post Graduate Institute of Basic Medical Sciences,
University of Madras, Taramani campus, Chennai- 600113.
Phone: +91 9840742105; Fax: +91 44 24540709
E-mail address firstname.lastname@example.org
Context: Co-morbid STIs are documented to serve as risk factors that facilitate the acquisition and transmission of HIV. The cryptic plasmid has been linked to Chlamydial virulence and serves as a key target of diagnostic PCR assays. Reports on the higher incidence of Chlamydia trachomatis infection and the emergence of plasmid-less isolates in developing countries have raised concern.
Aim: The study was aimed to determine the prevalence of active C. trachomatis infection among high risk subjects in South India.
Materials and Methods: Serum and first-void urine samples were screened for C. trachomatis using IgM ELISA and COBAS AMPLICOR PCR respectively.
Results: The study participants include, 100 HIV seropositive patients, 51 Non-HIV-subjects attending STI clinic and 25 healthy adults. The incidence of C. trachomatis infection among HIV patients (n= 100) as measured by positive IgM ELISA result was 3%, while 0% positivity was observed among the cohort II and III. However, PCR analysis revealed that the cryptic plasmid was not detected in the three EIA positive patient samples.
Conclusions: We report here of low incidence of C. trachomatis infection among HIV patients in south India. Discrepancies were noted between the results of IgM ELISA and plasmid- PCR. Our results suggested the existence of plasmid-less/natural variant strains of C. trachomatis in South India. Thus, IgM ELISA still remains the method of choice in the laboratory diagnosis and obviates the use of plasmid based NAATs which could only under estimate the incidence of C. trachomatis infection among the HIV patients.