Rickettsial diseases: revisiting an old enemy

Abstract

The history of rickettsioses in Sri Lanka dates back to 1930-1940s. Since of late, rickettsial infections have re-emerged in many parts of the world, including Sri Lanka. We observed patients presenting with serious complications such as encephalitis, myocarditis, pneumonitis and multi-organ involvement carrying high morbidity and mortality due to rickettsioses. Such presentations made us realize the importance of establishing diagnostic facilities in the country in order to face the challenge posed by rickettsioses. After initial collaborative work with the Centers for Disease Control and Prevention, Atlanta, USA, we established IFA based diagnostics in the Faculty in 2008. Subsequently we were able to describe the epidemiological pattern, different clinical presentations, and new serological cut-off points for IFA-IgG based serological diagnostics based on sero-prevalence. Thereafter, in collaboration with the University of Texas Medical Branch at Galveston, USA, we were able to describe the diverse distribution of scrub typhus serotypes in two different localities in Sri Lanka. Subsequently, in collaboration with ImmuneMed diagnostic laboratory at Incheon, South Korea, we were able to identify antibody-based rapid diagnostic tests which could be employed for rapid diagnosis and identification of scrub typhus strains in Sri Lanka.