Rickettsial infections in acute coronary syndromes

Abstract

INTRODUCTION AND OBJECTIVES: Rickettsiae are a group of obligate intraceliular pathogens which invade endothelial cells causing vasculopathy. Vasculitis of any cause may result in acute coronary syndromes (ACS). Objectives were to assess the prevalence of Rickettsial infections in patients with ACS from Western province, Sri Lanka. METHODS: Prospective patients from Western province with ACS admitted to Professorial Medical Unit, Colombo North Teaching Hospital, Ragama from April-December 2011 were recruited as the study group. A matched control group was selected from in-ward-patients without fever or ACS. Serum samples (2ml) collected at enrolment and after 2 weeks were analysed. Rickettsial-antibody (IgG) titre >128, or a rising or a declining titre were considered positive for acute rickettsioses. A static titre was considered as previous exposure to rickettsioses (sero-prevalence). RESULTS: Of the 46 patients with ACS 11 (23.9%) were male and of the 52 controls 26 (50%) were male. Mean age was, ACS=60.7 years and controls= 55.98 years. None had evidence of acute rickettsiel infection. In ACS group, 3 and 7 were positive for [gG-OT-Orientia tsutsugamushi (prevalence=0.065) and lg-RC-Rickettsia conori (prevalence=0.152) respectively. In the control group 2 were positive for IgG-OT( prevalence = 0.038) and 6 for IgG-RC (prevalence = 0.115). There was no significant difference in sero-pre valence of rickettsie- antibodies in the study group compared to controls; odds-ratio IgG-OT 1.744 (CI, 0.278-10.928) and IgG-RC 1.376 (CI, 0.427-4.438). CONCLUSION: Sero-prevaSence of Orientia tsutsugamushi was 0.038 while that of Rickettsia conori was 0.115 in the selected population. Rickettsia conori was more prevalent than Orientia tsutsugamushi in the Western province of Sri Lanka. There was no significant association between sero-prevalence of rickettsioses and acute-coronary-syndromes.