Detection of Rickettsioses and Q fever in Sri Lanka

Abstract

Abstract. Current serological evidence suggests the presence of scrub typhus and spotted fever group (SFG) rickettsiosis in Sri Lanka. Our objective was to identify rickettsial agents/Q fever as aetiological causes for patients who were presumed having rickettsioses by the presence of an eschar or a rash. Sera from patients with unknown origin fever from Matara were tested by immunofluorescence for SFG rickettsial antigens, typhus group rickettsiae, Orientia tsutsugamushi, and Coxiella burnetii antigens. Thirteen (7.3%) of the patients presented with a rash, 11 (6.1%) had an inoculation eschar, and 16 patients recalled a tick or flea bite. We found that 25 (14%) patients had scrub typhus, 6 (3%) SFG rickettsioses, 3 (1.6%) acute Q fever, 3 (1.6%) murine typhus, and 3 (1.6%) were infected by Rickettsia felis. In addition to already described scrub and murine typhus, we found that R. felis and C. burnetii infections should be considered in Sri Lanka.

Coxiella burnetii-positive PCR in febrile patients in rural and urban Africa

“…Microimmunofluorescence (IFA) is the reference technique for diagnosing Q fever. 16,17 However this was not performed because IFA requires highly experienced technicians, 9 and such expertise was not available in the local laboratories that participated in this study. As a result, in the absence of serological data, we could not determine if our C. burnetii-positive patients were suffering from acute Q fever or Q fever endocarditis.…”

Rickettsia sibirica mongolitimonae infection, Sri Lanka

“…Although R. sibirica mongolitimonae was firstly isolated from Hyalomma asiaticum collected in China [7], to date, human cases of R. sibirica mongolitimonae infection have been never described in Asia. Current serological evidence suggests the presence of scrub typhus and SFG rickettsiosis including Rickettsia conorii [8] in Sri Lanka [9] (Table 1). However, serology makes difficult to identify the infecting rickettsial species because of cross-reactivity among antigens of pathogens within the same genus.…”

Rickettsioses in Sri Lanka – A mini review

“…A hospital based study conducted in District General Hospital, Matara in 2009 identified 25 (14%) patients with scrub typhus, 6 (3%) with SFG rickettsioses, 3 (1.6%) with acute Q fever, 3 (1.6%) with murine typhus and 3 (1.6%) infected by Rickettsia felis. 21 A study conducted at Teaching Hospital, Karapitiya where 883 paired sera were analyzed, identified 17.7% with confirmed rickettsioses. Spotted fever was the most common type of rickettsioses identified in this study.…”

“…33 In studies conducted in Sri Lanka, inoculation eschar has been mostly associated with scrub typhus. 21 The proportion of patients with confirmed scrub typhus with eschar ranged from 25% to 89%. 16,21,23 Rash is generally associated with a lesser proportion of patients with scrub typhus, sometimes being absent.…”

“…21 The proportion of patients with confirmed scrub typhus with eschar ranged from 25% to 89%. 16,21,23 Rash is generally associated with a lesser proportion of patients with scrub typhus, sometimes being absent. 21,23 Spotted fever rickettsioses in Sri Lanka presents predominantly with fever and rash.…”