• Manisha Biswal, Kamran Zaman, Vikas Suri, Srikanth Gopi, Abhay Kumar, T Gopi, Shashi Vig, Navneet Sharma, and Ashish Bhalla.
• Department of Medical Microbiology, Postgraduate Institute of Medical Education & Research, Chandigarh, India.
• Indian J Med Res. 2020 Jan 1; 151 (1): 59-64.

Background & ObjectivesIn India, spotted fever group rickettsiae (SFGR) are an underdiagnosed cause of acute febrile illness (AFI). The non-specific Weil-Felix test is the first diagnostic modality for the diagnosis of SFGR in many laboratories due to the lack of advanced diagnostic facilities in developing countries. The aim of this study was to detect SFGR using molecular methods in the patients, presenting with AFI in a tertiary care centre in north India.MethodsConsecutive patients (>14 yr of age) with AFI were enrolled over a six month period. Standard investigations for common pathogens causing AFI in India (malaria, dengue, scrub typhus, leptospirosis and enteric fever) were carried out. In patients who were negative for all of the above investigations, blood was subjected to polymerase chain reaction (PCR) targeting outer membrane protein A (ompA) gene of Rickettsia.ResultsOf the 51 patients with an undiagnosed aetiology, three were positive by ompA PCR. Two of the PCR products produced good sequences and BLAST identification confirmed them as Rickettsia conorii. The sequences of R. conorii reported from south India clustered with two previously reported novel rickettsial genotypes. The study sequences clustered in a group different from that of Rickettsia spp. of the south Indian sequences reported earlier.Interpretation & ConclusionsThis study showed the existence of R. conorii in north India. Testing for SFGR may be included in the diagnostic workup of AFI for better disease management.

42 keywords...

hide…