ABSTRACT
Background & objectives: In 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. Methods: Consecutive 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. Results: Of 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 & conclusions: This 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.
ABSTRACT
Purpose: Among the major groups of rickettsiosis, the commonly reported diseases in India are: (a) Typhus group induced—scrub typhus, murine flea-borne typhus; (b) Spotted fever group induced—Indian tick typhus; and (c) Q fever. Though many scrub typhus outbreaks have been reported from India, only one outbreak of spotted fever—serologically proven Indian tick typhus (Rickettsia conorii)—has been reported. We report for the first time ocular manifestations of serologically proven R. conorii infection in a cluster of patients. Methods: In this retrospective study, case records patients with serologically proven Indian tick typhus (Rickettsia conorii) were reviewed for clinical manifestations and treatment outcomes. Results: In the months of February to April 2016, a cluster of 12 patients (23 eyes) visited us with defective vision. Examination showed multifocal retinitis; mostly bilateral; patients had a history of fever approximately 4 weeks prior to onset of symptoms. After excluding other causes of multifocal retinitis, a diagnosis of rickettsial retinitis was made after Weil–Felix test (WFT) was significantly positive, and enzyme-linked immunosorbent assay was positive for R. conorii. Course of the disease, visual outcome, and investigations are discussed. Doxycycline along with oral corticosteroids was effective in treating the condition. Conclusion: Systematic fundus examination should be part of the routine evaluation of any patient who presents with fever and/or skin rash living in or returning from a specific endemic area. Clinical clues to diagnosing ocular rickettsiosis could be multifocal retinitis predominantly involving the posterior pole and macular involvement in the form of serous macular detachment or macular hard exudates. A positive WFT still serves as a useful and cheap diagnostic tool for laboratory diagnosis of rickettsial disease. Doxycycline along with oral corticosteroids was effective in treating the condition.
ABSTRACT
Optic neuritis (ON) may be associated to a range of autoimmune or infectious diseases. We report herein a case of ON induced by Rickettsia conorii. A 53-year-old woman presented with a recent decrease in visual acuity and headache. ON was diagnosed on the basis of ophthalmologic examination and flash visual evoked potentials. Etiological investigation made in our department eliminated first autoimmune disorders (vasculitis and connective tissue diseases). Rickettsial optic neuritis was confirmed by detection of specific antibodies in serum and the negativity of other serologic tests. An association between corticosteroids and cyclines was prescribed with improvement of visual acuity.
ABSTRACT
Optic neuritis (ON) may be associated to a range of autoimmune or infectious diseases. We report herein a case of ON induced by Rickettsia conorii. A 53-year-old woman presented with a recent decrease in visual acuity and headache. ON was diagnosed on the basis of ophthalmologic examination and flash visual evoked potentials. Etiological investigation made in our department eliminated first autoimmune disorders (vasculitis and connective tissue diseases). Rickettsial optic neuritis was confirmed by detection of specific antibodies in serum and the negativity of other serologic tests. An association between corticosteroids and cyclines was prescribed with improvement of visual acuity.