Monitoring Weil–Felix test in epidemic retinitis

Purpose: The objective was to study the positivity of the Weil–Felix test (WFT) in epidemic retinitis (ER) during the course of the disease. Methods: This is a retrospective, observational case series of patients diagnosed with ER and presented to a tertiary eye care hospital in south India. Patients with positive WFT at the presentation, and who underwent a follow?up WFT during or after the resolution of ER were studied from September 2019 to March 2022. Patient’s demographics, timings of clinical presentation and resolution, and investigation details with a special focus on WFT positivity and its duration were noted. Results: Sixteen patients were studied. Patients presented after 5 weeks of the fever (range: 2?12 weeks, median: 4). After 1?2 months, WFT was still positive in eight patients (50%). Only in one patient titers increased after 1 month, while in others, the titers decreased (n = 11) or remained the same (n = 4). Repeated tests in those patients (n = 6) after 3?4 months turned negative. Resolution of ER was seen at 1.35 months (range: 1?3 months) after the presentation. The mean duration for WFT to turn negative was 2 months from the presentation (range: 1?4 months) or 3.2 months of the fever (range: 1.5?6 months). Conclusion: In contrast to the reported physician’s observation of increasing titers of WFT after rickettsial fever, ophthalmologists may observe decreasing WFT titers in ER. The clinical resolution of ER may precede the normalization of WFT. Follow?up WFT titers should be studied in larger series in confirmed cases of rickettsial?ER to validate the affordable and readily available WFT in India

A clinico-epidemiological profile of scrub typhus cases admitted in a tertiary hospital in South India

Scrub typhus (ST) is a consistently underreported disease. The disease is spreading to newer areas, and an understanding of disease epidemiology is needed in the local Indian and current context. This study describes the demographic characteristics, monthly distribution, clinical and laboratory presentations, and treatment outcome of the ST cases recently identified. Case sheets of 15 ST patients diagnosed from January 2019 to December 2020 were analyzed. The majority of the patients were male. Eighty percent of the patients were from rural or suburban areas. Higher admission was observed from September to December. Fever (100%), skin rash (73.3%), body ache (53.3%), and vomiting (53.3%) were the most common clinical features. The onset of fever till the appearance of skin rash was 3 ± 1.2 days. The mean day from onset of symptoms till diagnosis was 6.8 ± 3.9 days. Eschar was found in only two patients. Nine (60%) patients already had complications at the time of admission. Most patients presented a laboratory picture of thrombocytopenia, neutrophilic leukocytosis, and anemia. Complications such as septic shock, acute kidney injury, and hepatic involvement were observed. All responded to doxycycline within 48 h. No fatalities were observed. Early clinical suspicion of ST among those with high fever, skin rash and thrombocytopenia, and transaminitis showed positive clinical outcome.

Clinicopathological profile of rickettsial fever in tertiary healthcare centre: a prospective case study

Background: Rickettsia are obligate intracellular proteobacteria spread by eukaryotic vectors like ticks, mites, fleas and lice. Rickettsial infections are generally incapacitating and difficult to diagnose; Case fatality rates up to 45 percent is seen in cases with multiple organ dysfunction. The disease continues to be under diagnosed and treated. Objective of this study was to study the clinicopathological profile and outcome of children admitted with rickettsial fever. To study the correlation between Rathi-Goodman-Aghai score and Weil-Felix test. To study the response of rickettsial fever to Doxycycline.''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''Methods: This study is a prospective observational study conducted from December 2017 to April 2019 at a tertiary health care center in South India, involving patients admitted between 2 months to 18 years of age with a diagnosis of Rickettsial fever. Clinical data and investigations were collected and analysed. The response to doxycycline was recorded.'''''''''''''''''''''''''''''''''''''''''''''''' '''''''''Results: Total of 49 patients were enrolled in the study. Most common age group affected was between 1 to 5 years accounting for 32.7% of the cases. 78% of the patients hailed from rural background. Most common presentation being fever, present in 100% of the cases. 81.6% of patients had significant Rathi-Goodman-Aghai score of >14. Weil felix showed significant titres (1:80) in 97.9% out of which serology suggestive of scrub typhus was found in 79.6% patients. There was no statistical significance between rickettsial score and Weil-Felix test (p value= 0.736). 26.5% of the cases required respiratory support and 2% cases required dialysis. 10.2% cases succumbed and 89.8% cases improved.Conclusions: Rickettsial infection is re-emerging with propensity for life threatening complications. There is no statistical significant correlation between Rickettsial score and Weil Felix test. Early treatment has better outcome.

Ocular manifestations of Rickettsia conorii in South India

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.

Outbreak of scrub typhus in Puducherry & Tamil Nadu during cooler months.

Background & objectives: The southern part of India has witnessed an increase in scrub typhus (ST) during the past ten years. ST outbreaks occurred during winter months but at intervals of one to three years. With only a few reports of ST in Puducherry, this study was undertaken to look for the persistence of ST cases in Puducherry and Tamil Nadu in the winter months. Methods: During relatively cooler months of September, 2012 to March, 2013, a total of 45 patients with fever and clinical suspicion of ST and who provided both acute and convalescent blood samples were included. Total WBC, platelet counts, serum creatinine, liver enzymes levels and a rapid immunochromatographic test (RICT) for ST were first done. Paired serum samples were analysed by two specific tests - ST IgM and IgG ELISA- and a non-specific, but widely used Weil-Felix (WF) test. Results: Of the 45 patients, 21 adults and seven children were confirmed as ST based on clinical and laboratory findings, and positivity in specific serological test(s). Setting ST IgM and IgG ELISA as reference, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for RICT were 91.67, 85.71 per cent; 90.48, 100 per cent; 91.67, 100 per cent and 90.48, 80.95 per cent, respectively. Similarly, for WF the values were 83.33, 75 per cent; 95.24, 100 per cent; 95.24, 100 per cent and 83.33, 70.83 per cent, respectively. Interpretation & conclusions: ST continues to persist in the cooler months in Puducherry and neighbouring Tamil Nadu with fever and myalgia as prominent features. None of the tests evaluated in this study was found to be ideal, but ST IgM/IgG ELISA was useful for batch testing and the non-specific WF test can be used in resource poor settings.

Rickettsial diseases in children.

In a tropical country like India, fevers are caused by different etiological agents. Rickettsial infections, which have a global distribution is one of the differential diagnosis in such cases and are reported from almost all parts of India. Rickettsial diseases widely vary in severity from self-limited mild illnesses to fulminating life-threatening infections. They are obligate intracellular gramnegative coccobacillary forms that multiply within eukaryotic cells which makes it difficult to culture them on artificial culture medium. With globalization there is rapid spread of disease across the continents and therefore, skills for diagnosis and management of the disease attains global importance. Rickettsial diseases can be clinically classified as Spotted Fever group, typhus group, distinctive clinical rickettsiae and emerging rickettsiae. The clinical course will have incubation period, stage non-specific clinical signs and symptoms followed by typical/classical features depending on the type of rickettsiae infecting a person. However the clinical manifestation varies from one geographical area to another area for same species. The rickettsial diseases once thought to have been eradicated from India are re-emerging in many parts of our country. Their presence has recently been documented in at least eleven states of our country. Greater clinical awareness, a higher index of suspicion, better use of available diagnostic tools would increase the frequency with which rickettsial diseases are diagnosed.

Serological evidence of rickettsial infections in Delhi.

Background & objectives: Rickettsial infections remain under-diagnosed due to lack of diagnostic facilities in developing world. Here we present our experience at National Centre for Disease Control, Delhi, about a serosurvey done in Delhi for rickettsial disease with easy to perform low cost, low expertise Weil Felix test. Methods: On the basis of cut-off titre obtained in healthy population, Weil Felix test results were interpreted along with clinical data. Entomological investigation was also carried out in select areas of Delhi. Rodents were trapped from houses and gardens and vector mites were collected. Results: When serum samples were collected during initial 5 yr period from patients with fever of unknown origin, seropositivity was 8.2 per cent whereas when rickettsial infection was kept as one of the differential diagnosis by clinicians seropositivity increased to 33.3 per cent. Rickettsial infections detected were scrub typhus (48.2%) followed by spotted fever group (27.5%) and typhus group (6.8%) during 2005-2009. In preliminary entomological survey vector mite Leptotombidium deliense was found on rodents. Interpretation & conclusions: Our findings showed that results of Weil Felix test should not be disregarded, rather clinically compatible cases should be treated to save lives.

Rickettsial Infections: Indian Perspective.

Context: Underdiagnosed and misdiagnosed rickettsial infections are important public health problems. They also lead to extensive investigations in children with fever of undetermined origin contributing to financial burden on families. The present review addresses the epidemiology, clinical features, diagnosis and management issues of these infections, primarily for a practicing clinician. Evidence acquisition: We did a PubMed, Medline and Cochrane library search for literature available in last 40 years. Results : Rickettsial infections are re-emerging and are prevalent throughout the world. In India, they are reported from Maharashtra, Tamil nadu, Karnataka, Kerala, Jammu and Kashmir, Uttaranchal, Himachal Pradesh, Rajasthan, Assam and West Bengal. In view of low index of suspicion, nonspecific signs and symptoms, and absence of widely available sensitive and specific diagnosic test, these infections are notoriously difficult to diagnose. Failure of timely diagnosis leads to significant morbidity and mortality. With timely diagnosis, treatment is easy, affordable and often successful with dramatic response to antimicrobials. As antimicrobials effective for rickettsial disease are usually not included in empirical therapy of nonspecific febrile illnesses, treatment of rickettsial disease is not provided unless they are suspected. Knowledge of geographical distribution, evidence of exposure to vector, clinical features like fever, rash, eschar, headache and myalgia alongwith high index of suspicion are crucial factors for early diagnosis.