Kyasanur forest disease: a state-of-the-art review

A Case Series on the Spectrum of Complications Observed in Kyasanur Forest Disease

Background Kyasanur Forest Disease (KFD) has emerged as an important differential diagnosis of febrile illness for physicians caring for patients in the Western Ghats of South India over the last decade.  Aim This study seeks to familiarize physicians with the clinical presentation and the clinical, laboratory and imaging findings of the various complications of KFD. It also seeks to review the literature on the complications of KFD described. Material and methods This was a records-based retrospective study of the patients with KFD referred for tertiary care management to Government Medical College Kozhikode, Kerala over 11 years, from January 2013 to December 2023. Results A total of 12 case records were obtained and analysed. All the patients in this case series belonged to tribal ethnic groups enhancing its social significance. The complications of KFD (as calculated in the 11 patients for whom all the records were available) were altered sensorium (nine, 82%), persistent shock (seven, 64%), Acute Respiratory Distress Syndrome (ARDS)/pneumonitis (six, 55%), encephalitis (six, 55%), myocarditis (six, 55%), bleeding manifestations (six, 55%), hepatitis (six, 55%), acute kidney injury (four, 36%), rhabdomyolysis (three. 27%), hemophagocytic lymphohistiocytosis (HLH) (two, 18%), stress hyperglycaemia (two, 18%), pancreatitis (one, 9%), peritonitis (one, 9%). The case fatality rate in this series was 42%( n=5/12). An autopsy was done on one patient which showed congested and oedematous lungs with subpleural haemorrhage. Petechial haemorrhages were noted in the liver, spleen and kidney. The total leucocyte count was lower than 2500 c/mm3 in 10 (90%) patients. Out of the four patients in whom serum ferritin was tested, it was elevated (above 500 ng/ml) in all patients; and was above 1000 ng/ml in three patients. Hemophagocytic lymphohistiocytosis was diagnosed in two patients. This is a unique finding of our series. Both of these patients succumbed to the illness. A cerebrospinal fluid study was done in six patients and revealed normal values except in one patient. Troponin assays were done in seven patients and were positive in five patients indicating that myocarditis is a major contributor to shock, which is one of the commonest complications in KFD. Serum creatinine phosphokinase ranged from 656 to 23,000 U/L. Conclusions Altered sensorium was the most common alarming symptom that warrants referral to a higher centre. The major organ involvements that dominated the clinical presentation and course of illness were neurological complications, hypotension, significantly contributed by myocarditis and acute respiratory distress syndrome/pneumonitis. Encephalitis, myocarditis, ARDS and HLH were the major complications that caused mortality in our series. The elevated serum ferritin and the mortality associated with HLH described need further research to investigate the role of the macrophage system in the pathogenesis of severe KFD.

Simplified visual detection of Kyasanur Forest Disease virus employing Reverse Transcriptase-Polymerase Spiral Reaction (RT-PSR)

Among recently prevalent tick-borne infections in India, Kyasanur Forest Virus Disease (KFD) is an important public health concern. During last decade the emergence of cases apart from endemic zone raised concern about case positivity. Early diagnosis is therefore very important in disease management and primary containment. This study, aimed to develop a simplified viral RNA extraction in combination to dry down format of novel isothermal assay for (Reverse Transcription- Polymerase Spiral reaction) specific and rapid identification of Kyasanur Forest Disease Virus targeting viral envelope gene. The one step method was optimized by magnetic bead based viral RNA extraction followed by isothermal RT-PSR assay in heat bath at 63⁰C for 60 minutes. Further, visual results interpretation was done by color change of Hydroxy Naphthol Blue dye. The detection limit of the assay was found 10 RNA copies/rxn with comparable to silica column based viral RNA combined real time qPCR. No cross reactivity was observed with other closely related flaviviruses. The assay was evaluated with clinical samples has shown >99% concordance between two methods. This is the first report of sample extraction coupled isothermal detection of KFD in a simplified manner without a need of any hi-end equipment. The assay developed here has potential to use as an alternate for field-based detection in resource limited settings for KFD.

Clinical and laboratory profile of patients with Kyasanur forest disease: A single-centre study of 192 patients from Karnataka, India

INTRODUCTION

Kyasanur forest disease (KFD) is a biphasic tick-borne viral fever that is endemic to 16 districts and five states of Southern India. The aim of this study was to describe the clinical/ laboratory manifestations of KFD.

MATERIALS AND METHODS

This is a retrospective cohort study of confirmed KFD patients admitted in our hospital between December 2018 and June 2019. The demographic, clinical and laboratory parameters of patients during the first and second phase of illness was recorded in a pre-defined case study form.

RESULTS

A total of 192 patients from Karnataka were diagnosed with a mean age of 46.2 ± 15.6 years and a male preponderance (57 %). Fever (99 %), myalgia (52 %), headache (43 %), cough (14 %), conjunctival congestion (14 %), altered sensorium (13 %) and haemorrhagic manifestations (8%) were seen in the first phase. A total of 18 % of the patients came back with a second febrile episode. The features of meningoencephalitis were seen in 34 % of the patients during the second phase. Leucopenia, thrombocytopenia, and increase in liver enzymes, creatine phosphokinase (CPK) and activated partial thromboplastin time (APTT) was seen in the first phase but not in the second phase. Higher age, myocarditis, altered sensorium in the first phase, hypotension at admission, lower platelet count, elevated liver enzymes, higher APTT and CPK, were significantly associated with mortality.

CONCLUSION

The primary care physicians or travel medicine practitioners should be aware of the distinct clinical and laboratory manifestations of KFD, including the ones that may signify requirements of higher levels of care.

Approach to acute febrile illness during the COVID-19 pandemic

Coronavirus disease 2019 (COVID-19) is a febrile respiratory illness that has spread rampantly across the globe and has emerged as one of the biggest pandemics of all time. Besides the direct effects of COVID-19 on mortality, collateral impacts on diagnosis and management of acute febrile illnesses (AFI) is a matter of great concern. The overlap in presentation, shunting of available resources and infection control precautions in patients with suspected COVID-19 result in a significant delay in diagnoses and management of AFI. This review highlights the challenges in the management of acute febrile illness during COVID pandemic and possible solutions for the same.