Monkey fever or Kyasanur Forest Disease is a tick-borne haemorrhagic fever that has claimed two lives in Karnataka. All about the symptoms and prevention tips.
Monkey fever or Kyasanur Forest Disease (KFD) has claimed two lives in Karnataka calling for urgent action and implementation of preventive measures to contain spread of the disease. The tick-borne haemorrhagic fever, usually contracted by monkeys, is caused by KFD virus which is an arbobirus of the family Flaviviridae. An 18-year-old girl and a 79-year-old man have so far succumbed to the disease, out of 49 positive cases in the state. The initial symptoms of the viral disease are sudden fever, headache, body ache, vomiting, abdominal pain, and diarrhoea. while severe disease with haemorrhagic symptoms may occur later. It is important to control tick populations in wildlife, particularly monkeys, to prevent the spread. (Also read: India on the verge of eliminating ‘black fever’ kala-azar, second deadliest parasitic disease)
Kyasanur Forest Disease (KFD) commonly known as Monkey Fever is a viral haemorrhagic disease that was first identified in 1957 in the Kyasanur Forest in the Western Ghats of India. It is caused by KFD virus (KFDV) which is an arbovirus of the family Flaviviridae.
“Initially confined to the Western Ghats of Karnataka, the disease has expanded its presence over the past decade, with reported cases extending to neighbouring states along the Western Ghats, such as Kerala, Maharashtra, and Tamil Nadu. The disease’s burden is on the rise, reflecting a shift in its epidemiological profile and establishing it as an emerging tropical disease in India,” says Dr Laxman Jessani – Consultant Infectious Disease, Apollo Hospitals Navi Mumbai.
“Recently, 31 cases have been detected in Karnataka’s Uttara Kannada district with patients either being treated at home or admitted to hospitals but are reported to be stable. This indicates ongoing transmission and the need for continued surveillance and preventive measures in affected areas,” says Dr Jessani.
How does Monkey fever spread?
“Infection occurs through tick bites carrying the virus or, less commonly, contact with infected animals, primarily monkeys. Symptoms include fever with possible haemorrhagic and/or neurological features. While approximately 80% of patients recover without post-viral symptoms, around 20% may develop severe haemorrhagic or neurological issues. Estimates suggest that around 500 human KFDV infections occur annually with a case fatality rate of 3-5%. As it is life-threatening and there is lack of effective countermeasures, KFDV is classified as a Biosafety level 4 (BSL4) pathogen,” says Dr Jessani.
Symptoms of Monkey Fever
After an incubation period of 3 to a week post-tick bite, monkey fever starts abruptly with fever, chills, headache, and severe exhaustion.
“As the disease progresses, symptoms can escalate to include nausea, vomiting, stomach pain, diarrhoea, meningitis, confusion and even haemorrhagic signs like nose bleeds and bleeding gums. Without proper supportive treatment, complications like shock, dehydration, electrolyte disturbances, haemorrhage and organ failure can arise and become fatal,” says Dr Shruti Sharma, Consultant-Internal Medicine, Yatharth Super Speciality Hospital.
“The virus has a 3-8 day incubation period and manifests in two or rarely four stages. In the first phase, symptoms include sudden fever, headache, body ache, conjunctiva inflammation, vomiting, abdominal pain, and diarrhoea. Clinical examination reveals lymphadenopathy, hepato-splenomegaly, weakness, and fatigue. Haemorrhagic symptoms may occur, with most patients recovering in 10-14 days,” says Dr Jessani.
“The initial symptoms often include a sudden onset of high fever accompanied by chills. Severe headaches and muscle pain are common, making the infected person feel extremely unwell. Nausea, vomiting, and diarrhoea may occur, impacting the digestive system. In severe cases, it can lead to bleeding tendencies, which may result in a range of complications,” says Dr Manjusha Agarwal, Senior Consultant, Internal Medicine Global Hospitals, Parel, Mumbai.