Till date the disease has claimed four lives
A team from the National Centre for Disease Control (NCDC), Delhi, is presently in Goa carrying out detailed investigation of the outbreak Kyasanur Forest Disease(KFD) and also give expertise in prevention and control measures in the affected areas.
Already four persons have died of the disease in north Goa’s Pali village in Valpoi taluk.
On confirmation of the etiology of fever outbreak at Pali, Thane, the Directorate of Health Services took the help of the Department of Animal Husbandry & Veterinary Services and the Forest Department so that necessary tick control measures are taken. Also Health Officer, CHC Valpoi is been asked to conduct awareness activities in the locality.
KFD is caused by the Kyasanur Forest Disease Virus (KFDV). The virus was identified in 1957 when it was isolated from a sick monkey from the Kyasanur Forest in Karnataka (formerly Mysore State).
Since then, between 400-500 humans cases per year have been reported. Hard ticks (Hemaphysalis spinigera) are the reservoir of the KFD virus and once infected, remain so for life. Rodents, shrews, and monkeys are common hosts for KFDV after being bitten by an infected tick, KFDV can cause epizootics with high fatality in primates, explained a health official here on Monday.
Transmission to humans may occur after a tick bite or contact with an infected animal, most importantly a sick or recently dead monkey. No person-to-person transmission has been described.
Dr. Jose D’Sa, Chief Medical Officer of Goa Health Services, said the disease as of now was stated to be transmitted through monkeys. Large animals such as goats, cows, and sheep may become infected with KFD but play a limited role in the transmission of the disease.
These animals provide the blood meals for ticks and it is possible for infected animals with viremia to infect other ticks, but transmission of KFDV to humans from these larger animals is extremely rare.
Furthermore, there is no evidence of disease transmission via the unpasteurised milk of any of these animals.
After an incubation period of 3-8 days, the symptoms of KFD begin suddenly with chills, fever, and headache. Severe muscle pain with vomiting, gastrointestinal symptoms and bleeding problems may occur 3-4 days after initial symptom onset. Patients may experience abnormally low blood pressure, and low platelet, red blood cell, and white blood cell counts.
After 1-2 weeks of symptoms, some patients recover without complication. However, the illness is biphasic for a subset of patients (10-20 per cent) who experience a second wave of symptoms at the beginning of the third week. These symptoms include fever and signs of neurological manifestations, such as severe headache, mental disturbances, tremors, and vision deficits. The estimated case-fatality rate is from 3 to per cent for KFD.
The disease has historically been limited to the western and central districts of Karnataka State, India. However, in November 2012, samples from humans and monkeys tested positive for KFDV in the southernmost district of the State which neighbours Tamil Nadu State and Kerala State, indicating the possibility of wider distribution of KFDV.
People with recreational or occupational exposure to rural or outdoor settings (e.g., hunters, herders, forest workers, farmers) are potentially at risk for infection by contact with infected ticks.
Seasonality is another important risk factor as more cases are reported during the dry season, from November through June.
Diagnosis can be made in the early stage of illness by molecular detection by PCR or virus isolation from blood. Later, serologic testing using enzyme-linked immunosorbent serologic assay (ELISA) can be performed.
Prevention
Doctors at the State Health Services say there is no specific treatment for KFD, but early hospitalisation and supportive therapy is important. Supportive therapy includes the maintenance of hydration and the usual precautions for patients with bleeding disorders.
A vaccine does exist for KFD and is used in endemic areas of India. Additional preventative measures include insect repellents and wearing protective clothing in areas where ticks are endemic.
