Kyasanur Forest Disease (KFD) – colloquially known as ‘monkey fever’ – is a disease known to spike on a yearly basis in and around Karnataka. An estimated 500 cases of KFD are reported in India every year. Though the disease shows only a limited number of cases on a yearly basis, it is of particular concern due to its mortality rate of around ten percent.
According to the BBC, “most researchers believe that KFD was endemic for centuries in the forests of the Western Ghats in India, circulating silently among primate, bird and rodent populations, and the ticks they carry.”
The symptoms can include a haemorrhagic fever that sets in with chills and nosebleeds and can progress to neurological issues such as severe headaches and vision defects. KFD has no specific treatment beyond symptom management and hospitalisation.
Health Issues India previously noted a major advantage in the fight against KFD – it is vaccine-preventable. Research into the disease and its epidemiology has developed a system of risk-mapping tools to allow targeted vaccination drives in the hopes of entirely isolating the disease.
“The mapping system takes a multidisciplinary approach. It pools data regarding human cases, risk factors and predictions, historical patterns in KFD spread, geographical risk factors such as types of forests and plantations, the altitude, the amount of forest loss, densities of people and cattle, and tick and monkey surveillance to produce a risk assessment map. With this map, the spread of the disease can be monitored and predicted to allow for optimal allocation of vaccine delivery.”
In theory, all individuals within ten kilometres of an outbreak are to receive vaccination in order to contain the infection. In many cases, this has not occurred, allowing the infection to effectively leapfrog between villages.
Increasing exposure to the disease is raising the risk of larger-scale outbreaks. Experts found through satellite imagery that areas prone to outbreaks coincided with those that were currently witnessing deforestation. This deforestation typically meant that human activity in the area increased, often bringing farm animals which could also potentially harbour the ticks.
The BBC notes areca palm plantations as being a “transition spot” for the disease. The plantations have often been placed in areas which were formerly dense, untouched forestry. These plantations are often still flanked by dense forest, and form a zone of frequent contact between humans and diseases previously contained to the forest area.
This issue is not without precedent, as a previous large-scale outbreak of KFD that occurred in 1983 was linked to a similar issue. News articles at the time noted that 400 hectares of virgin forests in the Western Ghats were cleared to establish cashew plantations. Many cases occurred not only during the running of the new plantations, but even within the period the forest was being cleared, as it brought humans into frequent contact with the ticks that cause the disease.
While the issue of KFD is limited to an endemic region of India, it serves to highlight an issue occurring across the globe. Zoonotic diseases are a global concern, from ongoing threats such as malaria, to pandemics such as COVID-19. Localised issues such as KFD and Ebola have been worsened through the destruction of habitats and the infringement of farming and agricultural industries in these areas. With the potential for pandemics and large-scale outbreaks, environmental health must be urgently prioritised, as it is linked directly to human health.