- High mammal species richness in the Western Ghats was associated with increased Kyasanur forest disease (KFD) virus risk but only in areas of low forest loss. In deforested landscapes, disease risk is tied to low numbers of species in a specific geographic area, says a new study.
- There is good potential for cooperation between animal and human health infrastructure at the municipal level that could underpin a novel ‘One Health surveillance’ architecture and service delivery, according to the researchers.
- There are challenges to implementing One Health on the ground; working models of One Health are needed to put the intersectoral approach into practice.
As outbreaks of Kyasanur Forest Disease (KFD) or ‘monkey fever’ rapidly expand across the Western Ghats, a study finds that in landscapes undergoing forest loss, a lower number of mammalian species is tied to high disease risk.
High mammal species richness in the Western Ghats was associated with increased KFD virus risk but only in areas of low forest loss which points to the role of forest loss in substantially tweaking the association between species richness and outbreaks. Landscapes of highest risk are those that have been subjected to diminished biodiversity following habitat fragmentation (i.e. forest loss).
“These landscapes tend to be dominated by species that are resilient to human pressure, as those that are less resilient and which can be found in areas of greater biodiversity tend to disappear as habitat is lost. These species that are more resilient to human pressure also tend to be species that are more efficient viral hosts because those aspects of their biology that make them resilient also make them more efficient hosts,” study’s corresponding author Michael Walsh, a landscape epidemiologist with the Sydney Institute for Infectious Diseases and the Sydney School of Public Health, told Mongabay-India.
The findings of the modeling study that estimates local mammalian species richness across the Western Ghats suggest narrowing down monitoring of wildlife to areas of marked habitat fragmentation across the Western Ghats states to develop wildlife surveillance infrastructure under the ‘One Health’ approach at the taluk (sub-district) level across the states.
Spread by infected ticks, the KFD affects people typically living and working in the Western Ghats, presumably due to greater human exposure to infected animals and ticks during January to June, before the onset of the monsoon. Haemaphysalis spinigera ticks are identified as the main vector. A wide range of small rodents, monkeys and birds are thought to play a role in Kyasanur Forest Disease Virus (KFDV) transmission. The disease first emerged in Kyasanur in Karnataka’s Shimoga/Shivamogga district in 1957 after the forest ecosystem was increasingly degraded by human activities.
Since 2012 the disease has spread to new districts in Karnataka and neighbouring states of Tamil Nadu, Goa, Maharashtra, and Kerala in the Western Ghats. Researchers at ICMR-National Institute of Virology (ICMR-NIV) chalk up the KFDV spread between states to movements of tick-infested monkeys in these forests along with changes in agricultural and occupational practices that encourage the proximity to humans and/or their dwellings.
Prashanth N. Srinivas at the Institute of Public Health, Bengaluru, who was not associated with the study adds that the results are not surprising but they are important. The findings are also broadly in line with a paper co-authored by Srinivas on predicting disease risk areas in Shivamogga district in Karnataka. It echoes that creation of habitat mosaics, when the forest is removed for paddy cultivation and plantations, precipitates the emergence of the KFD in humans.
“One of the primary factors that valuable for prediction is the change in purpose for which the land is used which typically happens for mega projects such as road construction or felling forest for rubber plantations versus small scale impacts that traditional forest dwellers have on the forest because they have a more organic rel