Western Ghats

Tick-borne monkey fever strikes again

  • Kyasanur forest disease or monkey fever strikes monkeys and humans bitten by virus-infected ticks.
  • The disease has spread through the Western Ghats and with increased awareness, more instances have come to light.
  • Detected in 1957 from Karnataka, it was officially reported in Maharashtra only in 2016. But scientists have now found evidence of previous episodes in the state’s rural population.

Kyasanur forest disease (KFD) is a tick-borne illness that was once restricted to the southern Indian state of Karnataka. It was first detected in the 1950s from Karnataka’s Shivamogga district, in the forest of Kyasanur, after which it is named. Back then the local community, noticing that monkeys were dying and making humans sick (whoever came in close contact with the sick monkeys), dubbed it the ‘monkey fever.’ But monkeys themselves, like humans, are hosts; the actual causative agent of KFD is a virus carried by ticks.

KFD rears its ugly head post-monsoon when young ticks, called nymphs, actively look for warm-blooded animals to attach to and feed on. With the bite of an infected tick, the virus gets into the bloodstream of humans, causing fevers, headaches, bleeding and, in some cases, death.

Over the past decade, KFD has been reported from the states of Maharashtra, Goa, Kerala and Tamil Nadu – outside its original range in Karnataka. In Maharashtra, it was first documented in 2016.

Now, a team of researchers from the National Institute of Virology, Pune, have investigated the 2016 KFD outbreak in Maharashtra and found that it may not have been the first episode of KFD for the state.

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Bonnet monkey. Photo by Raju Kasambe / Wikimedia Commons.

First, the researchers estimated the KFD prevalence in Dodamarg cluster of villages at Sindhudurg district in Maharashtra. Using data from house-to-house surveys conducted by health workers and patient records from hospitals in the district, they shortlisted 488 individuals whose symptoms matched with that of the disease.

They further screened these individuals and confirmed 130 to be KFD-positive. Three of the 130 patients died. A vaccine against KFD is available but none of the patients had received it.

Vocation, living conditions linked to tick exposure

When researchers looked at the possible reasons for the patients’ exposure to ticks, they learnt that vocation and living conditions had a major role to play. About 93 percent of the KFD-infected patients had visited the forest in Dodamarg before coming down with the disease. They had ventured into the forests to work in cashew, betel nut or coconut farms, to collect firewood or to graze their cattle, and likely got bitten by ticks there.

According to the Indian Council of Medical Research (ICMR), “clearing of forest area for cultivation causes changes in tick fauna and is considered as an important risk factor for outbreaks.”

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Kyasanuru village on Google Maps.

Incidentally, Dodamarg borders Goa, where KFD struck in 2015, and Karnataka, where it continues to prevail. Its forests are also home to the red-faced bonnet monkey (Macaca radiata) and black-faced langur (Semnopithecus entellus) – species that are susceptible to monkey fever. “It is possible that the monkeys carry and spread ticks around when they move from one forest of the Western Ghats to another,” said researcher Pragya Yadav.

Monkeys do not play a direct role in the transmission of KFD, which is not aerosol-generated, Yadav clarified, but they do act as hosts. After a monkey dies from infection, the ticks drop off and scramble to find new hosts, which could be humans. “When they find a warm-blooded animal, they run like crazy creatures because they want to suck its blood.”

Sick of ticks before

Yadav and colleagues checked blood samples for antibodies against the virus in KFD-affected villages of Dodamarg. Overall, 9.7 percent of the individuals had antiviral antibodies in their blood. A study of healthy, uninfected individuals in KFD-unaffected villages 15 km away, surprisingly, showed a similar prevalence of antibodies.

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Black-faced monkeys in the Western Ghats. Photo by Jrimman / Wikimedia Commons.

The antibodies persist for at least two years after a tick bite, according to Yadav. This means that the two areas had been exposed to the virus before and 2016 was not the first time that Maharashtra had had a KFD outbreak. The previous cases probably went undetected, Yadav says, indicating that many people got tick bites, recovered and were doing fine.

Yadav’s analysis of the 2016 outbreak was published online earlier this year. New cases of KFD continue to emerge everyday from the region as we near the middle of the peak season. Not only this, the virus seems to be spreading geographically as well. During 2016–17, Yadav says, already many villages of Sindhudurg were affected but now it’s being detected in more villages.

CITATION:
Gurav, Y.K., et al. (2018). Kyasanur Forest Disease Prevalence in Western Ghats Proven and Confirmed by Recent Outbreak in Maharashtra, India, 2016. Vector-Borne and Zoonotic Diseases. https://doi.org/10.1089/vbz.2017.2129.

(I wrote this piece originally for Mongabay-India.)

What’s behind the recent spate of discoveries?

Deepak Veerappan was in-between research jobs when, out of boredom, he started exploring the parched open lands in the south and west of India. He ventured out on his own into sun-baked landscapes in search of a “fan-throated lizard” – a small lizard with a large double chin. His post-doctoral position at the Indian Institute of Science, and thus funding, were yet to come but he had already laid the foundation of what would keep him busy for the next few years.

Only two species of the unusual lizards Veerappan loved watching had been known from India. From observing them in the wild, he knew there were actually more than two. This led Veerappan to discover five new species of fan-throated lizards – named so because the males have loose, stretchable skin hanging from their necks.

This spectacular find is one among a slew of discoveries we have seen so far this year in India. Wherever you look, be it the shores in the south or mighty mountains in the north, sun-scorched lands of the west or wet hills of the east, new species are being found everywhere. And yet scientists say there’s more to come. What on earth is going on?

To find out, read the full feature at The Wire.

Photo credit: Varad Giri

The tadpoles that swim in sand

In 2014, 14 new species of “dancing frogs” were discovered in the Western Ghats, a wildlife-rich mountainous region along the west coast of Peninsular India.

5. Tadpoles of Micrixalus herrei

These Indian dancing frogs are named for the antics males get up to when they want to grab the attention of a female.

Perched on a wet rock in a noisy, fast-flowing stream, a male sings and waves to the females. He lifts and stretches a leg to flag his white, webbed toe.

Any rival males on the territory are literally kicked out by the singing-and-dancing male.

It now turns out that this foot-waving, which was observed in nine species of the genus Micrixalus, is not the only bizarre trait that runs in the family. For the first time, researchers have found the tadpoles of a dancing frog, specifically the Kallar dancing frog (Micrixalus herrei).

Unlike most tadpoles, which live in water, they live underground until they develop into froglets.

Read more about the tadpoles here at BBC Earth.

Photo credit: SD Biju

Meet the Western Ghats’ new freshwater crabs

Five new species of brightly coloured freshwater crabs have been found in the Western Ghats, India’s wildlife haven. Of these, two species belong to the genus Ghatiana (discovered in 2014) and the remaining to Gubernatoriana (known since 1970).

Behind the discoveries are an undergraduate student and researchers from the Zoological Survey of India and the Indian Herpetological Society. They described the five new species, named Ghatiana atropurpurea, Ghatiana splendida,Gubernatoriana thackerayi, Gubernatoriana waghi, and Gubernatoriana alcocki, in the journal Zootaxa on February 23.

Prior to this, 36 species belonging to 14 different genera were known from the Western Ghats in the family of freshwater crabs called Gecarcinucidae. So the latest discoveries bring the total species count to 41.

Read all about the new crabs at The Wire.

Photo credits:  Shailesh Bhosale

Found: Snake that remained hidden for 145 years

Indian researchers, in collaboration with the Natural History Museum in London, have found a new species of burrowing, non-venomous snake that has smooth, shiny scales.

The species remained misidentified and stashed among museum specimens for a long time before scientists thought it might be distinct. To confirm their doubts, they looked in the wild – and unlike many museum finds that are extinct by the time they are discovered, this one still existed. And it continues to do so in the semi-evergreen forests of the Western Ghats of India.

Read the full story at Nature India.

Photo credit: Varad Giri

What’s driving the endangered purple frog to extinction?

For indigenous communities living in and around the forests of Kerala, tadpoles of a rather puffy, purplish frog are a cherished delicacy. The practise of consuming tadpoles has been around for decades but researchers worry that harvesting them any more will soon push the endangered frog to the verge of extinction.

Found only in the Western Ghats, the Indian purple frog, Nasikabatrachus sahyadrensis, is a rather weird-looking creature known for its rather strange behaviour. It spends much of its time below ground, save the few days when it comes out to mate, after which it disappears into its burrow again. This elusive frog has tiny eyes, short limbs, a pointed nose and a large body – all adapted to a life underground.

Discovered in 2003, the purple frog was soon classified as endangered in the International Union for Conservation of Nature’s Red List due to its already declining habitat and a geographical range of less than 5,000 square km. We still don’t know a lot about the frog’s life, since much of the action happens underground, or about its dwindling numbers.

Now, a five-year survey (2008–2012) by the scientist who discovered the species has revealed that a single tribal household of four consumes an average of about 1,500 tadpoles in one monsoon season (July to September). There are 100 to 150 households in the area where the survey was conducted.

Read the full story at The Wire.

Photo credit: SD Biju

A map that tells where elephants are

Ecologists have mapped Asian elephants in the Indian state of Karnataka down to the smallest forest administrative unit. The detailed map, which shows where elephants exist inside and outside protected areas, could help conservation planning and minimize human–elephant conflicts.

Karnataka has the largest population of Asian elephants (Elephas maximus) in India. But recent decades have witnessed increased pressure on their habitat and clashes between people and the jumbos. A detailed map of elephant distribution is crucial to understand where humans should get priority, where elephants should and where they can coexist. Yet, there is no microscopic map of Asian elephants anywhere.

Read the rest over at Nature India.

Photo credit: Subhra Priyadarshini

Treasure trove of new frogs found in India

Nine new species of bush frog have been discovered in the Western Ghats, a mountainous region in southern India that is a hotspot of biodiversity.

Bush frogs are tiny animals, found mainly in South and South-East Asia, some of which can fit onto a 20 pence coin. Beginning in 2008, S. P. Vijayakumar, then at the Indian Institute of Science in Bangalore, has been scouring the Western Ghats to find them. The new species he has found all belong to the genus Raorchestes, and he has identified them based on their appearance and genetics. Vijayakumar and his colleagues have published their findings in Zootaxa.

The Western Ghats is home to many species of frog, including the 14 dancing frogs discovered earlier this year. That’s because it is a fragmented landscape, with hills, valleys and plateaus. This means populations of frogs can easily wind up evolving in isolation.

Read the rest at BBC Earth.

Photo credit: S. P. Vijayakumar

Helping humans coexist with elephants

Promoting coexistence of humans and elephants in Anamalai Hills (literally “The Elephant Hills”), situated in the Western Ghats of southern India, has been the key objective of M. Ananda Kumar for over a decade. A wildlife biologist with the Nature Conservation Foundation, Kumar is a staunch believer in the benefits that involving local communities in conservation work can reap. Kumar’s work on human–elephant conflict resolution in the Ghats has been recognized with the Carl Zeiss Wildlife Conservation Award.

In an interview with me, Kumar speaks of the change that has been brought about in the attitude of people towards elephants—from hostile to tolerant.  

Excerpts from the interview:

What threatens elephant survival in India?

Activities such as setting up of micro hydel projects, dams, power lines or roads in prime elephant habitats pushes these animals out of their habitat into neighbouring towns and villages. That leads to negative interactions between people and elephants, and is detrimental to the elephant population in the country.

Read the rest of the interview at IndiaBioScience.

Photo credit: M. Ananda Kumar.