Researchers hope that a new approach and a swanky tool can turn the table on the zoonotic Kyasanur Forest Disease (KFD), popularly known as Monkey Fever, which is endemic to a few parts of south India.

Monkey Fever vaccination drive in Karnataka
news Health Tuesday, November 30, 2021 - 14:28

Rathnamma (44) and Harshita (31), both Community Health Officers in the hilly Kargal region of Shivamogga district in Karnataka, have a thankless, unenviable job. Harshita was eight-month pregnant when she was recalled to work through the COVID-19 lockdowns in 2020. Since then, the two grassroots health workers have been setting off early in the morning, traversing up to 60 kilometres in public transport and arduous hikes through dense forests to tend to COVID-19 cases or to raise participation in the vaccination drive. By November 2021, all but 300 people of the nearly 10,000 people in the Kargal village have taken at least one dose of the COVID-19 vaccine.

However, their work hasn’t eased. Harshita hasn’t been able to spend time with her child as duty continues to beckon. This time, the focus is to convince residents of this village to take another vaccine, for Kyasanur Forest Disease (KFD), or popularly known as Monkey Fever — a tick-borne viral haemorrhagic fever endemic to this part of the Western Ghats. Despite their persistence, the answer to taking the vaccine is often a blunt ‘no.’

“We have hiked through forests with 100 doses of the vaccine against KFD, and been able to convince just 10 to take it. People think that monkey fever is not a threat to them; or for many, they are tired of vaccines. They’ve already taken COVID-19 vaccines, and some have taken KFD vaccines previously. They ask why we keep forcing them to take vaccines,” says Harshita who has been a healthcare worker for 12 years and is barely paid Rs 11,000 a month.

The Kargal village in Sagar taluk has been a vulnerable pocket for the viral disease since 2019 when a large outbreak ravaged the neighbouring Aralagodu village. The village had then seen three cases and two deaths. Vaccine drives for Monkey Fever remains a critical tool to curtail the spread of the disease, whose mortality rates can be as high as 10%.

Soon after the deadly outbreak in 2019, nearly 7,661 out of 10,362 people (above the age of six who are eligible for the Moneky Fever vaccine) took the first dose. A month later, just 4,674 people came forward to take a second dose. Unlike the COVID-19 vaccine, a KFD vaccine requires multiple booster doses to become effective. Less than 17% of the eligible population in the village have taken a booster dose.

“It takes a lot of effort to convince people to conduct KFD vaccines. We can do it if this was our sole focus. But we have to monitor COVID-19 here, as well as carry out other health surveillance activities,” says Rathnamma.

The Kargal healthcare centre has no permanent doctor. Rathnamma and Harshita have to cover for the lack of personnel in two other health subcentres in the region. The burden of curtailing the pandemic and epidemic falls on the shoulders of the underpaid and overworked grassroots workers.

Healthcare workers Harshita (L) and Ratnamma (R)

COVID-19 disrupts KFD monitoring

Kargal is not an outlier among the 53 Primary Health Centres considered to be vulnerable to KFD in the district. In Haridawati village that abuts Sharavathi Wildlife Sanctuary in Sagar taluk, the only person given a dose in the first two hours of a scheduled camp on a particular day was the cleaner of the PHC.

In multiple PHCs visited by TNM, the story repeated: scepticism over the presence of monkey fever in their village, missed doses, low interest in the vaccine, difficulties in tracking doses that are done manually by healthcare workers, and an overburdened health system.

The Karnataka government procures over 2.9 lakh vaccines against Monkey Fever annually. A majority of these vaccines are allocated to the Shivamogga district, which has become the hotspot for the disease.

Raghunandan, Deputy Director of Virus Diagnostic Laboratory (VDL) in Shivamogga, which is the nodal agency for monitoring KFD in Karnataka, says that COVID-19 has posed hurdles to their aim of achieving monkey fever vaccination drives by end-December.

“A KFD shot can only be taken 14 days after a COVID-19 shot and this has made it all the more difficult for health workers to keep track of who has to be given doses. Additionally, our grassroots healthcare workers are overburdened because of the COVID-19 vaccine drive. But we do hope to catch up,” he says.

COVID-19 has done more than just break up the KFD vaccination schedules. It has affected the surveillance of fevers. On average, the Virus Diagnostic Laboratory receives 7,000 samples of suspected KFD cases annually. Since the pandemic, this has come down to 4,000 samples annually. Officials and grassroots healthcare workers attribute this to the “fear of reporting fevers” as villagers were worried about the mandatory quarantines if they tested positive for coronavirus.

Latent risks persist

KFD is a seasonal disease that breaks out when the forests dry up post monsoon rains, usually between November and June.

During the monsoons, adult ticks (primarily, those from the Haemaphysalis species of ‘hard ticks’) lay eggs that hatch into larvae when the rains abate. These larvae turn into nymphs that feed gluttonously on the blood of primates, small mammals and birds. The nymphs (immature insects) can carry the KFD Virus (of the genus, flavivirus). These infected nymphs can eventually transfer the virus to humans who enter forests or if nymphs are carried into human settlements through cattle or monkeys.

The unseasonal November rains along the Western Ghats (the four Malnad districts have received 270% excess rainfall in November) has ensured a delay in the start of the KFD season. 

However, the latent threat of KFD — this season or the next — still persists. After all, the seeds of the 2019 Aralagodu outbreak began in 2017-18 with just one positive case. At the time, barely 20% of the village had been vaccinated. By 2019, the tiny village reported over 200 cases and 18 deaths.

Darshan Narayan, a research associate with VDL, keeps a keen eye on places where the KFD virus had been detected recently. The pandemic-related lockdowns may have resulted in cases being missed or monkey deaths going unnoticed. The vigil for this epidemic must go on despite the larger panic over the COVID-19 pandemic.

He takes Kargal as an example. It is the only land connection for Aralagodu that is surrounded on three sides by the backwaters of the Sharavathi reservoir.

“The year 2019 showed that the forests in the region had a high load of KFD-carrying ticks. Aralagodu is like a peninsula,” he says. “The only way for animals (which can carry ticks) to move is through the forests of Kargal. That’s why vaccination and monitoring here remain critical.”

Predicting the next outbreak

Since 1957, when Monkey Fever was first reported from the forests around Kyasanur village in Shivamogga district, the disease has infected at least 10,307 people along the Western Ghats. Since 2010, cases have been reported in parts of five states — Karnataka, Kerala, Tamil Nadu, Maharashtra and Goa. At least 36 people have succumbed to the disease since 2014.

However, the epidemic remains a neglected disease that gains attention only through outbreaks. Currently, tackling Monkey Fever relies on being vigilant for the first signs of the disease — ticks testing positive during routine screening or, more commonly, the death of monkeys linked to KFD. Adding to the woes is an outdated KFD vaccine that was first developed in 1966, and requires at least three doses within a year to be effective. In new areas of the outbreak, it is often too late to vaccinate the entire village quick enough to prevent an outbreak.

“So far, we have only been running behind the disease,” says SK Kiran, who has been in-charge of the state’s response to KFD between 2014 and 2021.

However, officials hope that a new approach may turn the tide. Instead of just reacting to KFD outbreaks, what if officials can proactively react to it? That is, can one predict where the next outbreak is likely to happen?

Since 2016, a group of researchers across disciplines (zoologists, botanists, microbiologists, ecologists, public health officials, sociologists, doctors, veterinarians, among others) have been studying the spread of KFD in the Shivamogga district as part of the Monkey Fever Risk project. After all, KFD is a zoonotic disease whose emergence is closely linked to forests, the environment and human behaviour.

Their preliminary research showed that changes in forest landscapes (for instance, conversion of dense forests into areca plantations), the proximity of human settlements to evergreen forests and increased cattle densities were key factors driving the spread of monkey fever. These factors have been used to make a preliminary version of a predictive tool.

“The predictive tool is an important component of this inter-disciplinary research. It was made to predict high-risk areas and to pre-empt the occurrence of next KFD hotspots,” says Abi T Vanak, a senior fellow at the Ashoka Trust for Research in Ecology and the Environment (ATREE) in Bengaluru who is part of the Monkey Fever Risk Project.

“This can be useful to determine places to increase tick sample collection or emphasis on vaccines or lower the exposure of villagers to ticks by curtailing activities such as the collection of firewood or leaf litter from forests (which are used in Arecanut fields),” he says.

A version of the tool, which has not been released to the public, currently exists in Shivamogga’s Virus Diagnostic Laboratory. Officials and researchers believe that more data will help fine-tune the accuracy of the model. But, for this to happen, more departments, apart from the health department, need to get involved.

“Landscape change — that is, conversion of forests to plantations — is an important factor for KFD spread. The Agriculture Department can provide such data. The forest department can also do more than monitor monkey deaths. Details of species richness in forests will aid in increasing the accuracy of these models,” says Dr Vanak.

A One Health committee

Diseases like KFD need more than just the health department monitoring them. In 2019-2020 itself, the veterinary department was seen as an important stakeholder to curb KFD. Cattle, which are often left to graze in forests, return to villages with infected ticks on their body. A pilot was started for the department to administer anti-parasital injections to cattle, hoping that this would reduce tick densities on livestock.

While VDL officials see some success in the pilot, veterinary department officials say it is impractical to continue this on a large scale. “Our doctors will have to go door-to-door to inject this every few months. We don’t have the resources or the budget for this,” said a senior veterinary official in Shivamogga.

Taking a cue from this, VDL has sent the state government a proposal for a “One Health” committee. One Health is an approach that sees multiple departments collaborate to contain the spread of diseases. A copy of the proposal accessed by TNM shows that the committee will comprise health officials, public health experts, epidemiologists, animal husbandry and veterinary sciences officials and experts, virologists, forest department, agriculture department, biodiversity experts, and even departments of tourism, education, food safety officials, and social scientists, among others.

The programme approach is gathering momentum in India with the creation of a national group on One Health, while the Union government announced the setting up of a One Health institute as part of the 2021-22 budget. KFD, believe researchers and officials, is ripe for a collaboration to stem the next big outbreak.

“Tackling a zoonotic like KFD needs year-round activity and not just before each KFD season. The district officials need to conduct training of officials, educate villagers, or carry out cattle vaccinations. During an outbreak, you need all these departments to come together to make quick decisions. Currently, each department has its own protocol. With a One Health committee, decisions can be taken much faster while funding can be pooled from all departments,” says Raghunandan, Deputy Director at VDL.

‘Fear drives change’

Bitter experiences drive change and Aralagodu (neighbouring Kargal) is a testament to that. Pushpa S (44), the Community Health Officer, recalls “the hell on earth” that descended on this nondescript village in 2019. For nearly three months, the silence of the remote village was disrupted by the near-constant wails of ambulance sirens. Labour workers refused to come to work in the fields of the village and the village economy crashed. 

“We’d have a death almost every day. Each morning would reveal a new KFD case. Ours was a small healthcare centre. We had to even create makeshifts beds on the porch outside the hospital,” she says.

But things changed soon. Each day, Pushpa calls up 50 people reminding them that their KFD booster dose is due. Nearly 20 turn up for vaccinations. “The rest come within the work, or I visit them at their homes to give the vaccinations. Often, one has to walk 5kms just to cover one set of households. It is necessary because we don’t want a repeat of 2019. This fear makes it easier to people to accept the vaccine,” she says.

Nearly, all of the 2,971 people (above the age of six years) in the village have been vaccinated.

Since then, the village hasn’t reported any signs of KFD virus: whether it is monkey deaths or the presence of KFD, even in a random sampling of ticks.

But it isn’t just the vaccine that is the village’s cover against the disease. Villagers, who work in plantations adjacent to forests or enter forests frequently to collect grasses, firewood and other forest produce, regularly use tick repellent oil.

Meanwhile, the gram panchayat is leaving no stone unturned: from following up with hamlets for vaccinations to distributing shoes to school students to prevent tick bites and conducting coordination meetings with forest departments and other government agencies.

“We have not had a KFD case in two years now. But, we’re not complacent, but what I can say is that fear has given way to hope. And, we hope that KFD will never resurface in the village,” says BR Meghraj, President of Arodi Gram Panchayat, which encompasses Aralagodu.

All images courtesy Vaidya.

Mohit M Rao is an independent reporter based out of Bengaluru. This story was supported by Internews’ Earth Journalism Network Asia-Pacific Project on Zoonotic Disease and One Health.

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