Kosra village in Bihar’s Sheikhpura district is seeing a sudden spurt in the number of kala azar cases. Fifty cases have been detected since January, of which nine have been recorded in June alone. This is a large number of cases even for a village in Sheikhpura, which is one of 33 districts in Bihar where kala azar is endemic.

Kala azar or visceral leishmaniasis is transmitted to humans by the bite of female sand flies. The disease is characterised by bouts of fever, weight loss, anaemia, and an enlargement of the spleen and liver that shows up as a pot belly.

Sheikhpura has had few kala azar cases in recent years and has been classified as a low endemic district for the disease. In 2016, the district had only 10 cases of kala azar. The sudden surge of kala azar infection raises doubts about the government’s plan to eliminate kala azar in India by the end of 2017.

Kosra village had only three kala azar cases in 2016. In March this year, members of the non-government organisation Care India, which aids the government with spraying indoor pesticides to control the disease, found a large number of kala azar infections when they visited Kosra. Health authorities then stepped in to test residents for the disease and find out how many have been infected.

The village has a population of about 4,000 people but only one section of the village seems to have been affected by kala azar. Of the 50 cases in the village, about 40 are from a single Dalit community of about 150 people, said one health official.

“Except two cases, all other cases were from the Majhi and Chamar (both scheduled castes) tolas,” said Dr Arvind Kumar, Sheikhpura district’s vector-borne disease control officer. “These are very poor people and live in mud houses (where sand flies thrive).”

Kala azar often leads to enlargement of the spleen, which shows up as a pot belly.

Dr MP Sharma, Bihar’s programme officer for control of kala azar and other vector-borne diseases, said that about 40% of the patients had migrated to other parts of the country – West Bengal, Punjab and Tripura – to work in brick kilns.

“They were hale and hearty when they left for work, but came back [ill] in six to seven months,” said Sharma. “Kala azar has an incubation period of between 10 days and 15 years. It is possible that they had already contracted the diseases in Bihar which was under incubation and flared up after they started working in brick kilns.”

Where did the infection occur?

Migrants who move for work because they have no source of livelihood in their villages work under harsh conditions. They are often undernourished and this compromises their immune systems. If they had been infected with kala azar in their native villages, they could have started showing symptoms of the disease away from home under these conditions.

Another possibility is that these migrant workers contracted the disease from outside Sheikhpura. Kala azar is also endemic in some parts of West Bengal and Tripura close to the Bangladesh border, said Kingsuk Misra, India programme manager for KalaCORE, a consortium of international agencies that is helping treat and control kala azar. KalaCORE has been working with the Indian government since 2014 on its Kala Azar Elimination Programme to battle the disease in the four states where it is endemic – Bihar, Jharkhand, West Bengal and Uttar Pradesh.

Misra said that it is less likely that Kosra residents contracted kala azar from outside the district.

Officials from the World Health Organisation’s Neglected Diseases Wing conducted a house-to-house survey in the Kosra village from June 5 to June 8 where they checked for people with symptoms and tested them for the disease. The WHO official also conducted a detailed surveillance on the sudden rise in cases, which involved taking a detailed history of the patients. Health authorities have been treating kala azar patients in the village with the drug liposomal amphotericin B. Each patient has also received Rs 6,600 compensation – the standard government incentive for kala azar patients who get treated at government health facilities.

WHO officials conducting a surveillance on the sudden rise in number of kala azar cases in Kosra village, Bihar

How many deaths?

In the last two years, 20 people died in Kosra village. Five of these people had symptoms similar to that of kala azar, said a health expert. Relatives of all these five deceased availed of kala azar treatment since January this year. The sand fly, which transmits kala azar, hops over only short distances so the disease tends to spread in small clusters of people, like within families

However, the National Vector Borne Disease Control Programme has said that there were no kala azar deaths in 2016. They have not confirmed any kala azar deaths in 2017 either.

“Many of these deaths were supposedly due to typhoid or malaria, or tuberculosis,” said a health official. “We do not know if they had kala azar. The surveillance is very poor and health seeking behavior of these people is also very poor.”

Bihar had made good progress with tackling kala azar in recent years. The number of highly endemic districts had come down to 23 this year from 33 last year. But the recent surge in cases in Kosra shows that Bihar’s kala azar surveillance and control measures may not be up to scratch.

The state government has been conducting operations to spray pesticide to kill sand flies inside homes in those villages where kala azar has been reported. Spraying has not been done in villages where no kala azar cases have been reported for more than three years. By these norms, of the 37,540 villages in Bihar’s kala azar endemic districts, only 7,584 villages are currently eligible for pesticide spraying twice a year.

“That is about 20% of the villages, among all endemic villages,” said Sharma. “I can’t say anything about (surveillance and pesticide control) the remaining villages.”

Elimination targets

In his budget speech this year, Finance Minister Arun Jaitley announced the government’s target of eliminating kala azar in India by the end of 2017, which has been seconded by Minister of Health and Family Welfare JP Nadda. The disease is declared eliminated when annual incidence is brought down to less than one case per 10,000 population at the block level. India could be just a quick, concerted push away from achieving this health target but a sudden resurgence like the current one in Sheikhpura could set it back. Bihar has the more than 70% of the kala azar cases in India and the disease is endemic in 33 of its 38 districts.

Currently, there could be a little more than four kala azar cases among every 10,000 people in a block in Bihar, according to Misra of KalaCORE. “We will need to review this elimination target perhaps by October-November,” he said.

People from Kosra village in Bihar's Sheikhpura district shown a video on kala azar

To eliminate the disease, the government needs to have a strong surveillance system to identify an outbreak early and the capacity to fight it. An expert with an international agency aiding the government’s kala azar control programme said that such surveillance systems and capacity are still missing in Bihar. Kosra is an example of how a surge in cases has not been detected quickly enough.

“I will be very happy if we manage to eliminate the disease this year,” he said. “But it looks very tough.”

Meanwhile, Sharma is taking a slightly longer-term view. “For the elimination target, it has to be less than one case in a year at the block level,” he said. “This has been crossed in Sheikhpura. We will see what happens in 2018.”