Uncovering the scourge of leprosy

At least 20,000 hidden cases of leprosy were detected during a massive door-to-door campaign conducted by the Union Ministry of Health and Family Welfare from September 14 to October 4. A team of over 200,000 volunteers, including Accredited Social Health Activists, travelled to 163 districts across 20 states, only to find that the fight against leprosy is far from over.

Maharashtra (7,000) and Bihar (4,000) have collectively reported more than half of the total hidden cases, with West Bengal also reporting a high number of hidden cases. These cases go unreported, mainly due to the fear and stigma associated with the disease.

 

India is home to 60 percent of the world’s leprosy patients, and according to the National Leprosy Elimination Programme (NLEP), at least 127,326 cases of leprosy were recorded in 2015-16, an increase of 1.22 percent from 2014-15, when 125,785 cases were detected.

According to Anil Kumar, deputy director-general of NLEP, around 32 crore people were screened in various states and those identified with the symptoms will be referred to medical treatment.

In March-April, a similar detection programme was conducted in 50 districts across seven states. Out of 65,427 suspected cases, 4,120 were later confirmed. These leprosy case detection programmes are undertaken “on a war-footing” to identify hidden cases and start immediate treatment.

The mass screening programmes seek to cover all districts in high-burden states that have a prevalence rate of more than one leprosy case in a population of 10,000 in the past three years. According to data available in NLEP website, Chhattisgarh has a prevalence rate of between two and five in every 10,000 persons. In Odisha, two in every 10,000 persons are infected with leprosy. Delhi and Chandigarh have more than one case in a population of 10,000.

According to government data, leprosy cases of grade II disability (damage to limbs and nerves) increased to 5,794 in 2014-15 from 3,019 in 2005. Even the percentage of grade II disability among new cases detected has increased from 3.10 percent (2010-2011) to 4.61 percent (2014-2015). It indicates that the cases were being detected late.

 “The rise in cases of disability is a bad sign. This occurs when an active case of leprosy infection goes unreported for a long time and is untreated for over two years of active infection,” said Kumar.

 A case of leprosy starts showing signs of disability like loss of fingers and toes two years after the setting in of the infection. Disability can be avoided by starting timely treatment when symptoms like discolouration, oily patches or nodules on the skin are reported early.  Soon, the government will start administering the drug, Rifampicin, to people in contact with the leprosy patients.

 In November 2015, Down To Earth highlighted how new leprosy patients are showing resistance to multi-drug therapy (MDT), especially those who discontinue the treatment.

 Treated but not cured

 

In December 2005, the Indian government declared it had less than one case of leprosy per 10,000 people. This announcement of elimination, as defined by the World Health Organization (WHO), brought relief to a country known to have the highest burden of the disease. But the sense of relief is disappearing fast.

 Since 2009, the incidence of new cases has remained almost constant. In fact, new cases are being detected at nearly the same rate at which patients are getting cured, says Kiran Katoch, former director of the National Jalma Institute of Leprosy and Other Mycobacterial Diseases in Agra.

 In 2013-14 alone, 127,000 new leprosy cases were reported from across the country, making India home to 78 percent of the new cases detected worldwide. That year, 433 treated patients relapsed into the disease.

Worse, since 2014, India has joined the growing list of countries, including Brazil and China, where leprosy can no longer be treated by the conventional multi-drug therapy (MDT)—a specific combination of three pills which takes from six months to a year to kill the leprosy-causing germ, Mycobacterium leprae, and has helped countries significantly reduce the disease burden since its introduction in 1982.

What’s worrying is that new patients are now showing resistance to MDT, whereas drug resistance is usually experienced by those who discontinue the treatment.

Consider the case of Shahla (name changed to protect identity). The 24-year-old lives in a slum near Delhi’s Vijay Nagar area along with her family of eight. She says no one in her family or friends had ever contracted leprosy. So in 2007, when she developed skin lesions, she ignored it. The disease remained undiagnosed for two years till she developed numbness in the affected area, indicating peripheral nerve damage. Doctors treated her with MDT and declared her cured by early 2014. But within six months, she developed erythema nodosum leprosum (ENL) lesions, a complication of leprosy that can result in deformity. Subsequent blood tests showed that Shahla is resistant to MDT. Doctors at the Delhi hospital of The Leprosy Mission (TLM), an international charitable organisation, are now treating her with the second-line of treatment. They say Shahla will take another two years to be cured.

So far, the long delay between the onset and detection of leprosy had been a major obstacle to “eliminating” the disease. It usually takes five to 10 years before the symptoms show up. Now, with the emergence of a drug-resistant strain of M leprae, its elimination will become further difficult, says Jalaz Rahmi, Medical Officer at TLM Hospital, Delhi. Diagnosis of the drug-resistant type of leprosy is time-consuming. Besides, the second-line anti-leprosy drugs are not available easily and for free. More than 13 percent of the new cases and 44 percent of the relapsed cases are showing resistance to rifampicin, one of the three drugs of MDT, say researchers with Stanley Browne Laboratory in Delhi, a centre of WHO for the surveillance of drug resistance in leprosy. 

The researchers arrived at a conclusion after diagnosing 215 new and 16 relapsed cases visiting the TLM Hospital, Delhi, between 2009 and 2014. The study was published in Clinical Microbiology and Infection in November 2015. “Rising cases of drug resistance since 2014, particularly among new patients, shows that resistant strains are actively circulating in India,” says Mallika Lavania, a researcher with Stanley Browne Laboratory.

The bacterium is also being transmitted continuously. It is evident from the fact that children, who rarely suffered from leprosy given the long incubation period of M leprae, now account for a significant percentage of the newly reported cases. In several states, according to the Progress Report of the National Leprosy Eradication Programme (NLEP), 2014-15, children account for over 10 percent of the new leprosy cases; in Lakshadweep, the proportion is 75 percent.

So far, M leprae is believed to be transmitted through the discharge of droplets from the nose and mouth of an infected person. Prolonged contact and an over-crowded environment increase the risk. But recent evidence suggests that environment could also be responsible for spreading the bacteria, both resistant and non-resistant.

 

 To understand the mode of transmission of the bacteria, in 2011 researchers with Stanley Browne Laboratory in Delhi tested soil samples from leprosy endemic areas of Purulia district in West Bengal for the presence of M leprae. They collected 207 soil samples from bathing and washing areas around houses, common sitting places, community ponds and areas around borewells. They found DNA of M leprae in 71 of the 207 samples. The bacteria DNA was present in 27 percent of the 82 samples collected from the houses of infected leprosy patients, and in 39 percent of the samples taken from areas near washing and bathing places, notes the study published in Infection, Genetics and Evolution in November 2011. The presence of M laprae in soil could lead to indirect infection, the study suggests.

 The environment also acts as the reservoir of several other Mycobacterium species, which make people susceptible to leprosy. One such species is M gilvum. The Stanley Browne Laboratory researchers stumbled upon this rare species in 2014, while studying the transmission of M leprae in the population of an endemic village in Purulia. They isolated the species from the accumulated water in the drain connected to the bathing place of leprosy patients in the village. Previous studies had shown that M gilvum can grow rapidly and is resistant to antibiotics meant for several life-threatening diseases. Though there is no direct association of this bacterium species with leprosy, M gilvum belongs to the group of M vaccae, which suppresses the immune system of the host and increases susceptibility to leprosy, note the research paper, published in the International Journal of Mycobacteriology in October 2014. Between 2011 and 2014, the village with a population of 1,600 had reported 66 new leprosy cases.