India has a huge burden of endemic as well as emerging zoonotic infections: NCDC

Zoonotic diseases (zoonoses) are infections that are spread between people and animals. These infections are caused by germs, including viruses, bacteria, parasites and fungi. Aware of the situation, the NCDC has enrolled 32 sentinel sites in 21 states across the country for the systematic assessment of spatial and temporal trends of zoonotic diseases. It is proposed to expand this network up to 80-100 sites over the next five years.

New Delhi: The National Centre for Disease Control (NCDC) has said that scrub typhus (zoonotic disease) has witnessed a remarkable increase over the years with a significant rise in the burden of this disease seen with 2023 alone recording 29 outbreaks of the disease, highest in any single year. The outbreak of emerging zoonoses like Nipah virus, Crimean-Congo haemorrhagic fever (CCHF), Kyasanur forest disease (KFD) and Zika virus were reported more in 2014-2023 than in the 2009-2013 period, it said.

Other endemic zoonoses with significant burden are Japanese Encephalitis (JE) and Leptospirosis. Scrub typhus (Bush typhus), is a disease caused by a bacteria called Orientia tsutsugamushi. Scrub typhus is spread to people through bites of infected chiggers (larval mites). The most common symptoms of scrub typhus include fever, headache, body aches and sometimes rash.

According to a survey conducted by the NCDC, scrub typhus outbreaks have been reported from 23 states across the country. Rajasthan and Himachal Pradesh were the most affected states in the Northern region with a cumulative 17 outbreaks of the infection between 2009 and 2023. Similarly, Assam and Arunachal Pradesh were most affected in the North-Eastern with a cumulative of 31 outbreaks, West Bengal (three outbreaks) in the Eastern, Madhya Pradesh (seven outbreaks) in the Central, Maharashtra (11 outbreaks) in the Western and Puducherry and Tamil Nadu with a cumulative of 13 outbreaks in the Southern region.

Zoonotic diseases (also known as zoonoses) are infections that are spread between people and animals. These infections are caused by germs, such as viruses, bacteria, parasites and fungi. Some can be severe and life-threatening, such as rabies and others may be milder and get better on their own

The NCDC has further revealed that the highest number of JE outbreaks (176 ) were reported between 2009 and 2023 from the North-Eastern region in which Assam accounted for the highest number of outbreaks (139), followed by Manipur, Arunachal Pradesh and Meghalaya.

Other severely affected states with JE included Bihar, Jharkhand, West Bengal, Uttar Pradesh and Maharashtra. West Nile fever outbreaks have been reported from Kerala and Assam.

Leptospirosis burden has been observed highest in the Southern region, followed by the Western region. Tamil Nadu reported the highest number of outbreaks, followed by Kerala and Maharashtra during the same period, the NDC said.

Though brucellosis is prevalent across India in animals, a cumulative of 12 outbreaks have been only reported in humans from Kerala, Assam and Rajasthan. Other endemic zoonotic diseases for which outbreaks were reported included animal bites, human rabies and Influenza A and Visceral Leishmaniasis.

“Zoonotic diseases inflict huge burdens on both the human and animal healthcare systems in India and their economic burden in terms of lost production in animals is also considerable,” the NCDC said.

The NCDC has admitted that India has a huge burden of endemic as well as emerging zoonotic infections, so systematic surveillance among both human and animal population is necessary for zoonotic disease epidemic preparedness and control.

“The Health Ministry is working in collaboration with the Department of Animal Husbandry and Dairying (DAHD), the Indian Council of Agricultural Research (ICAR) and the Ministry of Environment Forest and Climate Change (MoEFCC) for strengthening zoonotic disease surveillance, laboratory diagnostics and outbreak response using one health approach,” the NCDC said.

Interestingly, the NCDC in New Delhi has initiated sentinel surveillance for zoonotic disease projects across the country for the systematic assessment of spatial and temporal trends of zoonotic diseases and to study the exposure factors related to them.

The sites will target priority zoonoses based on the endemicity in their region. By December 2023, the NCDC had enrolled 32 sentinel sites in 21 states across the country. It is proposed to expand this network up to 80-100 sites over the next five years.

“A special surveillance module has been developed on the Integrated Health Information Platform for real-time data entry of laboratory-confirmed cases from these sites. It is expected that these sentinel surveillance sites will strengthen the surveillance and diagnostic capacity of states for zoonotic diseases, which would help in reflecting the accurate burden of the same,” the NCDC said.