Communicable diseases, animal health and One Health

Prelims and Mains

A sandfly bite in a village in Gujarat or Rajasthan can end in brain inflammation, and it is children who are affected. What is still unsettled is how the virus actually reaches them, which is why the investigation is running through animals as well as insects.

• Chandipura virus is spread mainly by sandflies, and causes a fever that can progress to acute encephalitis syndrome, brain inflammation.
• It falls mostly on children.
• At least 22 children had died in Gujarat and Rajasthan by 6 August 2026.
• Mosquitoes, ticks and mites are being tested alongside the sandfly as vectors.
• Cattle, buffaloes and goats are being tested as reservoir hosts, so the National Centre for Disease Control (NCDC), ICMR and the Department of Animal Husbandry went in as one team.
• Testing animals beside people is One Health in practice, the approach that also ties crowded, antibiotic dosed livestock farming to antimicrobial resistance and to the spillover of pathogens.

Background reading: PIB, 5 Aug 2026: Chandipura virus outbreak: national response team deployed (opens in a new tab)

Prelims and Mains

Kerala's monsoon leaves standing water that rodents have been in, and a bacterium in it enters through a cut on a bare foot. It is a zoonotic infection, carried from animals rather than from other people, and what kills is usually how late it is recognised.

• Leptospirosis is caused by the bacterium Leptospira, and does not pass from person to person.
• It is picked up from water or soil contaminated by infected animals, through cuts or mucous membranes.
• Heavy monsoon rain, floods and humidity help Leptospira survive, and rodents living near homes are its reservoir.
• Farmers, cleaners and construction workers are the most exposed.
• It killed 50 people in Kerala in July 2026, which made it the State's deadliest communicable disease.
• Late diagnosis is what carries the infection on to pulmonary haemorrhage and multi-organ failure.

Prelims and Mains

Subtypes of influenza A are named for two proteins on the virus surface, haemagglutinin (H) and neuraminidase (N). H1N1 is the pairing that caused the 2009 pandemic, and it did not go away afterwards but settled into the seasonal mix.

• By 3 September 2026 seasonal influenza had surged across India, with H1N1 reported from several cities.
• This season's vaccine matched the circulating H1N1 strain, but uptake is low.

See also: Influenza surveillance

Prelims and Mains

The surge was the first real test of the surveillance India built after COVID-19. What it exposed is a system that watches continuously without ever having to declare that anything has begun.

• An integrated command structure was proposed to replace that split.
• Surges are compared fairly by incidence rather than by raw case counts.
• Wastewater surveillance can give early warning of a novel pathogen.

Background reading: Frontline, 8 Sep 2026: Public health is political: Brian Wahl (opens in a new tab)

See also: Influenza A (H1N1)

Prelims and Mains

A biological disaster is handled under disaster management law rather than as a health emergency alone, which puts several agencies into the same response. In August 2026 the Health Ministry set out how India prepares for one, and what it listed was the pieces already in place since before the pandemic rather than one new plan.

• The Ministry of Health and Family Welfare is the nodal ministry for a biological disaster.
• The National Disaster Management Authority (NDMA) issued Guidelines on Management of Biological Disasters in 2008.
• The National Disaster Management Plan of 2019 sits alongside them.
• ICMR runs over 150 Virus Research and Diagnostic Laboratories and two mobile BSL-3 laboratories.
• National Disaster Response Force (NDRF) teams are trained for chemical, biological, radiological and nuclear (CBRN) response.
• PM-ABHIM, the Pradhan Mantri Ayushman Bharat Health Infrastructure Mission, builds capacity against emerging diseases.

Prelims

Lumpy skin disease reached India's cattle in 2019 and has not left, so the work against it is surveillance and vaccination rather than a declared end to it. Because an insect carries it from animal to animal, control has to work on the vector as much as on the sick animal.

• India's first cases were recorded in West Bengal and Odisha in 2019.
• The Department of Animal Husbandry and Dairying reported that cases have come sporadically since July 2026, mainly in unvaccinated animals.
• It has strengthened surveillance, vaccination and disease control in response.

Prelims and Mains

Dengue has four serotypes, and where all four circulate together, a state called hyperendemicity, a person infected with two at once is more likely to develop severe dengue.

Prelims and Mains

The National Action Plan for Prevention and Control of Zoonoses is built on the One Health approach and names ten priority zoonoses, from anthrax and brucellosis to Nipah, rabies and Zika, with each State to write its own plan on the same lines.

Prelims

The Pathogen Access and Benefit Sharing system links the sharing of pathogens with pandemic potential to the sharing of the vaccines, tests and treatments made from them, and is the annex left unfinished when the WHO Pandemic Agreement was adopted in May 2025.

Prelims and Mains

The programme, launched in 2018, aims to eliminate viral hepatitis as a public health threat by 2030 through free screening and treatment and the hepatitis B birth dose.

Prelims

Amoebic meningoencephalitis is a rare and usually fatal brain infection caused by free living amoebae in warm fresh water that enter through the nose, reported in Kerala among people who bathe in ponds.