Communicable diseases, animal health and One Health

Prelims and Mains

Chandipura virus, a rhabdovirus related to rabies, is carried mainly by sandflies and causes fever that can turn into acute encephalitis, inflammation of the brain, in children, killing within days; outbreaks recur in summer in Gujarat, Maharashtra and Rajasthan. How the virus reaches children is unsettled, so investigations test mosquitoes, ticks and mites as vectors and cattle, buffaloes and goats as reservoir hosts. Testing animals beside people is One Health in practice, which is why the National Centre for Disease Control, the Indian Council of Medical Research and the animal husbandry department go in as one team.

Prelims and Mains

Leptospirosis is a bacterial zoonosis: Leptospira from the urine of rodents and other animals survives in standing water and soil and enters through cuts or mucous membranes, so it peaks after monsoon floods among farmers, cleaners and construction workers, and it does not pass from person to person. Treated early with antibiotics it is mild; diagnosed late it goes on to pulmonary haemorrhage and multi organ failure, which is what kills.

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.

See also: Influenza surveillance

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

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.

Prelims and Mains

India watches disease through three networks: the Integrated Disease Surveillance Programme, which collects weekly reports from every district; the Indian Council of Medical Research's Viral Research and Diagnostic Laboratory network, 163 laboratories with four regional sequencing hubs; and sentinel sites for named diseases, 887 hospitals and 27 apex laboratories for dengue. Wastewater surveillance can give early warning of a new pathogen before patients appear. What the system lacks is a trigger: it watches continuously without a rule for declaring that an outbreak has begun, and the bodies that watch are not the bodies that act.

• Surges are compared fairly by incidence, new cases per population over a period, not by raw counts.

See also: Influenza A (H1N1)

Prelims and Mains

A biological disaster, an epidemic, a pandemic or a deliberate release, is handled under the Disaster Management Act, 2005 as well as health law, which puts several agencies into one response. The Health Ministry is the nodal ministry; the National Disaster Management Authority's Guidelines on Management of Biological Disasters of 2008 and the National Disaster Management Plan of 2019 set out who does what; the Indian Council of Medical Research's virology laboratories and two mobile BSL 3 laboratories do the testing; National Disaster Response Force teams are trained for chemical, biological, radiological and nuclear response; and the Ayushman Bharat Health Infrastructure Mission builds the capacity.

Prelims

Lumpy skin disease is a pox virus infection of cattle and buffaloes, spread by biting insects, that causes fever, hard skin nodules and a fall in milk; it does not infect people. It reached India in 2019 in West Bengal and Odisha and has not left. Control works on the vector as much as the sick animal: ring vaccination around an outbreak with Lumpi ProVacInd, the indigenous vaccine developed by the Indian Council of Agricultural Research's National Research Centre on Equines at Hisar, and insect control.

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.