In 1880, German physician Rudolf Virchow coined the term “zoonoses”, which means infectious diseases that can be naturally transmitted between animals and humans. This discovery continues to affect mankind even after a century, with diseases like nipah, ebola and zika catching everyone’s attention. Additionally, anthrax, plague, leptospirosis, rabies and worm infestations are some of other zoonotic diseases that occur regularly in India.

After the catastrophic floods in Kerala in 2018, the State grappled with massive loss of life and property. Adding to its woes was the threat of infectious diseases. Leptospirosis, commonly known as rat fever or Andaman haemorrhagic fever, claimed lives and affected many in Kerala, post-floods. The Integrated Disease Surveillance Programme (IDSP) data show that as of October 31, 2018, there have been 1,807 confirmed cases and 74 confirmed deaths.

Bacterial infection

Leptospirosis, a bacterial infection caused by ‘spirochaete’, is naturally carried by more than a dozen species of rodents, wildlife and domestic animals. Dogs, cattle and rabbits also transmit the infection. Rodents have an enormous ability to excrete large number of leptospirae in the urine, which is the main source of contamination incriminating human and animal leptospirosis.

Infection can also occur through aborted foetuses, afterbirth or uterine discharges of cattle or the semen of an infected bull. Humans can become infected by all these animals, and especially if mucous membranes and/or skin is damaged, the bacteria get an opportunity to invade.

Clinically, patients may suffer from non-specific symptoms like fever, body ache, vomiting, redness of eyes, cough and chest pain. There can be severe kidney and liver impairment in some cases. Leptospirosis during pregnancy has adverse outcomes especially in first trimester and near-term mothers.

On emergence of earliest signs, one should immediately report to the nearest health facility and get tested for the leptospira infection by methods available depending on the stage of illness.

Once the diagnosis is established, immediate treatment should be started. A medicine named Doxycycline 100 mg should be prescribed twice a day for seven days and ampicillin/amoxicillin should be prescribed to children and pregnant and lactating women for seven days.

Severely ill patients need an aggressive treatment format with parenteral therapy. Hygienic practices including avoiding direct and indirect human contact with animal urine are recommended as preventive measures.

Doxycyline can also be given as a preventive drug in the dose of 200 mg per week maximally for eight weeks, to those exposed and at great risk, especially in a flood situation.

Kerala has been successful in tackling the menace of leptospirosis post floods when water receded. This is due to the timely leadership showcased by the Central and Kerala Governments that initiated immediate action. The State health authorities have provided appropriate health care to the affected, including setting up of medical camps, deployment of health personnel, provision of drug supplies and emergency healthcare services.

The Kerala disaster is the perfect example of the importance of collective action that resulted in timely mitigation of the after-effects of the events.

The writer is Secretary, Department of Health Research, and Director-General, Indian Council of Medical Research, New Delhi.