Goa has high viral diversity


Nandkumar M Kamat

Viruses are not novelties in the tropics. The entire western Ghats and Arabian sea ecosystems are teeming with wild viruses many of which are still locked up in their natural quarantines like the bats. The present scare on SARS like new coronavirus – COVID-19 needs to be contrasted with several deaths classified wrongly in the reports of births and deaths of the registrar of births and deaths- attributed to Arthropod borne Encephalitis (ABE) which actually is caused by tick-borne viruses. In 1989, 27 people died due to ABE. This rose to 42 in 1992 and 67 in 1993, 28 in 1994, 58 in 1995, 56 in 1996, 30 in 1997, 40 each in 1998 and 1999. Despite 388 people dying from 1992-1999 due to an arbovirus strangely we have no reports of testing of any samples for presence of tick-borne viruses. Therefore, we need to look carefully at the present viral diversity in Goa and the viral disease load.

Since Liberation, the health department has procrastinated on establishing local viral testing laboratory. Hundreds of patients have died due to wrong diagnosis because timely identification of viruses could not be done. The entire Western Ghats region and surrounding talukas like Ponda and Dharbandora are now harbouring a tick-borne virus known as Kyasnur Forest Disease Virus (KFDV). There are millions of bats hiding in various caves, caverns, under cliffs, large trees etc, and these are carriers of many viruses like Nipah and coronaviruses but no studies of bat-borne viruses in Goa have been done. During this monsoon there is possibility of a Nipah virus outbreak again

 in Kerala.

Goa is not safe from viruses. Different types of anti-viral antibodies would be discovered if the local population is tested. Sewage contamination of waterbodies causes hepatitis virus outbreaks. Hepatitis viruses B and C are found in Goa. Then we have a dominant serotype of Human Immunodeficiency Virus in Goa known as HIV-2. By September 2018 the HIV infections were 17,018 and AIDS cases were 1,804. For a small state, 1,161 deaths due to HIV in 30 years is a very serious matter. On average 30-40 people die due to HIV resulting into full

blown AIDS.

Mosquitoes carry a lot of viral diversity in Goa. Japanese encephalitis virus (JEV), dengue (DEN), and chikungunya are major viruses. Among these in coming months DEN and chikungunya are going to cause localised outbreaks where mosquito breeding sites have not been eliminated. All four strains of DEN are found here. Japanese encephalitis virus had tormented Goa in the 1990s but after 2013 the number of cases has fallen. The JEV has been also found in local pigs. Climate change may see its re-emergence soon.

Rabies virus is still a huge threat to the local population because a study from Goa Medical College in 2009 had shown how the virus can remain active for 25 years if one comes into contact with saliva of rabid stray dogs. The doctors were stunned to find the presence of anti-rabies antibodies in the brain after autopsy of the patient who showed the symptoms of rabies after 25 years. Until people coming in contact with stray dogs are tested for anti-rabies antibodies none of them are safe and Goa can’t be declared a rabies free state this year. It has to be proven that people are not incubating the rabies virus without

any symptoms.

The foot and mouth disease virus affecting the cattle is also prevalent in Goa and it adds another dimension to overall hygiene in milk processing industries. From 2013, there had been rising cases of children’s hand, foot and mouth disease caused possibly by a non-poliomyelitis enterovirus known ascoxsackievirus A16. However, there are no tests done to pinpoint the strain prevalent in Goa as paediatricians don’t insist on accurate differential diagnosis. Other viruses also cause this disease.

Technically what is not free from viral load? Cultivated prawns are infected by viruses like pono, baculo,white spot, and almost all our fruits and vegetables attract viral infections. However, there is very little work on crossbreeding of plant and human RNA based viruses. Respiratory viruses like lentiviruses and coronaviruses are common in Goa. There are 160 different strains of common cold viruses belonging to three species of rhinovirus but we don’t know how manyof thesestrains cause infections in Goa. Technically speaking a person suffering from cold two to three times a year would have been exposed to at least a hundred strains during his

or her lifetime.

Swine flu virus H1N1 has established its presence in Goa with more than 100 cases reported last year. Information on avian or bird flu is also very scanty. Antibody testing of people in poultry business would clearly reveal the presence of avian or

bird flu virus.

In summary with such vast viral diversity and heavy viral exposure load in local population,Goa can face the COVID-19 situation with confidence provided government establishes a world class virological testing laboratory to rapidly detect any type of virus infecting peoplefor precise differential diagnosis.