Nandkumar M Kamat
VIRUSES seem to have fallen in love with Goa’s developmental models and it is just matter of time that we are told by molecular virologists about discovery of a new viral strain – the Goa serotypes of viruses of either KFD or dengue. It would be bad news if the Goa serotypes turn out to be more virulent. Conditions are just perfect in highly-urbanised Goa, with stagnated drainage works and mountains of rotting solid waste for airborne, waterborne and food-borne viral outbreaks.
After Dengue outbreak in Vasco it could be Panaji’s turn unless the most dreaded mosquito Aedes egyptii is hunted down from the capital city on war footing. A quick survey of Campal to Caranzalem and Bhatulem to Santa Inez areas shows several stagnated pools of water due to destruction of traditional drainage systems discharging on the beach or in the creek. Caranzalem paddy fields have turned into large reservoirs and ideal breeding grounds for mosquitoes. Panaji MLA Siddarth Kunkalienkar has decided to galvanise the health administration this week to tackle any outbreak of mosquito-borne diseases including Dengue or Chickungunya.
Goa Scores Poorly
Margao, Sanvordem-Curchorem, Mapusa, Sankhali and Ponda need to also be on high alert. But by the yardstick of prevalence of insect-borne viral diseases, Goa scores poorly in ensuring better quality of life for citizens. Any viral illness leaves not only the patient but the full family drained and stressed. The sword of secondary infection always hangs over the head. So far there is very little informed debate in civil society on spread of viral diseases which were not heard of ten or twenty years ago. There is also ignorance about the long-term impact of viral infections on physical and mental health of children and the immunity of adults.
With new man-made mosquito breeding habitats, forest ticks forced to come out in open, the dense network of roads, numerous social functions causing intermingling of people and more than five million footfalls of tourists, Goa is an ideal location for emergence and spread of new viral diseases. The outbreak of Dengue virus (DENV) first at Sao Jose de Areal, a village disfigured by stone quarries and illegal scrapyards and then in overcrowded Vasco town made me sit and take notice because it followed summer outbreak of Kyasanur Forest Disease (KFD) in Sattari.
Both KFD virus – KFDV and DENV belong to Flaviviridae – the same family which includes many important human pathogens causing hemorrhagic fever and encephalitis, such as yellow fever virus (YFV) and Japanese encephalitis virus (JEV). Flaviviruses may be either arthropod-borne, infecting a range of vertebrate hosts through mosquito or tick bites or presumed to be limited to vertebrates alone or apparently limited to insects alone. Although DENV is not new in Goa, its appearance following KFD needs to cause concern because such flaviviral outbreaks are indicators of human impacts in ecosystem unless we are made to believe that some unknown entity is testing viral bio-weapons in Goa.
An estimated 50 million dengue infections occur worldwide annually and about half a million people with dengue hemorrhagic fever – DHF require hospitalization each year. About 90 per cent of them are children aged less than five years, and about 2.5 per cent of those affected die. Children of Goa don’t expect a future to face viral outbreaks like Dengue. It would leave the young generation immunologically weak. The nature is sounding alarm bells questioning Goa’s reckless models of unsustainable urbanisation and increasing human interference in natural ecosystems.
Dengue is a remark passed by the nature about overcrowding and poor sanitation in the location. Vasco has everything to shelter Aedes egyptii. Sattari also interfered with original dense forest ecosystems and brought the quarantined forest ticks in contact with humans. Dengue is caused by infection with one of four dengue virus serotypes dengue 1 to 4 (DEN-1 to DEN-4). Although all four serotypes are anti-genically similar, they differ and elicit cross-protection for only a few months after infection by any one of them. The first major DHF outbreak in our country occurred in 1996 by dengue virus serotype 2, and after a gap of seven years we faced yet another Dengue Fever (DF) outbreak in the year 2003 by dengue virus serotype 3.
Goa government is silent on local Dengue serotypes. We need to see which serotypes of DENV are creating havoc at Sao Jose de Areal and Vasco and whether any novel serotype has emerged under local conditions because for many years local population is exposed to DENV. Incidences of Malaria may be under control but Dengue infections are rising alarmingly and unpredictably. The health department needs to check blood samples to see whether those infected with one DENV serotype are getting re-infected by the other serotypes. Secondary infection with another serotype or multiple infections with different serotypes can lead to severe form of DHF and dengue shock syndrome (DSS).
Local doctors encountering examining Dengue cases would be at their wit’s end because differential diagnosis is not easy. The vast majority of dengue infections are asymptomatic. Only a proportion manifest as not easy to diagnose fevers and even fewer progress to severe disease. How to know for sure without any antigenic tests that a patient is suffering from Dengue? DENV causes high fever, with muscle pains, abdominal pain, nausea and vomiting or diarrhea. It may also appear as flu – like illness when no rash is present and the signs and symptoms are overlapping with many infections. Dengue is dreaded because it is often clinically confused with Malaria, Chikungunya, Rickettsial infections, Leptospirosis, KFD, and Influenza like illness and Typhoid. KFDV and DENV now seem to have found sanctuary in Goa. How KFDV reached Goa since it was limited only to Shimoga, Chikkamagalore, Uttara Kannada, Dakshina Kannada and Udupi districts of Karnataka state? After November 2012 it had spread to southernmost parts of Karnataka bordering Tamil Nadu and Kerala. But the mystery still remains how KFDV surfaced directly hundreds of kms northwards from these endemic regions in Sattari bypassing Karwar, Supa, Canacona, Sanguem, Quepem? Forthcoming Goa assembly session needs to seriously discuss KFD and DENV outbreaks in public interest.