Dengue Fever in India
India observes National Dengue Day on May 16 every year as suggested by the Union Health Ministry to create awareness about the disease spread by mosquitoes.
Mosquitoes and mosquito-transmitted diseases have been the bane of Indians and travellers to India. Till even about the ’70s, malaria was the much-dreaded disease. The development of effective malaria vaccines along with awareness and highly effective drugs such as Chloroquine, Mefloquine, and Doxycycline, have considerably reduced fatalities. We may have conquered our fear of Malaria but this has been replaced by the suffering and the deaths caused by Dengue, Chikungunya, and such diseases each year.
Both Dengue and Chikungunya virus are transmitted by the bite of the female Aedes aegypti mosquito and the Aedes albopictus mosquito. Dengue is not transmitted by touch (from person to person) but the disease causes massive bleeding and “Dengue shock” often resulting in the death of the victim.
Death Due To Dengue
During the monsoon season, when the mosquito menace is at its peak, Dengue fever is widespread. In 2015, the national capital Delhi alone reported over 1,800 cases. This was double the numbers reported in 2014. The death toll was pegged at over 60. By September 2016, over 1,000 Dengue cases had been reported in the capital. West Bengal, too, reported over 5,600 Dengue cases by early September 2016.
Reports of Dengue outbreak and related deaths came pouring in from Assam, Tamil Nadu and Maharashtra, too. According to one news site, there were over 27,879 cases of Dengue infection reported from the different states by the first week of September. The next question that naturally arises is about the treatment and prevention of Dengue in the country which, perhaps, is the worst affected country (by Dengue) in the world.
By November 2019, more than 1,36,422 people across India have been diagnosed with dengue, reports the National Vector Borne Disease Control Programme (NVBDCP) show. The reports also show, the disease had claimed 132 lives.
Current Treatment Options
There are no outlined treatment options available for Dengue fever at the moment. Victims are put on a high fluid diet to keep them hydrated and to make up for the electrolyte loss. Acetaminophen is generally preferred by physicians to combat fever and body ache.
Blood platelet counts are closely monitored in case of Dengue victims and hospitalisation suggested if the platelet count drops below 20,000. In such cases, the Dengue hemorrhagic fever causes excessive bleeding and the patient may require platelet transfusion. Recurrent Dengue attacks may only leave the patient debilitated and vulnerable.
The Elusive Dengue Vaccine
Search for an effective Dengue vaccine has been on since 1977. Decades have past and we are no closer to finding a vaccine that is both safe and effective. Serum India, based in Pune, is one of the largest vaccine makers in the world. The company has been working relentlessly towards finding a vaccine and it announced last year that it was developing a single shot inoculation for lifelong immunity.
The vaccine is ready for the test on animals but would still take years to be ready for human use, the company said. Meanwhile, Mexico-based Sanofi Pasteur has come up with a dengue vaccine which is in an advanced stage of clinical trials (most of which are being conducted in India).
Mutation of the Dengue Virus
One of the greatest challenges to the elimination of Dengue in the country is the constant mutation undergone by the Dengue virus. Dengue is commonly caused by one of four different strains of the virus – DENV 1, DENV 2, DENV 3 or DENV 4. These four stereotypes have a number of substrains. The viruses are constantly undergoing mutation, doctors believe. This is making it more difficult for researchers to discover an effective vaccine.
Doctors believe that while the symptoms of Dengue fever remain unchanged by the mutation, the viruses themselves undergo genetic change. This makes treatment and prevention (by way of vaccination) difficult. The strength or virulence of the disease itself is not dependent on the strain, they say.
Way back in 2012, AIIMS doctors were researching the mutation undergone by this virus in an attempt to understand the progression and to prevent Dengue-related deaths. In 2013, doctors from Jaipur reported that Dengue virus could not be detected in IgG and IgM tests due to the mutations they had undergone. Typically, Dengue is diagnosed by the antibodies produced by the body (as found in the IgG and IgM tests).
The Wolbachia Approach
To be able to eliminate Dengue altogether, we will need to look at novel approaches. While vaccinations (still underway) may only prevent the disease if a person is inoculated and medicines (none as yet) look at a cure, the Eliminate Dengue Research Program of Australia has developed a new method to eliminate the disease altogether.
The researchers discovered that the presence of Wolbachia, a bacteria that occurs naturally, greatly diminishes the ability of Dengue virus-carrying mosquitoes to transmit it. The team faced great challenges in testing their research. Convincing various communities to allow the release of Wolbachia carrying bacteria was one such challenge.
The program is now conducting large scale research. This could be the tool India is looking for when it comes to eliminating the menace of Dengue altogether.
Prevention Better Than Cure
Till we find a reliable vaccine for Dengue or find a way to eliminate the disease altogether, we must fall back on preventive methods. A few precautions suggested by the Government of India’s National Health Portal include –
- Prevention of water stagnation and garbage pile up in the neighbourhood.
- Regular removal of water from water coolers, tanks, and other such containers.
- Using aerosol-based sprays and ointments to prevent mosquito bites.
- Use of mosquito nets at night.