Context: India is moving closer to developing its first-ever vaccine against dengue, as the indigenous drug-makers Serum Institute of India (SII) and Panacea Biotech have applied for collaboration with the Indian Institute of Medical Research's (ICMR) collaboration on Phase-3 trials.

• Every year on May 16, the country marks National Dengue Day as part of an initiative spearheaded by the Ministry of Health and Family Welfare.

About Dengue and its Status in India

• Dengue, often known as break-bone fever, is a viral virus that passes from mosquitoes to humans, resulting in a considerable number of deaths worldwide.

• According to the World Health Organization, over half of the world's population is now at risk of dengue, with an estimated 100-400 million illnesses occurring each year.

• According to the National Center for Vector Borne Disease Control, there were 1,93,245 dengue cases and 346 fatalities registered across the country in 2021.

• More than 30,000 individuals were infected with dengue last year, with the number soaring during the monsoon season.

• There has also been an increase in the spread of the infection to the rural areas – with rural India accounting for up to 45 per cent cases by 2021 up from 32 per cent in 2015,

• Every year, from July to November, there is an increase in dengue fever cases, owing mostly to water logging and unsanitary conditions. The illness has a seasonal pattern, which indicates that the peak occurs after the monsoon.

• Dengue virus is spread by the bite of a female Aedes mosquito. Aedes is a day feeder with a limited range of 400 meters. Dengue mosquitoes can’t breed once the temperature falls below 16 degrees.

Factors responsible for spread of Dengue

• Mosquito Vector: Dengue is primarily transmitted by the Aedes aegypti mosquito, which thrives in urban and semi-urban areas of India. The mosquito breeds in stagnant water sources like uncovered water storage containers, discarded tires, and puddles, making it easy for them to reproduce and spread the disease.

• Urbanization and Population Density: Rapid urbanization, unplanned construction, and population growth in cities contribute to increased human-mosquito contact, creating favorable conditions for dengue transmission. Crowded urban areas with inadequate sanitation and waste management systems provide ample breeding grounds for mosquitoes.

• Climate and Weather: Dengue transmission is influenced by climatic factors. India's tropical and subtropical climate, with high temperatures and humidity, provides an ideal environment for the mosquito vector to thrive and reproduce. Monsoon seasons, characterized by heavy rainfall and water accumulation, further facilitate mosquito breeding.

• Lack of Awareness and Education: Insufficient knowledge and awareness about dengue prevention among the general public, healthcare providers, and policymakers contribute to the spread of the disease. Lack of awareness about vector control measures, such as eliminating mosquito breeding sites and using protective measures, hampers effective prevention.

• Inadequate Vector Control Measures: Inconsistent implementation of mosquito control measures, including larval source reduction, insecticide spraying, and fogging, leads to the persistence of mosquito breeding sites. Limited resources, infrastructure, and coordination among different stakeholders hinder the effectiveness of vector control efforts.

• Weak Healthcare Systems: Inadequate healthcare infrastructure, including diagnostic facilities, trained personnel, and timely reporting, pose challenges in accurately diagnosing and managing dengue cases. Delayed diagnosis and lack of prompt treatment can contribute to the severity of the disease and its spread.

Initiatives by the Government to Combat Dengue

• The Government has developed a Long Term Action Plan for the Prevention and Control of Dengue in the nation.

• National recommendations for the clinical management of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome have been published.

• Sentinel Surveillance Hospitals were established, with laboratory assistance, to supplement diagnostic facilities for Dengue in endemic countries.

• National Dengue Day is marked in India on May 16 at the advice of the Ministry of Health and Family Welfare to raise awareness about dengue and to increase preventative measures and readiness for disease control in the country before the transmission season begins.

Conclusion

• It is believed that the vaccine, which is projected to be available within two years, will lower the incidence of dengue, the burden of hospitalization, and, most crucially, death. There is currently no particular therapy for dengue, hence there is an urgent need to develop effective vaccines against dengue viral disease.