Context: National Vector Borne Disease Control Programme (NVBDCP) is an important topic for UPSC Prelims and GS Paper2.

Introduction

National Vector Borne Disease Control Programme (NVBDCP) was launched in 2003-04 by merging the National anti-malaria control programme, National Filaria Control Programme and Kala Azar Control programmes. Japanese B Encephalitis and Dengue/DHF have also been included in National Vector Borne Disease Control Programme. The directorate of NAMP is the nodal agency for the prevention and control of major Vector Borne Diseases.

List of NVBDCP Legislations:

1)    National Anti - Malaria programme

2)    Kala - Azar Control Programme

3)    National Filaria Control Programme

4)    Japenese Encephalitis Control Programme

5)    Dengue and Dengue Hemorrhagic fever

1)    NATIONAL ANTI - MALARIA PROGRAMME

Malaria is one of the serious public health problems in India. At the time of independence, malaria was contributing 75 million cases with 0.8 million deaths every year prior to the launching of the National Malaria Control Programme in 1953. A countrywide comprehensive programme to control malaria was recommended in 1946 by the Bhore committee report that was endorsed by the Planning Commission in 1951. The national programme against malaria has a long history since that time. In April 1953, Govt. of India launched a National Malaria Control Programme (NMCP).

Objective:

• To bring down malaria transmission to a level at which it would cease to be a major public health problem.

2)    KALA -AZAR CONTROL PROGRAMME

Kala-azar or visceral leishmaniasis (VL) is a chronic disease caused by an intracellular protozoan (Leishmania species) and transmitted to man by bite of female phlebotomus sand fly. Currently, it is a main problem in Bihar, Jharkhand, West Bengal and some parts of Uttar Pradesh. In view of the growing problem planned control measures were initiated to control kala-azar.

Objectives:

The strategy for kala-azar control broadly included three main activities.

• Interruption of transmission by reducing vector population through indoor residual insecticides.
• Early diagnosis and complete treatment of Kala-azar cases; and
• Health education programme for community awareness.

3)    NATIONAL FILARIA CONTROL PROGRAMME

Bancroftian filariasis is caused by Wuchereria bancrofti, which is transmitted to man by the bites of infected mosquitoes - Culex, Anopheles, Mansonia and Aedes. Lymphatia filaria is prevalent in 18 states and union territories. Bancroftian filariasis is widely distributed while brugian filariasis caused by Brugia malayi is restricted to 7 states - UP, Bihar, Andhra Pradesh, Orissa, Tamil Nadu, Kerala, and Gujarat. The National Filaria Control Programme was launched in 1955. The activities were mainly confined to urban areas. However, the programme has been extended to rural areas since 1994.

Objectives:

• Reduction of the problem in un-surveyed areas
• Control in urban areas through recurrent anti-larval and anti-parasitic measures.

4)    JAPANESE ENCEPHALITIS CONTROL PROGRAMME

Japanese encephalitis (JE) is a zoonotic disease and caused by an arbovirus, group B (Flavivirus) and transmitted by Culex mosquitoes. This disease has been reported from 26 states and UTs since 1978, only 15 states are reporting JE regularly. The case fatality in India is 35% which can be reduced by early detection, immediate referral to hospital and proper medical and nursing care. The total population at risk is estimated 160 million. The most disturbing feature of JE has been the regular occurrence of outbreaks in different parts of the country.

Govt. of India has constituted a Task Force at National Level which is in operation and reviews the JE situations and its control strategies from time to time. Though the Directorate of the National Anti-Malaria Programme is monitoring the JE situation in the country.

Objectives:

• Strengthening early diagnosis and prompt case management at PHCs, CHCs and hospitals through training of medical and nursing staff.
• IEC for community awareness to promote early case reporting, personal protection, isolation of amplifier host, etc.;
• Vector control measures mainly fogging during outbreaks, space spraying in animal dwellings, and antilarval operation where feasible; and
• Development of a safe and standard indigenous vaccine. Vaccination for high-risk population particularly children below 15 years of age.

5)    DENGUE AND DENGUE HEMORRHAGIC FEVER

One of the most important resurgent tropical infectious diseases is dengue. Dengue Fever and Dengue Hemorrhagic Fever (DHF) are acute fevers caused by four antigenically related but distinct dengue virus serotypes (DEN 1,2,3 and 4) transmitted by the infected mosquitoes, Aedes aegypti. Dengue outbreaks have been reported from urban areas in all states. All four serotypes of the dengue virus (1,2,3 and 4) exist in India. The Vector Aedes Aegypti breed in peridomestic freshwater collections and is found in both urban and rural areas.

Objectives:

• Surveillance for disease and outbreaks
• Early diagnosis and prompt case management
• Vector control through community participation and social mobilization
• Capacity building

EDITORIAL-Fighting mosquito-borne diseases: work in progress

More tools are available to prevent some diseases caused by mosquitoes

• Mosquito-borne diseases have been a scourge for thousands of years, with huge armies defeated, and economies shattered. We were therefore relieved to read reports announcing an effective malaria vaccine, following clinical trials in Burkina Faso conducted by the University of Oxford, the Serum Institute of India and others.
• This West African country(Burkina Faso) has a long and hot season followed by monsoon rains, when mosquitoes emerge in huge swarms. The R21 vaccine has shown an efficacy of 77%, and targets the ‘circumsporozite’ protein (CSP) of the malarial parasite, Plasmodium falciparum.
• The sporozite stage of this parasite secretes CSP. Mosquito bites transfer the CSP and sporozites into the human bloodstream, and the CSP nudges the parasite towards the liver, where it enters liver cells, matures and proliferates. The release of mature merozites marks the onset of the symptoms of malaria.

Efficient vaccines

• The WHO has just cleared another vaccine, called Mosquirix, from Glaxo Smith Kline (GSK) of the U.K. With the involvement of the London School of Hygiene and Tropical Medicine, the vaccine has been tested in Kenya, Malawi and Ghana on over 800,000 children and shows an efficiency of over 50% in the first year, but dropping as time progresses.
• The Global Vaccine Alliance (GAVI) is planning to purchase the vaccine for countries that request it.
• Bharat Biotech of Hyderabad has entered into a deal with GSK to develop this vaccine in India, with a dedicated facility at Bhubaneswar.
• Another rapidly spreading disease is dengue. It is spread by Aedes aegypti mosquitoes, which happily grow in small stagnant pools of water, such as in discarded tyres.
• Four serotypes of the dengue virus are found. Serotypes make vaccine development difficult, as a different vaccine is needed against each serotype.
• A vaccine against dengue, DENGVAXIA, from Sanofi Pasteur, is approved in several countries and shows efficacies ranging from 42% to 78% against the four serotypes of the virus.

Fighting dengue

• In India, Zydus Cadilla has been developing a DNA Vaccine against dengue. Dr. Easwaran Sreekumar at the Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram has modelled a consensus of the four serotypes, which is the basis for Zydus Cadilla’s DNA vaccine, using a platform that the company successfully developed for their COVID-19 vaccine.

Using parasites

• Other innovative methods to fight dengue have been in the pipeline. One particularly interesting strategy involves a bacterium, Wolbachia pipientis, an intracellular parasite commonly found in many insects, but not in the dengue-carrying mosquito.
• When introduced into this mosquito’s cells, this parasite competes successfully against other parasites such as the viruses that cause dengue, chikungunya, yellow fever and Zika.
• Aedes mosquitoes, doped with Wolbachia in the laboratory, are released in localities where the disease is prevalent.
• They quickly spread the bacterium to native Aedes mosquitoes, and the incidence of new dengue cases starts to decline.
• In a controlled release study in Djakarta, researchers from the Gadjah Mada University placed clusters of Aedes mosquito eggs infected with Wolbachia in 12 localities of the city in December 2017 (9 other localities served as controls – no Wolbachia released). By the time the study was halted in March 2020 due to the pandemic, the 12 localities registered 77% fewer cases of Dengue fever compared to the control localities. The intensity of the fever was less, too, with an 86% drop in hospitalisations due to Dengue.

Prevention of disease

• Another way of preventing, rather than curing, mosquito-borne diseases is to accurately predict the next outbreak, and focus your healthcare and mosquito control machinery accordingly.
• Both mosquitoes and the Plasmodium parasite need warm, moist weather to flourish. Using data continuously gathered by environmental satellites such as the NOAA-19, scientists at ICMR’s National Institute of Malaria Research have built elaborate models that correlate monthly rainfall data and data on the annual state-wise incidence of dengue and malaria with the El-Nino Southern Oscillation, which influences global atmospheric circulation.
• The result is an early warning tool that forecasts the start of an outbreak and the dynamics of its progression, along with estimates of the likely number of cases. Therefore, health authorities can begin cautionary measures, several weeks in advance, to minimise the impact of an outbreak. This information is currently available for the Indian States. Refining it to the district level should be the next step.

Way Forward

With the rise of new infections and pandemics, that humans face today, countries need to collaborate with each other and with multilateral institutions like WHO, in terms of finances, technology and human resource to curb the challenges related to health and diseases.