Wastewater Surveillance for Vector-Borne Diseases

GS  Paper II

News excerpt:

There is a debate on the feasibility of using wastewater surveillance to track malaria and dengue in India.

More details on news:

  • Wastewater surveillance has proven effective in certain contexts, its application to tracking vector-borne diseases in India presents unique challenges.
  • The debate revolves around the issue whether India should also use wastewater surveillance to track vector-borne disease like the developed countries.

Vector-Borne Diseases

  •  Vectors act as a medium for transmitting infectious germs from animals to humans and in some cases, between humans.
  • These organisms first get infected by the disease-causing pathogens, and once infected, they can transmit the pathogen to humans throughout their life whenever they come in contact with a human host.
  • Diseases transmitted through such vectors are called vector-borne diseases. Some vector-borne disease examples are Malaria, Dengue, Lymphatic Filariasis, Kala-azar, Japanese Encephalitis and Chikungunya.

Views in favour of using wastewater surveillance

  • Early detection and monitoring: Wastewater surveillance has proven to be a valuable tool globally, offering early insights into the presence of pathogens. It played a crucial role in detecting the Omicron variant in Bengaluru by the Tata Institute for Genetics and Society (TIGS), showcasing its effectiveness in providing timely information.
  • Cost-effectiveness: One of the significant advantages of wastewater surveillance is its cost-effectiveness. It serves as an economical method to confirm the presence of pathogens independently before laboratory testing, providing a proactive approach to disease monitoring.
  • Global success stories: Developed countries, such as the U.S., have successfully used wastewater surveillance to track various diseases beyond COVID-19, including monkeypox, influenza, and cholera. This highlights the versatility and potential applications of wastewater surveillance.

Views against using wastewater surveillance

  • Endemic nature of diseases: Malaria and dengue are endemic in India, with transmission occurring almost throughout the year. Unlike sporadic outbreaks in the U.S. and Europe, the constant presence of these diseases poses challenges in the exclusive identification of human-excreted pathogens in wastewater.
  • Low Virus Shedding and Diverse Hosts: In the case of dengue, humans exhibit low virus shedding, making it difficult to detect viral RNA in wastewater at levels similar to SARS-CoV-2. Moreover, the presence of diverse animal hosts, including nonhuman primates, complicates the exclusive identification of human-excreted pathogens in tropical countries like India.
  • Vector-borne challenges: Wastewater surveillance may not be sufficient for vector-borne diseases. For diseases like malaria and dengue, where mosquitoes serve as vectors and have other reservoir hosts, a comprehensive approach involving mosquito surveillance is essential. Wastewater surveillance alone may not provide a complete solution.

Vector-Borne Diseases in India

  • Vector-Borne Diseases (VBDs) have been a public issue in India for decades. VBDs have become a serious threat to the health and wellbeing of the population.
  • In 2021, the leading cause of death due to vector-borne diseases was dengue, with a total of 247 deaths across the country .
  • The reasons for the diseases’ spread include climate change, lack of sanitation and cleanliness, as well as stagnant water, which can be a breeding ground for mosquitoes.

Steps taken by the government to control vector borne disease

  • In view of its vector-borne disease burden like malaria, dengue, chikungunya, Japanese encephalitis, lymphatic filariasis and kala-azar, India has set ambitious goals to eliminate and eradicate malaria and lymphatic filariasis by 2030.
  • The National Vector Borne Disease Control Programme (NVBDCP) is an umbrella programme for prevention and control of Vector Borne Diseases.
  • Directorate of National Vector Borne Disease Control Programme (NVBDCP) is the central nodal agency for prevention and control of six vector borne diseases (VBDs) i.e. Malaria, Dengue, Lymphatic Filariasis, Kala-azar, Japanese Encephalitis and Chikungunya in India.
  • The government, through the Union health ministry, has proactively responded to the heightened risk of vector-borne diseases in India.
  • The ministry from time to time issues advisories to states and Union Territories, urging collaboration with civic agencies for swift action.

Way forward

  • Comprehensive surveillance approach: A comprehensive approach, combining wastewater and mosquito surveillance, is crucial to address the complexities posed by these diseases.
  • Careful pathogen selection for wastewater surveillance: The selection of priority pathogens for wastewater surveillance should carefully consider India's specific context, sanitation systems, and host-parasite geography.
  • Integrated surveillance strategy: While wastewater surveillance holds promise, a balanced strategy that integrates multiple surveillance methods is essential for a more effective and accurate disease monitoring system.
  • Digital public infrastructure: The role of Digital Public Infrastructure (DPI) is important in advancing the SDG 3 (Good Health and Well Being) by leveraging digital technologies for healthcare solutions.
  • Collaborative efforts for SDG 3: There is a need for active participation and collaboration between the government, private sector, and non-governmental social welfare organizations to collectively contribute to achieving the 2030 target for SDG 3.

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