To understand the spread of vector-borne diseases in India due to extreme weather conditions such as heat waves and heavy rains, it is essential to consider how these are significantly influenced by three main factors:

1- Breeding habitats

2- Vector behaviour

          3- Human vulnerability

 1- Breeding Habitats : Heavy rains create stagnant water, ideal breeding grounds for mosquitoes, which are vectors of diseases such as dengue, malaria, and chikungunya. This can be exacerbated by flooding and the establishment of additional breeding sites in unexpected areas.

2- Vector behavior : Heat waves may modify vectors’ behaviour and their lifetime. The development of pathogens in vectors may be accelerated, the incubation period shortened and transmission rates increased due to higher temperatures. For example, in hotter conditions the development cycle of an Anopheles mosquito that disseminates malaria is accelerating.

3- Human Vulnerability : Extreme weather events frequently result in displacement and overcrowding of shelters, increasing the risk for spread of disease. The risk of vector borne diseases is further increased by poor infrastructure and lack of access to clean water and sanitation during such events.

               These factors contribute to a favourable environment for the proliferation of vector borne diseases in India, which poses significant health problems.