Lecture 27

How do extreme weather events impact the spread of diseases?

Extreme weather events can bring about diseases, particularly tropical diseases, as they have the greatest effect on vector-borne diseases. The development of parasites is climate-dependent, and climate change can affect the extrinsic incubation period (EIP) of pathogens.

What is the extrinsic incubation period (EIP) of a disease?

The extrinsic incubation period (EIP) is the time it takes for a pathogen to develop and become infectious within the vector (such as mosquitoes). For a disease to be transmitted, the EIP needs to be shorter than the vector's life expectancy.

How does climate change affect the EIP of diseases?

Climate change can impact the EIP of diseases. In hotter climates, the EIP may be reduced, leading to a shorter duration of infectiousness. Additionally, hotter climates can increase the likelihood of survival for vectors, contributing to the spread of diseases.

What is the relationship between El Niño and diseases like dengue?

El Niño, a climate phenomenon, is statistically associated with diseases such as dengue. El Niño causes weather changes globally, including increased rainfall, which creates favorable breeding conditions for mosquitoes. This can lead to an increase in the transmission of diseases like dengue.

How does temperature and precipitation influence the transmission of the blue tongue virus?

Temperature plays a role in the transmission potential of the blue tongue virus. Warm or hot periods in autumn and summer increase the virus's transmission potential, while warm nights and winters contribute to the virus's persistence. Precipitation governs the size and persistence of semi-aquatic breeding sites, which can impact the spread of the virus.