CBSE Class 6 Answered

Climate change can affect human health as far as infectious diseases are concerned. Three components are essential for most infectious diseases: an agent (or pathogen), a host (or vector) and transmission environment. Some pathogens are carried by vectors or require intermediate hosts to complete their lifecycle. Appropriate climate and weather conditions are necessary for the survival, reproduction, distribution and transmission of disease pathogens, vectors, and hosts. Therefore, changes in climate or weather conditions may impact infectious diseases through affecting the pathogens, vectors, hosts and their living environment. Studies have found that long-term climate warming tends to favor the geographic expansion of several infectious diseases and that extreme weather events may help create the opportunities for more clustered disease outbreaks or outbreaks at non-traditional places and time. Overall, climate conditions constrain the geographic and seasonal distributions of infectious diseases, and weather affects the timing and intensity of disease outbreaks.