Many infectious diseases break up seasonally, similar to the flu.
This is the conclusion of a researcher from New York's Columbia University in the journal PLOS Pathogens. In her study, she presents evidence of seasonal dynamics in 69 infectious diseases, including sleeping sickness, zika, chickenpox, polio and hepatitis B. The author identifies four possible main factors: climatic influences, which also affect mosquito density, for example. Social rhythms such as school and holiday periods. Ecological factors such as algae growth, which in turn can benefit bacteria. And biological rhythms – for example, hormone fluctuations that affect the immune system. For her study, the scientist on data from the WHO, the US Centers for Disease Control and Prevention and back published studies. With that she created a calendar that shows the temporal pattern of outbreaks.