User:CFCF/Draft:Seasonality in disease

Seasonality in disease refers to the predictable and often regular change in occurrence of certain diseases throughout the year. This phenomenon is often influenced by environmental factors, human behavior, and in case of infectious diseases also by host-pathogen interaction s.

Infectious disease
Many infectious diseases that significantly impact public health exhibit seasonality, where the incidence of the disease increases during specific seasons or times of the year. This phenomenon has been recognized since the times of Hippocrates, yet the reasons for the seasonality of infectious diseases transmitted from person to person are still not fully comprehended. Infectious diseases that exhibit such seasonality include many respiratory tract infections such as influenza, coronavirus infections (including Covid-19), the common cold as well as vector-borne diseases such as malaria, dengue fever, and zika virus infection.

Noncommunicable disease
Some noncommunicable diseases also display seasonal patterns. For instance, the incidence of relapses in multiple sclerosis is reduced in fall within temperate climates. Additionally, several psychiatric disorders, including seasonal affective disorder and mania in bipolar disorder, are known to have distinct seasonal patterns. Auto-inflammatory disorders also display seasonal patterns, such as sarcoidosis, which is thought to indicate a possible underlying association with pathogen exposure. Sports injuries typically occur with variation of injury type and incidence over the on and off season. Cardiovascular disease

Mechanisms
Seasonal variations in infectious diseases can be attributed to changes in host behavior, vector dynamics, environmental factors such as temperature and rainfall, and direct effects of seasonal changes on pathogens themselves.