All infectious diseases likely to be seasonal

A new study conducted by a researcher at the Mailman School of Public Health at Columbia University suggests that all infectious diseases are caused by seasonal elements.

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Micaela Martinez, professor of environmental health sciences, collected data for She then mapped the time of year when epidemics tended to occur, ranging from common infections to rare tropical diseases.

As. 69 Infectious Diseases from United States Centers for Disease Control and Prevention, World Health Organization and from the articles of peer-reviewed journals reported in the journal PLOS Pathogens she discovered that, in a given year, influenza outbreaks were declared in winter, the chickenpox in the spring and polio and gonorrhea in the summer

The study describes four main factors that drive seasonal influence on the disease.Seasonal influenza is influenced by environmental factors such as as humidity and temperature, and in vector-borne diseases such as Zika, the environment affects the proliferation of mosquitoes.

Host behaviors also play a role. The proximity of children during the school year, for example, is a factor involved in the spread of measles.

Ecological factors are also involved. For example, the bacteria at the origin of cholera is kept in water fed with algae.

Being aware of these factors of seasonal epidemics could help public health officials intervene to prevent the spread of the disease. For example, they could set up a strategy to ensure the survival of the bacteria that cause cholera in water bodies filled with algae

Seasonal biological rhythms, like those that control migration and hibernation of animals, are another potential factor in diseases such as polio. However, this possibility requires further research.

Martinez argues that seasonality is a powerful and universal feature of infectious diseases, but that the scientific community has largely ignored it when considering the majority of infections.

Much remains to be done to understand the strength of disease seasonality and how we can leverage it to design interventions to prevent epidemics and treat chronic infections.

Professor Micaela Martinez, author of the study