The "epidemic calendar" shows the seasonality of 69 infectious diseases

Influenza is not the only long-lasting infectious disease.

Analyze the published data, Micaela E. Martinez, PhD, an assistant professor of environmental health sciences at the Mailman School of Public at Columbia University, has created an "epidemic calendar" which, she says, shows the seasonality of 69 infectious diseases, including Ebola, gonorrhea and the Zika.

According to Martinez, seasonal drivers not only affect the transmission of acute infectious diseases such as measles, but also contribute to outbreaks of infection from chronic infections such as hepatitis B. His findings have been published today in PLOS Pathogens.

"Seasonality has been recognized for a number of acute infectious diseases, particularly epidemic-prone diseases – such as influenza, cholera, polio, measles," said Martinez. Infectious Diseases News. "But aside from these classic epidemic-prone diseases, which have been studied in depth, the seasonality of infectious diseases has so far not been recognized as an ubiquitous feature of acute or chronic infectious diseases."

According to Martinez, the timing of epidemics is influenced by seasonal variations, also known as seasonal forcing, in the transmission of infectious diseases. Martinez said the seasonal forcing of some important public health diseases, such as measles, influenza and cholera, had been monitored over the past century, but that "the seasonality of the disease still needs to be characterized systematic and / or rigorous for the majority of infections. "

Martinez collected data from the websites of the CDC, WHO and the European Center for Disease Prevention and Control, compiling a list of 69 communicable diseases of interest to public health and categorizing them as being acute or chronic. Martinez also used Google Scholar to search for additional information about the seasonality of the disease.

According to Martinez, four seasonal factors may influence the dynamics of transmission: environmental factors, host behavior, host phenology, and exogenous biotic factors. Environmental factors can affect transmission due to weather conditions, such as rainfall or temperature, on hosts and / or parasites, noted Martinez. Host behavior is the best example of high measles transmission during the school year, when children have more contacts. According to Dr. Martinez, host phenology "includes the life of the host, annual cycles (eg, migration and hibernation), and endogenous circanistic rhythms (ie, seasonal changes in physiology). induced by the disease). Exogenous biotic factors are the "interactions that take place within hosts and the interactions within the ecological community of hosts, reservoirs and vectors".

It is well known that the winter months include the influenza season. According to Martinez, the month of March begins the chickenpox season. The gonorrhea season is from May to July, and polio transmission has always occurred every summer. According to Martinez, public health agencies and officials could improve the fight against infections by knowing the seasonality mechanisms of diseases.

"There needs to be a systematic review of the seasonality of these infectious diseases," Martinez said. "Especially for chronic infections, if we understand when someone is at risk of relapse or a sudden surge, we may be able to anticipate this and be more proactive about treatment or screening." – by Marley Ghizzone

Disclosure: Martinez does not report any relevant financial information.