You probably already know when the flu occurs, but what about the chicken season or the gonorrhea season? Well, according to a new review study, a series of infectious diseases have "stations" during which their activity is pricked.
The study, which reviewed information on dozens of scientific papers, found seasonal tests in at least 69 different infectious diseases.
These diseases vary from common diseases such as pneumonia and Salmonella infections to relatively rare diseases such as Ebola and African sleep disorder.
Some of the more seasonal infectious diseases described in the US. UU. They are the flu, which (as you might know) peaks in winter; Chickenpox, what peaks in the spring; and gonorrhea, which spills in summer and in autumn.
The study even found evidence that certain chronic diseases have a seasonal component. For example, some studies suggest that hepatitis B infections increase in spring and summer in certain parts of the world. And the first research suggests that HIV / AIDS can also be seasonal in certain areas of Africa, where seasonal nutritional deficiencies can affect the progression of HIV to AIDS. [27 Devastating Infectious Diseases]
"Seasonality is a powerful and universal feature of infectious diseases, although the scientific community ignored it in most infections," Micaela Martínez, Assistant Professor at Columbia Mailman School of Public Health, said in a statement. The study was published today (November 8) in the PLOS Pathogens magazine.
In fact, for many infectious diseases, there are few investigations about exactly why they reach their peak in certain seasons. Martínez asked for more studies so that scientists can better understand the specific reasons behind the seasonal peaks and the infectious disease indexes. "We have to work hard to understand the forces that guide the seasonality of the disease and understand how we can take seasonality to design interventions to prevent outbreaks and treat chronic infections," said Martínez.
But, in general, there appear to be four main factors of the seasonality of infectious disease, according to the review:
Environmental factors, such as temperature and humidity, are thought to play a role, for example, in the transmission of influenza. (Studies suggest that influenza virus particles may stay in the air for longer and travel longer distances, in cold and dry conditions). In addition, the temperature plays a role in the spread of certain diseases transmitted by insects. For example, mosquitoes reproduce at warmer temperatures, increasing transmission of mosquito-borne diseases such as Zika in hotter months.
Host behaviors, such as children who start school in the fall and who are closely united to each other, who plays a role in the spread of measles, for example.
Ecological factors, such as the proliferation of algae in the water, that help in the spread of bacterial anger.
Biological rhythms, migration and hibernation in animals, or fluctuations in hormone levels in people, which can affect the immune system.
To better understand why individual illnesses reach peak in certain seasons, researchers could begin by analyzing databases that contain information on "notifiable diseases" or on diseases that should be regularly reported to health officials. Researchers could combine this data with disease transmission models and possible transmission drivers, be environmental, ecological, behavioral or physiological.
"Discovering the seasonal mechanisms for disease systems would enable the public health community to better control the infection," Martínez wrote. And with this information, the researchers would know the best time to take control measures of these infections.
Martinez is studying whether seasonal fluctuations in the hormone melatonin can affect the immune system and play a role in the susceptibility of people to certain infectious diseases.
Originally Posted in Live science.