Infectious diseases are defined as those caused by pathogenic microorganisms, including bacteria, fungi, parasites, and viruses. A person can be infected with a pathogenic microorganism directly or indirectly (transmitted by vectors) as it passes from one person to another.
Infectious diseases. Image credit: Rost9 / Shutterstock.com
Although many organisms live in the human body without harming our health and can often be beneficial, as is the case with the bacteria that help break down the foods we eat and the microbiota of our digestive system that play a role in our immune system. . , invasive organisms are usually the cause of the disease.
The path to infection depends on the pathogen and the nature of the disease it causes. Some are easily transmitted from person to person, while others are transmitted by animals and insects. Some pathogens are introduced into the body through infected food or contaminated water, while others can be collected in certain environments.
The symptoms of infectious disease vary considerably, depending on the type of pathogen responsible for the infection. Symptoms often include fatigue and fever, although the various diseases caused by infections have a wide range of symptoms, from mild to severe and sometimes life-threatening. Although the mildest symptoms can often be treated with home remedies and over-the-counter medications, some infectious diseases are serious and require professional medical care and even hospitalization.
Infectious diseases are caused by bacteria, fungi, parasites and viruses. Bacteria are responsible for common infections such as streptococcus, urinary tract infections, and tuberculosis. Fungi are the root cause of many skin diseases, including ringworm and athlete’s foot. Other fungi can infiltrate the lungs and nervous system, causing more serious illnesses.
Parasites are responsible for malaria, an infectious disease that kills more than 400,000 people annually. Although it is transmitted by mosquitoes, it is caused by a tiny parasite. Other parasites are responsible for other infectious diseases. Finally, viruses are another cause of many infectious diseases with various health implications. Viruses cause the common cold, but they also cause AIDS.
Although anyone can get an infectious disease, some populations are at higher risk. Those with a compromised immune system, such as those undergoing chemotherapy or those who have recently had organ transplants, have a higher risk of contracting infections. In addition, some jobs place people in situations more likely to expose a person to infections such as those working in health care.
In addition, people who have not received vaccines are not protected against certain infections and are therefore at increased risk. Finally, people traveling to certain destinations with a high presence of particular infections are also at greater risk.
The global burden of infectious diseases
Recent research published by The Lancet has revealed the global burden of infectious diseases. Measured by the cost of disease in disability-adjusted life years (DALY), the report finds out how infectious disease affects different subgroups and how progress in medicine and government initiatives has affected this in recent years.
Of the ten leading causes of DALY in children under 10, six were infectious diseases: lower respiratory infections (second), diarrheal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (fully represented by congenital syphilis; tenth position). However, the burden for children in this age group decreased significantly from 1990 to 2019, mainly due to the reduction of lower respiratory infections, diarrheal diseases and meningitis, which were reduced by more than 60% during this time period.
In addition, the study found that lower respiratory infections also appeared in the first ten DALYs of the 75-year + age group.
For those in the 25-49 age group, HIV infection ranked second among the top ten causes of DALY in 2019. Fortunately, the data revealed that the incidence of HIV had decreased since 2005, when ART became available.
Regarding the disease burden by geography, the study revealed that some locations worldwide were especially affected by specific infections. Egypt, for example, had previously suffered heavily from the hepatitis C infection. Now, after the introduction of large-scale screening and low-cost treatment, Egypt is expected to see a dramatic drop in hepatitis C. cirrhosis and liver cancer-related deaths that are frequently caused by hepatitis C infections.
The future of infectious diseases. | Paul Cosford | TEDxUoChesterPlay
Prevention of infectious diseases
It is true that infectious diseases carry a huge burden and that millions of people are affected every year, either by falling ill or by dying from an infectious disease. Fortunately, there is a great opportunity to reduce the impact of infectious diseases through preventive methods.
Thanks to scientific research, much is already known about the nature of infectious disease and the pathways to infection. Although different pathogens have different routes of infection, in general, various strategies can be introduced into daily practices to maintain people’s safety: frequent and effective hand washing (especially during food preparation), vaccination. , use of antibiotics only when required, stay home when showing symptoms of infectious diseases, disinfect areas of the home that may have high concentrations of bacteria, have safe sex and travel with caution.