A few days ago, I read an interesting report about a British woman who was diagnosed with autoimmune radiculitis caused by a bug bite that resulted in general paralysis. In fact, similar cases are very common in daily life, and this is just a very serious exception. The reason why this happens starts with us. We live in a world full of pathogenic microorganisms, but rarely get infected thanks to our body’s loyal defenders – the immune system. The cells of the immune system monitor all parts of the body on a daily basis, and when non-human pathogens are detected, the immune cells attack them until they are removed from the body. There are two types of weapons applied by the human immune system, one is the production of antibodies against pathogen proteins. One is to break down the pathogen protein into small fragments and make a viral ID card (peptide fragment on the surface of dendritic cells), through which the killer T lymphocytes in the body recognize the virus-infected cell and thus kill this cell. It can be seen that the protein composition of the foreign pathogen plays a very important role in this process. This is where the problem actually lies. Sometimes, the protein composition of pathogens, including germs or viruses, can be so similar to that of certain organs in the body that the immune system mistakenly attacks these otherwise normal organs, leading to damage to these organs. More commonly, following streptococcal tonsillitis, rheumatic endocarditis and acute glomerulonephritis often result due to the similarity of streptococcal proteins to those of the human kidney and heart lining. In fact, many autoimmune diseases such as rheumatoid arthritis, multiple sclerosis, and myasthenia gravis are related to infections in some way, however, we do not need to worry too much about the occurrence of such autoimmune diseases because, in addition to the infection factor, our own differences also play a key role. The so-called self-differences are determined by genetic differences in each individual, and these genetic differences lead to different reactions to pathogens in each individual. Only a small percentage of people will develop an autoimmune disease caused by infection, and the chances of developing a serious or even fatal autoimmune disease associated with infection are even smaller. The immune system is arguably our most faithful partner and defender, yet due to the diversity of pathogens and body proteins, as well as certain evolutionary affinities, hysterical overreactions like malingering are sometimes difficult to avoid. Therefore, if you travel to a foreign country and are bitten by mosquitoes or locally injured, the injured area should be carefully disinfected to avoid further infection and to prevent the occurrence of infection-induced autoimmune reactions. In addition, if there is numbness, inactivity, breathing difficulties, etc., should be promptly to the regular hospital for medical treatment, which can often avoid serious complications.