What is toxic shock and what are the pathological causes of toxic shock?

Toxic shock syndrome (TSS) is a severe circulatory and organ failure caused by bacterial toxins, usually caused by the Staphylococcus group of bacteria. So what exactly is toxic shock?

background

Toxic shock syndrome (TSS) is a serious life-threatening, low-incidence bacterial infection named by Todd et al. in 1978. It is caused by toxins released by bacteria (mainly Staphylococcus aureus and Streptococcus) and is characterized by shock and multiple organ failure. It is generally believed that TSS occurs mostly in women during menstruation and its pathogenic bacteria is Staphylococcus aureus. About 10% of cases occur in non-menstrual women and men.

Epidemiology

The main pathogens of TSS are Staphylococcus aureus and Streptococcus pyogenes, and a few are caused by group B, C, and E streptococci. The annual incidence of staphylococcal TSS (SaTSS, Staphylococcal toxic shock syndrome) is 0.5/100,000; streptococcal TSS (SeTSS, Streptococcal toxic shock syndrome) is 0.4/100,000. Of course, the incidence rates vary in different places. The mortality rate of SaTSS during menstruation is less than 5%, the mortality rate of SaTSS during non-menstruation is 5-22%, and the mortality rate of SeTSS is 30-70%. The incidence of invasive streptococcal infection during pregnancy is 20 times that of non-pregnant women. TSS in pregnant women mainly occurs in the third trimester.

Case warning 1: TSS occurred at 21 weeks of pregnancy, and the doctor was forced to perform surgery to terminate the pregnancy. The fetus weighed only 360 grams

Case warning 2: Mosquito bites can cause TSS [picture below] and skin desquamation. A 30-year-old male patient with good health was bitten by a mosquito on the right lower jaw the day before. When he came to the hospital the next day, his temperature was 40.1°C, pulse was 140bpm, blood pressure was 80/50mmHg, respiratory rate was 40 times/min, white blood cell count was 13500/μL, and CRP was 182 mg/L. [BMJ Case Report, 2015, April]

p.s. Please click on the lower left corner of the above case link to read the original text. Links are provided to the corresponding pages.

Why does it happen more during menstruation?

This is related to the use of vaginal suppositories during menstruation. Vaginal suppositories contaminated with Staphylococcus aureus can multiply in menstrual blood and at suitable temperatures to produce phage type I Staphylococcus aureus. At the same time, vaginal suppositories can cause mucosal dryness and epithelial changes, which are beneficial to the absorption of toxins. Non-menstrual women, men and children may also develop the disease through wound hematoma or packing materials such as gauze, which may allow Staphylococcus aureus to multiply. Clinical women are also more susceptible to TSS because of the disruption of the skin and mucous membranes during childbirth and the change in vaginal pH after rupture of the amniotic sac, which can promote the proliferation of microorganisms.

pathology

SaTSS and SeTSS are the result of T cell stimulation by the superantigen TSST-1, enterotoxin B or C, or exotoxin A or B. Superantigens can stimulate monoclonal T cells by ligating the major histocompatibility complex class 2 assay and the T cell receptor on antigen presenting cells (APC). This leads to the production of large amounts of interferon gamma, IL-1, IL-6, tumor necrosis factor alpha, and tumor necrosis factor beta, forming the so-called inflammatory cascade chain. Superantigens can stimulate T cells to a level three orders of magnitude greater than normal antigens. In addition, TSST-1 can directly damage blood vessels and produce a synergistic effect with LPS of normal flora, thereby increasing vascular permeability and hypotension. Therefore, patients without TSST-1 antibodies are at high risk. SaTSS during menstruation is mainly caused by TSST-1, while non-menstrual patients are generally caused by TSST-1, and others are caused by enterotoxins. Superantigens can now be detected using PCR in some centers, but it is not yet widely used.