Recall that two different types of bacteria are the main causes of toxic shock syndrome. Staphylococcus aureus is responsible for most of the cases, but Streptococcus pyogenes also causes the disease. Other bacteria produce conditions similar to toxic shock. These diseases include exanthematous viral syndromes; Gram-negative sepsis; Kawasaki syndrome (a little-known bacterial infection), which is rare in patients older than 4 years; leptospirosis, caused by an organism related to organism that causes syphilis meningococcemia; and Rocky Mountain spotted fever, which is spread by deer ticks. Sometimes cases of toxic shock syndrome are confused with severe allergic responses to certain drugs. Many of the signs of toxic shock syndrome are allergic reactions to bacterial toxins. Thus, it is understandable that toxic shock syndrome was confused with allergies and other diseases. Staphylococcal toxic shock syndrome, STSS, was the first type of toxic shock syndrome diagnosed and consequently has the most thorough epidemiological database.Most study of the illness occurred after 1980, when its increased occurrence alerted the medical community to a possible large-scale outbreak (Figure 6.1). The number of cases of toxic shock syndrome recorded between 1970 and 1978 remained consistent at fewer than 200 new cases per year. A lack of knowledge about toxic shock syndrome by the medical community prevented epidemiologists from understanding the true cause of these cases. However, some data showed that one of two strains of Staphylococcus aureus caused most of the cases. Over 75 percent of the cases were due to a strain that produced the potent TSST-1 exotoxin described in Chapter 4. The number of cases of toxic shock syndrome grew steadily to approximately 1,200 cases from 1970 to 1980. The CDC recognized this quick rise as an outbreak and carried out an intensive investigation of the disease. It was also at this time that the CDC required all physicians to keep comprehensive records on the disease and report new incidents to the CDC. The death rate, or mortality, from the disease ranged from 3 percent to 6 percent of treated people. The highest mortality occurred early in the outbreak. The 1980 outbreak of toxic shock syndrome ultimately led to the discovery of the dramatic increase in the disease. The large number of cases provided ample information about the way the bacteria cause toxic shock syndrome and how the organisms spread. Epidemiological studies showed that the incidence of disease went up mostly in women who were menstruating at the time of diagnosis. Over 90 percent of all the TSS cases occurred in females. Menstruating females accounted for 92 percent of the outbreak cases seen in females. The few male patients ranged in age from 1 to 75 years old, whereas the females had a narrower age range clustering around 23 years old. This information led public health officials to suspect a link between menstruation and the outbreak. Further investigations revealed that the outbreak resulted from a particular type of tampon used by that age group. Tampons are feminine hygiene products used to prevent the leakage of menstrual fluids during menstruation. Extensive laboratory experiments showed that the tampons were responsible for the increased chance of contracting TSS. Research studies conducted on tampons showed how bacterial growth was fostered by the tampons and encouraged the bacteria to cause toxic shock syndrome. Upon confirming these results, the United States Food and Drug Administration (FDA), stopped the sale certain types of tampon. The FDA also encouraged the labeling of tampons to ensure their use in a manner that reduced the chances of contracting toxic shock syndrome (Figure 6.2). By 1982, a new investigation into toxic shock syndrome showed a steady decline in the number of cases, to slightly more than 600 newly diagnosed occurrences. Further changes in tampon technology resulted in a greater decrease in toxic shock syndrome. These changes caused a dramatic decline between 1982 and 1989. The number of new cases reached the same level of occurrence before 1978. Toxic shock syndrome incidences decreased 10 percent more between 1989 and 1996. The occurrence of the disease then stabilized to fewer than 50 cases a year, the level at which it stands today. Only 71 percent of the toxic shock syndrome cases reported between 1981 and 1986 occurred in menstruating females. The occurrence in menstruating females dropped to 59 percent between 1987 and 1997. Very few cases today are due to tampon use in menstruating females. Public health officials believe that the pattern of decline was due jointly to the improvement of tampons and to public awareness programs. Tampon boxes still carry warning labels, although toxic shock syndrome from tampon use is infrequent today. Public health officials believe that removing the labels could lead to a recurrence of the disease. It took further study to understand the occurrences of toxic shock syndrome not related to tampon use. Physicians are particularly interested in this information with the development of antibiotic-resistant strains of bacteria. Staphylococcus aureus has strains that are resistant to all of the major antibiotics. This can lead to incurable forms of toxic shock syndrome, possibly raising the mortality to 70 percent, as if the disease had run its course untreated. The contagious nature of the bacteria could set in motion an epidemic of Staphylococcus aureus diseases. Scientists did not study streptococcal toxic shock syndrome (StrepTSS) as well during the initial outbreak and subsequent decline of toxic shock syndrome. This was mostly due to its rarity. It took the sharp rise in staphylococcal toxic shock syndrome to alert the medical community to StrepTSS. Most studies indicate that StrepTSS, unlike staphylococcal toxic shock syndrome, is unrelated to tampon use. This led to a new round of epidemiological studies to investigate the causes of StrepTSS. Also unlike staphylococcal toxic shock syndrome, incidences of StrepTSS have been on the rise since 1995. A breakthrough came when medical researchers noted a link between milder Streptococcus diseases and an occurrence of StrepTSS. Now physicians pay close attention to patients ailing from Streptococcus pyogenes infection, to prevent it from developing into StrepTSS. Several cases of StrepTSS occurring between 1991 and 2000 associated StrepTSS with surgery. This led to a new epidemiology of StrepTSS. Researchers at the University of Iowa College of Medicine warned physicians in 1991 to watch for StrepTSS in patients after surgery. They noted several incidents of patients developing fevers and rashes resembling StrepTSS. Scientists then confirmed that Streptococcus pyogenes could invade surgical wounds that were not clean or were not healing properly. They cautioned that the disease could have a high mortality if not recognized early. Other incidents of StrepTSS occurred after cosmetic or plastic surgery. Another group of studies conducted in 1998 came to the same conclusion about patients having reconstructive surgery involving medical implants. A growth in cosmetic and reconstructive surgery was solely responsible for the increase in what is now termed postoperative StrepTSS. Physicians now have to caution patients about the chance of getting StrepTSS even from simple facelift procedures. Complex surgeries involving breast implants and facial reconstruction are more prone to invasion with Streptococcus pyogenes. Unfortunately, the increasing demand for cosmetic surgery produced conditions in which physicians were not performing the surgery under ideal conditions. Consequently, people undergoing cosmetic surgery were more likely to get an infection than patients operated on under better conditions.
Scientists learned that certain tampons and the improper use of feminine hygiene products started the toxic shock syndrome outbreak of the 1980s. As can be seen in this graph, incidences of toxic shock syndrome decreased dramatically after 1990, when new regulations and warnings were required for tampon manufacturing and sales.
Figure 6.2 The FDA encouraged the labeling of tampons to ensure that they were used in a manner that reduced the chances of contracting toxic shock syndrome. These labels can be found on all tampon boxes. An example of the label is shown in this figure.
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