Diphtheria among alcoholic urban adults: a decade of experience in Seattle

Diphtheria, once a common disease affecting the mucous membranes of the throat, has been reduced thanks to immunization of infants, but the disease still occurs in the form of a skin disease. There were three outbreaks of diphtheria causing a total of 1,100 infections in Seattle between 1972 and 1982. Eighty-six percent of the infections involved the skin and 14 percent affected the nasopharynx. The outbreaks occurred among alcoholic adults who were living in Seattle's Skid Row, and affected Native Americans primarily. Diphtheria is caused by the bacteria Corynebacterium diphtheriae and the outbreaks were traced to three different strains of the bacteria, intermedius, mitis, and gravis. Another bacterium, Streptococcus pyogenes, was isolated from 73 percent of the lesions caused by diphtheria and 41 percent of nondiphtherial lesions. Complications occurred in 21 percent of the infections of the nasopharynx but in only 3 percent of the skin infections caused by the strain intermedius. The complications occurred more frequently in individuals who were over 60. The antibiotic erythromycin was used to treat the diphtheria and pyodermas, but the bacteria which caused the diphtheria became resistant to erythromycin. The outbreaks of cutaneous diphtheria were associated with poor hygiene of the alcoholics, underlying skin disease, seasonal occurrence (with peaks in the winter and spring), high rates of environmental contamination such as contaminated fomites (objects, such as dirty clothing, that contain the bacteria), co-infection with Streptococcus pyogenes and the emergence of new strains of bacteria which were resistance to erythromycin. (Consumer Summary produced by Reliance Medical Information, Inc.)