Epidemic diphtheria and skin infections in Trinidad

Patients with nephritis and schoolchildren in South Trinidad were surveyed for the presence of Corynebacterium diphtheriae in throats and skin lesions. The incidence of positive cultures was higher in skin leisons than in throat cultures. None of the children experienced symptoms of systemic intoxication. Subsequent to the increase in cutaneous infections, however, the indidence of symptomatic nasopharyngeal diphtheria also increased in Trinidad, suggesting that the skin lesions constituted an important reservior of infection. One group of schoolchildren was reexamined after six months, and the levels of antitoxin in serum were correlated with the presence of C. diphtheriae in skin leisons and throat cultures. The high levels of antitoxins observed apparently resulted from natural immunization in the absence of clinical signs of diphtheria. No effect of C. diphtheriae was noted on the colonization of skin lesions by streptocci or on the incidence of acute glomerulonephritis in the population. (AU)

Relationship of acute rheumatic fever to acute glomerulonephritis in Trinidad

The incidence of acute rheumatic fever decreased during a major epidemic of acute glomerulonephritis in Trinidad in 1965. Subsequently, several minor increases in the incidence of acute rheumatic fever have been coincident with more marked increases in the incidence of acute glomerulonephritis. The relation of streptococcal infections to acute glomerulonephritis has been studied in Trinidad for the past six years. Their relation to acute rheumatic fever also has been examined during the last year of these studies. The streptococcal strains isolated from patients with acute rheumatic fever generally have differed from those found in patients with acute glomerulonephritis. Moreover, while streptococcal skin infections have been associated with acute glomerulonephritis, no such association has been apparent with rheumatic fever. However, titers of antistreptolysin O were relatively low, while titers of antihyaluronidase were makedly increased in the patients with acute rheumatic fever, much as they have been in most patients with acute glomerulonephritis in Trinidad (AU)

Changing types of nephritogenic streptococci in Trinidad

The relation of seven different M types of streptococci to acute glomerulonephritis associated with skin lesions in South Trinidad has been studied by means of type-specific antibody assays as well as by isolation and identification of the strains. The data indicate that, one after another, five of these strains have prevailed among patients with acute glomerulonephritis during the past five years. At least three of the strains (M-types 55,49,57, and/or 60) were associated with epidemic increases in nephritis cases. The appearance of five consecutively predominant types of nephritogenic streptococci during a relatively short period of time is in contrast to the continuing prevalence of M-type 12 strains among nephritogenic streptococci primarily associated with respiratory infections in temperate zones. These observations suggest that the skin sores commonly found on children in tropical Trinidad, provide a particularly suitable environment for development of nephritogenic types. It remains to be seen whether these types will recur or whether new types will continue to emerge in Trinidad. (AU)