RESUMEN
We have been looking for differentiating aspects of the streptococcal infections associated with acute rheumatic fever (ARF) and acute alonerulonephritis (AGN) in Trinidad since November 1969. At this meeting last year, we reported our first 10 months' observation which were made during a period when AGN was endemic. Since then an outbreak of scabies accompanied by a major epidemic of AGN has occurred which afforded an excellent opportunity to study and compare the related streptococcal infections. Observations to be reported presently include the following: (1) While the number of cases of AGN increased nearly 10-fold to over 150 in both August and September, ARF increased only to less than 20 cases a month during the height of the epidemic of AGN. (2) The scabies epidemic was associated with AGN while skin lesions continued to be relatively rare in patients with ARF. (3) The streptococcal strains isolated from patients with AGN and ARF were not the same, the epidemic M-type 55 being associated with AGN but not ARF while M-type 11 strains were found in many patients with ARF and in none with AGN, (4) Antibody titres were similar in the two groups of patients as reflected by ASO and AH titres; the former continued to be low, while the latter continued to be increased. Thus, we conclude that although the antibody responses of patients with ARF and AGN are similar in Trinidad, skin infections are associated with AGN but not with ARF and the nephritogenic and rheumatogenic streptococcal strains are different (AU)