Scabies infestation has been reported to the PAHO/WHO Caribbean Epidemiology Centre (CAREC) from Trinidad and Tobago (T&T), Grenada, Dominica, the Turks and Caicos Islands (T&CI) and, more recently, St Lucia. Epidemic scabies was being reported from T&CI in 1981 (1200/100,000 population), but there were no reports from T&T until 1982 (8/100,000). The first phase of the bimodal epidemic in Grenada occurred between 1982 and 1984 (132/100,000) and the explosive second phase from 1985 to 1987 (474-699/100,000). In T&T there was a low incidence of scabies until 1985 (0-59/100,000) and in Dominica the rate fluctuated (67-14/100,000) during the same period. From 1986 to 1988, scabies infestation reached epidemic proportions in T&T (410-709/100,000) and fluctuated in Dominica (108-117/100,000). In Tobago alone, scabies was not reported until March 1986, and by December the incidence rate was 105/100,000; by 1988 it had increased to 1124/100,000 population. Although no secondary infections have been reported from Grenada, Dominica, T&CI or St Lucia, T&T has reported increased streptococcal skin infections and epidemic post-streptococcal acute glomerulonephritis (PSAGN). The observed trend of increasing scabies infestation, increasing streptococcal isolates from skin lesions, and increasing PSAGN in T&T is noteworthy.

The group G streptococcus has generally not been considered a prominent pathogen. In a 1982 study of the colonization rate by beta-haemolytic streptococci in apparently healthy children, age 5-11 years, 25 of 69 isolates belonged to group G. This surprisingly high rate of group G colonization (14.3%) led to a retrospective study of school surveys in 1967 which showed that the colonization rate with this organism was 2.3% (range 1.3-3.5%). A review of bacitracin-sensitive streptococcal isolates from hospital admissions of patients with acute glomerulonephritis (AGN), rheumatic fever, and their siblings, between January 1967 and July 1980, was conducted. Of 1063 bacitracin-sensitive isolates, 63 were group G, and 52 of these were isolated from AGN patients and their siblings, i.e. 7 from skin lesions of AGN patients, 40 from the throats of siblings and only 5 from the skins of the siblings. The other 11 group G isolates were from rheumatic-fever patients and their siblings. Thus, the group G colonization rate fluctuates in the population. The isolation of only group G streptococci from skin lesions of patients with AGN suggests a possible association between group G streptococcal pyoderma and acute post-streptococcal glomerulonephritis.

Acute rheumatic fever (ARF) has the characteristics of an autoimmune disease, triggered by cross-reactive antigens shared by the group A streptococcus and a variety of tissues including the heart, endothelium, and basal ganglia. Using two parameters of cellular reactivity, migration inhibition and blastogenic transformation, ARF patients from Trinidad show significant lymphocyte reactivity to streptococcal antigens, particularly those from an ARF associated streptococcal strain. This reactivity, studied over a 2-year period, peaked at 1 to 6 months after the acute onset and remained significantly elevated for at least 2 years. The reactivity is directed mainly toward a nonionic detergent extractable material in the cell membrane. These studies suggest a possible streptococcal strain specificity in ARF and demonstrate persistent sensitization, which explains the increased susceptibility to recurrences in the 2 years following the acute episode.

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SUMMARYThe objectives of this study were to determine the prevalence of scabies in an infested village; to educate the residents on self-treatment and prevention by the use of 5% monosulfiram soap; to evaluate the short term effectiveness of this intervention by determining, 2 weeks later, the compliance to self-treatment and prevention; and to determine the prevalence rate on the second visit. In 59 households (967 % of the village) containing 313 persons, an educational session was held and a leaflet distributed on the use and availability of the soap. Thirteen persons (4-2 %) from eight households (13-6 %) had scabies. After 2 weeks, 7 persons (2-2 %) (2 persisting and 5 new cases) from 5 households (8-5 %) were infested. Thus a cure rate of 85 % was obtained though the prevalence rate showed no statistically significant difference. Among the under 15 year olds, the numbers infected decreased from 10 to 3 while among the over 15 year olds, the numbers infected increased from 3 to 4, neither reading significance at the 5 % level.