The incidence of severe leptospirosis in Trinidad.

Between February 1977 and September 1982, sera from febrile patients from all areas of Trinidad were examined for leptospiral agglutinins; 158 of 1714 patients (9%) were confirmed as current cases of leptospirosis (annual average 26 or 2.6 per 100,000 population). Of the remaining 1556 patients only 711 provided paired sera; 167 of these (23%) showed evidence of previous leptospiral infection. Of the 845 single samples, 125 were positive. The true incidence of the disease is probably much higher than reported here. Males comprised 74% of the current cases; their highest rate of infection was in the 30-39 year age group, the incidence in late teenage approaching this rate. For females, incidence increased with age up to late middle-age. The presumptive infecting serogroups most commonly recorded among the 158 current cases were Icterohaemorrhagiae (37%), Canicola (16%) and Autumnalis (11%). 13 of the cases died (case fatality rate, 8.2%).

A serosurvey for leptospirosis in Trinidad among urban and rural dwellers and persons occupationally at risk.

A survey for leptospiral antibodies was made of 1,375 persons in northern Trinidad between mid-1977 and mid-1978. The subjects were employees in seven occupational categories thought to entail a high risk of exposure to leptospires, and members of the general population of three rural and two urban communities. They were questioned inter alia about their leisure and occupational activities, household water supply and effluent, and contact with animals. Leptospiral infection was found to be widespread in the general population but not primarily associated with employment. Among the occupational groups the highest prevalence of antibodies was found in sugar-cane workers (45% infected), while among the communities prevalence was highest in the rural village of Cacandee (37%) and lowest in Woodbrook (Port-of-Spain) (5%). Keeping cattle, hunting and walking barefoot in the countryside were significantly associated with leptospiral serology. Over-all, serogroups Icterohaemorrhagiae and Autumnalis each accounted for about 25% of the seropositives in the general population. Among the occupational groups Autumnalis was the most commonly found (36%). It accounted for 42% of the seropositive sugar-cane workers and 57% of the seropositive rice farmers.

Serological studies on leptospirosis in livestock and chickens from Grenada and Trinidad.

Sera from 1,206 livestock animals and chickens on Grenada and Trinidad were tested for leptospiral antibodies by the microscopic agglutination test. 376 of the sera were positive (25% of those tested on Grenada and 44% on Trinidad). The positive sera were obtained from 25% of 324 cattle, 35% of 130 pigs, 35% of 146 sheep, 25% of 44 goats and 11% of 175 chickens on Grenada; and 92% of 26 cattle, 53% of 122 pigs, 76% of 87 horses and donkeys and 11% of 144 chickens on Trinidad. Eight sera from ducks and geese on Trinidad were tested and found to be negative. The serogroups most commonly found to react with the sera of the Grenadian animals were Autumnalis, Icterohaemorrhagiae, Hebdomadis and the related serogroups Sejroe and Mini, and Pyrogenes; in the Trinidadian animals they were Icterohaemorrhagiae, Autumnalis, Hebdomadis and its related serogroups, and Panama. Strains of serogroup Pomona do not appear to have become established as livestock pathogens on the islands.

Serological studies on leptospirosis in livestock and chickens from Grenada

Sera from 1206 livestock animals and chickens in Grenada and Trinidad were tested for leptospiral antibodies by the microscopic agglutination test. 376 of the sera were positive (44 percent of those tested in Trinidad and 25 percent of those tested in Grenada). The positive sera were obtained from 25 percent of 324 cattle 35 percent of 130 pigs, 35 percent of 126 sheep, 25 percent of 44 goats, and 11 percent of 175 chickens in Grenada; and 92 percent of 26 cattle, 53 percent of 122 pigs, 76 percent of 86 horses, and 11 percent of 144 chickens in Trinidad. 8 sera from ducks and geese in Trinidad were tested and found to be negative. The serogroups most commonly found to react with sera of the Grenadian animals were Autumnalis, Icterohaemorrhagiae, Hebdomadis and the related serogroups Sejroe and Mini, and Pyrogenes; in the Trinidadian animals they were Icterohaemorrhagiae, Autumnalis, Hebdomadis and its related serogroups and Panama. Strains of serogroup Pomona do not appear to have become established as livestock pathogens on the islands (AU)

Leptospires in wildlife from Trinidad and Grenada.

Serum samples from 894 wild animals (representing 31 species) from Trinidad and Grenada were examined by the microscopic agglutination test for leptospiral antibodies; 198 were positive. These included 39 bats, 88 mongooses, six opossums, 10 peridomestic rodents, 15 forest rodents, 10 lizards, and 30 toads. Thirteen pathogenic serogroups were involved. Thirty-nine Leptospira isolates were reported from mongooses, opossums, rodents and toads.

Leptospires in wildlife from Trinidad and Grenada

Serum samples from 894 wild animals (representing 31 species) from Trinidad and Grenada were examined by the microscopic agglutination test for leptospiral antibodies; 198 were positive. These included 39 bats, 88 mongooses, six opossums, 10 peridomestic rodents, 15 forest rodents, 10 lizards and 30 toads. Thirteen pathogenic serogroups were involved. Thirty-nine Leptospira isolates were reported from mongooses, opssums, rodents and toads. (AU)

A survey of leptospirosis in febrile patients mainly from hospitals and clinics in Trinidad.

Acute and convalescent sera were obtained from 202 febrile patients, most of whom were admitted to or attended hospitals or clinics in northern Trinidad during the 12 months from mid-February 1977 to mid-February 1978. Laboratory tests confirmed that 10 of the patients were suffering from current leptospirosis while another 54 had serological evidence of previous leptospiral infections. Antibodies to strains of the Icterohaemorrhagiae serogroup were most commonly found, followed by those to the Hebdomadis and Autumnalis serogroups. Isolates were obtained from the blood of two and the urine of three of the 10 current cases. Four of these strains were identified as belonging to copenhageni serovar of the Icterohaemorrhagiae serogroup and one to serovar brasiliensis of the Bataviae serogroup. Seven of the patients suffering from leptospirosis were males, all rural dwellers, and all except one under 20 years of age. Two of the three female patients were over 60 years old and were urban dwellers. It was not possible to identify the sources of infection with certainty, although dogs may have been responsible for three of the Icterohaemorrhagiae and one of the Canicola infections. Of the 192 patients who were not currently infected, serological evidence of previous infection was obtained in 31 (40%) males and 23 (21%) females and was most common among farmers and rural workers.

A survey of leptospirosis in febrile patients mainly from hospitals and clinics in Trinidad

Acute and convalescent sera were obtained from 202 febrile patients, most of whom were admitted to or attended hospitals or clinics in northern Trinidad during the 12 months from mid-February 1977 to mid February 1978. Laboratory tests confirmed that 10 of the patients were suffering from current leptospirosis while another 54 had serological evidence of previous leptospiral infections. Antibodies to strains of the Icterohaemorrhagic serogroup were the most commonly found, followed by those to the Hebdomadis and Autumnalis serogroups. Isolates were obtained from the blood of two and the urine of three of the current cases. Four of thoses strains were identified as belonging to copenhageni serovar of the Icterohaemorrhagiae serogroup and one to the Bataviae serogroup. Seven of the patients suffering from leptospirosis were male, all rural dwellers, and all except one under 20 years of age. Two of the three female patients were over 60 years old and were urban dwellers. It was not possible to identify the sources of infection with certainty, although dogs may have been responsible for three of the Icterohaemorrhagiae and one of the Canicola infections. Of the 192 patients who were not currently infected, serological evidence of previous infection was obtained in 31 (40 percent) males and 23 (21 percent) females and was most common among farmers and rural workers. (Summary)

Pathogenic leptospira isolates from the Caribbean Islands of Trinidad, Grenada and St. Vincent.

All known isolates of Leptospira interrogans obtained in Trinidad, Grenada and St. Vincent up to the end of 1979 are listed. There were 80 from Trinidad, 20 from Grenada and 2 from St. Vincent, representing at least 20 serotypes from 11 or more serogroups. Six of the serotypes were first reported from Trinidad. The leptospires were isolated from man, domestic animals and wildlife species.

Human leptospirosis in Trinidad - abstract

An investigation of leptospirosis in patients with pyrexia of undetermined origin (PUO) at Port of Spain General Hospital, San Fernando General Hospital, and two health centres/clinics in northern Trinidad was undertaken between 1977 and the end of 1979. Icteric patients were first screened for Hepatitis B antigen (HBsAg) and 3.3 percent were found to be positive. Of 791 patients examined for leptospirosis, 55(7.0 percent) were diagnosed as current cases by sero-conversion; 8 isolates were obtained from these patients. The proportion of cases per year varied from 4.4 percent to 9.0 percent. The four infecting serogroups most commonly found in these sick patients were Icterohaemorrhagiae (23 or 41.8 percent) (this figure may be as high as 28 or 50.9 percent if the 5 Icterohaemorrhagiae/Autumnalis cross reactors are included), Canicola (10 or 18.2 percent), Hebdomadis (5 or 9.1 percent) and Autumnalis (3 or 5.5 percent). The nine others comprised 16.3 percent. Additionally, there were 165 (20.9 percent) seropositive individuals among these febrile patients who were considered to be old cases with low titres and not currently infected. The proportion per year varied from 16.0 percent to 24.9 percent. Here, serogroups Hebdomadis, Autumnalis and Panama accounted for over 56 percent of the seropositives, and Icterohaemorrhagiae for just under 25 percent. In a serological survey of 1,389 indiviuals in possible at-risk occupations there was evidence of a high degree of previous exposure in certain categories. 45 percent, 36 percent, 35 percent and 33 percent of sugarcane farmers, vegetable and fruit cultivators, slaughtermen and rice farmers, respectively, were seropositive. In addition, 20 percent of animal husbandrymen and 12 percent of animal workers such as veterinarians and assistants, rodent control employees, zoological gardens staff, and dog handlers, were seropositive. By comparison, 11 percent of the urban controls and 28 percent of the rural family control groups were seroreactors. Serogroup Autumnalis predominated in all categories associated with rural dwelling and occupations, while Icterohaemorrhagiae was the predominant infective group among the urban controls, abattoir employees and animal workers. Leptospirosis is more common in the Caribbean than is generally realized. The high proportion of Icterohaemorrhagiae cases (and to a lesser extent of Canicola cases) among hospital and clinic patients almost certainly reflects the often severe pathogenicity of these two serogroups, and not their prevalence. Probably Autumnalis, Icterohaemorrhagiae, Hebdomadis, Canicola and Panama are the five most common serogroups in Trinidad, though the predominant role of Autumnalis may sometimes be taken by Hebdomadis (AU)

Pathogenic leptospira isolates from the Caribbean Islands of Trinidad, Grenada and St. Vincent

All known isolates of Leptospira interrogans obtained in Trinidad, Grenada and St. Vincent up to the end of 1979 are listed. There were 80 from Trinidad, 20 from Grenada and 2 from St. Vincent, representing at least 20 serotypes from 11 or more serogroups. Six of the serotypes were first reported from Trinidad. The leptospires were isolated from man, domestic animals and wildlife species.(AU)

Leptospirosis in patients from Grenada, West Indies.

Evidence of leptospirosis in humans from Grenada, W.I., is reported here for the first time. Of 139 hospital patients with pyrexia of undetermined origin, 94 were jaundiced, and 16 (17%) of these were positive for hepatitis B antigen (HBsAg) and not examined further. 20 of the remaining 123 (16%) febrile patients were positive for leptospiral antibodies; 11 of them were current or recent cases. 25 of 182 (14%) afebrile out-patients showed evidence of previous exposure to leptospiral organisms. The most frequently encountered serogroups in the 45 seropositive in- and out-patients were Icterohaemorrhagiae (38%), Panama (24%) and Canicola (11%).

Leptospirosis in patients from Grenada, West Indies

Evidence of leptospirosis in humans from Grenada, W.I., is reported here for the first time. Of 139 hospital patients with pyrexia of undetermined origin, 94 were jaundiced, and 16 (17 percent) of these were positive for hepatitis B antigen (HBsAg) and not examined further. 20 of the remaining 123 (16 percent) febrile patients were positive for leptospiral antibodies; 11 of them were current or recent cases. 25 of 182 (14 percent) afebrile out-patients showed evidence of previous exposure to leptospiral organisms. The most frequently encountered serogroups in the 45 seropositive in- and out- patients were Icterohaemorrhagiae (38 percent) Panama (24 percent) and Canicola (11 percent) (Summary)