Inflammatory bowel disease: incidence, prevalence, and disease characteristics in Barbados, West Indies.

BACKGROUND: The incidence of inflammatory bowel disease (IBD) may be lower among people of African descent than Caucasians. However, incidence studies among the former are uncommon and are often limited by incomplete case ascertainment or uncertainty about the size of the "at-risk" population. METHODS: We report the incidence and prevalence of IBD among people of African ancestry in Barbados from island-wide disease surveillance over a 25-year period beginning January 1980. RESULTS: The annual incidence of IBD age standardized to the world population was 1.85 per 100,000 person-years (95% confidence interval [CI] 1.53-2.22) for ulcerative colitis (UC) and 0.70 per 100,000 person-years (0.51-0.95) for Crohn's disease (CD). These incidence rates increased to 2.09 and 0.76 when standardized to the US population. The UC incidence rate increased from 1.3 in 1980-1984 to 2.3 in 1995-1999, and decreased to 1.6 in 2000-2004. The CD incidence rate followed a similar trend, rising from 0.3 in 1980-1984 to 1.3 in 1990-1994 before decreasing to 0.6. IBD prevalence in December 2004 was 44.3 per 100,000 person-years (36.7-53.0) for UC and 16.7 per 100,000 person-years (12.2-22.4) for CD. In the island-nation of Barbados, with a population in 2000 of 270,000, we expect between 4.3 and 6.1 new cases of UC and between 1.5 and 2.6 new cases of CD each year. CONCLUSIONS: The reported rates are generally lower than reported for European and North American Caucasians, and are similar to The French West Indies--the only other IBD disease register in the Caribbean.

Evaluation of a commercial latex agglutination assay for serological diagnosis of leptospirosis.

Leptospirosis is a febrile zoonosis of worldwide distribution. A latex agglutination assay was evaluated in two studies, the first using a panel of well-characterized sera from patients with leptospirosis and from patients with other disease states and the second, a prospective hospital-based study, evaluating sera from 186 consecutive patients admitted to hospital with acute febrile illness. The confirmed leptospirosis serum panel included paired acute- and convalescent-phase specimens from 40 cases, of which 34 gave positive latex tests (case sensitivity, 85%; 95% confidence interval [95% CI], 70 to 94%). The other diseases represented in the panel of 112 specimens from nonleptospirosis patients included autoimmune diseases, brucellosis, dengue, melioidosis, malaria, syphilis, toxoplasmosis, viral hepatitis, and a number of other viral infections. The specificity of latex agglutination using this panel was 81% (95% CI, 73 to 87%). Among the patients with acute febrile illness, there were 25 cases of leptospirosis and 161 patients with other diagnoses. The sensitivity and specificity of latex agglutination in this group were 88% (95% CI, 72 to 97%) and 98% (95% CI, 95 to 100%), respectively. In this evaluation, the two distinct groups of specimens gave similar results for sensitivity, but specificity was different in each study. The sensitivity and specificity observed for the hospital study were similar to those obtained in evaluations of other rapid tests in the same population. The results of this study suggest that multiple evaluations of new diagnostic assays should be performed, because performance characteristics may vary in different populations.

Helicobacter pylori infection in the Caribbean: update in management.

Helicobacter pylori infection of the stomach is one of the commonest chronic infections worldwide and in the Caribbean, over 50% of the population are affected. H pylori is probably transmitted from person to person by oro-faecal and oro-oral means. H pylori is directly associated with peptic ulcer disease, chronic antral gastritis, gastric carcinoma and B-cell lymphoma of the stomach. In patients with peptic ulcers and H pylori infection, eradication of infection with antibiotics significantly decreases recurrence of ulcers. All patients with H pylori related disease should be tested and treated if positive. The treatment of H pylori infection has evolved over the years but at present triple therapy which includes two antibiotics is recommended.

Two methods for rapid serological diagnosis of acute leptospirosis.

Leptospirosis is a common and underdiagnosed zoonosis. Two rapid assays for serological diagnosis of acute leptospirosis in diagnostic laboratories, the immunoglobulin M (IgM)-dipstick assay and the indirect hemagglutination assay (IHA), were evaluated and compared with standard assays. Sera were examined from 104 patients admitted to a hospital for investigation in a leptospirosis diagnostic protocol. Specimens for serology were taken on days 1 and 4 of the patients' hospital stay. Antibodies were detected using an IgM-enzyme-linked immunosorbent assay (ELISA), microscopic agglutination test (MAT), an IgM-dipstick assay, and an IHA. Fifty-one patients were found to have leptospirosis. The sensitivity of the IgM-dipstick assay was 98%, its specificity was 90.6%, its positive predictive value was 90.9%, and its negative predictive value was 98%. The sensitivity of the IHA was 92.2%, its specificity was 94.4%, its positive predictive value was 95.9%, and its negative predictive value was 92.7%. The standard IgM-ELISA and MAT, were positive in the first samples tested from 67 and 55% of the cases, respectively, and the rapid IgM-dipstick assay and IHA were positive in 71 and 49%, respectively, in the first sample tested. Both rapid assays are highly sensitive and specific. Neither requires specialized equipment, and both are suitable for use in diagnostic laboratories.

Helicobacter pylori infection in the Caribbean: update in management

Helicobacter pylori infection of the stomach is one of the commonest chronic infections worldwide and in the Caribbean, over 50 of the population are affected. H pylori is probably transmitted from person to person by oro-faecal and oro-oral means. H pylori is directly associated with peptic ulcer disease, chronic antral gastritis, gastric carcinoma and B-cell lymphoma of the stomach. In patients with peptic ulcers and H pylori infection, eradication of infection with antibiotics significantly decreases recurrence of ulcers. All patients with H pylori related disease should be tested and treated if positive. The treatment of H pylori infection has evolved over the years but at present triple therapy which includes two antibiotics is recommended.

Detection of dengue infection in patients investigated for leptospirosis in Barbados.

The annual incidence of leptospirosis in Barbados is approximately 13 severe cases/100,000. The peak incidence occurs in October to December of each year, coinciding with the months of heaviest rainfall. During the second half of 1995, an epidemic of dengue type 1 infection produced almost 1,000 laboratory-confirmed cases. During the same period, leptospirosis mortality was twice the average, suggesting that some cases of leptospirosis were being misdiagnosed and treated inappropriately. Sera from patients investigated for dengue or leptospirosis were analyzed retrospectively to determine the extent of misdiagnosis. During 1995 and 1996, 31 of 139 and 29 of 93 patients, respectively, were confirmed as having leptospirosis. Sera from the remaining leptospirosis-negative patients were tested for IgM antibodies to dengue virus. During 1995 and 1996, 48 of 108 patients and 21 of 64 patients, respectively, were found to have dengue. In 1997, sera from all patients investigated for leptospirosis were also tested prospectively for IgM antibodies to dengue: 38 of 92 leptospirosis-negative patients (41%) were dengue IgM-positive, while 2 of 25 leptospirosis cases also had serologic evidence suggesting acute dengue infection. A second large outbreak of dengue caused by serotype 2 occurred in 1997. During the 1995 and 1997 dengue epidemics in Barbados, dengue cases outnumbered leptospirosis cases investigated in the leptospirosis diagnostic protocol. During 1997, patients investigated but negative for dengue were also tested for anti-leptospiral IgM: 7.3% (19 of 262) were IgM-positive. Substantial misdiagnosis of both dengue and leptospirosis can occur and greater public awareness and clinical suspicion of the similar presentations of these two diseases are necessary.

Severe primary HIV-1 infection among black persons in Barbados.

Descriptions of primary HIV-1 infection have so far been based on Caucasians living in industrialized nations. Due to studies of leptospirosis in the predominantly black population of Barbados, serum was available for patients admitted with acute febrile illnesses to the Queen Elizabeth Hospital (QEH). By searching the medical records of 510 adult patients with known HIV-1 infection we identified 10 patients who had stored serum from an admission for an acute febrile illness that predated or coincided with their first HIV-1-positive test. Serological testing confirmed primary HIV-1 infection in 9 and was suggestive in the 10th patient. The clinical features of these 10 patients were in keeping with previous descriptions of primary HIV-1 infection but differed from leptospirosis cases seen at the QEH. One patient died during his seroconversion illness and another died 3 months after seroconversion. The findings suggest that severe primary HIV-1 infection could be a relatively uncommon occurrence, that the condition may be misdiagnosed, and that cases may not occur until the AIDS epidemic is established.

PIP: A retrospective review was conducted of the medical records of 510 HIV-1-positive adult patients who had attended the Queen Elizabeth Hospital (QEH) to determine whether any had been admitted for an illness compatible with a diagnosis of primary HIV-1 infection. A serum bank, created from patients who had been admitted with acute febrile illnesses and investigated for leptospirosis, provided serological evidence for primary HIV-1 infection in 10 patients. Serological testing of the serum samples confirmed primary HIV-1 infection in nine patients and was suggestive in the tenth. The clinical features of the 10 patients fit the earlier descriptions of primary HIV-1 infection, but differed from the leptospirosis cases seen at the QEH. One patient died during his seroconversion illness and another died 3 months after seroconversion. These findings suggest that severe primary HIV-1 infection could be a relatively uncommon occurrence, that the condition may be misdiagnosed, and that cases may not occur until the AIDS epidemic is established.

Epidemiology of Helicobacter pylori infection in Barbados.

The epidemiology of Helicobacter pylori infection in Barbadian patients and controls was studied. H. pylori was isolated from biopsies from 50/100 (50%) adult patients undergoing endoscopy for investigation of upper gastrointestinal tract symptoms. Urease was detected in biopsies from 54 patients and gastritis was detected by histology in 71 patients. Serology was performed using a commercial ELISA method. Using an IgG concentration of 10 U/ml as a threshold, antibodies were detected in 78% of 100 patients undergoing endoscopy, 72% of 230 blood donors and 22% of 50 children. The mean antibody concentration was significantly higher in patients (92 U/ml) than in blood donors (49 U/ml) or in children (9.5 U/ml). Culture-positive patients (120 U/ml) had higher IgG concentrations than culture-negative patients (64 U/ml). Using isolation of H. pylori or a positive biopsy urease test as a measure of true prevalence of infection, the sensitivity of serology was 96%, the specificity 42%, positive predictive value 67% and negative predictive value 90%. Seroprevalence increased with age, to a peak of more than 90% in blood donors aged 50-59 years and in patients aged over 60 years. The epidemiology of H. pylori in Barbados is similar to that in developed countries, where few children are infected, but resembles other developing countries in the high seroprevalence observed in middle-aged adults. Our results confirm the utility of serology for detecting H. pylori by a non-invasive technique.

Evaluation of the polymerase chain reaction for early diagnosis of leptospirosis.

Early diagnosis of leptospirosis is important because severe leptospiral infection can run a fulminant course. The polymerase chain reaction (PCR) was evaluated for the detection of leptospires in clinical samples from patients with acute leptospiral infection. Blood and urine samples from 71 patients with leptospirosis were examined by PCR, culture or serology. Samples from 44 (62%) patients with the diagnosis of leptospirosis were positive by PCR as compared to 34 (48%) by culture. The presence of leptospires was demonstrated by PCR in 13 patients before the development of antibodies, as well as in two patients who were seronegative during their illness and at autopsy. Samples from 16 patients without leptospirosis were seronegative and culture negative, and also negative by PCR. We conclude that PCR is a rapid, sensitive and specific means of diagnosing leptospiral infection, especially during the first few days of the disease.

A twelve-year study of leptospirosis on Barbados.

Between November 1979 and December 1991, 398 cases of severe leptospirosis were confirmed on Barbados (range for 1980-1991 23-56; mean 32.7; incidence 13.3/100,000/year). For the six-year periods 1980-1985 and 1986-1991 there was no significant change in incidence with time. Incidence is unlikely to change significantly in the next decade. Monthly average case numbers ranged from 1.4 (July) to 4.3 (November). The average (2.8) for June to December (the 7 wetter months) was not significantly higher than that (2.5) for January to May (the 5 drier months). The age range was 7-86. There were three times as many male cases (302) as female (96), and nearly 10 times as many in those < 35. Although the highest number of cases (69) was in males aged 15-24, the highest incidence was in the older age groups, particularly the male 65-74 year-olds, and the female 55-64 year-olds. Leptospirosis was the proven cause of death in 55 (13.8%) hospital patients (annual range 0-13, mean 4.5). Some of a further 39 fatalities might have been cases. Death from leptospirosis was nearly twice as common among the women as among the men. Only one patient under 20 years of age died. Leptospira were isolated and identified from 117 (29.4%) of the 398 sick patients. The infecting organisms were bim (serogroup Autumnalis--75), copenhageni (Icterohaemorrhagiae-26), arborea (Ballum-14) and bajan (Australis-2). These infecting serovars could not be distinguished clinically, but infection was milder in children than in adults. Despite its predominance in surveyed children, serogroup Panama was virtually absent in this study. Rainfall is the major factor affecting the distribution of cases; not surprisingly, sanitation workers and agricultural workers appear to be the groups at highest risk. The general lack of clear-cut risk factors reflects the ubiquity of leptospires in the environment and the fact that the disease is not entirely occupational.

Neuroleptic malignant syndrome among acute psychiatric admissions in Barbados.

The main features of the Neuroleptic Malignant Syndrome (NMS), a complication of neuroleptic therapy, are fever, muscle rigidity, autonomic dysfunction, and an alteration in consciousness level. We describe five cases of NMS comprising 0.6% of acute neuroleptically-treated admissions to a psychiatric hospital over a one-year period. All patients, four females aged 26 to 63 years, and one male, aged 65 years, were of African origin and received multiple neuroleptic drugs, at least one of which was a depot preparation. Four were being treated for functional psychiatric disorders while one had dementia. All patients had fever and depressed consciousness level while four had rigidity and autonomic dysfunction. Serum creatine phosphokinase was elevated in 4 cases, and there was indirect evidence of myoglobinuria in 3 cases suggested by a positive urine dipstick test for blood despite the absence of red cells on microscopy. Rhabdomyolysis was associated with renal failure in one case. Both bromocriptine mesylate and dantrolene sodium were given in two cases. Three patients died in hospital, one with persistent rigidity and progressive decubitus ulceration, one from peritonitis following peritoneal dialysis, and another suddenly. Early recognition of NMS is important; it should be considered in any patient on neuroleptic therapy who develops fever, rigidity or alteration in consciousness level.

Neuroleptic malignant syndrome among acute psychiatric admissions in Barbados

The main features of the Neuroleptic Malignant Syndrome (NMS), a complication of neuroleptic therapy, are fever, muscle rigidity, autonomic dysfunction, and an alteration in consciousness level. We describe five cases of NMS comprising 0.6 per cent of acute neuroleptically-treated admissions to a psychiatric hospital over a one-year period. All patients, four females aged 26 to 63 years, and one male, aged 65 years, were of African origin and received multiple neuroleptic drugs, at least one of which was a depot preparation. Four were being treated for functional psychiatric disorders while one had dementia. All patients had fever and depressed consciousness level while four had rigidity and autonomic dysfunction. Serum creatine phosphokinase was elevated in 4 cases, and there was indirect evidence of myoglobinuria in 3 cases suggested by a positive urine dipstick test for blood despite the absence of red cells on microscopy. Rhabdomyolysis was associated with renal failure in one case. Both bromocriptine mesylate and dantrolene sodium were given in two cases. Three patients died in hospital, one with persistent rigidity and progressive decubitus ulceration, one from peritonitis following dialysis, and another suddenly. Early recognition of NMS is important; it should be considered in any patient on neuroleptic therapy who develops fever, rigidity or alteration in consciousness level.

An investigation of some risk factors for severe leptospirosis on Barbados.

Between November 1979 and the end of December 1986 (7.17 years), 248 cases of leptospirosis were confirmed among hospital patients on Barbados (mean 35 per year; range 25-57). Considering the 235 who were greater than or equal to 15 years of age, the annual incidence of leptospirosis was 19.2/100,000 population (14.0 for all age groups). There were 173 males and 62 females, and for cases aged 15-34 leptospirosis was 9.6 times more common in men than women. Among men, incidence increased fairly steadily with age, and an even steadier increase was apparent in women up to age 64, with some decline in later years. The incidence of disease was much higher among agricultural than other workers and the non-employed. Highest case numbers were recorded in the parishes of St Michael (65 or 28%) and Christ Church (36 or 15%), though the incidence was lowest in these two parishes (13.1/100,000 and 17.4/100,000, respectively). The highest incidence rates were in St Andrew and St Joseph (50.2 and 36.1/100,000, respectively). The incidence in areas with rainfall greater than or equal to 1600 mm (32.6/100,000) was nearly twice that in areas with rainfall less than 1600 mm (17.3/100,000). There is a clear link between cases of severe disease and recent rainfall. Using 134 patients greater than or equal to 15 years of age with fever due to other illnesses as controls, a higher proportion of cases than controls came from rural areas. The risk of contracting leptospirosis was increased for all categories of manual workers relative to the group at lowest risk (non-manual indoor workers). Sugar-cane workers were five times more likely to contract leptospirosis than were non-manual indoor workers, while those whose families minded livestock were 2.5 times more likely, and those with rodents in their garden/yard were 1.8 times more likely to do so. Other risk factors examined did not show significant associations with the disease. Despite increasing mechanization and the use of more protective clothing, agricultural workers are still at high risk from leptospirosis. The annual range of cases is likely to stay much as it is in the foreseeable future.

Hyperamylasemia and pancreatitis in leptospirosis.

Hyperamylasemia has been documented in up to 65% of our patients with leptospirosis and jaundice. However, pancreatitis is an uncommon complication of leptospirosis. Three patients with leptospirosis and pancreatitis are described and compared with two leptospirosis patients who had hyperamylasemia but in whom the diagnosis of pancreatitis could not be substantiated. The cause of the hyperamylasemia in the latter patients was nonpancreatic. The elevation of the amylase in these latter two patients could not be explained by renal insufficiency, because the level of the amylase was greater than three to four times the normal value, the upper limit to which amylase rises in renal failure. Thus, hyperamylasemia in patients with leptospirosis can be from pancreatic and nonpancreatic sources. Leptospirosis should be considered in the differential diagnosis of hyperamylasemia and pancreatitis.

Questionnaire detection of problem drinkers among acute medical admissions.

The study was designed to determine the prevalence of alcoholism/problem drinking among emergency medical admissions. Of 203 emergency admissions to two medical wards, 18% were found to be problem drinkers, using the brief Michigan alcoholic screening test (MAST) questionnaire. Problem drinking was found in 31% of males and 5% of females. Most drinking was done with friends (77%) and at the "rum shop" (62%). Fifty-one per cent of problem drinkers started between the ages of sixteen and twenty years. Seventy per cent of all problem drinkers had a first degree family relative who drank compared to 28% of non-drinkers. A high prevalence of alcoholism (48%) was found among smokers. Housestaff detected just over half of male (56%) and female (60%) alcoholics who were MAST-positive. Medical diagnoses among MAST-positive patients were gastrointestinal (cirrhosis, pancreatitis and hepatitis) in 32%, neurological (delirium tremens, seizures and subdural hematoma) in 27% and cardiovascular (cardiomyopathy, heart failure and dysrhythmias) in 16%. The detected level of problem drinking is likely to cause significant morbidity, and allows an important opportunity for intervention. The use of questionnaire methods to screen for alcoholism needs further evaluation in the region.

Questionnaire detection of problem drinkers among acute medical admissions

The study was designed to determine the prevalence of alcoholism/problem drinking among emergency medical admissions. Of 203 emergency admissions to two medical wards, 18% were found to be problem drinkers, using the brief Michigan alcoholic screening test (MAST) questionnaire. Problem drinking was found in 31% of males and 5% of females. Most drinking was done with friends (77%) and at the "rum shop" (62%). Fifty-one percent of problem drinkers started between the ages of sixteen and twenty years. Seventy per cent of all problem drinkers had a first degree family relative who drank compared to 28% of non-drinkers. A high prevalence of alcoholism (48%) was found among smokers. Housestaff detected just over half of male (56%) and female (60%) alcoholics who were MAST-positive. Medical diagnoses among MAST-positive patients were gastrointestinal (cirrhosis, pancreatitis and hepatitis) in 32%, neurological (delirium tremens, seizures and subdural hematoma) in 27% and cardiovascular (cardiomyopathy, heart failure and dysrhythmias) in 16%. The detected level of problem drinking is likely to cause significant morbidity, and allows an important opportunity for intervention. The use of questionnaire methods to screen for alcoholism needs further evaluation in the region.

Leptospirosis in Barbados. A clinical study.

A 39-month clinical study of leptospirosis was undertaken at the Queen Elizabeth Hospital, Barbados. Eighty-eight patients had a confirmed diagnosis of the disease during the period. The major serogroups identified were autumnalis (including a new serovar bim), icterohaemorrhagiae, ballum and canicola. The majority of patients presented with jaundice (95%,) anorexia and headaches (85%), fever (76%) and conjunctival suffusion (54%). While abnormal creatinine levels were seen in 49% of patients on admission, only 16% were judged to have had renal failure. The urine to plasma urea ratio showed high sensitivity and specificity in the diagnosis of pre-renal azotemia. Cardiac arrhythmias and myocarditis occurred in 18% of patients and pericarditis in 6%. An elevated serum amylase was found in 65% of cases. The bilirubin level took 5.5 weeks to return to normal. Thrombocytopenia was shown not to be due to a disseminated intravascular coagulation, and a randomised trial of high dose penicillin did not reveal any benefit to jaundiced patients. The overall mortality during the study was 5.7%.

Leptospirosis in Barbados: a clinical study

A 39-month clinical study of leptospirosis was undertaken at the Queen Elizabeth Hospital, Barbados, Eighty-eight patients had a confirmed diagnosis of the disease during the period. The major serogroups identified were autumnalis (including a new serovar bim), icterohaemorrhagiae, ballum and canicola. The majority of patients presented with jaundice (95%,) anorexia and headaches (85%), fever (76%) and conjunctival suffusion (54%). While abnormal creatinine levels were seen in 49% of patients on admission, only 16% were judged to have had renal failure. The urine to plasma urea ratio showed high sensitivity and specificity in the diagnosis of pre-renal azotemia. Cardiac arrhythmias and myocarditis occurred in 18% of patients and pericarditis in 6%. An elevated serum amylase was found in 65% of cases. The bilirubin level took 5.5 weeks to return to normal. Thrombocytopenia was shown not to be due to a disseminated intravascular coagulation, and a randomised trial of high dose penicillin did not reveal any benefit to jaundiced patients. The overall mortality during the study was 5.7%

Leptospiral infection in school-children from Trinidad and Barbados.

A serological survey for leptospiral agglutinins was undertaken between 1980 and 1983 in over 500 Barbadian and 500 Trinidadian school-children aged 7-14 years. The children were selected randomly from urban and rural schools, and examined three times at approximately annual intervals. A total of 12.5% of the Barbadian children and 9.5% of the Trinidadian children were seropositive at a titre of 50 using the microscopic agglutination test. On both islands, seroprevalence was higher in males than females, the difference being significant in rural schools. There was no evidence of a difference in prevalence between urban and rural schools, or between junior and secondary age-ranges. Analysis of the association of serology with socio-economic and behavioural factors showed a significant association in Trinidad with father's occupation, but most other variables on both islands showed only weak non-significant associations. Fourteen children in Trinidad and three in Barbados seroconverted. Seroconversion in Trinidad occurred at a rate of 1.6% per annum and was significantly associated with livestock contact and with absence of a tapped water supply. In Trinidad, Autumnalis was the most commonly recorded serogroup, but this accounted for less than a quarter of seropositives. In Barbados, Panama accounted for over half the seropositives and was about four times more common than the next most common serogroup, Autumnalis. In Barbados, 39 persons aged 19 or less were hospitalized with leptospirosis between November 1979 and December 1986. Average annual incidence rates were 2.2, 4.9 and 13.3 per 100,000 in the 5-9, 10-14 and 15-19 age-groups, respectively.