Is oral penicillin an effective chemoprophylaxis against leptospirosis? A placebo controlled field study in the Kandy District, Sri Lanka.

Leptospirosis poses a severe threat to the lives of farmers in Sri Lanka, thus, development of an effective chemoprophylaxis is deemed essential. We tested oral penicillin as chemoprophylaxis against leptospirosis in high transmission areas in central Sri Lanka in October 2005. Eight hundred active farmers were randomly assigned to take either oral penicillin (500 mg bid) or a similar looking placebo over a month during active farming season. The primary study point was the incidence of serologically confirmed leptospirosis. Data were available for 602 subjects of whom 319 (152 taking penicillin and 167 taking placebo) had good compliance, shown by tablet count. Of 5 subjects hospitalized with fever, 3 had serological evidence of leptospirosis, all of whom belonged to the placebo group. Therefore, oral penicillin may be effective chemoprophylaxis against leptospirosis.

Admission to medical schools in Sri Lanka: predictive validity of selection criteria.

OBJECTIVE: To assess the extent to which current selection criteria predict success in Sri Lanka's medical schools. METHODS: The study sample consisted of all students selected to all six medical schools in two consecutive entry cohorts. The aggregate marks of these students at the General Certificate of Education (GCE) Advanced Level examination, the district of entry, admission category, candidate type (school/private) and gender, were identified as entry point variables. Success in medical school was measured in four ways: the ability to pass the first summative examination and the final examination at the first attempt, and obtaining honours in either examination. Multivariate analysis using logistic regression was used to assess the extent to which these entry point factors predict variability in outcome measures. RESULTS: Aggregate scores among the 1740 students in the study sample ranged from 212 to 356, with a median of 285. The male:female ratio was 1.4:1. Private candidates (taking the examination for the third time) accounted for 22% of students. Being a school candidate, female and having a higher aggregate score, were the only independent predictors of success for all four outcome measures. The aggregate score alone accounted for only 1-7% of the variation in performance in medical school. CONCLUSIONS: Marks obtained at the A Level examination (the only academic criterion currently used for selection of medical students in Sri Lanka) is a poor predictor of success in medical school.

Routine antibiotic therapy in the management of the local inflammatory swelling in venomous snakebites: results of a placebo-controlled study.

OBJECTIVE: To evaluate the value of routine antibiotic therapy in the management of the local swelling of patients with venomous snakebites. METHODS: A prospective, placebo-controlled study at the General Hospital, Anuradhapura, Sri Lanka where 144 patients with envenoming and local swelling in the leg were allocated to receive either antibiotics (Group A = test group) or placebo (Group B = controls). Benzyl penicillin 2 mega units intravenously 6 hourly and metronidazole 500 mg by intravenous infusion 8 hourly for 5 days from the first day of the bite were given to Group A. Ethical committee approval was obtained from the Committee of General Hospital, Anuradhapura. MAIN OUTCOME MEASURES: Circumference difference between the affected limb and the normal limb, length of the swelling measured in centimetres, and the physical characteristics of the local swelling of both groups were compared. RESULTS: Group A had 69 patients and the Group B 75. The mean circumference difference (MCD) of the leg between the groups showed no significant difference for 4 days (P > 0.05), except at the site of the bite on the third day when the Group B showed a significant improvement (p = 0.02). There was no significant difference in the length of the local swelling or the score of physical characteristics between the two groups (P > 0.05). The proportions of recovery of the local swelling on the fourth and fifth day had no significant difference between the groups (P > 0.05). CONCLUSION: The routine use of antibiotics (penicillin and metronidazole) does not seem to be of value in reducing the local inflammatory swelling in venomous snakebite.

A seroepidemiological study of toxocariasis and risk factors for infection in children in Sri Lanka.

A seroepidemiology study using TES-ELISA was carried out in 1,020 children aged 1-12 years in the Hindagala Community Health Project, Sri Lanka. Toxocariasis seroprevalence was 43% with 16.6% showing high antibody levels. Unconditional logistic regression analysis showed 7-9 year olds to be at the highest risk (OR 3.0820; CI = 1.95-4.87). Dog ownership, especially puppies (OR 29.28; CI = 7.40-116.0), and geophagia-pica (OR 6.3732; CI = 3.87-10.50), were significant risk factors. Family clustering of toxocariasis was significant (chi2 = 88.000; p = 0.0001). Abdominal pain (45%), cough (30%), limb pain (23%) and skin rashes (20%) were significantly associated with seropositivity indicating that toxocariasis causes covert morbidity. These findings are, overall, applicable to other areas in Sri Lanka. However, in the dry zone, survival of infective eggs in the soil could be affected by the climate while more importantly, in agricultural areas with a high buffalo population, Toxocara vitulorum could account for human toxocariasis. Using a species specific double sandwich ELISA based on 57 kDa protein of T. canis ES antigen, it is demonstrated that 91% of the seropositives were due to T. canis. Thus along with rabies and dirofilariasis, toxocariasis is an important zoonotic health hazard from dogs in Sri Lanka and prevention is indicated.