A study of epidemiology, risk factors and preventive measures against snake bites.

The epidemiology and exposing causes of snake bites were studied in 274 patients between 1 January 1982 and 30 December 1990. They comprised 142 males (51.82%) and 132 females (48.18%). Their ages ranged from 1 month to 86 years old. The age group most frequently bitten found in this study was between 15 to 29 years old amounting to 106 cases (38.69%). Of those 274 cases, 212 (77.37%) were the victims of poisonous snakes, namely, the green pit viper (Trimeresurus spp.) 156 cases (73.58%), the cobra (Naja naja) 53 cases (25.00%), Russell's viper (Vipera russellii siamensis) 3 cases (1.42%), while 13 cases (4.74%) were bitten by non-poisonous snakes, and in the remaining 49 cases (17.88%), the biting snakes were not clearly seen. It was found that 56 cases (20.44%) were bitten in the house, 50 cases (18.25%) were bitten within the precincts of the residence. However the highest number, 168 cases (61.31%) were bitten outside. It was also interesting to learn that 221 cases (80.66%) out of 274 were bitten in Bangkok, 91 cases (33.21%) were bitten from 6.00 p.m. to 9.00 p.m., 129 cases (47.08%) were bitten between June and September, 98 cases (35.77%) were bitten on a foot and 77 cases (28.10%) were bitten on a finger. The high risk factor of being bitten by a snake was walking along a farm or a ranch with masses of grass or undergrowth during the night without self-prevention and good caution. Therefore, health education on preventive measures were elucidated.

Severe cases of green pit viper snake venom poisoning.

Two severe cases of green pit viper bites were reported. The clinical manifestations were severe bleeding and diarrhea. The first patient had acute renal failure complicated from severe diarrhea and hypovolemia. Hematological findings showed hypofibrinogenemia and thrombocytopenia. Renal biopsy performed in the first case showed a picture compatible with that of the recovery phase of acute tubular necrosis. Green pit viper antivenine serum together with symptomatic and supportive treatment was given. Both patients recovered uneventfully.

Hygienic status of food handlers.

The study demonstrated bacterial species on hands and nails of food-handlers before and after hand-washing. Those were Staphylococcus spp., Streptococcus spp., Micrococcus spp., Bacillus spp., Diphtheroid, Aeromonas hydrophila, Klebsiella pneumoniae, Acinetobacter, Enterobacter cloacae, Escherichia coli, Pseudomonas spp., Proteus mirabilis, Serratia spp., Citrobacter freundii. Before hand washing, each food-handler harboured one to eight bacterial species. After hand-washing (eight with water from plastic boxes, 97 from pipe water, 57 out of 97 (58.8%) used soap or detergent with water), disappearance of one to four bacterial strains from hands and nails were found in 47.6 per cent of food-handlers. Cultures of water used for washing from eight plastic boxes yielded Staph. spp., Strep. spp., Aeromonas hydrophila, Kleb.pneumoniae, Acinetobacter anitratus, Enterobacter cloacae. From pipe water, Diphtheroid in 4, 4.1 per cent Micrococcus in 1, 1.03 per cent were shown. Comparing bacterial species found in food-handlers with long nails and short nails, 4-8 more species were revealed in the former than the latter for 35.7 per cent. After hand-washing, there was recontamination of bacterial species in 17 food-handlers. This was probably due to dirty napkins or dresses during hand-drying or from water in plastic boxes.

Experiences from a one-year supervision of pulmonary tuberculosis patient and Their associates.

Monthly scheduled follow-ups of 28 sputum-smear-culture-positive tuberculosis patients and 110 members of their families revealed 14 suspected cases of pulmonary tuberculosis and several interesting findings: (1) the incidence of tuberculosis was mostly among poor families with unsuitable shelter; (2) assessing family members and close associates of patients proved to be a fruitful approach for case-finding; (3) several BCG-vaccinated persons were found to have developed tuberculosis; (4) despite enthusiastic supervision of patients undergoing treatment, the defaulter rate was high (19.5%); and (5) all the antituberculotic regimens prescribed in this paper proved effective, as indicated by negative sputum examination from the fourth month of therapy onwards and a relapse rate of only 3.0 percent. Suggestions are made for improving the control of tuberculosis among the general public.

Systemic and intestinal immunities after different typhoid vaccinations.

The comparative studies of systemic and intestinal immunities to S. typhi were performed in 29 healthy volunteers during 2 years after receiving oral vaccination with attenuated S. typhi Ty21a in gelatin capsule, parenteral vaccination with acetone inactivated or heat inactivated-phenol preserved S. typhi Ty2. The methods used were immunobead ELISA for total secretory IgA and indirect ELISA for specific secretory IgA in the intestinal lavage fluid. The specific systemic IgG, IgM and anti-O, anti-H agglutinins were measured by indirect ELISA and Widal test respectively. The leukocyte migration inhibition test was used for the measurement of systemic cell mediated immunity. The results indicate that the oral S. typhi Ty21a stimulated intestinal immunity better than both parenteral vaccines but evoked less systemic antibody response. The stimulation of systemic cell-mediated immunity by the live attenuated and acetone inactivated vaccine was comparable while stimulation by heat inactivated-phenol preserved vaccine was less pronounced. The same studies were performed in 26 healthy volunteers during 6 months following different doses of oral vaccination with S. typhi Ty21a in enteric-coated capsule. The results suggest that the stimulation of intestinal and systemic immunities by this vaccine is dosage dependent. Three doses of vaccine provide better stimulation than two doses and one dose, respectively.