EXPERIMENTAL STUDIES ON THE SURVIVAL OF THE TUBERCLE BACILLUS OF THE GUINEA PIG CADAVERS AFTER INTERMENT

Abstract

According to the recent governmental statistics, about 50,000 death are attributed to tuberculosis. Tuberculosis death occurs mostly in the domestic dwellings like other deaths, because of limited medical facilities. Cadavers are usually disposed of by a conventional method of interment. Handling of cadavers is for the most cases performed by close relatives since the funeral system of western standards is lacking. Although sanitary regulations require cremation or interment with strict provision of the cadavers resulted from acute communicable diseases, sanitary control of those resulted from chronic diseases like tuberculosis is not strongly enforced. Furthermore, current land planning programs often necessitate removal of buried cadavers, thus generating risk of unhygienic handling of infected cadavers. This experiment was designed to observe how long the bacilli can survive in the cadavers after interment. Two strains of tubercle bacilli, a H37RV standard strain, and a resistant strain called H531 were used for the study. The H531 strain was isolated from a tuberculosis patient and found to have developed resistance to INH(10r/ML) and Streptomycin (10r/ML). The bacterial suspension was inoculated into 300 guinea pigs weighing 300 gms on the average by way of intracardiac, intraperitoneal and subcutaneous routes. Morbid or dead animals were sacrificed and isolation of the bacilli was made of the lungs, liver, spleen and mesenteric lymph nodes, using 3% KH2PO4 Ogawa media. Simultaneously these necropsied animals were buried in the ground with depth of 1.5 meters from the surface. After internment for different lengths of time periods, the reisolation of the bacilli was made of specimens taken from the decaying cadavers. The experiment was carried out from December 1963 to the end of 1965. The following can be summarized: 1. The recovery rate of tubercle bacilli, the H37RV strain, from the cadavers was 100% after interment for 30 days of the Winter period, December-February. The rate, however, decreased to 29.4% after 60 days. 2. When buried in Spring month, March, bacilli, the H37RV strain, were recovered with 100% after 30 day internment and 14.3% after 60 days. 3. When buried during Summer months, June-July, the bacilli, the H37RV strain were recovered with 100% after 30 days, 33,3% after 60 days and nil after 70 days. 4. The recovery rate of the bacilli of the resistant strain, from the cadavers, was 100% after 30days of interment in Spring season, March-May and decreased to 33.3% after 60 days. 5. When buried during Summer months, June-July, the bacilli were recovered with 100% after 30 days and 22.5% after 60days. 6. No difference on the survival rate of the vacilli was observed between two strains. 7. The recovery rates of the bacilli, H37RV strain, from the cadavers framed with different conditions are 100% in all cases after 30 days internment. The rates, however, differed after 60 days interment according to the condition of framing, wiz the rate for a wooden box was 53.3%, that for a vinyl sac was 33.3% and those buried with the naked condition showed nil. 8. No survival of the bacilli, either the strain of H37RV or that of H534 was seen after 70 days internment during any month of he year. 9. It was confirmed that the drug resistance of the bacilli by no means differs between groups before and after interment. 10. It was observed through animal experimentation, that the resistant strain, H543, produced a definite sign of progressive tuberculosis though possessed low virulence.