DISEASE GERMS KILLED BY COLD

Auckland Star, Volume LXVII, Issue 235, 3 October 1936, Page 7 (Supplement)

DISEASE GERMS KILLED BY COLD

TESTS CONDUCTED ON BATS Heat speeds up life processes; cold slows them down. The studies on which this rather obvious biological fact are based were made on micro-organisms outside of the body. What of the behaviour of th» organisms in the body itself! It has been observed that in iibernating animals epidemio diseases develop at a relatively slow pace. This gave a group of zoologists of the Moscow State University an idea. Inject deadly •microbes in animate, let them hibernate and see what happens. The observers, N. P. Kalabuchov and L. B. Levinson, publish their results in "Doklady Akademii Nauk" (Reports of the Academy of Sciences of the U.S.S.R.). The microbes selected were trypanosomes, which are usually transferred to the blood of animals and human foeings through insect bites. The sleeping sickness of Africa is thus transmitted. One of these trypanosomes (the variety known to bacteriologists as equiperdum) was cultivated in white mice. Thereupon the culture was injected into the blood stream of bats. Some of the bats were kept in refrigerators at temperatures of 3 and 10 degrees C. (37.4 and 50 degrees F.); others (controls) at 20 t0,25 degrees C. (68 to 77

degrees F.). Both sets of bats were given identical rations of food and water. Every day a sample of blood was withdrawn from the bats and the microorganisms counted. At regular intervals temperatures were taken with special thermo-electrical apparatus. The bats kept at 3 degree C. in the refrigerator had a body temperature only two or three degrees above that of the surrounding air. After ten days 110 trypanosomes could be found in their blood. Even after they were transferred to rooms and kept at room temperature they remained healthy. The bats at 10 degrees C. passed more slowly into the hibernating stage. Parasites developed in the blood of some after a day. But the next day all were free from infection, and remained free even after having been /transferred to ordinary room temperatures. All the controls died in from nine to 13 days after inoculation. A Refrigeration Cure. Having found that the parasite fails to develop in the blood at low temperatures, the Soviet experimenters decided to cure animals which had been infected. They inoculated bats, kept them at room temperature until their blood was alive with trypanosomes, and then transferred them to refrigerators. Same result. The microbes disappeared, but reinoculation was easy. Evidently low temperature slows down the life processes, makes it impossible for the trypanosomes to live, but does not confer immunity. It looks as if an animal that goes 3 to sleep for the winter is provided with a special defence mechanism.