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KMID : 0353019690060020245
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Korean Journal of Public Health
1969 Volume.6 No. 2 p.245 ~ p.254
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The Influence of Various Enviromental Conditions upon the Eggs and Larvae of Hookworm
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Abstract
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This study was conducted to find out the survival conditions of hookworm eggs and infective larvae during the course of transmission. Since the main species of hookworm prevalent in Korea is Ancylostoma duodenale, the materials used in this study were the eggs and larvae of Ancylostoma duodenale. The hookworm eggs were obtained from a patient who was heavily infected with Ancylostoma duodenale alone. The larvae of a ten-day culture at 28℃ were used as the infective larvae material. The length of survival of the eggs at several different grades of temperature in human stool and mixture of equal amounts of stool and urine, survival of the infective larvae which attached to vegetables (celery cabbage was used), washing effect in removing the larvae which attached to the vegetables, resistance of the larvae to several different temperatures, and resistance of the larvae to several kinds of food-preservative substances, were observed. And the following results were obtained:
1) The eggs in the stool completely lost their viability after 30 days at 28℃. 22 days at 5℃ and 12hours at -10℃ respectively.
2)The eggs in the mixture of equal amounts of stool and urine completely lost their viability after 10 days at 28℃, 17 days at 5℃ and 12 hours at -10℃ respectively.
3) The infective larvae which attached to the vegetables were all dead after 4 days at -10℃, 15 days at 5℃ and 22 days at 28℃ respectively.
4) Nearly all infective larvae which were removed after 4-time washing in a water container.
5) In resistance of the infective larvae to temperatures, the larvae preserved in physiological saline solution were all dead after within 1 day at -10℃, 15 days at 5℃, 3 months and 10 days at 28℃, 10 minutes at 50℃ and within 1 minute at 55℃ respectively. But most larvae survived after 30 minutes at 45℃.
6) The solutions, infusions or juices of food-preservative substances such as salt, sugar, acetic acid(vinegar), red pepper, garlic, ginger, Welsh onion (stoneleek), mustard and black pepper showed larvicidal effects to the infective larvae in single or combined compositions. The degree of the larvicidal effects of foodpreservative substances were different in some extent by the kind and the concentration of the substances.
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