Frequency and Causes of Life-long Labour Force Loss in Rural Population of Korea / 예방의학회지

This study was conducted on order to observe some descriptive epidemiological findings and causes of life-long labour force loss in the rural population of Korea, and to consider, on the basis of these observations, some principles of the necessary control measures. The total number of subjects in the study was 27,172, all family members of 4,174 households. The study population was located in the 81 counties, out of a total of 138 counties, where the college students conducted service activities during the summer of 1974. In each village area where these service activities were conducted, one household per student interviewer was randomly selected. Student interviewers were instructed on the contents of the questionnaire prior to the survey. The main contents of the questionnaire form included address, name, sex and age of each family members, and present life-long labour force loss, if any, of each family member. In cases of current labour force loss, the age of onset and causes were recorded. Of the total households surveyed, 8.9% had family members(1-4 in number) with life-long labour force loss. Of the total persons surveyed, the crude prevalence rate for life-long labour force loss was 15.1 per 1,000; and the age-standardized prevalence rates for male and female were 16.3 per 1,000 and 13.4 per 1,000, respectively. The rates, in both sexes, were gradually increased as the agee were increased. The prevalence rates per 1,000, in order, for life-long labour force loss by the causes were 10.2 for senility, 2.4 for impairment of extremities, 1.2 for chronic diseases of internal organs, 0.5 for other conditions of musculoskeletal system, 0.4 for blindness in both eyes, 0.2 for impairment of spine, 0.2 for psychoses, and 0.1 for epilepsy. Among them the causes of impairment of extremities were stroke, poliomyelitis, accidents, arthritis and injury due to was operation, in that order of higher relative frequency. The frequency ratios by age of onset were also observed by the causes and sex.

Investigation of a Staphylococcal Food Poisoning Outbreak Among School Children / 예방의학회지

There was an outbreak of food poisoning on the 17 October, 1970 among the primary school children who came from a rural area, Yeongi-gun, Choongcheongnam-do to Seoul City on an educational trip. Of the 199 children participating in the trip, 149 cases of food poisoning developed a 74.9% attack rate. The acute onset of symptoms, of abdominal pain, diarrhea, vomiting and headache which occurred 1-5 hours after eating their lunch suggests that the outbreak was due to staphylococcal food poisoning. The common source of food was identified as the lunch packed in a chip-box which were eastern on October 17 during the trip. Most probable kind of food of the lunch as the cause was the flavoured fish paste. The lunch were prepared at restaurant A in Seoul City. One of the personnel of the restaurant had a unhealed cut wound on the third finger tip of the left hand, from which it was considered that the food was contaminated with Staphylococcus during preparation. The chance of multiplication of staphylococcus to produce enterotoxin in the food might be existed during flavouring the food with some degree of heat, an also during about 10 hours elapsed before serving the food after preparation.

Investigation of a Staphylococcal Food Poisoning Outbreak Among School Children / 예방의학회지

There was an outbreak of food poisoning on the 17 October, 1970 among the primary school children who came from a rural area, Yeongi-gun, Choongcheongnam-do to Seoul City on an educational trip. Of the 199 children participating in the trip, 149 cases of food poisoning developed a 74.9% attack rate. The acute onset of symptoms, of abdominal pain, diarrhea, vomiting and headache which occurred 1-5 hours after eating their lunch suggests that the outbreak was due to staphylococcal food poisoning. The common source of food was identified as the lunch packed in a chip-box which were eastern on October 17 during the trip. Most probable kind of food of the lunch as the cause was the flavoured fish paste. The lunch were prepared at restaurant A in Seoul City. One of the personnel of the restaurant had a unhealed cut wound on the third finger tip of the left hand, from which it was considered that the food was contaminated with Staphylococcus during preparation. The chance of multiplication of staphylococcus to produce enterotoxin in the food might be existed during flavouring the food with some degree of heat, an also during about 10 hours elapsed before serving the food after preparation.

The Present Status and a Proposal of the Prospective Measure for Parasitic Control in Korea / 예방의학회지

The present status of control treasures for public health important helminthic infections in Korea was surveyed in 1969 and the following results were obtained The activities of parasitic examination and Acaris treatment for the positives which were done during 1966 to 1969 were brought in poor result and could not decrease the infection rate. It is needed to improve or strengthen the activities. The mass treatment activities for paragonimiasis and clonorchiasis in the areas which were designated by the Ministry of Health were carried out during 1965 to 1968 with no good results in decrease of estimated number of the patients. There were too many pharmaceutical companies where many kinds of anthelmintics were produced. It may be better to reduce the number of anthelmintics produced and control the quality. The human feces, the most important source of helminthic infection, was generally not treated in sanitary ways because of the poor sewerage system and no sewage treatment plant in urban areas and insanitary latrines in rural areas. The field soils of 170 specimens were collected from 34 areas out of 55 urban and tourist areas where night soil has been prohibited by a regulation to be used as a fertilizer, and examined for parasites contamination with the result of Ascaris egg detection in 44%. Some kinds of vegetables of 64 specimens each from the supply agents of parasite free vegetables and general markets were collected and examined for parasites contamination with the results of Ascaris egg detection in 25% and 36% respectively. The parasite control activities and the ability of parasitological examination techniques in the health centers of the country were not satisfactory. The budget of the Ministry of Health for the parasite control was very poor. The actual expenditure needed for cellophane thick smear technique was 8 Won per a specimen. As a principle the control of helminthic infections might be led toward breaking the chain of events in the life cycle of the prasites and eliminating environmental and host factors concerned with the infections, and the following methods may be pointed out. 1) Mass treatment might be done to eliminate human reservoirs of an infection. 2) Animal reservoirs which are related with human infections might be eliminated. 3) The excretes of reservoirs, particularly human feces, should be treated in sanitary ways by the means of sanitary sewerage system and sewage treatment plant in urban areas and sanitary latrines such as waterborne latrine, aqua privy and pit latrine in rural areas. The increase of national economical development and prohibition of the habit of using night soil as a Fertilizer might be very important factors to achieve the purpose. 4) The control of vehicles and intermediate hosts might be done by the means of prohibition of soil contamination with parasites, food sanitation, insect control and snail control. 5) The improvement of insanitary attitudes and bad habit which are related with parasitic infections might be done by the means of prohibition of habit of using night soils as a fertilizer, and improving eating habits and personal hygiene. 6) Chemoprohylactic measure and vaccination may be effective to prevent the infections or the development of a parasite to adult in the bodies were invaded by parasites. Further studies and development of this kind of measures are needed.

Experimental observations on water contamination by the second intermediate host infected with Paragonimus westermani

In this study the authors observed the status of water contamination by crayfish, Cambaroides similis, either alive or dead infected with Paragonimus westermani. The crayfish used as materials were infected heavily with metacercariae of Paragonimus westermani. The live crayfish were kept in water for a long time, and then the sediments of the water were examined to find out whether or not the liberation of the metacercariae from the body of the crayfish had caused contamination of the water with metacercariae. Killed crayfish were also preserved in water for some time. Physical stimuli in terms of mederate degree of shaking were added to the preserved water once a day and half amount of the water was replaced with tapped water of same temperature everyday. Status of the decay of the crayfish, liberation of the metacercariae from the body of the crayfish or contamination of the preserved water by the metacercariae, and numbers of metacercariae harboured in the body of the crayfish were examined everyday. The fate of the metacercariae liberated from the crayfish into water was also observed. Status of the decay of the crayfish, liberation of the metacercariae from the body of the crayfish or contamination of the preserved water by the metacercariae, and numbers of metacercariae harboured in the body of the crayfish were examined everyday. The fate of the metacercariae liberated from the crayfish into water was also observed. The results of this study can be outlined as follows: No metacercaria was detected in the water which contained live crayfish infected with Paragonimus westermani. The preserved water with dead or killed crayfish was found to be contaminated by the metacercariae of Paragonimus westemani, which had been caused by the decay and dispersion of the flesh of the crayfish The liberated metacercariae survived for 10 days in the water at 21-27 C. The liberated metacercariae were found to be sinking into water of s.g. 1.000 with average velocity of 35.8 cm per minute.

Study on the status of helminthic infections in Koreans

This study was undertaken to evaluate the present status of intestinal helminthic infections in Koreans, from April 1967 through May 1969. The nationwidely collected stool specimens and scotch-tape anal swabs from primary schoolchildren, middle school students, draftees to army recruitment camp, soldiers and inhabitants of various parts of Korea were examined. The methods employed were Kato's cellophane thick smear technique and formalin-ether sedimentation technique in 40,581 for the prevalence rate of various intestinal helminths, scotch-tape anal swab technique in 8,585 for the prevalence rate of Enterobius vermicularis and by Stoll's dilution egg counting technique in 1,174 for the evaluation of the worm burden of some helminths. The results are as follows. Result of stool examination: The positive rate of intesinal helminthes of any kind was 90.5% among 40,581. In rural people, it was 92.3% in average in contrast to 85.0% in Seoul inhabitants. The infection rate of A. lumbricoides in 40,581 was 58.2%. It was higher in rural people 62.9% than in Seoul inhabitants and highest in 5-9 year-old group by age. The infection of Trichocephalus trichiurus showed the highest prevalence rate in Koreans and it was 74.5%. No remarkable difference was observed between Seoul inhabitants(72.2%) and rural people(75.2%). The tendency of higher prevalence rate with the older age group was observed. The infection rates of hookworm and Trichostrongylus orientalis in 40,581 examinations by cellophane thick smear were 5.1% and 5.8% respectively. But in 4,949 examinations for which refined cellophane thick smear technique and formalin-ether sedimentation technique were employed, the infection rates were turned out 17.6% in hookworm and 15.9% in T. orientalis. Although rural people showed higher infection rate of hookworm(18.8%) than Seoul inhabitants(13.8%), the reverse was true in T. orientalis infection rate(14.5% : 20.3%). Both kinds of infections were tend to be higher with the increase of age. The infection rates of Clonorchis sinensis and Metagonimus yokogawai were 4.7% and 0.4% respectively. In both kinds of infections male showed higher infection rates than female and the tendencies of higher infection rate in the older age group were observed. The provinces which showed the higher infection rate of C. sinensis were South and North Kyongsang Do and North Cholla Do, all of which are provinces of southern part of Korea. Some endemic foci of M. yokogawai were noticed in South Kyongsang Do and South Cholla Do. The infection rate of Taenia spp. by applying only the stool examination was 0.7% throughout the survey. No sex difference in infection rate of Taenia spp. was noticed, but in older age group it was increased. Cheju Do, the island of extreme southern part of Korea seemed the most endemic area and South and North Cholla Do were next in ranking of Taenia infection rate. The ova of Hymenolepis nana were observed in 0.2% and all of them were under the age of 20 except only one caes. The infection rate seemed higher in female (0.3%: 0.1%). No geographical difference was noticed except 1.1% of schoolchilderen and students of Cheju Do. Result of Scotch-tape anal swab technique for E. vermicularis infection. The infection rate of E. vermicularis in 8,585 urban and rural schoolchildren and rural inhabitants was 46.6%. Female (57.9%) had definitely higher infection rate than male (41.4%). The infection rate was significantly higher in rural people than Seoul schoolchildren. The exteme example was 79.7% in schoolchildren of South Cholla Do. Result of worm burden examination by Stoll's dilution egg-counting technique: Among 1,174 examinations, countable(E.P.G.> 100) cases of A. lumbricoides were 745(63.5%) and the mean E.P.G. was 9,723. The mean E.P.G. in Seoul inhabitants was 5,835 in contrast to 10,820 in rural people. The age group of 5-9 showed the heaviest mean E.P.G., 11,337. 70.6% of 745 cases were less than 10,000 in E.P.G. which means light infection. Countable cases by Stoll's technique for T. trichiurus ova were 63.5% and mean E.P.G. was 649. No difference between Seoul and rural inhabitants was observed. Grade I and II in which E.P.G. is less than 5,000 involve 99.3% of positive cases. 91 cases (7.9%) in 1,174 were positive for hookworm ova by Stoll's technique and mean E.P.G. was 501. All cases were in Grade I and II which were less than 5,000 in E.P.G. Trichostrongylus orientalis was positive only in 25 cases (2.1%) by Stoll's technique and mean E.P.G. was 340. No cases were found to have more than 5,000 in T. orientalis E.P.G. The mean E.P.G. of Clonorchis sinensis among the referred cases of clonorchiasis to Department of Parasitology, Seoul National University, was 9,416. On the other hand mean E.P.G. of C. sinensis was 21,376 among cases in the hyperendemic area of Kimhae, South Kyongsang Do, and 3,073 in cases from other various localities. Among referred clonorchiasis cases to our Department, 21.6% were turned out to have the E.P.G. more than 10,000. The cases who have the E.P.G. more than 10,000 in hyperendemic area, Kimhae were 40.7% and in other various localities were 9.1%

An experimental study on uptake of Cr(51) tagged red blood cells to Paragonimus westermani in definitive host

Authors carried out the experimental study to investigate whether the Paragonimus westermani would uptake the blood in the parasitic definitive host, and also tried for the amount and distribution of the blood which would be harbored in a worm body, and so on. Experimental animals used in this study were dogs and cats, and they were infected with metacercariae of P. westermani. Several months later of the infection, Cr(51) tagged red blood cells were administered to each animal, and the animals were sacrificed and autopsy was done after 24 or 48 hrs of the administration. One part of the detected P. westermani adult worms of each animal were bred in Tyrode's solution and the others were killed by fixing in formalin solution. By Well-type scintillation counter, the radioactivities were measured for the alive and killed worms and of the blood of each experimental animal which was collected at autopsy . In conclusion, it was found that P. westermani worms uptake blood in parasitic definitive host, and amount of the blood harboring in a worm of 56 infection-days(size of worm; 4 x 3 x 1 mm) was 0.002 ml, 0.004 or 0.005 ml in 103 infection-days(size of worm: 8 x 5 x 3 mm) and 0.011 ml in 217 infection-days(size of worm: 9 x 7 x 4 mm). Almost of the whole blood uptaked in the worms was distributed in intestine. It was observed that the blood uptaked in the worm body was excreted continuously through the excretory pore, so that the radioactivity could not measured almost completely in cases of 24 hrs-breeding worms.

A Study on the chemotherapy in clonorchiasis. Report 1. An experimental study on chemotherapy with Dithiazanine iodide and Bithionol sulfoxide in clonorchiasis

Authors carried out experimental study on chemotherapy with oral administration of Dithiazanine iodide (D.I.) and Bithionol sulfoxide(B.S.) in rabbit clonorchiasis. And the following result was obtained. In change of the E.P.G (eggs per gram feces) by D.I. administration, it was rather increased in early stage of the administration than prior to administration, and thereafter decreased gradually. In the change of the C.S. worm body by D.I. administration, there was not only prominent change of supporting tissue but also the change of reproductive organ was found. In considering the wormicidal effect of D.I. from detecting rate of survival worms, the effect was slight in group of 100 mg(80 mg/kg) per day dosage, but the effects were very excellent and almost complete by proper times of administration in groups of 200 mg (130 mg/kg) per day or higher dosage. But the side effect and intoxication sign of D.I. were appearent in groups of 200 mg or higher dosage. By B.S. administration, E.P.G. was decreased gradually. In changes of the C.S. worm body by B.S. administration, prominent inhibitory chnnge was seen in egg formation ability. Slight wormicidal effect of B.S. was observed in groups of 140 mg (100 mg/kg) per day or higher dosage. Side effect and intoxication sign of B.S. were found little in groups of 140 mg or lesser dosage.

Comparison of detection rate of some trematodes' eggs by combined technique of formalin-ether sedimentation and zinc sulfate flotation

Combined technic of formalin-ether sedimentation and zinc sulfate flotation was carried out to compare the detection rate of Paragonimus eggs in feces between formalin-ether sedimentation technic and zinc sulfate centrifugal flotation, using the feces of cat infected with Paragonimus westermani for former and intestinal contents of rabbit infected with Metagonimus yokogawai for latter. And following results were obtained. Zinc sulfate method was highly excellent in detection of Paragonimus eggs in feces, on the contrary, formalin-ether technic was very poor, and the other hand, formalin-ether technic was highly excellent in detection of Metagonimus eggs, on the contrary, zinc sulfate method was extremely poor. The time which was needed in carrying out the combined technic was shorter than the cumulative time of each of the formalin-ether technic and zinc sulfate method was. Author emphasizes that the combined technic may be used in general parasitic examination of feces, so that excellent results would be obtained in detection of all kinds of helminthic ova and protozoa.

Field survey on the freshwater snails in Cheju Province(Quelpart lsland), Korea: Especially on presence or not of Parafossarulus manchouricus

The question of infectivity and prevalence of Clonorchis sinensis in Cheju province (Quelpart Island) was arisen to authors since the several surveys on the endemic diseases were performed in this island. Therefore, authors decided to solute this question. Then the survey on the possible second intermediate host of Clonorchis sinensis was performed and reported already with negative finding. At present time, authors carried out the collection of all kinds of fresh-water snails through all areas of this island, to confirm the presence or not of Parafossarulus manchouricus, the only first intermediate host of Clonorchis sinensis in Korea . And the following results were obtained. The fresh-water snails collected in the survey were Semisulcospira libertina Gould and Lymnaea ollula Gould. Parafossarulus manchouricus Bourguigant was not collected in this island. It is confirmed that the Clonorchis sinensis can not be prevalent in this island.

Studies on paragonimiasis in Ko-Hoong County, Korea (Report 1.). An epidemiologic survey for human paragonimiasis by the use of intradermal screening test

Authors carried out the survey for human paragonimiasis in Ko-Hoong County, Chun-Nam Province, Korea from July to September 1964 by the use of intradermal screening test with Veronal buffered saline antigen. Eight myuns (village) out of 13 myuns of this county were selected for the survey, regarding balanced selection. The number of 2,916 primary school children of high class and 764 residents of all age groups in these areas were examined (total 3,680; male 1,961; female 1,719). The following results were obtained in this survey. As a whole, 20.1 per cent of the examiners showed positive reaction, with sexual difference of 20.9 per cent in male and 19.1 per cent in female. In regional differences of positive rate, the highest rate(50.1 per cent) was showed at Po-Doo myun and lowest rate(3.6 per cent) was showed at Do-Yang myun. In age group, the highest positive rate was showed in 16 to 20 age group (46.7 per cent). In regional comparison of paragonimiasis infectivity of whole nation (province and county), Ko-Hoong County as nearly same as the Hea-Nam County, Chun-Nam Province follows next of Cheju Province, the highest prevalance area of paragonimiasis in Korea, in concentration of prevalence of paragonimiasis.