No abstract available.
Fishes* ; Parasitic Diseases*

No abstract available.

We examined stool specimens of the residents in the emigration camp in Tijuana, Mexico for helminth eggs or protozoan cysts with formalin-ethyl acetate concentration method in February and July 1992. Out of 92 examined samples, number of positive was 49 (53.3%). While number of cumulative positive was 66 (71.7%). Cysts of Entamoeba coli (29.3%) Giardia lamblia (9.8%), Entamoeba histolytica (7.6%), and eggs of Taenia spp. (6.5) were most frequently observed. Filtered water supply and chemotherapy were required in this camp.
Adolescent ; Adult ; Aged ; Animals ; Child ; Child, Preschool ; Concentration Camps ; *Emigration and Immigration ; Eukaryota/isolation & purification ; Feces/parasitology ; Female ; Helminths/isolation & purification ; Humans ; Intestinal Diseases, Parasitic/*epidemiology/parasitology ; Male ; Mexico/epidemiology ; Middle Aged

The present study was performed to investigate the infection status with helminth in a group of feral cats in Korea. More than 29 helminth species including adults or eggs were detected in visceral and fecal samples of the examined cats. Among these were a host of nematodes, including toxocarids, Ancylostoma sp. and the larva of Anisakis simplex; trematodes, including Clonorchis sinensis, Paragonimus westermani, Eurytrema pancreaticum, Pharyngostomum cordatum, Metagonimus spp., Heterophyes nocens, Pygidiopsis summa, Heterophyopsis continua, Stictodora fuscata, Stictodora lari, Acanthotrema felis, Stellantchasmus falcatus, Centrocestus armatus, Procerovum varium, Cryptocotyle sp., Echinostoma revolutum, Echinostoma hortense, Echinochasmus japonicus, Stephanoprora sp., Plagiorchis muris, Neodiplostomum sp. and diplostomulum. We also detected a variety of cestodes, including Spirometra erinacei, Taenia taeniaeformis and unidentified species of tapeworm. We also found examples of the acanthocephalan, Bolbosoma sp. In our assessment of the stools, we detected at least 12 species of helminth eggs. These findings confirmed that feral cats in Korea are infected with a variety of helminth parasite species. Furthermore, among the helminths detected, E. pancreaticum, S. fuscata, S. lari, A. felis, S. falcatus, C. armatus, P. varium, Cryptocotyle sp., E. revolutum, E. japonicus, Stephanoprora sp., P. muris, Neodiplostomum sp. and Bolbosoma sp. represent helminth fauna which have not been reported previously in feral cats in the Republic of Korea.
Acanthocephala/*isolation & purification ; Animals ; Cat Diseases/*parasitology ; Cats/*parasitology ; Cestoda/*isolation & purification ; Feces/parasitology ; Helminthiasis, Animal/*parasitology ; Korea ; Nematoda/*isolation & purification ; Parasite Egg Count ; Species Specificity ; Trematoda/*isolation & purification

Surface ultrastructure of Parvatrema timondavidi developmental stages was studied using a scanning electron microscope. The metacercariae were collected from the marine clam, Tapes philippinarum, and juvenile and worms adult were recovered at 1, 2, 3, and 7 days after experimental infection of mice. The metacercariae had a large oral sucker and characteristic lateral projections. Around the lip of the oral sucker many type I and type II sensory papillae were observed, and type III papillae were located symmetrically on the medial side of the lateral projection. Numerous type I papillae were grouped around the genital pore. The tegumental spines were distributed over the worm surface except the lip of the sucker and genital pore. The 1-day old worm had a well-developed ventral sucker, with 6 type II sensory papillae on its outer surface and another 6 type I papillae on the inner side, Two small type I papillae were seen on the anterior side of the ventral sucker. The genital pore was and 15 type I papillae were grouped around it. The 2-, 3-, and 7-day worms revealed that as they grew to be adults, the spine tips became multipointed, the genital pore formed a genital atrium, and the cytoplasmic process became well differentiated. In 2- and 3-day worms 10 type II papillae encircling the lip of the oral sucker, and additional 4 papilled at the dorsal side of 4 dorsal type II papillae were a characteristic feature. The distribution pattern of sensory papillae around the oral sucker and genital pore, and 2 type I papillae on the anterior side of the ventra sucker, was so peculiar in P. timondavidi, that they seem to be useful keys for taxonomic differentiation from other gymnophallids.
parasitology-helminth-trematoda ; Parvatrema timondavidi ; surface ultrastructure ; scanning EM, sensory papilla ; spine ; cytoplasmic process

This study was undertaken to figure out the basic patterns of the frequency distribution of Ascaris lumbricoides in rural Koreans and to find out the effects of changing endemicity on the frequency distribution pattern. Total 853 cases in 6 areas were surveyed from November 1975 to February 1978. The mean ova positive rate was 33.1% and in the range from 23.9 to 66.7% by the surveyed unit. From the analyses of the collected data, the following results were obtained. The overdispersion pattern of worm burden per case was mathematically fitted both to the theoretical values of the negative binomial and Poly-Eggenberger distributions. However, when "0" and lower burden cases were considered, the better fitness was observed in the negative binomial than in Polya-Eggenberger distribution. Although the endemicity of Ascaris is changed, the relative frequency of the lower burden cases is rather constant. The false negative rate of stool examination and unfertilized ova passers in the population were not changed significantly according to the endemicity. And the rate of unfertilized ova passers in infected cases was increased when the endemicity was lowered. From the above results, it is concluded that the overdispersed frequency distribution pattern of Ascaris in an endiemic area is changed by the relatively rapid decrease of heavy burden cases and increase of non-infected cases according to the lowered endemicity due to the impact of the control.
parasitology-helminth-nematoda ; Ascaris lumbricoides ; egg ; epidemiology ; frequency distribution

In Ascaris lumbricoides infection, the faecal examination, undertaking for ova detection, is not always diagnostic. It is just because some of the infected cases has Ascaris worm(s) which do not produce eggs. In the present study, the authors attempted to analyse quantitatively the egg discharging patterns in Ascaris infected cases with low worm burden. The following results were obtained: In 1,861 Ascaris worms collected from 853 cases, the sex ratio was 1: 0.74 (female: male). Sex combinations in each burden of case were always fitted with theoretical values from the binomial distribution; (m+f)(n)= (0.426+0.574)(n). In each worm burden, their sex combination indicated different egg discharging patterns; false negative cases, unfertilized ova passers and fertilized ova passers. When the relative frequency of the above three egg discharging patterns was plotted to worm burden per case, a definite relationship was found. The cases with six or more worms have nil probability to be false negative case or unfertilized ova passer. Out of 853 cases, we found 129 false negative cases. The collected worms from 125 cases were morphologically analysed. It was found that 52% of them were infected with only male worm(s) and 24% were infected with young female worm(s). And in 8.8%, old female(s) with empty uterus were infected. The cause of 15.2% was remained unexplained, even though the collected worms were scrutinized.
parasitology-helminth-nematoda ; Ascaris lumbricoides ; egg ; epidemiology

A status survey on Metagonimus yokogawai infection along the Tamjin River basin, South Cholla Do, Korea was conducted from September to November 1977. The snail intermediate host, Semisulcospira sp., the fish host, Plecoglossus altivelis and the inhabitants in three villages in Jangheung and Kangjin Guns were examined for detection of this trematode infection respectively. The results could be summarized as follows: Out of 452 snails, Semisulcospira sp., 105 (23.2%) were found positive for rediae and/or cercariae of M. yokogawai in Jangheung Gun. All of 20 sweetfishes, P. altivelis were infected with metacercariae of M. yokogawai and the mean number per fish was 15,688 and per gram of fish muscle, 234. Out of 606 inhabitants in three villages, 160(26.4%) persons were found infected with M. yokogawai and the mean E.P.G counts per infected cases were 2,078. Sixty cases (9.8%) were positive for ova of Clonorchis sinensis with mean E.P.G., 846, frequently mixed-infected with M. yokogawai. From the above results, it was turned out that the Tamjin River basin is one of the endimic foci of metagonimiasis in Korea. The relatively low infection rate of human host in spite of much higher infection of intermediate hosts were considered to be due to the less population of sweetfishes in the Tamjin River than in the Sumjin River basin.
parasitology-helminth-trematoda ; Metagonimus yokogawai ; epidemiolgy

This study was undertaken to estimate the reinfection incidence of Ascaris lumbricoides after biannual blanket mass chemotherapy and to figure out the characteristic seasonal fluctuation pattern in a Korean rural village. A total of 612 residents from 4 Ri's of Hwasung Gun, Kyunggi Do, Korea was selected and divided into 6 groups according to hamlets, each of which consisted of about 100 inhabitants. Each group received blanket biannual mass chemotherapy with 10 mg/kg of pyrantel pamoate respectively in each month, during the period from April 1977 to September 1978 (Group A-April and October 1977 and April 1978, Group B-May and November 1977 and May l978, and so on). Beforehand Ascaris infection status was evaluated by examining eggs and worms expelled exactly after the first mass chemotherapy checked during the first 6 months and the reinfection incidences were estimated in follow-up examinations during next l2 months by the above two kinds of methods and by detection of young Ascaris positive cases. Young Ascaris was defined as worm shorter than l3 cm and lighter than 500 mg and considered to have introduced to human host during the period from the previous 2 months to 2 weeks. The results were summarized as follows: Beforehand infection rate with Ascaris were 42.3 percent (34.4-50.6 percent by group) by egg detection and 46.2 percent (36.2-51.9 percent by group) by worm detection methods in average. Number of worms per infected case was 2.7 (1.5-4.2 by group) in average. Reinfection rates estimated by egg detection ranged from 8.0 to 3l.5 percent (l6.9 percent in average) in the first follow-up period and from 14.0 to 20.0 percent (l7.5 percent in average) in the second follow-up. Seasonal fluctuation was found marked and there were roughly two peaks, of which the larger appeared from February to March and the smaller from August to September. Reinfection rates by worm detection method ranged from 20.6 to 34.9 percent(25.7 percent in average) and from 14.3 to 21.9 percent (19.6 percent in average) in respective follow-up examinations. Seasonal fluctuation was also observed and the peak incidence appeared one month earlier than those made by egg positive conversion. Number of worms per infected case decreased to 1.6 in average in both follow-up. Young Ascaris detection rates ranged from 6.0 to 12.9 percent (9.4 percent in average) and from 2.3 to 5.8 percent (3.8 percent in average) in respective follow-up. Seasonal fluctuation was also observed. From January to February, the positive rates were up to 12.9 percent and 12.7 percent respectively, which formed the higher peak. Lower one was observed during July to August. From the above results, the actual time of Ascaris reinfection were November to December for the higher peak and May to June for the lower one in Korean population. Pickled vegetable was suggested as a most probable source of Ascaris reinfection during late autumn to winter season.
parasitology-helminth-nematoda ; Ascaris lumbricoides ; reinfection ; epidemiology

The efficacy of reduced single doses of mebendazole against Ascaris lumbricoides infection was evaluated by cellophane thick smear and egg counting techinques, in two rural populations from December 1977 to March 1978. Total 191 infected cases were divided into five dose groups; 100 mg single dose, 200 mg single dose, 300 mg single dose, 400 mg and 600 mg in repeated doses. The cure rate of mebendazole in the treatment of Ascaris infection was remarkably high and satisfactory in every dose groups. The egg reduction rates were all over 98 percent in every dose groups. Side effects were observed during the treatment, mainly mild and transient gastrointestinal troubles, and not exacerbated by the increase of doses upto 300 mg in single dose. Above results confirmed that in case of mass chemotherapy of Ascaris infection, 100 mg or 200 mg of single dose treatment is sufficient to achieve the economic and acceptable method of treatment.
parasitology-helminth-nematoda ; Ascaris lumbricoides ; chemotherapy-mebendazole