Experimental infection with Taenia saginata (Poland strain) in Taiwanese pigs

Two 22-day-old Landrace-Small Ear Miniature (L-SEM) pigs, five 45 to 66-day-old Small Ear Miniature (SEM) pigs, and one 16-day-old Holstein calf were each fed 1000, 3000 or 10,000 Taenia saginata (Poland strain) eggs respectively and killed 34-77 days after inoculation. Four of the five SEM pigs and the Holstein calf were susceptible to this parasite. However, two L-SEM pigs and one SEM pig remained negative. The cysticerci recovery rates for the SEM pig and Holstein calf were 36% and 3%, respectively. All cysticerci from the SEM pigs were found in the livers, more in the parenchyma (89%) than on the surface (11%). Only eleven cysticerci in two SEM pigs were mature and the remainder were either immature, degenerated or calcified. The cysticerci in the calf were distributed throughout the body: leg muscles (248), heart (27), tongue (17), intercostal muscles (14), diaphragm (5), kidney (1) and liver (1). Most (299) of the cysticerci were mature, one was immature and 13 were degenerated or calcified. The length, width, diameter of the protoscolex and sucker of the cysticerci from the calf were larger than those from the SEM pigs. However, the diameter of the rostellum of the latter was slightly larger than the former. Hooklets were not found on any mature cysticercus recovered. The results of the present study provide evidence that the SEM pig can be used as an experimental intermediate host for T. saginata.

Clinical manifestations of taeniasis in Taiwan aborigines

From 1974 to 1989, a total of 24,500 aborigines at 67 villages in ten mountainous districts/towns in Taiwan were examined for the Taiwan Taenia infection and 12% were found to be infected. In order to define the clinical manifestations of taeniasis caused by the Taiwan Taenia, 1661 aborigines in ten mountainous districts were surveyed. The overall clinical rate was 76%. The clinical rate was highest among Atayal aborigines (81%), followed by Bunun (66%) and Yami (61%) aborgines and lowest among Ami aborigines (40%). Among 1153 infected people, 10% had passed gravid segments in the faeces for less than 1 year, 24% for 1-3 years, 17% for 4-5 years, 23% for 6-10 years, 16% for 11-20 years, 7% for 21-30 years, and 3% over 30 years. Twenty-six occurrences of gastrointestinal and neurological symptoms were reported by 1258 infected persons. Passing proglottides in the faeces (95%) was the most frequent sign, followed by pruritus ani (77%), nausea (46%), abdominal pain (45%), dizziness (42%), increased appetite (30%), headache (26%), etc.

Studies of taeniasis in Taiwan. XIV. Current status of taeniasis among Yami aborigines on Lanyu Island, Taitung County, southeast Taiwan

In December 1989, 1,457 Yami aborigines in six villages on Lanyu District (Lanyu Island), Taitung County, Southeast Taiwan, were examined by questionnaire and demonstration of the proglottides or by scotch tape perianal swab technique for taeniasis. The overall infection rate was 5%. The highest rate was found at Yehyin (8%) and the lowest at Yujen (2%). However, the rate did not significantly differ among the villages. The infection rate peaked in the 51-60 yr age group (15%) and the lowest rate was observed in the 11-20 yr age group (less than 1%). No infection was found in the 21-30 yr age group. The infection rates of men and women were similar (5%). Twenty-one per cent of 304 families was found to include one or more infected members and a family with five infected person was observed at Yehyin. The infection rate of taeniasis on Lanyu Island decreased from 16% in 1984 to 5% in 1989. However, 51 persons who were negative in 1984 were positive at present, 26 were found to be positive in both studies, and 216 (12 died) who were positive in 1984 were now negative. These results indicate that the Yami people still eat raw meat and viscera of animals.

Evaluation of efficacy of four pediculicides against head louse (Pediculus capitis) infestation

To evaluate the efficacy and to determine the minimum effective dosage of four pediculicides against head louse infestation, as well as to select a safe, effective, practical, and cheap agent, 1,657 infested school children in 25 primary schools in Szu-Hu, Kou-Hu, and Ku-Keng Districts of Yunlin County were treated and 1,611 of them were examined. The overall cure rate was 73% and the rate for boys (84%) was higher than that for girls (71%). The cure rate of Nix (permethrin 1%) cream rinse was 81%. The cure rate for single dosages of 1, 2, 3 and 4 cases/tube (56 gm/tube) was 87%, 83%, 81% and 71%, respectively. The cure rate of Para aerosol (bioallethrine 0.66%) was 78%. The cure rate for single dosages of 30 and 40 cases/tube (90 gm/tube) was 87% and 70%, respectively. The cure rate of Prioderm (malathion 1%) cream shampoo was 64%. The cure rate for single dosages of 10, 15 and 20 cases/tube (40 gm/tube) was 74%, 71% and 52%, respectively. The cure rate of Delice (1% gamma benzene hexachloride) was 71%. The cure rate for single dosages of 5 and 10 ml/case was 64% and 76%, respectively. Of the 226 infested girls, 181 (80%) were found to be infested with 1-10 head lice, 33 (15%) with 11-50 lice, 7(3%) with 51-100 lice and 5 (2%) with over 100 lice. Of the 2,160 head lice collected, 1,788 (83%) were nymphs, 284 (13%) females, and 88 (4%) males. The mean number of head lice in each infested girl was 10 (range 1-137). The low cure rates obtained in the present study may be due to the fact that many school girl & have long hair. In comparison, Nix had the highest cure rate (81%) but the highest price (NT$ 120/case). The cure rate and price of Para aerosol (78%, NT$ 7.2/case) and Delice (71%, NT$ 16.7/case) came next. Prioderm (64%, NT$ 10.0/case) had the lowest rate and a slight offensive smell. Preliminary trials show that based on the cost-effectiveness, Para aerosol is best in head louse infestation control.

Experimental infection of Philippine Taenia in domestic animals

In the present study, six 34-44-day-old Small-Ear-Miniature pigs and one 14-day-old Holstein calf were each fed 10,000 Philippine Taenia eggs and sacrificed 27-43 days after inoculation. The infection rate was 100% for both pigs and calf with cysticerci recovery rates of 11 and 6%, respectively. A total of 6431 cysticerci were recovered only from the livers of the six pigs and 597 only from the liver of the calf; more occurred in the parenchyma (pigs 75%, calf 83%) than on the surface (pigs 25%, calf 17%). Mature cysticerci were found in four of the six pigs. A total of 317 cysticerci recovered from the pig livers were mature and the rest were either immature (926), degenerate or calcified (5188). All 597 cysticerci recovered from the liver of the calf were degenerate or calcified. Measurements of length, width, diameter of protoscolex, rostellum, and sucker and hooklet pattern indicated that Philippine Taenia is very similar to Taenia from Taiwan, Korea, Indonesia and Thailand and very different from classical T. saginata and T. solium.

Eating habits of East Asian people and transmission of taeniasis

In order to understand the role of raw meat and viscera eating habits in the transmission of taeniasis in Asian countries, 1502 infected aborigines in ten mountainous districts/towns of six counties in Taiwan, 58 infected persons in two villages on Cheju Island, Korea, and 97 cases in Ambarita District on Samosir Island, North Sumatra, Indonesia were studied during the field surveys. All infected Taiwan aborigines had the habit of eating raw meat and viscera of wild and/or domestic animals. Among these aborigines, 73% ate wild boar, 66% flying squirrel, 65% wild goat, 56% muntjac, 49% wild rats, 46% monkey, 38% hare, 20% civet-cats, 18% weasel, 17% pheasant, 14% squirrel, 4% grouse, 1% deer, 1% snake, less than 1% bamboo partridge, less than 1% frog, less than 1% bear, less than 1% dog, and less than 1% fox. Of the 58 infected persons with Taenia on Cheju Island, Korea, 72% ate raw meat and/or viscera of pig and cattle, 19% raw pork only, and 9% raw beef only. Among 12 infected persons infected with T. saginata-like tapeworms, 7 had eaten raw pork, 2 raw beef and pork and 3 raw pork. Almost all of the 97 cases of taeniasis on Samosir Island of North Sumatra, Indonesia, had eaten only undercooked pork. Eleven of 15 cases were found to be infected with T. saginata-like tapeworms. Eating habits observed suggest an unusual way of transmission of Taenia in East Asia.

Present status of head louse (Pediculus capitis) infestation among school children in Yunlin County, Taiwan

In December 1990, 35 children in one kindergarten; 7,870 children in twenty-six primary schools and 2,657 students in three junior high schools in Kou-Hu, Ku-Keng and Szu-Hu Districts in Yunlin County, Taiwan, were examined by naked eye observation (NEO) for head louse infestation. The overall infestation rate was 16%. The infestation rate was highest in Kou-Hu (25%) and lowest in Ku-Keng (8%). The rate was higher among primary school children (21%) than among junior high school students (2%). The infestation rate of girls (34% in primary school children and 4% in junior high school students) was higher than that of boys (9%, less than 1% respectively). Among the primary school children the rate was highest in girls in grade 5 (39%) and boys in grade 4 (14%). The lowest rates were in girls in grade 6 (27%) and in boys in grades 5 and 6 (6%). In junior high school students, the rate of grade 1 (4%) was higher than those of grade 2 (less than 1%) and 3 (less than 1%).

Poor efficacy of albendazole for the treatment of human taeniasis

In order to evaluate the efficacy of albendazole for the treatment of taeniasis, regimens of 400 mg x 1 day, 800 mg x 2 days, 800 mg x 3 days, 1200 mg x 2 days, and 1200 mg x 3 days were compared. Of 66 cases treated and investigated 7-14 days after treatment, 52 were still expelling proglottids. Three months posttreatment, these cases were re-treated with atabrine at 1.2 g per case for males and 1.0 g per case for females. Fifty-seven patients expelled worms or parts of tapeworms. The nine negatives may represent the number cured by the treatment with albendazole. The cure rates with albendazole for various regimens were up to 50% for 800 mg x 3 days, 1200 mg x 2 days or 1200 mg x 3 days, 14.3% for 800 mg x 2 days, and 0% for 400 mg x 1 day or 800 mg x 1 day. This study shows that albendazole is not very effective in the treatment for taeniasis.

The pig as an intermediate host for Taiwan Taenia infection

Eggs (1000-100,000/animal) of Taiwan Taenia were inoculated per os into 14 Small-Ear-Miniature (SEM), 19 Landrace-Small-Ear-Miniature (L-SEM), and 5 Duroc-Yorkshire-Landrace (DYL) pigs. These animals were sacrificed 7-107 days after infection. Thirty-four pigs were found to be infected with Taiwan Taenia cysticerci and the infection rates of SEM, L-SEM, and DYL were 86%, 89% and 100% respectively. The cysticerci recovery rates of SEM, L-SEM and DYL pigs were 27.2%, 1.7% and 0.27% respectively. Cysticerci were recovered only from the livers and none were found in muscles, viscera or other parts of the carcasses. More cysticerci were located in the liver parenchyma (71%) than on the liver surface (29%). Taiwan Taenia cysticerci were smaller than those of classical T. saginata or T. solium. Moreover, Taiwan Taenia cysticerci had 2 rows of rudimentary hooklets on the scolex. The results of this study indicate that young pigs are good intermediate hosts for Taiwan Taenia and that the SEM pig is a satisfactory host for experimental studies with this tapeworm. These results were similar to other studies with different geographic strains of the T. saginata-like tapeworm in the Far East. These strains appear to be the same and possibly a new species.

Prevalence of taeniasis and enterobiasis among aboriginal children in mountainous areas of Taiwan

Children numbering 6,197 were tested for taeniasis. Those children were examined from May, 1981 to July, 1989. Sixty one primary schools, in eight mountainous districts provided the test group of children. The method used in these tests was the Scotch tape perianal swab. The overall infection rate of taeniasis was 1%. A total of 6,667 children were also examined for enterobiasis and the infection rate was 10%. There was no significant difference in the rate of taeniasis and enterobiasis by sex. The infection of taeniasis was highest in Tatung District (3%), Ilan County. However, there was no significant difference among the rates by district. The prevalence of enterobiasis was highest in Jenai District (17%), Nantou County and lowest in Lanyu District (2%), Taitung County. Taeniasis was not found among non-aboriginal school children, while 3% of aboriginal school children were infected with Taenia. However, the infection rate of Enterobius vermicularis among non-aborigines (39%) was much higher than that among aboriginal children (5%). These findings indicate that aboriginal children still eat raw meat and viscera of wild animals and acquire Taenia infection.

Efficacy of niclosamide against aboriginal taeniasis in Taiwan

The present field trial attempts to test the efficacy of niclosamide by a modified chemotherapeutic schedule to collect the purged stool samples consecutively to search expelled worms. Nineteen patients with taeniasis were given 1 gm of niclosmaide with 3 gm sodium bicarbonate twice at 30-minute interval, then purgative was administered. The patients were allowed only fluid meal or fruit juice before treatment. In all, 33 worms (11 with scolex, 22 without), 17 strobilae and 247 segments were collected from consecutive purged stools. The scolex recovery rate was 33%. After taking the purgative, 5 female patients showed side-reactions (nausea, vomiting and dizziness) which were mild and transient. Two months after the treatment, 14 patients were still passing strobilae and/or proglottides in the stools but 5 were not. Four months after the treatment, only 3 cases were still passing strobilae and/or segments in the stools showing a cure rate of 84.2%. The results indicate that niclosamide is a good taenicide but with a slow effect.

Studies of taeniasis in Taiwan. XII. Prevalence of taeniasis among Atayal aborigines in Wufeng District, Hsinchu County, northwest Taiwan

In order to determine the prevalence of taeniasis in the Wufeng District of Hsinchu County, 341 school children from 2 primary schools and 748 Atayal aborigines from 4 villages were examined with a scotch tape perianal swab and by questionnaire and demonstration of proglottides. The infection rates of taeniasis and enterobiasis among the school children were 1% and 8%, respectively. The overall infection rate of taeniasis among the Atayal aborigines was 6%, and 189 previously treated and cured persons were also discovered. The highest rate was found at Taoshan Village (9%) and the lowest at Chulin Village (3%). The infection increased with age from less than 1% among those under 10 years of age to a peak of 11% for those over 50 years. The infection rate in males (7%) was similar to that in females (6%). Fourteen percent (43/305) of the families were found with one (91%) or two (9%) infected members. The infected persons had been eating raw meat and viscera of wild boar (70%), flying squirrel (65%), muntjac (58%), wild goat (56%) and the raw meat of other 6 kinds of wild animals. Passing proglottides in the feces (100%) and pruritus ani (91%) were the two most important clinical manifestations. One-third (33%) of the patients had passed proglottides for 21-30 years.

Experimental infection of Thailand Taenia (Chiengmai strain) in domestic animals

Twenty-five gravid proglottides of a Thailand Taenia were obtained from a patient in Chiengmai, Thailand, and brought to our laboratory. The tapeworm was determined to be T. saginata-like by counting uterine branches (mean number 16, range 12-19 on each side). The eggs from these proglottides remained infective under storage at room temperature for 14 days followed by refrigeration (4-8 degrees C) for 131 days. Eight Small-Ear-Miniature pigs and two Holstein calves were each fed with 3000 eggs and sacrificed 12-76 days afterwards. Six pigs became infected and 16 cysticerci were recovered from the livers. Thirteen degenerated/calcified cysticerci were also recovered from the livers of the two calves. More cysticerci were found in the liver parenchyma (55%) than on the liver surface (45%) of the infected animals. Measurements of length, width, diameters of protoscolex, rostellum and sucker and hooklet pattern show that Thailand Taenia is similar to Taenia from Taiwan, Korea and Indonesia but different from T. saginata and T. solium. These findings indicate that Thailand Taenia, Taiwan Taenia, Korea Taenia, and Indonesia Taenia may be of the same species or sub-species.

Experimental studies of Korea Taenia (Cheju strain) infection in domestic animals

In the present study, one DYL pig (five-day old), four L-SEM pigs (37-day old), three SEM pigs (44-day old), one Holstein calf (eight-day old) and two Sannean goats (five-day old) were each fed 1000, 30,000, or 380,000 eggs of the Korea Taenia (Cheju strain) and were sacrificed 16-105 days after inoculation. All DYL, L-SEM, and SEM pigs and the Holstein calf were susceptible to Korea Taenia, and one of the two Sannean goats became infected. The cysticerci recovery rates for L-SEM, SEM and DYL pigs, Holstein calf, and Sannean goat were 5.6, 1.7, 0.06, 0.03 and 0.02% respectively. Cysticerci were recovered only from the livers of the infected animals, and more cysticerci were found in the parenchyma (51%) than on the surface of the liver (49%). Immature cysticerci were first observed on day 16 after infection, mature ones on day 29, and degenerated or calcified cysticerci on day 30. Inoculation of a huge number (380,000) of Korea Taenia eggs lead to early degeneration or calcification of the cysticerci. The length, the width, and the diameters of protoscolex, rostellum, and sucker of the cysticerci were largely proportional to the period of inoculation. The measurements and patterns of the hooklets indicate that Korea Taenia is very similar to Taiwan Taenia but is different from T. saginata and T. solium. The results of the present study provide evidence that Korea Taenia and Taiwan Taenia may be of the same species.

A study on enterobiasis among aboriginal children in Nanao and Tatung districts, Ilan county, northeast Taiwan

From May 1981 to March 1984, consecutive surveys with Scotch tape perianal swab for enterobiasis were conducted among school children in 8 primary schools in the Nanao District, also involved were 1 junior high and 8 primary schools from the Tatung District, Ilan County, Northeast Taiwan. Field treatments with mebendazole (10 mg) or albendazole (400 mg) were also conducted following 9 periods of screening for pinworm. Prior to treatment, the infection rates in Nanao and Tatung were 14.1% and 8.3%, respectively. These rates were reduced to 0.4% and 1.1% by March 1984, respectively. Throughout the study, significantly higher infection rates were generally found during the months of September, November, and December and lower rates were obtained in June. There was no difference between the infection rates of aboriginal school boys and girls. The results of the present study indicate that monthly chemotherapy is the best method for controlling pinworm infections in these mountainous regions.

Studies on taeniasis in Taiwan. V. Field trial on evaluation of therapeutic efficacy of mebendazole and praziquantel against taeniasis

Taeniasis is a major public health problem among the aboriginal populations on Taiwan, and is highly prevalent and wide spread in the mountain areas of 10 Counties. Over 27,000 cases of tapeworm infection are estimated influencing the health and economy in the endemic areas. A treatment of taeniasis with mebendazole and praziquantel followed by a re-treatment with atabrine has been done in the field trial, and confirmed that praziquantel is highly effective agent against tapeworm infection, but mebendazole is not. Based upon experiments reported here praziquantel in a single dose of 150 mg, and 450 mg are highly effective against taeniasis and hymenolepiasis respectively.

[Survey of helminthic infections and treatment of Taenia species infection among the aborigines in Chien-Shih District, Hsin-Chu County, northern Taiwan]

Six hundred and sixteen out of 770 (80%) aborigines examined were found to be infected with intestinal helminthes. A total of 7 species of parasites were detected with the formalin-ether concentration technique. The infection rate of Ascaris lumbricoides was 77.1%, Trichuris trichiura 28.8%, Taenia sp. 18.4%, Enterobius vermicularis 1.6%, and there was one case each of hookworm, Hymenolepis nana and H. diminuta infections. Infection rate was slightly higher among females (81.3%) than males (78.9%). It was also higher in Yu-Feng (86.9%) than Shiu-Luan villages (75.5%). The incidence of helminthic parasites was found in all ages. 11-20 age-group was the highest (84.4%), followed by 1-10 (81.5%), 51 and more (80.6%), 41-50 (77%), 31-40 (76%), and 21-30 (72%). In general, the rate seems to be higher among the young and old. But, the rate of Taenia sp. was increased with the increase in age. Taenia sp. was found to be of considerable high prevalence. However, only 7 out of the 252 (2.7%) junior high school students were found infected in contrast to the 18.4% found in the villages. After atabrine treatment, 108 adult worms, 83 with and 25 without scolices were obtained from 54 of 72 treated cases. The number of expelled worms varied from 1 to 8, with an average of 2 worms per infected person. 29 (53.7%) aborigines expelled only one worm, and 25 (46.3%) cases expelled more than one worms.

Epidemiology of Enterobius vermicularis infection among orphans in orphanages in Taipei City

Children of eight orphanages at the different districts in Taipei were examined with scotch adhesive tape method and flotation of saturated NaCl solution from Sept. 1973 to Jan. 1974. The results are summarized as following: General incidence of Enterobius verminularis was 74.40% in 461 cases examined, male 76.45% (224/293), female 70.83% (119/168). There was no significant statistical difference between the male and female. Incidence of Enterobius among the orphanages was 83.33% (25/30) in Po-Ai, Fu-Ann 82.61% (38/46), Ta-Tung 82.43% (61/74), Hau-Sen 77.25% (34/44), Chung-I 75.00% (51/68), Jen-Ai 72.97% (23/37), Ti-Hwei 72.50% (29/40) and Sen-Tao 63.93% (78/122). There were no significant statistical differences among the orphanages except the differences between Sen-Tao and Ta-Tung; Sen-Tao and Fu-Ann, Sen-Tao and Po-Ai. Incidence of Enterobius according to age-groups: The highest rate was 79.34% (242/305) in primary school group followed by 70.00% (21/30) in kindergarten group, 64.40% (73/114) in Junior high school and the lowest was 63.64% (7/11) in nursery group. There was a significant statistical difference between primary school group and junior school group. (Table 3) The larger the space for the children's free activity was the lower the incidence of Enterobius, and the smaller space resulted in the higher incidence. The distribution of Enterobius ova in the different body parts of the 461 orphans was 80.91% (373/461); The highest 74.40% (343/461) at perianal area and the lowest 11.93% (55/461) at ears. The incidence of Enterobius on the various objects in the orphanages was found as the following: 85.71% (6/7) on bed pans, 83.67% (333/398) on linens, 78.46% (51/65) on w. c. appartus, 77.39% (89/115) on specimens of dust, 13.33% (1/15) on stairrails 8.04% (32/39) on bedposts, 7.33% (11/150) on closets, 4.24% (5/118) on desks and 3.64% (2/55) on toys.