Growth of Enterobius vermicularis in a chimpanzee after anthelmintic treatment

The growth of Enterobius vermicularis in a chimpanzee was investigated by observing worms discharged in feces after administration of pyrantel pamoate. Just after the final molting, immature adult male pinworms developed to a fully mature stage in 2 wk, after passing through a stage corresponding to the so-called Enterobius gregorii, which was surmised to be a younger adult form of E. vermicularis. The frequency distribution of body length forms 2 peaks in both male and female pinworms, with a depression in the transitional forms from the immature to the fully mature stage.This depression seems to be the result of more rapid growth or lower susceptibility to the drug in this transitional stage. Pyrantel pamoate effectively eradicated mature males, but gravid females were continuously observed in the feces after treatment. The complete eradication of pinworm infection by pyrantel pamoate could be achieved by repeated treatment at intervals shorter than 2 wk. This treatment would eradicate male worms first, resulting in females producing only unfertilized eggs, from which only males might hatch.     

Chimpanzee pinworm, Enterobius anthropopitheci (Nematoda: Oxyuridae), maintained for more than twenty years in captive chimpanzees in Japan

The chimpanzee pinworm, Enterobius anthropopitheci (Gedoelst, 1916), was found in chimpanzees, Pan troglodytes, reared in Kumamoto Primate Research Park, Sanwa Kagaku Kenkyusho Co., Ltd., Kumamoto, Japan, in 2006. Because the chimpanzees in this institution originated from chimpanzees imported from Africa before 1984, it is considered that E. anthropopitheci infection has persisted for more than 20 yr in the chimpanzees. Analysis of pinworm specimens preserved in the institution revealed that transition of predominant pinworm species occurred, responding to the change of anthelmintics used for pinworm treatment. Present dominance of E. anthropopitheci is surmised to be caused by fenbendazole, which has been adopted from 2002. Scarcity of mixed infection with E. anthropopitheci and Enterobius vermicularis suggests interspecific competition between the pinworms.     

Enterobius vermicularis eggs discovered in coprolites from a medieval Korean mummy

While the presence of pinworm eggs in archaeological samples has been reported by many researchers in the New World, those have been detected very scarcely in the Old World, especially in East Asian countries. In fact, many parasite species were recovered from the archeological remains in Korea, eggs of Enterobius vermicularis had not been found. Recently, a female mummy buried in the 17th century was discovered in the Joseon tomb from Dangjin-gun, Chungcheongnam-do, Korea. After rehydration process for 12 days, investigations were carried on the luminal surface of the colon. From them, 3 eggs of E. vermicularis were recovered. They were elliptical, transparent with a thin egg shell, 50.3±5.2 μm (length) and 28.2±3.9 μm (width) in size. This is the first discovery of E. vermicularis eggs in East Asia.     

Prevalence of Enterobius vermicularis among preschool children in Gimhae-si, Gyeongsangnam-do, Korea

The present study was performed to determine the prevalence of Enterobius vermicularis among preschool children in Gimhae-si, Korea. A total of 6,921 preschool children in 76 kindergartens were examined using the cellotape perianal swab method. The overall egg positive rate (EPR) was 10.5%. The EPR in boys was higher than that in girls (adjusted odds ratio [AOR]: 1.5, P<0.001), and it was higher in rural than in urban children (AOR: 1.2, P=0.022). The present study confirmed that the prevalence of E. vermicularis infection is fairly high among preschool children in Gimhae-si. Therefore, systematic control and preventive measures should be adopted to reduce morbidity associated with this nematode infection.     

Prevalence of Enterobius vermicularis among Preschool Children in Muan-gun, Jeollanam-do, Korea

We assessed the prevalence of Enterobius vermicularis infection and changes in the egg positive rate (EPR) over 1-year time, using the adhesive cellophane-tape perianal swab method in 2,347 preschool children in Muan-gun, Jeollanam-do, Republic of Korea in 2008 and 2009. The overall EPR for E. vermicularis was 4.1% in 2008 and 4.5% in 2009. A study population of 389 children was repeatedly examined for 2 years. Within this group, the EPR in 2009 was twice higher than in 2008, and the EPR of the group of 5-7-year-old children was significantly higher than that of other age groups. Moreover, in the group of 5-7-year-old children in 2009, the rates of positive and negative conversion were significantly higher and lower, respectively, than in other age groups. Conclusively, enterobiasis was prevalent during 2008-2009 among preschool children in Muan-gun, Jeollanam-do, and the increased EPR in 2009 was due to an increase in newly acquired infections among 5-7-year-old children.     

SL1 RNA gene recovery from Enterobius vermicularis ancient DNA in pre-Columbian human coprolites

Enterobius vermicularis, pinworm, is one of the most common helminths worldwide, infecting nearly a billion people at all socio-economic levels. In prehistoric populations the paleoparasitological findings show a pinworm homogeneous distribution among hunter-gatherers in North America, intensified with the advent of agriculture. This same increase also occurred in the transition from nomad hunter-gatherers to sedentary farmers in South America, although E. vermicularis infection encompasses only the ancient Andean peoples, with no record among the pre-Colombian populations in the South American lowlands. However, the outline of pinworm paleoepidemiology has been supported by microscopic finding of eggs recovered from coprolites. Since molecular techniques are precise and sensitive in detecting pathogen ancient DNA (aDNA), and also could provide insights into the parasite evolutionary history, in this work we have performed a molecular paleoparasitological study of E. vermicularis. aDNA was recovered and pinworm 5S rRNA spacer sequences were determined from pre-Columbian coprolites (4110 BC-AD 900) from four different North and South American archaeological sites. The sequence analysis confirmed E. vermicularis identity and revealed a similarity among ancient and modern sequences. Moreover, polymorphisms were identified at the relative positions 160, 173 and 180, in independent coprolite samples from Tulán, San Pedro de Atacama, Chile (1080-950 BC). We also verified the presence of peculiarities (Splicing leader (SL1) RNA sequence, spliced donor site, the Sm antigen biding site, and RNA secondary structure) which characterise the SL1 RNA gene. The analysis shows that the SL1 RNA gene of contemporary pinworms was present in pre-Columbian E. vermicularis by 6110 years ago. We were successful in detecting E. vermicularis aDNA even in coprolites without direct microscopic evidence of the eggs, improving the diagnosis of helminth infections in the past and further pinworm paleoepidemiological studies.     

Fatal acute Chagas disease in a chimpanzee

Background  Chagas disease (CD) or American trypanosomiasis is caused by a hemoflagellate protozoan, Trypanosoma cruzi . This organism has been isolated from more than 100 mammalian species and several insect vectors demonstrating a wide host distribution and low host specificity.
Methods  A 23-year-old male chimpanzee died acutely and a complete necropsy was performed to evaluate gross and microscopic pathologic changes. After observation of trypanosomal amastigotes in the myocardium, PCR and immunohistochemistry was employed to confirm the diagnosis of T. cruzi .
Results  Gross findings were consistent with mild congestive heart failure. Microscopic findings included multifocal myocardial necrosis associated with severe lymphocytic to mixed inflammatory infiltrates, edema, and mild chronic interstitial fibrosis. Multifocal intracytoplasmic amastigotes morphologically consistent with T. cruzi were observed in cardiac myofibers. Trypanosoma cruzi was confirmed by PCR and immunohistochemistry .
Conclusion  We report, to the best of our knowledge, the first fatal spontaneous case of T. cruzi infection in a chimpanzee.     

Egg positive rate of Enterobius vermicularis among preschool children in Cheongju, Chungcheongbuk-do, Korea

In an attempt to determine the prevalence of pinworm infection, the egg positive rate of Enterobius vermicularis was examined using the adhesive cello-tape anal swab method in 1,512 preschool children sampled from a total of 20 kindergartens in Cheongju city, in November to December of 2004 (951 children from 13 kindergartens) and September to October of 2005 (561 from 7 kindergartens). The overall egg positive rate was found to be 7.9% (119/1,512); 9.3% (73/784) for boys and 6.3% (46/728) for girls, respectively. The 5-year age group evidenced the highest egg positive rate (10.9%, 47/430) among the examined age groups. As compared to those reported from previous works (ranged from 9.2 to 26.1%), the prevalence of E. vermicularis in the Cheongju city area is relatively low.     

High Prevalence of Enterobius vermicularis Infection among Schoolchildren in Three Townships around Yangon,Myanmar

In order to determine the status of Enterobius vermicularis infection among schoolchildren in suburban areas of Myanmar, 761 primary schoolchildren in 3 different townships around Yangon City were subjected to a survey using cello-tape anal swabs. The subjected schoolchildren were 383 boys and 378 girls who were 5-7 years of age. Only 1 anal swab was obtained from each child. The overall egg positive rate of E. vermicularis was 47.2% (359 positives), and sex difference was not remarkable (48.6% in boys and 45.8% in girls). However, the positive rate was the highest in South Dagon (54.6%) followed by Hlaing Thayar (43.8%) and North Dagon (34.8%). This difference was highly correlated with the living standards of the people in each township. Nucleotide sequence of the 5S rDNA from the eggs on the cello-tape (2 children) revealed 99.7% identity with that of E. vermicularis reported in GenBank. The results indicated that E. vermicularis infection is highly prevalent among primary schoolchildren around Yangon, Myanmar.     

Enterobius vermicularis egg positive rate of pre-school children in Chunchon, Korea (1999)

Pre-school children were examined for the presence of Enterobius vermicularis egg by perianal swab method. We visited 67 nurseries and 25 kindergartens between January, 1999 and April, 1999 in Chunchon, Korea. Of the 4,711 children examined, 434 (9.2%) were found to be positive for E. vermicularis egg. The egg positive rates of boys and girls were 10.1% and 8.1%, respectively. The rates were 7.8% in kindergartens and 9.7% in nurseries. Positive rate of 50 institutions was less than 10%. Rate in 35 institutions was from 10% to less than 20%. Rate in 7 institutions was equal to or over 20%. Out of 1,113 children examined twice, 28 (2.5%) children were positive consecutively, 53 (4.8%) were positive with negative conversion, 47 (4.2%) were negative with positive conversion, and 985 (88.5%) were consecutively negative. It means that in the low endemic area of enterobiasis with around 10% positive rate, the two consecutive examinations may increase the egg detection rate of 4.2-4.8%. The small number of consecutive egg positive children also suggests that the worm burden of the positive children might be low. Since the egg positive rate of that age group in this City increased from 1.85% (1997), and 3.0% (1998), the more intensive regular control should be executed.     

Enterobius vermicularis egg positive rate in a primary school in Chungchongnam-do (province) in Korea

The egg positive rate of Enterobius vermicularis was investigated among students of a primary school and a kindergarten located in the rural area of Tangjin-gun, Chungchongnam-do in December, 1998. Of the 189 examinees, 28 (14.8%) were found to be infected with E. vermicularis by the adhesive cellotape anal swab method. The infection rates ranged from 4.2% to 26.1% among school children, and the highest rate was observed in children attending kindergarten. Three months after treatment with albendazole, four (14.3%) out of 28 infected children still remained infected with E. vermicularis. Through this survey, we were able to determine that E. vermicularis infection is still prevalent among children in rural areas of Korea.     

Lethal pneumonia in a captive juvenile chimpanzee (Pan troglodytes) due to human-transmitted human respiratory syncytial virus (HRSV) and infection with Streptococcus pneumoniae

Background  During an outbreak of respiratory disease in captive chimpanzees ( Pan troglodytes ), gorillas ( Gorilla gorilla ), Bornean orangutans ( Pongo pygmaeus ), and red-capped mangabeys ( Cercocebus torquatus ) also staff members showed non-specific upper respiratory signs. One infant female chimpanzee with severe respiratory symptoms died despite immediate medical treatment and was submitted for necropsy.
Methods  Routine post mortem, histological and bacteriological examinations were conducted. Additionally lung tissue samples form the chimpanzee and swab samples from the staff members and the other primates were examined by PCR.
Results  A severe catarrhal to purulent bronchopneumonia and an interstitial pneumonia were found and human respiratory syncytial virus (HRSV) as well as Streptococcus pneumoniae was detected in lung samples by PCR. Swab samples from one animal keeper revealed the same HRSV sequence as of the chimpanzee.
Conclusions  Therefore, it is suggested that the outbreak of respiratory disease within a zoological institution was due to transmission of HRSV between both human and primates.     

Prevalence of Enterobius vermicularis Infection among Preschool Children in Kindergartens of Taipei City, Taiwan in 2008

The prevalence of Enterobius vermicularis infection among preschool children was reported to be low based on a 5-year screening program in Taipei City, Taiwan. The Taipei City government intended to terminate the E. vermicularis screening program among preschool children. Thus, we were entrusted with confirming whether pinworm infections among preschool children in Taipei City had truly declined. From each of 12 administrative districts 2-3 kindergartens were randomly selected for investigation. In total, 4,349 children were examined, of which 2,537 were boys and 1,812 were girls. The cellophane tape adhered to a glass slide was used, and all examinations were done by certified medical technologists. Results indicated that the overall prevalence rate of pinworm infections was 0.62% (27/4,349). Although the infection rate was higher among boys (0.67%, 17/2,537) than in girls (0.55%, 10/1,812), no significant difference was found (χ² = 0.399, P = 0.62). According to the administrative district, the infection rate ranged from no positive cases of E. vermicularis infection in the Xinyi, Zhongzhen, and Wanhua Districts (0%; 0/299, 0/165, and 0/358, respectively), to 0.26% (1/131) in Songshan District, with the highest rate of 1.88% (7/373) in Wenshan District. Because the overall infection rate (0.62%, 27/4,349) in the present study was unchanged compared to that (0.40%, 197/49,541) previously reported in 2005, we propose that regular pinworm screening and treatment programs should be continued in some parts of Taipei City.     

Prevalence of Enterobius vermicularis infection and preventive effects of mass treatment among children in rural and urban areas, and children in orphanages]

An epidemiological study and mass treatments of Enterobius vermicularis infection among children near Wonju area of Kangwon province were carried out. The children were divided into 4 groups according to their residing localities; children in the mountainous area, rural area, urban area and in orphanage. They were examined by adhesive cellotape anal swab technique, and egg positive rates were obtained. The rates of egg reduction and re-infection rates after repeated mass treatments were also observed. The results obtained were as follows: 1. The overall egg positive rate of E. vermicularis in the first screening was 19.9% (251 out of 1,262 examinees; 19.7% in males and 20.1% in females). The positive rates were 13.0% in the mountainous area, 11.9% in the rural area, 15.1% in the urban (medium-sized) area and 61.9% in orphanages. 2. The highest positive rates were observed in the kindergarten children, and 1st and 2nd grade children of primary schools (26.2-32.2%), and the lowest rate (13.6%) in 6-year grade children of primary schools. 3. Cumulative detection rates from 3 repeated anal swabs at 4-5 days interval were higher (70.8%) than those from single anal swabs (50.0-59.2%). 4. Out of the examinees who showed the highest cumulative positive rate (70.8%), about 39.2% were consecutively positive in 3 anal swabs. Among different groups of children, the higher the total egg detection rates (87.5%), the higher the consecutive positive rates (71.9%). 5. A total of 2,609 (male: female = 1:12.4) worms were collected from 17 egg-positive cases treated with anthelmintics. The mean number of worms per child was 153 (range: 4-824).(ABSTRACT TRUNCATED AT 250 WORDS)