A new species of Wellcomia (Nematoda: Oxyuridae) in the plains viscacha (Rodentia: Chinchillidae) from Argentina, an emended diagnosis and an update of the genus Wellcomia

Wellcomia species (Oxyuridae, Syphaciinae) parasitise several families of rodents from Africa, Asia and America with diverse ecological characteristics. A new species of Wellcomia is described based on specimens obtained from the plains viscacha Lagostomus maximus (Chinchillidae) from Argentina. The description includes morphometric and ecological aspects and an emended diagnosis of the genus Wellcomia. In addition, a molecular characterisation (18S rRNA) and an exploratory analysis of the genetic distances of the species included in this genus are provided. The new species, Wellcomia hugoti n. sp., differs from other species of the genus in the morphology of the cephalic plate, the ventral rugose area in males and the vulva in females. The new species showed a low prevalence (7.7%) and a high mean abundance (73.8). The genetic distances detected do not allow a comprehensive assessment of the monophyly of the genus. This is the seventh record of this genus in rodents from the Americas, the second in rodents from Argentina and the first record for the family Chinchillidae.

Evaluation of Anthelmintic Resistance and Exhaust Air Dust PCR as a Diagnostic Tool in Mice Enzootically Infected with Aspiculuris tetraptera

The entry of infectious agents in rodent colonies occurs despite robust sentinel monitoring programs, strict quarantine measures, and stringent biosecurity practices. In light of several outbreaks with Aspiculuris tetraptera in our facilities, we investigated the presence of anthelmintic resistance and the use of exhaust air dust (EAD) PCR for early detection of A. tetraptera infection. To determine anthelmintic resistance, C57BL/6, DBA/2, and NCr nude mice were experimentally inoculated with embryonated A. tetraptera ova harvested from enzootically infected mice, followed by treatment with 150 ppm fenbendazole in feed, 150 ppm fenbendazole plus 5 ppm piperazine in feed, or 2.1 mg/mL piperazine in water for 4 or 8 wk. Regardless of the mouse strain or treatment, no A. tetraptera were recovered at necropsy, indicating the lack of resistance in the worms to anthelmintic treatment. In addition, 10 of 12 DBA/2 positive-control mice cleared the A. tetraptera infection without treatment. To evaluate the feasibility of EAD PCR for A. tetraptera, 69 cages of breeder mice enzootically infected with A. tetraptera were housed on a Tecniplast IVC rack as a field study. On day 0, 56% to 58% of the cages on this rack tested positive for A. tetraptera by PCR and fecal centrifugation flotation (FCF). PCR from EAD swabs became positive for A. tetraptera DNA within 1 wk of placing the above cages on the rack. When these mice were treated with 150 ppm fenbendazole in feed, EAD PCR reverted to pinworm-negative after 1 mo of treatment and remained negative for an additional 8 wk. The ability of EAD PCR to detect few A. tetraptera positive mice was investigated by housing only 6 infected mice on another IVC rack as a field study. The EAD PCR from this rack was positive for A. tetraptera DNA within 1 wk of placing the positive mice on it. These findings demonstrate that fenbendazole is still an effective anthelmintic and that EAD PCR is a rapid, noninvasive assay that may be a useful diagnostic tool for antemortem detection of A. tetraptera infection, in conjunction with fecal PCR and FCF.

Characterization of rat pinworm (Syphacia muris) epidemiology as a means to increase detection and elimination

Rodent pinworms persist in many institutions, suggesting deficiencies in eradication and diagnostic processes. When pinworms are detected, treatment success is common, but false-negative test results during health surveillance or after treatment likely contribute to the continued presence of this parasite. PCR testing is not always practical, and increased information regarding the life cycle and general epidemiology of pinworm infestations could improve the sensitivity of traditional nonPCR detection methods and improve eradication efforts. We therefore investigated a pinworm (Syphacia muris) infestation in Sprague-Dawley rats (Rattus norvegicus) to develop a more accurate testing strategy. In addition, we sought to determine the duration of egg viability by using an in vitro hatching protocol to assess environmental persistence. Finally, we tested the ovicidal efficacy of a disinfectant used at our institution. Eggs were shed in higher numbers in the midafternoon as compared with other times of the day, and the sex of the host had no consistent effect on egg shedding. Egg shedding showed periodicity over time, with shedding decreasing to 0 at 2- to 3-wk intervals. Neither cecal examination nor tape tests alone reliably predicted pinworm infestation, and results of the 2 tests did not necessarily coincide. Eggs aged for as long as 7 mo remained viable, indicating a potential for recontamination from the environment. Finally, gaseous chlorine dioxide was an effective ovicidal agent, with a kill rate of 99.7%. These results suggest that strategies for S. muris eradication can be optimized to increase detection and elimination.

False-positive results after environmental pinworm PCR testing due to Rhabditid nematodes in Corncob bedding

Modern rodent colonies are housed in individually ventilated cages to protect the animals from contamination with adventitious pathogens. Standard health monitoring through soiled-bedding sentinels does not always detect infections, especially in the context of low pathogen prevalence. Recently proposed alternatives include analyzing environmental samples from the cages or rack exhaust by PCR to improve the detection of rodent pathogens but optimal sampling strategies have not yet been established for different microorganisms. Although generally very sensitive and specific, these molecular assays are not foolproof and subject to false-positive and -negative results and should always be interpreted cautiously with an overall understanding of the intrinsic controls and all the variables that may affect the results. Here, we report a limited Aspiculuris tetraptera outbreak in a mouse barrier facility that was detected by fecal PCR in sentinels and confirmed by fecal flotation and direct cecal examination of both sentinels and colony animals. The outbreak led to a widespread survey of all facilities for pinworms by using environmental PCR from ventilated rack exhaust plenums. Environmental PCR suggested an unexpected widespread contamination of all ventilated racks holding nonautoclaved cages, but results could not be confirmed in sentinel or colony animals by fecal flotation, cecal and colonic examination, or cage PCR testing. After additional investigation, the unexpected environmental PCR results were confirmed as false-positive findings due to the nonspecificity of the assay, leading to the amplification of rhabditid nematodes, which are not infectious in rodents but which contaminated the corncob bedding.

[Helminths of some laboratory animals detected by necropsy and fecal examination]

A study was performed in order to determine helminths of laboratory animals. Fecal specimens obtained from 110 mice, 263 rats and 65 rabbits were investigated and 37 rats and 7 rabbits were necropsied. In general, 83.8% rats were found to be infected by necropsy, while 100% of mice,and 81.8% of rats were found to be infected with one or more helminths species by fecal examination. No rabbits were found to be infected by necropsy or fecal examination. In fecal examination of mice and rats, the prevalence of helminths was detected as follows: Syphacia muris, 100%; Aspicularis tetraptera, 53.6%; Syphacia obvelata, 46.4%; and Hymenolepis diminuta 17.9% in mice. The prevalence in rats was H. Diminuta, 62.5%; S. muris, 25%; Hymenolepis nana, 6.8%; and Trichosomoides crassicauda, 6.8%. In necropsy, S. muris was identified in all of infected rats, but only one was infected with A. tetraptera.

Prevalence of geohelminths in savana and forest areas of Côte d'Ivoire

BACKGROUND

Côte d'Ivoire has large regional variation in intestinal helminth prevalence.

STUDY DESIGN

In a large cross-sectional study conducted from 1997 to 1999, stool samples from 6952 children aged 4-15 years were examined for helminth eggs by the Kato/ Katz technique from 24 villages in the savanna (North) and from 21 villages in the forest (West) in Côte d'Ivoire.

RESULTS AND CONCLUSION

Ascariasis lumbricoides (0.7%) was the only species present in the savana area. In the forest area, ascariasis occurred most frequently (18.9%), followed by trichuriasis (2%), Strongyloidiasis (0.1%) and oxyuriasis (0.03%). Ascariasis prevalence was not significantly associated with age within each ecological zone, but was significantly higher in boys in the forest zone. This study confirms that in the more arid savanna, the conditions are less suitable for helminth transmission than in the forest zone.

[Gastrointestinal parasites of rabbits in coproscopic investigations]

BACKGROUND

Parasitological screening was carried out in a breeding herd of the New Zealand White rabbit breed in 2004.

MATERIAL AND METHODS

Mothers, together with their offsprings, were kept in boxes on deep litter, whereas young rabbits were transferred to cages with slatted floor. All the animals were fed a complete balanced pelleted feed with two coccidiostats added alternately (Lerbec, Robenidine), and droplet watering system was applied. No anthelmintic was used in the rabbitry. A total of 170 individual samples of fresh feces from females of breeding stock, and 55 pooled samples in the case of young animals 2-4 months of age, collected on a month intervals, were analyzed according to a modified concentration McMaster's method, using saturated salty water with sugar as a flotation fluid.

RESULTS

The presence of several species of coccidia was evaluated, with Eimeria stiedae, E. perforans, E. media and E. magna being found in great numbers. The dynamics of infection showed that both adults and young animals were affected by coccidia mostly in May (mean intensity reached at that time 24000 opg in young rabbits), and then until August the infection lasted on a high level. As regards coccidiosis, parasitism could be considerably cut back in the herd by frequent changing of the straw litter, which should also always be dry. Only Passalurus ambiguus was found from nematodes, and only in the feces of adults, probably due to the modern forage and watering system applied, which broke the other worms' life cycles.

Syphacia obvelata infections and reproduction of male domestic mice Mus musculus domesticus on a sub-Antarctic Island

The reproductive activity of feral male mice on an island of the sub-Antarctic Kerguelen archipelago was influenced by biological factors depending on periods within the breeding season. After having controlled host reproductive activity indices for body size, i.e. age, and body condition effects, Syphacia obvelata prevalence did not vary with host reproductive status or age either during the beginning or the middle-end of the reproductive season. Considering the beginning of the breeding season, worm abundance was more pronounced in males the year following a strong winter crash of the population than in years when high over wintering survival occurred. During the middle-end of the breeding season, males with the highest reproductive status were more infected than males with a lower reproductive status in years when oldest individuals dominated the population. It is suggested that this situation was due to an endocrine related increased host susceptibility partly influenced by a change in the age structure of the population, and that an increase in worm transmission was not directly related to male activity concurrent with reproductive status, nor to population density.

Redescription of some Spauligodon spp. and Parapharyngodon spp., and of skrjabinodon mabuyae (Sandground, 1936) inglis, 1968 (Pharyngodonidae: Oxyuroidea) from insectivorous South African lizards

As part of a study on the helminth parasites of South African lizards several species of saurians were collected from localities in the North West Province, the Northern Province, Mpumalanga Province and Gauteng Province. Spauligodon blydeensis (Hering-Hagenbeck, 2001) from the Cape thick-toed gecko, Pachydactylus capensis, Spauligodon molpoensis (Hering-Hagenbeck, 2001) from Wahlberg's velvet gecko, Homopholis wahibergii, Parapharyngodon margaritiferi, Hering-Hagenbeck, 2001 from the skink, Mabuya margaritifer, Parapharyngodon gerrhosauri, Hering-Hagenbeck, 2001 from the plated lizard, Gerrhosaurus flavigularis and Skrjabinodon mabuyae (Sandground, 1936) Inglis, 1968 from the skinks Mabuya punctatissima, Mabuya spilogaster and Mabuya varia are redescribed. The different Spauligodon spp. in the subcontnent may be separated on the presence or absence of spicules in the males, the presence or absence of spines on the tail of both the males and females, as well as on the size and shape of the eggs, and the configuration of the polar caps. The Parapharyngodon spp. are distinguished mainly by the morphological characters of the males, such as the width of the caudal alae and the size of the pre- and adanal papillae. Female Parapharyngodon spp. closely resemble each other and some could not be identified to the species level since males were absent. Spinose larvae, together with adult Parapharyngodon spp. were recovered from Mabuya margaritifer. All Parapharyngodon spp. larvae described to date are spinose and since the larvae in this study were collected together with adult Parapharyngodon spp., we consider them to belong to the same genus. Skrjabinodon mabuyae differs from the closely related Skrjabinodon mabuiensis in the presence of a spicule in the male and lateral alae in the female. The former nematode is described for the first time from skinks in South Africa.

Redescription of some Thelandros and Tachygonetria spp. (Pharyngodonidae: Oxyuroidea) from the omnivorous plated lizard, Gerrhosaurus validus validus A. Smith, 1849 in South Africa

Thelandros schusteri Hering-Hagenbeck, 2001, Thelandros luciusi Hering-Hagenbeck, 2001, Thelandros boomkeri Hering-Hagenbeck, 2001, Tachygonetria bainae Hering-Hagenbeck, 2001, Tachygonetria chabaudi Hering-Hagenbeck, 2001 and Tachygonetria petterae Hering-Hagenbeck, 2001 from the plated lizard, Gerrhosaurus validus validus A. Smith 1849 from three localities in the north-eastern region of South Africa are redescribed. Classification keys are available only for the males of the species and because male and female nematodes in copula were not observed in this study as well as the similarity of the females, it was not possible to identify the females to the species level. Thelandros schusteri, Thelandros boomkeri and Thelandros luciusi were provisionally paired with female Type E, Tachygonetria bainae with female Type C, Tachygonetria chabaudi with female Type A and Tachygonetria petterae with female Type D. Female Types B and F could not be paired. The richness and composition of species of the Pharyngodonidae of Gerrhosaurus validus validus is close to that of tortoises and differs from the pharyngodonid fauna of the insectivorous lizards that have been studied. In the latter, only the genera Spauligodon, Skrjabinodon and Parapharyngodon were recovered. The pharyngodonid fauna of Gerrhosaurus validus validus seems to have originated by capture from local herbivorous reptiles. The three Tachygonetria spp. most closely resemble forms in South African tortoises. The three Thelandros spp. redescribed here not only show strong similarities to those of herbivorous Agama spp., but also to those parasitic in tortoises and could have been acquired from either.

Syphacia longaecauda n. sp. (Nematoda: Oxyuridae) syphacinea from Melomys spp. (Muridae: Hydromyinae) from Papua New Guinea and Irian Jaya, Indonesia

A new oxyurid nematode Syphacia (Syphacia) longaecauda n. sp. is described from the caecum and colon of the hydromyine rodents Melomys monktoni (type host) and M. rubex from Papua New Guinea and Irian Jaya, Indonesia. Syphacia longaecauda has an oval, laterally extended, relatively large cephalic plateau and can be distinguished from other species of Syphacia with similar characters by, amongst other features, tail length. The significance of the distribution of S. longaecauda, apparently restricted to New Guinea, is discussed.

Seasonal and site specific variation in the component community structure of intestinal helminths in Apodemus sylvaticus from three contrasting habitats in south-east England

Seasonal fluctuations in the prevalence and abundance of infection with intestinal helminths were studied in Apodemus sylvaticus (wood mouse, n = 399), from three contrasting habitats in southern England, to test the hypothesis that both intrinsic (host sex, age) and extrinsic (season, site) factors influence parasite species richness and abundance. Five species of helminths were recovered but only one of these (Capillaria murissylvatici) was site-specific (Dungeness). Total species richness was therefore 5 at Dungeness and 4 at the other two sites. Mean species richness was 1.4, but in adult mice there was a pronounced difference between the sites, and an independent highly significant effect of season. Syphacia stroma and Corrigia vitta both showed marked differences between sites in respect of prevalence and abundance of infection. Capillaria murissylvatici was encountered at Dungeness mostly in the spring whereas seasonal changes in abundance of S. stroma were consistent across all three sites. Seasonal fluctuations in the abundance of Catenotaenia pusilla were compounded by differences between sites. Host sex was not a significant factor in any species, although a posteriori analysis of S. stroma worm burdens for the Isle of Wight site revealed a moderate local sex effect. Overall the principal determinants of variation in helminth burdens were the extrinsic factors, site and season.

Epidemiology and genetic variability of two species of nematodes (Heligmosomoides polygyrus and Syphacia stroma) of Apodemus spp

The epidemiology and genetic variability of 2 parasitic nematodes Heligmosomoides polygyrus and Syphacia stroma of Apodemus spp. were investigated. Both are parasites of the same host, exhibit a direct life-cycle and are dioecious. However, H. polygyrus has a diploid and S. stroma a haplodiploid mode of reproduction. Haplodiploidy may lead to a more female biased sex ratio and reduced genetic variability. Levels of genetic diversity were analysed using both isoenzyme electrophoresis and RAPDs (random amplified polymorphic DNA). Both parasites showed a female biased sex ratio with a stronger bias for the haplodiploid parasite. Results showed significantly fewer genetic polymorphisms as measured by RAPDs for the haplodiploid parasite S. stroma in comparison with H. polygyrus. Despite the observed female biased sex ratio this could not be explained by a significant amount of inbreeding. Heterozygote deficiency for individual allozyme loci--which could indicate inbreeding--was not found in either parasite species. Other features of the particular life-history of these species are likely to have an impact on the sex ratio and genetic variability too.

[Intestinal parasitic diseases in an urban environment in Sahel. A study in a district of Niamey, Niger]

Health and environment in Niamey, a capital in Sahel, are particularly linked owing to population growth, promiscuity and large pollution induced by human and animal excreta. One district, located in the centre of the town, was surveyed for drinking water quality (ammoniac and bacterial count) and use, as well as for the prevalence of parasites through both a random sample (fixed tools with methiolate-iodine-formaldehyde) and a systematic one (scotch-test). Water consumption was 16.5 litres/day/man from fresh water supplies (87%) and private wells (13%). Ammoniac measures were low in the wells but high in running water (pool and river). It was the same for faecal coliform bacteria. These results give evidence of biotope faecal pollution. The random sample (322 persons, male/female sex ratio 0,85, average age 20,6 years) showed a 42.1% parasitic prevalence. Amoeba was the most frequent parasite (53.6%); and Giardia (14.9%) was the most frequent pathogenic parasite. In the second sample (161 children under 10 years), 24.2% were carriers of oxyuris. This large intestinal parasitism, without any change in connection with previous data in Niger, points to an important fecal contamination of the people more by the way of "dirty hands" than consumption of drinking water. The parasites observed have a short biological cycle, not necessitating long-term maturation in the environment. Those whose ova or larvae must complete their cycle outside have no possibility of surviving in Sahel, thanks to the beneficial effect of sunlight (heat and ultraviolet light). The inhabitants of this district seem to have adapted to intestinal parasitism. But the occurrence of malnutrition linked to a new drought could lead rapidly to a very serious adverse result.

[Oxyuriasis: its indoor transmission correlated with crowding in housing]

In two different human settings in the province of Pavia, Italy, statistically significant correlations were found between socioeconomic level of the families or crowding in the houses, and prevalence of oxyuriasis in schoolchildren. An indoor transmission is postulated.

Prevalence of the nematode Spauligodon giganticus (Oxyurida: Pharyngodonidae) in neonatal Yarrow's spiny lizards, Sceloporus jarrovii (Sauria: Iguanidae)

Examination of the digestive tracts of 31 field-collected neonatal Sceloporus jarrovii Cope, 1875, estimated to be between 1 day and 2 wk of age revealed a prevalence of 74% (23/31) infection for eggs and/or larvae of the nematode Spauligodon giganticus (Read and Amrein, 1953) Skrjabin, Schikhobalova, and Lagodovskaja, 1960, and a prevalence of 3% (1/31) for the cestode Oochoristica sp. Twenty-two captive-born neonatal Sceloporus jarrovii, no older than 1 day revealed a prevalence of 14% for eggs of Spauligodon giganticus. Substrate licking, a behavior evident soon after birth, apparently is responsible for this almost immediate infection by S. jarrovii.

Prevalence of Enterobius vermicularis amongst adults living in hostels by six successive day examination

The prevalence of Enterobius vermicularis in four groups of adults, all trainee public health inspectors or public health nurses, aged 18-35 years and all living in hostels on campus was studied. The modified scotch tape technique was used and the subjects were taught to do the examination on themselves to detect the presence of eggs over a period of 6 successive mornings. Each was given an elaborately illustrated diagram on how and when to take the samples and given demonstration in groups. The samples were examined by trained people. Most of the subjects took samples on 6 consecutive days. Of the 119 subjects who returned samples, the overall prevalence of E. vermicularis was 9.2% and this was thought to be high for this particular age group. This was due to the higher prevalence (19.4%) in one group, whereas in the others the range was 3.5-8.0%. Based on the samples returned on the first day none of the subjects were detected as having the infection. After examination on 3 successive days (109 subjects) 10.1% were found to be infected (chi 2 = 10.704; d. f. = 1) and after examination on 6 successive days (72 subjects) 13.9% were found to be infected (chi 2 = 3.026; d. f. = 1). There was no significance between examination over 3 successive days and 6 consecutive days (chi 2 = 0.296; d. f. = 1). There was no difference in the prevalence between males and females.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence and symptoms of Enterobius vermicularis infections in a Peruvian shanty town

The prevalence and symptoms of pinworm infection were determined in a shanty town in Lima, Peru. In 206 families, pinworm infection rates were highest in primary school age children (42%). Approximately one-fourth of pre-school children and secondary school-age children were infected with pinworms. Two examinations detected 74% of patients who were positive after 5 examinations. Symptoms often attributed to pinworm infection, such as perianal itching enuresis, and teeth grinding, occurred in a similar proportion of infected children (15%, 17%, 13%, respectively) and non-infected subjects (11%, 13%, 11%, respectively). Enuresis was more common in primary school-age children with high pinworm egg counts than in their non-infected contemporaries. 52% (28/54) of children under 5 years old became reinfected within 6 months of effective treatment. In a community where water is scarce and hand washing is infrequent, the high rate of perianal itching is probably an important source of faecal-oral contamination. The low morbidity and high reinfection rate make routine treatment of pinworm infection in third world countries a low priority, except when clinically indicated.

[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)

[The socioeconomic criteria of the effectiveness of measures for the sanitary improvement of children's collectives against enterobiasis]

Using social and economic criteria, the efficacy of health improving measures against enterobiasis in the organized groups of pre-school children has been assessed. The introduction of mass treatment of children with vermox into a complex of antienterobiasis measures has a considerable health improving effect, without rendering the procedure more expensive. A considerable difference between the economic damage inflicted by enterobiasis and the economic efficacy of antienterobiasis complex, including mass children treatment, forms the basis for the wide use of anthelmintics in the control of this type of helminthiasis.

[The practical aspects of the enterobiasis problem in Lithuania]

The invasion with enterobiasis in individual groups and antienterobiasis measures performed in Lithuania over the 1980-1989 period have been analysed. An overall average 10-year infectivity of children with Oxyuris vermicularis was 9.4%. The infectivity averaged 17.2% in organized groups of preschool children and 8.1% in nonorganized groups of preschool children. According to the data of 1984-1989 the infectivity in the pupils of the first-fourth forms averaged 18.4%. The infectivity of adults with enterobiasis was considerably lower than in children (1.6-2.3% on the average). Sanitary helminthological surveys have been conducted to assess the degree of contamination of articles in children preschool institutions with invaded matter. An overall index of contamination of the articles under study with Oxyuris vermicularis oocysts was 1.1%. So far enterobiasis control in the Republic has been focussed on the isolation and treatment of the invaded persons, as well as on the sanitary helminthological control over the environment. However, the above measures proved insufficient in combatting the epidemic process. It has been shown that the morbidity might be considerably lowered, provided rules of personal hygiene are strictly and constantly observed, the most essential of them being washing of children in the evening and in the morning. The struggle against enterobiasis may be effective in case all the antiepidemic measures are strictly observed with participation of parents and the personnel of the children institutions.

[The comparative characteristics of the ontogenetic indices in healthy children and those with enterobiasis]

It should be noted that a total number of dysembryogenesis stigmas in an individual child must be taken into consideration in the formation of risk groups. Children with an increased number of stigmas (more than 7 in one child) are thought to be at high risk only of somatic pathology but also of the given helminthiasis and should be urgently examined for enterobiasis.

[Experience with enterobiasis control measures in the preschool institutions of Lithuania]

The efficacy of treatment and hygienic antienterobiasis measures have been studied in organized groups of preschool children in the Trakay district of Lithuania. Daily washing of all the children and treatment of the invaded children with Vermox once a year proved effective for the prevention of enterobiasis transmission.

[The level of enterobiasis infectivity in children in relation to the sanitary status of preschool institutions]

Nursery schools and kindergartens have been examined in Rostov-on-Don. Five most essential factors based on the determination of signs informativeness and prognostic coefficients and responsible for possible enterobiasis determination have been identified: the state of water supply, staffing with personnel, presence (absence) of the round-the-clock groups, overcrowded groups, location of bedrooms. An attempt is made to classify kindergartens according to these indexes.

[Experience in eradicating enterobiasis in children in the preschool institutions of the Lithuanian SSR]

The efficacy of hygienic measures and drug therapy of patients with enterobiasis has been compared in different organized groups of children in various regions of Lithuania. Nondrug measures and drug therapy were of similar efficacy. Vermox administration twice a year decreased the incidence of enterobiasis in children 1.9-fold, while nondrug measures decreased it 1.5-6.1-fold.

[The eggs of Enterobius vermicularis in room dust. I. Methods]

Results of anal swabs have been compared with room dust samples. The room dust was collected using little brushes as well as a vacuum cleaner from a standard surface of 0.25 m2. To collect room dust by vacuum cleaner, a slide was placed into a special chamber, connected to an absorbing device. Eggs of E. vermicularis have been found in samples made with anal swabs, room dust brushes and the vacuum cleaner, respectively, as follows: in the first examination 34%, 17.4% and 25.1%, in the second examination 35%, 17.7% and 15.7% and in the third examination 42%, 15.7% and 35.4%.. The results are discussed with regard to methodical and epidemiological aspects of the examination eggs of E. vermicularis in room dust.

[Intestinal parasites in primary schools of different socioeconomic status and environmental conditions]

Two hundred ninety-four stool sample obtained from primary schools of different social status and environmental conditions were examined for intestinal parasite. The age range was between seven and 13 years, 43% of the patients were females and 57% of the patients were males. In our study it has been observed that the parasite incidence was 29.3%. The predominant parasite was Giardia intestinalis (15.7%). Enterobius vermicularis (10.5%) and Ascaris lumbricoides (2.3%) have been followed respectively. There were three different parasites in the primary school of good social status and environmental conditions. In the contrary in the village school, there were five different parasites. In the conclusion parasite incidence was high in our region. In primary schools of different conditions there were no difference Giardia intestinalis but there were marked difference in the other parasites.

Consecutive examinations by scotch-tape perianal swabs in diagnosis of enterobiasis

In order to determine how many consecutive perianal examinations can increase the accuracy of the diagnosis of enterobiasis, nursery and kindergarten children were examined with 8 consecutive scotch-tape perianal swabs. Primary school students were examined with 4 consecutive swabs, while junior high school students were examined with one swab in the morning and another in the afternoon. The positive rates among nursery and kindergarten children increased from 17.3% and 34.6% by a single swab to 44.4% and 70.2% by 8 consecutive swabs respectively. Significant differences in rates among kindergarten children by class were found by 4 to 8 swabs (3rd year class 65.6-78.7%, 2nd year class 50.3-61.1%, 1st year class 52.3-69.5%). The rate among primary school students increased from 59.9% by a swab to 77.3% by 4 consecutive swabs. Significant differences were found among the rates by grade. The highest was detected in grade 3 and lowest in grade 6. There was no significant difference between the positive rates among junior high school students obtained in the morning (33.7%) and in the afternoon (31.3%), and also no significant difference among rates by junior school was found. There was no significant difference between positive rates by sex in kindergarten children (boys, 68.8%, girls, 71.9%) and primary school students (boys, 76.8%; girls, 77.9%). However, the positive rate of junior high school girls (47.3%) was significantly higher than that of junior high school boys (37.4%).(ABSTRACT TRUNCATED AT 250 WORDS)

[Survey of Enterobius vermicularis infection among school children in Tainan City]

A survey was conducted for enterobiasis, in six primary schools at Tainan city. The survey was conducted in 1986, involving 8,120 school children. The manner of testing, was two consecutive day, adhesive cellophane paper perianal swabs. The test resulted in general infection rate of 30.4%. The positive rates among those primary school children were significantly different (chi 2-test, p less than 0.001). The highest rate (40.3%), was in Shih-Men primary school and the lowest rate (18.7%) in Pao-Jeng primary school. Gender occurrence of enterobiasis was determined by making a statistic analysis between sex. We found significantly higher occurrence in males (32.4%) as opposed to females (28.3%) (chi 2-test, p less than 0.001). The infection rates were also significantly different by grade (chi 2-test, p less than 0.001). The highest rate was found in the lower grades (35.3%), the next in the middle grades (32.4%), and the lowest in the higher grades (21.6%). A questionnaire demonstrated that the family status and personal hygiene are the most important factors in transmission of pinworm infection, among the group surveyed. Moreover, the educational levels, occupations of parents, and facilities of bathrooms, (between both primary schools) were also found significantly associated with the transmission of pinworm infection. Therefore, we believe that these factors play a role in transmission of pinworm infection among school children.

[Study on incidence and validity of questionnaire in the diagnosis of oxyuriasis]

Oxyuriasis is one of the commonest infestations in our area, with rates ranging from 5% to 75% in several studies. The present study was carried out in 100% of schoolchildren in a rural town with a population of 1,000 in the Lerida province. The study had two parts. On the one side, the prevalence of oxyuriasis was evaluated with Graham's test; on the other side, a self administered questionnaire was distributed to assess the validity of the surveyed symptoms for the diagnosis of oxyuriasis. The results disclosed a 59.5% prevalence, which was somewhat higher in girls than in boys. The study of diagnostic validity showed that the only symptom with a high yield was the anal and/or genital pruritus. The remaining symptoms could be discarded due to their low reliability.

[Parasite prevalence in schools with different socioeconomic status and evaluation of methods for diagnosing intestinal parasitic diseases]

In this study; the parasite prevalence of schools with different socio-economical status and three methods for diagnosing intestinal parasitosis were evaluated. Children from two primary schools and one junior high school with different socio-economical status participated in the study. The three method used for diagnosing parasitosis in this study were direct wet mounts, concentrated saline flotation technique, and zinc sulfate centrifugal flotation method. Parasitosis was found in 69 fecal samples (18%). The distribution of the parasites found were Hymenolepis nana (29%), Ascaris lumbricoides (26%), Enterobius vermicularis (23%), Trichirus trichiura (18%), taenia saginata (4%). The parasite prevalence in schools with low and high socioeconomical status differed significantly (27% vs. 5% respectively). Combined methods were superior to single methods. The combined method of direct wet mounts and zinc sulfate centrifugal flotation was the most sensitive method (diagnosis rate 90%). But we think that the combined method of direct wet mounts and concentrated saline flotation technique is a simpler method with almost equal results (86%).

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.

Epidemiology and immunology of Necator americanus infection in a community in Papua New Guinea: humoral responses to excretory-secretory and cuticular collagen antigens

Baseline data from an immuno-epidemiological study of hookworm infection in a rural village in Madang Province, Papua New Guinea are reported. Necator americanus was found to be the commonest helminth infection, with a prevalence of near 100% and intensity of 40 worms per host in adults. Enterobius vermicularis, Ascaris lumbricoides and Trichuris trichiura were also present, at prevalences of 53, 10 and 3% respectively; Ancylostoma duodenale was absent. The frequency distribution of N. americanus was highly over-dispersed, and was well described by a negative binomial distribution with aggregation parameter, k, of 0.370. Intensity of infection was significantly related to host age, but did not differ between the sexes. Haemoglobin levels and haematocrit values were indicative of anaemia in the community, but were unrelated to hookworm infection. Levels of antibodies (IgG, IgA and IgM combined) against adult Necator cuticular collagen and excretory-secretory (ES) products were determined. Serum concentrations of the two types of antibody were significantly correlated with each other. Significant positive correlations were found between anti-ES antibody levels and hookworm egg production, and between anti-collagen antibody levels and host age. It is suggested that the level of anti-collagen antibodies may reflect cumulative exposure to infection, whereas levels of anti-ES antibodies may be more dependent on current worm burden. No evidence was found to suggest that either antibody response is important in regulating parasite population growth. Similarly, the presence of a positive correlation between eosinophil concentration and infection intensity in adults indicates that eosinophilia reflects, rather than determines, the host's worm burden.

[An evaluation of the efficacy of measures for preventing enterobiasis in Leningrad Province]

Assessment of the enterobiasis preventive measures in the children's institutions of Leningrad Province demonstrated that wide treatment-and-prophylactic measures didn't reduce enterobiasis. Low efficiency (0.5% of positive results) was found in the sanitary helminthological examination of utensils, which had been performed at the pediatric institutions. The authors found it inexpedient to make planned mass screening of children attending or just entering the preschool institutions. A set of sanitary-and-hygienic and sanitary education measures producing a sustained and reliable effect in enterobiasis control without therapy is proposed to be used.

[Enterobius gregorii Hugot, 1983: its presence in man in Italy and in the Central African Republic]

The presence of E. gregorii, a species recently identified by Hugot in France in man, is signaled by the authors in Italy and in the Central African Republic. The diagnosis was based on the differential morphological characters reported by Hugot and Tourte-Schaefer in 1985.

Cutaneous manifestations of intestinal helminthic infections

Several intestinal helminths may involve the skin. In cutaneous larva migrans and enterobiasis this is often the only organ involved, whereas hookworm and trichinosis are characterized by multisystem disease. The clinical spectrum of strongyloidiasis may range from a low-grade chronic dermatitis to a fulminant, often fatal, hyperinfection syndrome in the immunocompromised host. In the absence of recent breakthroughs in diagnostic testing, a meticulous history and knowledge of the life cycles and the often characteristic skin manifestations of these parasites remain essential to prompt diagnosis and effective treatment.

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.

Oxyuriasis at the Department of Pediatrics, Dr. Pirngadi Hospital, Medan

During the period of 3 months (February-April 1987), a prospective study on oxyuariasis among children had been conducted at Child Health Department of Dr. Pirngadi Hospital Medan. All children over 8 months of age were included in this study. The diagnosis was based on the modified Scoth's technique. Oxyuriasis ova were found in 21 out 119 children (17.65%). The peak incidence was found in the school age.

Enterobius vermicularis infection in a children's ward

Following the discovery that two patients on a children's orthopaedic ward were excreting Enterobius, all patients and staff on the ward were screened for the presence of pinworms. None of the staff was infected but 11 (55%) of 20 patients either had Enterobius ova on the anal margin or excreted worms following piperazine treatment. Epidemiological investigations indicated that this was unlikely to be a ward outbreak because four of the infected children had been on the ward for under 3 days, i.e., less than the prepatent period for Enterobius. Although none of the children was symptomatic, all children and staff on the ward were treated with piperazine. Faecal samples were collected from nine children and the majority of their worm load was shed within 32 h of starting therapy. Microscopic examination of the adult male worms showed that each patient was excreting both Enterobius vermicularis and E. gregorii.

Is pinworm a vanishing infection? Laboratory surveillance in a New York City medical center from 1971 to 1986

Records of our parasitology laboratory were reviewed to determine trends in the frequency of specimens submitted for diagnosis of pinworm infection, the proportion of such specimens that were positive, and the proportion of such positive results for the pediatric age group from 1971 to 1986 in a major New York City medical center. These data demonstrate a markedly declining trend in the absolute number of sticky tape tests sent for pinworm diagnosis, from 248 in 1971 to 38 in 1986, an average of 8% decline per year. The number of specimens identifying Enterobius vermicularis among those submitted has similarly declined, from 57 in 1971 to none being positive in 1986, an average of 16% decline per year. The dramatic decline in pinworm identification and the fall in the number of specimens sent by practitioners at this medical center, and reported elsewhere in the United States by other investigators, may reflect a genuine decline in oxyuriasis occurring in the patient populations served.

[The prevalence of intestinal parasites in the students of two primary schools in Ankara]

Four hundred stool samples obtained from two different primary school students were examined for intestinal parasite. Cellophane tape technique was also applied in order to detect the Enterobiasis incidence. It has been observed that the parasite incidence were 13.5% in TED College Students whereas 30.5% in the Incesu Primary School. It has been also concluded that the highest infection rate was connected with two parasites, namely Giardia intestinalis (11.5%) and Enterobius vermicularis (8%).