Gastrointestinal parasites of the colobus monkeys of Uganda

From August 1997 to July 2003, we collected 2,103 fecal samples from free-ranging individuals of the 3 colobus monkey species of Uganda-the endangered red colobus (Piliocolobus tephrosceles), the eastern black-and-white colobus (Colobus guereza), and the Angolan black-and-white colobus (C. angolensis)--to identify and determine the prevalence of gastrointestinal parasites. Helminth eggs, larvae, and protozoan cysts were isolated by sodium nitrate flotation and fecal sedimentation. Coprocultures facilitated identification of helminths. Seven nematodes (Strongyloides fulleborni, S. stercoralis, Oesophagostomum sp., an unidentified strongyle, Trichuris sp., Ascaris sp., and Colobenterobius sp.), 1 cestode (Bertiella sp.), 1 trematode (Dicrocoeliidae), and 3 protozoans (Entamoeba coli, E. histolytica, and Giardia lamblia) were detected. Seasonal patterns of infection were not apparent for any parasite species infecting colobus monkeys. Prevalence of S. fulleborni was higher in adult male compared to adult female red colobus, but prevalence did not differ for any other shared parasite species between age and sex classes.     

Intestinal parasitic infections in pre-school children in the Niger Delta

Stool specimens from 1,062 pre-school children in the Niger Delta were examined for the presence of intestinal parasites. Of that number, 77.6% harboured one or more than one species of intestinal parasites. Ascaris lumbricoides (51.9%) and Trichuris trichiura (41.7%) were the most prevalent species recorded. Other parasites harboured by these children included Hymenolepis sp. (18.3%), Giardia lamblia (9.2%), Entamoeba histolytica (4.6%), Strongyloides stercoralis (1.4%). Hookworm, Taenia sp., Isospora sp. and Trichostrongylus sp. occurred in less than 1% of the children examined. These high rates of infection are associated with poor sanitary conditions prevalent in the area. Improvement of environmental sanitation is advised to reduce human sufferings caused by parasites in that area particularly among children.     

The role of some cyclorrhaphan flies as carriers of human helminths in Malaysia

The role of some adult flies (Diptera: Cyclorrhapha) as carriers of helminth parasites of man was studied at four sites in Malaysia: a refuse dump, where no helminth-positive flies were detected, and in three peri-domestic situations where four species of flies carried up to three types of nematodes. The dominant fly species Chrysomya megacephala (Fabricius) carried eggs of the roundworm Ascaris lumbricoides L., the pinworm Trichuris trichiura (L.) and hookworm on the adult external body surface and in the gut lumen, in association with Bukit Lanjan aborigines. Chrysomya rufifacies (Macquart) and Sarcophaga spp. also had Ascaris lumbricoides and Trichurus trichiura eggs in their gut contents. Human helminths were not recovered from Lispe leucospila (Wiedemann), Lucilia cuprina (Wiedemann) or the housefly Musca domestica L. In an urban slum area of Kuala Lumpur city, filariform larvae identified as the hookworm Necator americanus (Stiles) occurred in the intestines of the face-fly Musca sorbens Wiedemann (22 larvae per 100 flies) and of Chrysomya megacephala (4.5 larvae per 100 flies). This concentration of apparently infective N. americanus in M. sorbens, a fly which often breeds in faeces and browses on human skin, could have transmission potential.     

Strongyloides ratti infection in the large intestine of wild rats, Rattus norvegicus

The large intestine of a rat has been neglected almost completely as a site of Strongyloides sp. infection. We reported that adult Strongyloides ratti remained in the large intestine for more than 80 days, producing more number of infective larvae than small intestine adults, and therefore hypothesized that parasitism in this site could be a survival strategy. In wild rats, however, no study has focused on large intestine infections of Strongyloides. The present study revealed that 32.4% of 68 wild rats, Rattus norvegicus, had the infection of S. ratti in the large intestine, with an average of 4.7 worms. These worms harbored normal eggs in the uterus. In a laboratory experiment with S. ratti and Wister rats, daily output of infective larvae by 4.7 females in the large intestine was estimated to be 4,638.4, suggesting that a few parasites could play a role in the parasite transmission. Five species of nematode found in the wild rats showed seasonality in infection intensity, with highest intensities in March-May. The number of S. ratti in the large intestine was also highest in these months.     

The efficiency of Lutz, Kato-Katz and Baermann-Moraes (adapted) techniques association to the diagnosis of intestinal helminths.

The association of Lutz/Kato-Katz and Lutz/Baermann-Moraes (adapted) techniques was used to improve better results that ranged from 0.4 to 11 times in the search of eggs of Ascaris lumbricoides, Schistosoma mansoni, Trichiuris trichiura, Taenia sp. and larvae of Strongyloides stercoralis.     

Annual follow-up of the gastrointestinal parasitosis of the tepezcuintle,Agouti paca (Rodentia: Agoutidae) in captivity in the Mexican tropic

Previous reports showed that the tepezcuintle (Agouti paca) is commonly infested by gastrointestinal parasites (GIP), mainly Eucoccidiida and helminths. However, there is no available information on the frequency of those parasites and their faecal egg excretions at different moments during the year. These information would provide a valuable baseline for the establishment of control strategies against GIP in tepezcuintles under captivity. The objectives of the present study were to determine the prevalence of GIP orders and genera that infest tepezcuintles under captivity and, to describe the dynamics of faecal egg and oocyst excretion in a year. Ten tepezcuintles were sampled (faeces) twice every month for twelve months. The faecal samples were processed by the flotation and McMaster techniques. Two orders of parasites were determined: Strongylida and Eucoccidiida. Two genera of nematodes were also determined: Strongyloides and Trichuris. The prevalence of Strongylida eggs, Eucoccidiida oocysts and Trichuris sp. eggs reached 10-20% of animals in certain months. The most important genus was Strongyloides, found in 60 to 100% of the animals year round. The average excretion of eggs in the group was 45 to 372 eggs per gram. Tepezcuintles kept under captivity in Yucatan are parasited with Strongyloides sp throughout the year, but only occasionally had oocysts of Eucoccidiida and eggs of Strongylida and Trichuris sp.     

Coprologic evidence of gastrointestinal helminths of forest baboons, Papio anubis, in Kibale National Park, Uganda

The gastrointestinal parasites of baboons have been well characterized from savannah and desert habitats, but little is known about their gastrointestinal parasites in forest habitats. From May to June 2004, we collected 41 fecal samples from free-ranging olive baboons (Papio anubis) within the forested Kibale National Park, Uganda. Samples were examined to determine the prevalence of gastrointestinal helminths in this forest dwelling population of olive baboons. The prevalence of nematodes identified from fecal flotation was Oesophagostomum sp. (85%), Trichostrongylus sp. (22%), Trichuris sp. (46%), Strongyloides sp. (44%), Ternidens sp. (5%), Abbreviata sp. (2%), and Molineus sp. (2%). Flotation techniques also recovered unidentified eggs, probably of hookworm origin (22%). No parasite eggs were recovered by sedimentation of eight samples. Coproculture techniques using 13 of the 41 samples recovered larvae from Oesophagostomum sp., Strongyloides sp., and Trichostrongylus sp. The high prevalence of nematodes recovered in this study seems to support previous theories of high nematode infections in forested habits.     

Liesegang rings in cytologic samples accompanied by calcium oxalate-like crystals. A report of three cases

BACKGROUND: The presence of Liesegang rings (LRs) in cytologic specimens is a morphologic curiosity. The exact mechanism of formation and composition of these peculiar rings is a mystery. Their morphologic resemblance to parasites is well recognized and illustrated. Their association with calcium oxalate-like crystals and their presence in a tubercular lymph node are described for the first time below. CASES: Giemsa-stained aspiration smears from an enlarged lymph node and two breast lumps showed purple rings of variable morphology resembling ova, larvae or adult parasites. Misdiagnosis of parasites was avoided by careful evaluation. In all three cases the LRs were associated with calcium oxalate-like crystals and were nonbirefringent. CONCLUSION: LRs can be mistaken for ova, larvae or adult parasites. Awareness of their varied morphology is helpful in avoiding misinterpretation and overdiagnosis of parasitic lesions. The coexistence of LRs and crystals was an unusual finding in this study.     

Forest fragmentation, the decline of an endangered primate, and changes in host-parasite interactions relative to an unfragmented forest

Forest fragmentation may alter host-parasite interactions in ways that contribute to host population declines. We tested this prediction by examining parasite infections and the abundance of infective helminths in 20 forest fragments and in unfragmented forest in Kibale National Park, Uganda. Over 4 years, the endangered red colobus (Procolobus rufomitratus) declined by 20% in fragments, whereas the black-and-white colobus (Colobus guereza) in fragments and populations of both colobines in unfragmented forest remained relatively stable. Seven nematodes (Strongyloides fulleborni, Strongyloides stercoralis, Oesophagostomum sp., an unidentified strongyle, Trichuris sp., Ascaris sp., and Colobenterobius sp.), one cestode (Bertiella sp.), and three protozoans (Entamoeba coli, Entamoeba histolytica/dispar, and Giardia sp.) were detected. Infection prevalence and the magnitude of multiple infections were greater for red colobus in fragmented than in unfragmented forest, but these parameters did not differ between forests for black-and-white colobus. Infective-stage colobus parasites occurred at higher densities in fragmented compared with unfragmented forest, demonstrating greater infection risk for fragmented populations. There was little evidence that the nature of the infection was related to the size of the fragment, the density of the host, or the nature of the infection in the other colobine, despite the fact that many of the parasites are considered generalists. This study suggests that forest fragmentation can alter host-parasite dynamics and demonstrates that such changes can correspond with changes in host population size in forest fragments.     

Data on intestinal parasites of lower monkeys in the Adler apery

Under captive conditions, a parasite fauna connected with the changes in ecological conditions, feeding, and mode of life is usually formed in monkeys. Species composition of the intestinal parasites has been investigated in six species of the monkeys (Macaca mulatta, M. fascicularis, M. nemestrina, Ceropithecus aethiops, Papio hamadryas, and P. anubis), which were born in the Adler apery and live there for a long time. A comparison with similar investigations carried out in the Sukhumi apery, where the climatic and keeping conditions are practically identical with those in the Adler apery, was conducted. Parasite fauna of monkeys in the Adler apery was found to include three species of Nematoda (Ascaris sp., Trichocephalus sp., and Strongyloides sp.) and two species of Protozoa (Balantidium coli and Lamblia intestinalis). In our material, Trichocephalus sp. is the dominant parasite species among helminthes, and Balantidium coli is the most frequent species of Protozoa. The commonness in the transmission of these parasites and similarity in their life cycles contribute to the forming of polyinvasions in monkeys.     

Prevalence of non-strongyle gastrointestinal parasites of horses in Riyadh region of Saudi Arabia

This study aimed to provide recent data on the occurrence of non-strongyle intestinal parasite infestation in horses in the Riyadh region of Saudi Arabia as a basis for developing parasite control strategies. We conducted necropsy for 45 horses from September 2006 to November 2007 in the Riyadh region, Saudi Arabia. 39 out of 45 horses were infected with intestinal parasites with an infestation rate of 86.6%. Infestations with seven nematode species and two species of Gasterophilus larva were found. The most prevalent parasites were Strongyloides westeri (64.4%) and Parascaris equorum (28.8%) followed by Habronema muscae (22.2%). Trichostrongylus axei and Oxyuris equi were less common at (11.1%) and (8.8%), respectively. Habronema megastoma and Setaria equine were found in two horses only (4.4%). Gasterophilus intestinalis larvae were recovered from 39 horses (86.6%) and Gasterophilus nasalis larvae were found in 17 horses (37.7%). Season had a significant effect on the prevalence of P. equorum and G. nasalis, while age of horses had a significant effect only on the prevalence of P. equorum. The husbandry in Saudi Arabia appears to be conductive to parasites transmitted in stables or by insects rather than in pasture.     

Strongyloides cf. fuelleborni and other intestinal helminths in Papua New Guinea: distribution according to environmental factors

Age graded prevalence rates for Strongyloides cf. fuelleborni, hookworm, Ascaris and Trichuris from various regions of Papua New Guinea were standardised using the standardised mortality technique. Using regression analyses on the resultant Standardised Prevalence Ratios (SPRs) of the four intestinal helminths and rainfall, altitude, slope and relief values, and population density for the various regions no environmental preference was shown which would account for their distribution. However, an examination of parasite distribution in relation to landform and rock type showed that Strongyloides was rare or absent from areas of limestone and polygonal karst although these substrates were quite suitable for other helminths. When the prevalence rates for each of the parasites were separated for high and low altitude (greater than 1,000 and less than 1,000 m a.s.l.) and then age standardised it was shown that there was no difference in hookworm prevalence rates for different altitudes. Both Ascaris and Trichuris had higher prevalences at the higher altitudes, whereas the reverse was true for Strongyloides. The data were also examined to determine whether there was any degree of association between the prevalence of one parasite and another. No association was established between hookworm and Ascaris, hookworm and Trichuris or Ascaris and Trichuris. A positive correlation was demonstrated between hookworm and Strongyloides, although this appears to be a statistical rather than a real association.     

A survey of gastrointestinal parasites of olive baboons (Papio anubis) in human settlement areas of Mole National Park, Ghana

Fecal samples from 55 free-ranging olive baboons (Papio anubis) in Mole National Park, Ghana, were collected 22 June-7 July 2008 and analyzed for gastrointestinal parasites. This is the first survey of baboon gastrointestinal parasites in Ghana and provides baseline data for this area. Ninety-three percent of samples were infected, leaving 7% with no parasites observed. Of those infected, there was a 76% prevalence of strongyles, 53% Strongyloides spp., 11% Abbreviata caucasica , 62% prevalence of Balantidium coli (trophozoites and cysts identified), 4% Entomeba hystolytica/dispar, and 47% unidentified protozoan parasites. Of the strongyle infections, 9% were identified as Oesophagostamum sp. One sample contained an unidentified spirurid nematode that resembled Gongylonema sp. Mole has a mixed forest-savanna habitat, and baboons frequently range into human areas, which makes them subject to parasites from each habitat and multiple sources of exposure. We found a high prevalence of nematode parasites, consistent with a wet or cooler forest environment, or high rates of fecal contamination. The presence of Strongyloides sp., E. hystolitica/dispar, and B. coli suggest potential public health risk from baboons, but molecular identification of these parasites, and documentation of their presence in local human populations, would be necessary to confirm zoonotic transmission.     

Effects of stocking density and food density on survival,growth and yield of laboratory-reared larvae of sea bream Archosargus rhomboidalis (L.) (Sparidae)*

Growth and survival of sea bream, Archosargus rhomboidalis (L.) larvae were affected by both abundance of eggs that were initially stocked in 75 1 rearing systems and by the concentration of copepod nauplii and copepodites that were fed to larvae. Stocking levels were 2, 4, 8,16 or 32 per litre while food abundance was maintained at approximately 100, 500, 1500 or 3000 per litre. Experiments were of 16 days duration at 26° C. Survival was best, often exceeding 60%, when food levels were 1500 or 3000 per litre and when stocking density did not exceed 8 eggs per litre. Growth was best at the lowest stocking densities and highest food levels. The highest total yields in wet weight occurred at 8 per litre stock density and 3000 per litre food level. Mean wet weight per survivor and yield per stocked egg were greatest at the lowest stocking densities and highest food levels. A 500 per litre food level was marginal for growth and survival, and 100 per litre produced significant survival only at the 2 per litre stocking density. Two experiments at 6000 and 10 000 per litre food levels at 4 per litre stock density gave the best observed growth, and survival as good as in any other experiments. Possible relations between sea bream larvae and their food supply in the natural environment are discussed. Results also are discussed in terms of their possible contribution to aquaculture efforts.     

Trichuris sp. and Strongyloides sp. infections in a free-ranging baboon colony

We conducted cross-sectional surveys of parasites infecting a large free-living colony of baboons at the Southwest National Primate Research Center in San Antonio in October 2003 and April 2004, immediately before, and 6 mo after, treatment with ivermectin. Trichuris sp. was the predominant species present, infecting 79 and 69% of individual animals in the 2 surveys, with fecal egg counts (FEC) of up to 60,200 eggs per g (epg) (mean = 1,235 in October 2003 and 1,256 in April 2004). Prevalence remained fairly stable across age groups, and intensity was highest in animals <1 or >15 yr old, in contrast to patterns observed in humans, where school-age children show the heaviest infections. Strongyloides sp. was also identified, but the species identity remains uncertain. Small subunit ribosomal DNA sequences differed from published sequences of Strongyloides fuelleborni at multiple sites, but resided in a monophyletic group with other Strongyloides species with 92% bootstrap support. This may reflect a recent acquisition from a local host, or that the published sequence of S. fuelleborni is incorrect. Widespread infections with 2 nematode genera in a free-ranging baboon colony that are an important source of morbidity in human populations provide a useful model system for work on the epidemiology, control, pathology, and genetics of these parasites in a host species that is physiologically, immunologically, and genetically similar to humans.     

Intestinal helminthiases and schistosomiasis among school children in an urban center and some rural communities in southwest Nigeria

Intestinal helminths and schistosomiasis among school children were investigated in an urban and some rural communities of Ogun State, southwest Nigeria. Fecal samples of 1,059 subjects (524 males, 535 females) aged 3-18 years were examined using direct smear and brine concentration methods between June 2005 and November 2006. The pooled prevalence of infection was 66.2%. Ascaris lumbricoides showed the highest prevalence (53.4%) (P < 0.001) followed by hookworms (17.8%), Trichuris trichiura (10.4%), Taenia sp. (9.6%), Schistosoma mansoni (2.3%), Strongyloides stercoralis (0.7%), Schistosoma haematobium (0.6%), and Enterobius vermicularis (0.3%). The prevalences of A. lumbricoides, hookworms, Taenia sp., S. mansoni, and S. stercoralis in the urban centre were similar (P > 0.05) to those in the rural communities. The fertile and infertile egg ratios of A. lumbricoides in the urban centre and the rural communities were 13: 1 and 3.7: 1, respectively. Each helminth had similar prevalences among both genders (P > 0.05). The prevalence of A. lumbricoides increased significantly with age (P < 0.001). The commonest double infections were Ascaris and hookworms, while the commonest triple infections were Ascaris, hookworms, and Trichuris. The study demonstrates the need for urgent intervention programmes against intestinal helminthiases and schistosomiasis in the study area.     

Occurrence of Gasterophilus intestinalis and some Parasitic Nematodes of Horses in Sweden

A survey was performed on the occurrence of some internal parasites in 461 horses (1–30 years old) slaughtered from October 1992 to September 1993 at the Linköping abattoir in central Sweden. Macroscopical examination was carried out specifically for parasites of the tear ducts and conjunctival sacs of the eyes, and of selected parts of the alimentary tract and car-dio-vascular system. The following parasites were found in selected parts of the large intestine: encapsulated cyathostome larvae (in 35.6% of the horses), and mature strongyle worms (17.4%); in the stomach: Gasterophilus intestinalis (12.3% during October-June) and Habronema muscae (1.1%); and in the conjunctival sac: Thelazia lacrymalis (3.1%). Significantly more encapsulated cyathostome larvae were found during January to June than during other times of the year, and horses aged 1–5 years harboured significantly more larvae than older horses. Severe damage to the cranial mesenteric artery and its main branches was noticed in 16 (6.1%) out of 263 horses specifically examined. However, the 4th stage larva of Strongylus vulgaris was only recovered in 6 (2.3%) of the horses. Quantitative and qualitative faecal egg counts were done on 412 and 384 of the horses, respectively. Eggs of strongyles, Parascaris equorum and Strongyloides westeri were found in 78.1%, 1.9% and 0.2% of the faecal samples, respectively. Highest prevalence of strongyle eggs was found during July to September. Third stage larvae of the following nematodes were recovered from faecal cultures: subfamily Cyathostomum sensu lato (78.1%) Triodontophorus spp. (6.5%), Strongylus vulgaris (3.6%), Trichostrongylus axei (1.3%), while Gyalocephalus sp., Oesophagodontus sp., Poteriostomum sp. and Strongylus edentatus each comprised less than 0.5%.     

Intestinal parasites in Kampuchea, Takeo Province

Fresh stool samples obtained from 1407 adult patients who sought treatment in Takeo province hospital and 332 Takeo preschool and school-age children from 3 to 18 years of age were examined for the presence of intestinal parasites using the technique of native preparation and the flotation method of Faust with subsequent staining with Lugol solution to demonstrate cysts. In hospital patients, a total of 13 protozoan and 9 helminth species were diagnosed. The prevalence of Entamoeba histolytica (cysts and trophozoites) was highest in the age group 15-18 years (18.3%), the peak prevalence of Gairdia lamblia (27.6%) occurred in children of the age group 6-9 years. The highest frequency distribution of Pentatrichomonas hominis (20.1%) was recorded in 3 to 5 years old, that of Enteromonas hominis (12.8%) in 6 to 9 years old. The predominant helminth was Ancylostoma duodenale, with the peak prevalence (65.2%) in patients older than 18 years, followed by Ascaris lumbricoides and Strongyloides stercoralis. Almost half of children patients under 6 was infected with at least two species of parasites, patients over 6 were infected simultaneously with two or more intestinal parasites in an absolute majority of cases. In Takeo preschool and school children the spectrum of diagnosed protozoan and helminth species was somewhat narrower than seen in hospital patients, but their prevalence rates were higher, except for the flagellate Pentatrichomonas hominis. The highest prevalence rates recorded were for E. histolytica 29.5% (age category 10-14 years), for G. lamblia 34.8% (age category 6-9 years), for P. hominis 19.3% (age category 3-5 years), for E. hominis 10.5% (age category 3-5 years), for A. duodenale 85.9% (age category 15-18 years), for A. lumbricoides 26.1% (age category 6-9 years), and for S. stercoralis 18.8% (age category 6-9 years). As many as 70% of children at the age between 6 and 15 years were simultaneously infected with two or three species of intestinal parasites.     

Intestinal parasites of Agouti paca (Rodentia: Dasyproctidae) in Costa Rica

In a sample of 23 breeding places of pacas (Agouti paca) in Costa Rica, the following parasites were found: Eimeria agoutii, Balantidium coli, Capillaria sp., Trichuris sp., Taenia sp., Strongyloides sp., and members of the superfamilies Strongyloidea and Ascaroidea.     

Helminth parasites of the Eurasian otter Lutra lutra in southwest Europe

The helminth fauna in 109 Eurasian otters (Lutra lutra L.) from France, Portugal and Spain was analysed, together with 56 faecal samples collected in Portugal and 23 fresh stools from otters included in a reintroduction programme. Seven helminth species were found in L. lutra in southwest Europe: Phagicola sp. (Trematoda), Aonchotheca putorii, Eucoleus schvalovoj, Strongyloides lutrae, Anisakis (third stage larvae) and Dirofilaria immitis (Nematoda), and Gigantorhynchus sp. (Acanthocephala). Eucoleus schvalovoj was the dominant species throughout southwest Europe. Strongyloides lutrae was significantly more prevalent in the Iberian Peninsula than in France. Apart from these two dominant nematodes and A. putorii, the other helminth species were incidental parasites of L. lutra in southwest Europe. The helminth fauna of L. lutra in southwest Europe is, in general, poorer than that reported in eastern Europe and in all other aquatic mustelids in southwest Europe. Phagicola specimens are reported for the first time in a non-marine wild carnivore in Europe. The prevalences of E. schvalovoj and S. lutrae obtained by necropsy were higher than those observed by coprological analysis using a formalin-ether concentration method (Ritchie). Nevertheless, the culture of fresh faeces appears to be the best method to study infection of L. lutra by Strongyloides.