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PubMed1998

Influence of antibodies in mother's milk on antigenic variation of Giardia lamblia in the murine mother-offspring model of infection.

In the present study, neonatal ZU.ICR mice and their mothers were infected with trophozoites of Giardia lamblia clone GS/M-83-H7 expressing the variant surface protein (VSP) H7. The infection experiments included a detailed analysis of the specificities of anti-Giardia immunoglobulin A (IgA) antibodies in mother's milk and a determination of the effects of the milk antibodies on both the growth of the parasite during in vitro cultivation and colonization of the parasite within the intestine of suckling offspring. These investigations revealed that transiently emerging milk IgA antibodies against a variant-specific 314-amino-acid N-terminal region of VSP H7 exhibit a strong parasiticidal effect on VSP H7-type trophozoites both in vitro and in vivo. These findings indicated that parasiticidal effects of local IgA antibodies against the N-terminal part of VSP H7 select for new variant types within the intestinal parasite population of suckling mice. The selective influence of such antibodies promotes in vivo antigenic variation of G. lamblia clone GS/M-83-H7 and modulates the early course of parasite infection in these animals.

Animals↗
PubMed1998

Preliminary identification of an intestinal coccidian parasite in man.

An unidentified coccidian parasite was observed in saline faecal smears of five immunocompromised patients. Very few of these organisms were observed in the oocystic stage. They were oval in shape with rounded edges and contained two sporulated sporocysts, 7.5-9.5 um in diameter with a nipple like projection. They are smaller than sporocysts of Sarcocystis hominis and suihominis. For further identification, the modified Ziehl-Neelsen stain was used. The sporocysts showed variability in staining. Most of them were unstained while those stained were more or less rounded with well defined four crescent shape sporozoites and a residual body but with an unstained cyst wall. Sporocysts were positively stained by phenol auramine which had the advantage of staining the cyst wall. Other coccidial parasites encountered in this study were Cryptosporidium parvum (18.2%), Cyclospora cayetanensis (1.8%) and Isospora belli (0.9%) they were differentiated from this organism. SEM showed oval sporocysts with thickened ridges on its surface dividing it into plates which is a characteristic feature of the family Sarcocystidae. From the above characters, the features of this parasite is suggested to be a Sarcocystis like Protozoa.

Animals↗
PubMed1979

Failure of nude (athymic) rats to become resistant to reinfection with the intestinal coccidian parasite Eimeria nieschulzi or the nematode Nippostrongylus brasiliensis.

The course of each of three successive infections with Eimeria nieschulzi in nude (athymic) rats was the same as the primary infection in nu/+ animals, with the production of more oocysts. This indicates that resistance to reinfection with this parasite is mediated by T lymphocytes but that these cells do not control the duration of the life cycle, since oocyst production was not prolonged in the nu/nu rats. After the three infections with E. nieschulzi, the rats were exposed twice to the intestinal nematode Nippostrongylus brasiliensis, and the nu/nu were completely susceptible even to the second infection. Egg production by both infections in the nu/nu animals was similar and continued at a high plateau level for 28 days before falling to a low level. It appears that the strain of N. brasiliensis used in this study is unable to sustain high egg production for more than 4 weeks in T cell deficient rats.

Animals↗
PubMed1979

Parasitic disease in humans: the extent in Canada.

Much is being said, often dramatically, about the potential hazards of parasitic diseases in Canada, but little or no attempt has been made to determine the true extent of the problem. Indigenous parasite pathogens are recognized in resident Canadians, and pathogens are acquired by travellers abroad or reported from immigrants. The role of each of these categories is important in the characterization of the problem of parasitic diseases in Canada. From data provided by provincial laboratories and hospitals it is estimated that 1 person in 1000 will spend 1 day per year in hospital because of intestinal parasites, and 1 in 100 each year will have a diagnosis of intestinal parasitic infection made from examination of a stool sample.

Amebiasis↗
PubMedDate not supplied

[Intestinal parasitosis in the inhabitants of a suburban zone in which the groundwater is polluted by nitrates of fecal origin (Yeumbeul, Senegal)].

This study was carried out in 1997 to 1998, to determine the prevalence of intestinal parasite infestations due to groundwater pollution at Yeumbeul, Senegal, and to follow the progression of parasite infestations following anti-parasite treatment. The study included 705 people living in a suburban zone in which the water table was polluted with nitrates of fecal origin. These individuals consumed either well water or water from springs. The overall prevalence of parasite infestation was 42.26%, but varied significantly with age (p < 0.001). Individuals who consumed well water were more frequently infested than those who consumed spring water, but the difference was not significant (p > 0.3). Giardia and Entamoeba coli were the most frequently isolated parasites, with Giardia predominating in the 0 to 9 year age-group. There was no significant correlation between the prevalence of the various parasites and indicators of water pollution (R2 = 0.0566 for nitrates and 0.1086 for fecal coliform bacteria). Similarly, no correlation was found with water pollution factors such as the depth of the water table (R2 = 0.027) and the distance between the wells and the latrines (R2 = 0.00007). Following specific treatment, the prevalence of parasite infestation fell to 30.81%. This indicates the limitations of drug treatment, which is always used alone to combat intestinal parasites, in the face of possible reinfestation.

Adolescent↗
PubMed1981

Intestinal disaccharidases in malnourished infant rats.

In infants suffering from protein-calorie malnutrition, the decreased intestinal mucosal lactase specific activity could be due either to the protein-calorie malnutrition or to the commonly associated enteritis (viral or bacterial) and intestinal parasites. We studied intestinal mucosal disaccharidase (lactase, sucrase, and maltase) specific activity in suckling (1 and 2 wk old), weanling (3 wk old), and postweaning (4 and 6 wk old) control and growth-retarded (malnourished) rats. Growth retardation was induced by feeding mother rats and postweaning rats a diet deficient in protein. In the malnourished rats, with few exceptions, specific activity of the disaccharidases in the intestinal mucosa were similar to those in the corresponding control groups of rats. However, because of marked mucosal atrophy total intestinal mucosal disaccharidase activities were more than 50% lower in the malnourished rats. These findings suggest that the specific activity of the intestinal mucosal disaccharidases is not affected by malnutrition per se.

Animals↗
PubMed1990

Enzyme-linked immunoassay for detection of Cryptosporidium antigens in fecal specimens.

Cryptosporidium sp. is a ubiquitous 4- to 6-micron protozoan parasite infecting the intestinal tract of humans. It causes mild to fulminant diarrhea in patients, especially immunocompromised persons, and it may be hard to detect by microscopic fecal examination. An indirect, double-antibody enzyme-linked immunosorbent assay (ELISA) was developed using specifically produced goat and rabbit antisera to detect Cryptosporidium antigens in human feces. Of 62 frozen stools from patients with cryptosporidiosis, as detected by at least two microscopic diagnostic techniques, 51 were positive by ELISA; all ELISA-negative specimens came from patients with fewer than five oocysts per 0.01 ml of concentrated fecal sample examined after modified acid-fast or fluorescent monoclonal antibody staining. A total of 182 specimens from persons without Cryptosporidium infection were negative by ELISA in 176 instances; 3 ELISA-positive specimens came from patients with cryptosporidiosis diagnosed earlier. The sensitivity of the assay was 82.3%, and specificity was 96.7%. The predictive value of a positive ELISA was 89.5%, and the predictive value of a negative ELISA was 94.2%. The ELISA was not affected by the presence of eight other intestinal parasites but was sometimes affected by repeated freezing and thawing of fecal specimens. All fecal specimens were heated to 100 degrees C for 2 min to reduce proteolytic enzyme activity, although the necessity of this step needs further evaluation. This first-generation ELISA is a simple, rapid, easily standardized test for Cryptosporidium antigens in stool samples which will be useful for diagnosis and for large-scale epidemiologic studies.

Animals↗
PubMed1991

Immunoglobulin E in the feces of children and adolescents from some tropical and subtropical countries.

Eighteen of 27 individuals, aged from 6 months to 19 years (mean 5 years, 7 months), from countries in the tropics or the subtropics had either intestinal parasitic infestations or intestinal enteropathogenic bacterial infections or both. Fourteen of those with intestinal pathogens had detectable concentrations of IgE in their fecal extracts, ranging from less than 0.5 to 420 IU/ml extract (mean 33 IU/ml). This rate of occurrence was significantly higher than the number of IgE-positive fecal extracts in a group of 54 healthy nonallergic Norwegian children (p less than 0.001), but did not differ from that of a group of 40 allergic children (p greater than 0.20). The individuals with intestinal helminthic infection had the highest fecal IgE concentrations. Of the 9 individuals who did not have any demonstrable intestinal pathogen, low concentrations of IgE could be detected in feces from only 2, which did not differ from the rate in the healthy Norwegian controls. The concentrations of IgE in the feces of the subjects from tropical/subtropical regions correlated linearly with the corresponding serum concentrations of IgE (r = 0.69; p less than 0.001). The results indicate that the combined load of intestinal pathogens, including helminths, protozoa, and enteropathogenic bacteria, may stimulate IgE production in the gut.

Adolescent↗
PubMed1977

Parasitic infections in Black children in an endemic schistosomiasis area in Natal.

Urine and stool specimens from 856 school children aged from 7 to 20 years, and from 80 preschool children, were examined for Schistosoma haematobium and intestinal helminths and protozoa. S. haematobium was present in 57% with a peak of 81% in 13-14-year-old children. Peak intensity preceded peak incidence and egg loads gradually decreased with age. There was no clear-cut difference between boys and girls with regard to intestinal parasites, nor was there a close correlation between the incidence of Schistosoma spp. and that of the intestinal parasites. There was a considerable reduction in the incidence of Ascaris lumbricoides and Trichuris trichiura infestation with age.

Adolescent↗
PubMed2002

Worm infestation and anaemia: a public health problem among tribal pre-school children of Madhya Pradesh.

A study to assess the status of intestinal parasitosis and anaemia was carried out among the pre-school children of Gond tribal community in Kundam block of Jabalpur district, Madhya Pradesh. A total of 985 pre-school children were covered. The results revealed that 48% pre-school children had intestinal parasitic infections. Common parasites observed among them were Hymenolepis nana, hookworms and roundworms. Mean epg for these parasites ranged from 371.2 to 1221.8. High prevalence of anaemia (86.7%) was also observed among them. This high prevalence of intestinal parasitic infections and anaemia could be due to indiscriminate defecation, low socio-economic status, ignorance and low standard of personal hygiene. Comprehensive control strategy with specific intervention measures need to be evolved and implemented specially in tribals as serious efforts are being madeby the Govt. for their overall development.

Anemia↗
PubMed2005

Concurrent infection with an intestinal helminth parasite impairs host resistance to enteric Citrobacter rodentium and enhances Citrobacter-induced colitis in mice.

Infections with intestinal helminth and bacterial pathogens, such as enteropathogenic Escherichia coli, continue to be a major global health threat for children. To test the hypothesis that intestinal helminth infection may be a risk factor for enteric bacterial infection, a murine model was established by using the intestinal helminth Heligomosomoides polygyrus. To analyze the modulatory effect of a Th2-inducing helminth on the outcome of enteric bacterium Citrobacter rodentium infection, BALB/c and STAT 6 knockout (KO) mice were infected with H. polygyrus, C. rodentium, or both. We found that only BALB/c mice coinfected with H. polygyrus and C. rodentium displayed a marked morbidity and mortality. The enhanced susceptibility to C. rodentium and intestinal injury of coinfected BALB/c mice were shown to be associated with a significant increase in helminth-driven Th2 responses, mucosally and systemically, and correlated with a significant downregulation of protective gamma interferon and with a dramatic upregulation of the proinflammatory tumor necrosis factor alpha response. In addition, C. rodentium-associated colonic pathology in coinfected BALB/c mice was significantly enhanced, whereas bacterial burden was increased and clearance was delayed. In contrast, coinfection in STAT 6 KO mice failed to promote C. rodentium infection or to induce a more severe intestinal inflammation and tissue injury, demonstrating a mechanism by which helminth influences the development of host protective immunity and susceptibility to bacterial infections. We conclude that H. polygyrus coinfection can promote C. rodentium-associated disease and colitis through a STAT 6-mediated immune mechanism.

Animals↗
PubMed1997

Blastocystis hominis among apparently healthy food handlers in Jeddah, Saudi Arabia.

A prospective study was carried out to investigate the prevalence of Blastocystis hominis among random sample of apparently healthy food handlers. A total of 250 non Saudi males over 21 years of age were examined. Ninety (36%) had pathogenic and non pathogenic intestinal parasites. A total of 143 parasites were detected in their stool specimens. Twenty were B. hominis (13.99%) while other parasites were 123 (86.01%). B. hominis was found in 20 positive cases (22.22%) with an overall rate of 8%. Of these twenty cases, two had B. hominis as a sole parasite, twelve as a double infection and six as a triple infection. Other intestinal parasites were found, Giardia lamblia (16.8%), Entamoeba histolytica (10%), E. coli (6.4%), Chilomastix mesnili (5.6%), Trichomonas hominis (1.2%), and Endolimax nana (0.8%). The helminths were represented by Ascaris lumbricoides (4%), Hymenolepis nana (3.2%), Enterobius vermicularis (1.2%) and Trichocephalus trichiura (0.8%). No doubt, B. hominis should be in mind of parasitologists and physicians when dealing with patients with gastrointestinal troubles.

Adult↗
PubMed1982

Studies on parasites of African snakes.

As part of the studies on the parasites of wild life, forty (40) snakes caught by trapping were examined for blood and gastro-intestinal parasites. Capillaria, Trichomonas intestinalis, Eimeria bitis, Ascaris and oxyurids were the the gastro-intestinal parasites found while Haemoproteus columbae was the only blood parasite found. In this investigation, parasites found in the snakes were identified as the public health importance of the disease examined.

Animal Population Groups↗
PubMed1976

Parasitic infections in humans in West Kalimantan (Borneo), Indonesia.

A survey was carried out among inhabitants of eight villages in West Kalimantan Province (Borneo), whereby blood smears were examined for malaria, stools examined for intestinal parasites and sera tested by the indirect hemagglutination test for antibodies to Entamoeba histolytica and toxoplasma gondii. The prevalence of malaria among 3017 people examined was 5.6% (Plasmodium vivax 2.8%, Plasmodium falciparum 2.8%). Brugia malayi microfilariae were found in 3.6% and Wuchereria bancrofti in 0.3%. Ninety-seven percent of 2101 stool specimens examined contained evidence of intestinal parasites. Trichuris trichiura (90%) was most common followed by Ascaris lumbricoides (76%), hookworm, (60%), Etamoeba coli (23%), Entamoeba histolytica (6%), Endolimax nana (6%), Iodamoeba butschlii (4%), Giardia lamblia (3%), Chilomastix mesnili (1%) and Strongyloides stercoralis (1%). Other parasites found were Entamoeba hartmanni, Trichomonas hominis, Balantidium coli, Enterobius vermicularis, Hymenolepis nana, Echinostoma sp. and Physalopterid, Dicrocoeliid, and Heterophyid type-eggs. The amoeba prevalence rate was 30%. Indirect hemagglutination antibody titers equal to or greater than 1:128 for Entamoeba histolytica and 1:256 for Toxoplasma gondii were detected in 7% and 3%, respectively, of 1511 sera tested.

Adolescent↗
PubMed2000

[Chronic diarrhea: value of microbiology in diagnosis].

Chronic diarrhoea of the adult is defined as diarrhea during 30 days or longer. Frequent causes of chronic diarrhea in the immunocompetent adult without recent travel to developing countries are noninfectious processes, including laxatives misuse, diseases causing chronic maldigestion, osmotically active artificial sweeteners (i.e. sorbitol), hormonal disorders or drugs with intestinal side effects. Infectious agents as the cause of chronic diarrhea are important in two populations, namely in travelers returning from tropical countries bearing a significant risk of intestinal parasitic infections and in immunocompromised patients, especially AIDS patients with CD4 cell counts below 50 per microliter. Intestinal parasites and C. difficile, Y. enterocolitica, Shigellae and Cytomegalovirus are the most important causative agents of chronic diarrhea. Intestinal pathogens were identified in 46% of chronic, but only in 16.5% of acute diarrhea episodes of HIV-infected patients. An extensive medical history including recent travel as well as the detailed characteristics of onset of symptoms and of their time course is essential for the diagnosis. All patients should have a complete differential blood count, ESR, determination of electrolytes, liver enzymes, creatinine, blood glucose, and serum albumin. Tests to exclude hyperthyriodism, or pancreatic insufficiency as well as a d-xylose absorption test can be included, if appropriate. Microbiological-parasitological investigations are obligatory in patients with chronic diarrhea returning from countries with increased risk of traveler diarrhea, in cases of suspected immunodeficiency, if sudden onset of symptoms with fever is reported, after antibiotic treatment, and in children below six years of age. As a rule, stool specimens are appropriate, for the detection of cytomegalovirus colonic biopsies are necessary. In the latter case colonosigmoidoscopy has no diagnostic advantage. One single stool specimen is sufficient for the detection of bacteria or toxins, in contrast to parasitological investigations, where only three consecutive specimens provide sufficient diagnostic sensitivity.

Adult↗
PubMed1977

Intestinal helminth parasites of the ray Raja naevus in British waters.

Five cestode, one monogenean, and two nematode species comprised the "normal" intestinal helminth fauna of Raja naevus in British waters. An additional two nematodes, a digenean, an acanthocephalan and a crustacean recorded are considered to be accidental infections. Geographical differences in the species composition and level of infection are noted and discussed. Short descriptions of the tetraphyllidean cestode Echeneibothrium sp. and the nematode Capillaria sp. are given, but the species, although probably both new, are left unnamed. The intensity of cestode infections show two patterns associated with host length and these are discussed in relation to variations in host diet. Speculations are made on the cestode life cycles. Only Echeneibothrium sp. numbers showed any significant variation associated with host sex.

Animals↗