Fecal Parasite Research Articles

Rapid trichrome stain.

A rapid trichrome stain procedure was evaluated. It saves considerable time, especially when only a few slides are stained, and allows for the accurate identification of amoebae and other fecal parasites.

Genetic control of resistance to infection with Nematospiroides dubius in mice: selection of high and low immune responder populations of mice

F1, Quackenbush (Q) x Wild (W) Mus musculus were assayed and selected for their level of immunity to secondary infections with 100 Nematospiroides dubius using faecal parasite egg counts. A significant positive linear correlation was found between the number of parasite eggs voided in the faeces and the number of N. dubius recovered after secondary infections in mice. Selection for immunity was not influenced by the conformation of the mice. High (H) and low (L) responder colonies together with a randomly (Rd) bred colony of mice were established over 5 generations. Adaptive immunity was more efficacious in protecting female than male mice and appeared to be controlled by a few dominant genes; the heritability (h2) of the trait was estimated at 0.56 for the parental stock and 0.55 for the F5 Rd colony and the realized heritability was 0.49. Higher anti-N. dubius antibody titres were detected in H than L mice. H mice harboured fewer and less fecund parasites than Rd colony mice; L mice had more worms with greater fecundities than Rd mice. The levels of primary infections in H and L mice related to the levels developed after secondary infection from F4. This suggested at least partial linkage of genes controlling innate with genes controlling adaptive immunity against N. dubius.

MULTIPLE INFECTIONS WITH NEMATOSPIROIDES DUBIUS IN MICE SELECTED FOR LIABILITY TO A SINGLE INFECTION

The faecal egg counts and worm burdens of mice selected over 7 generations as refractory (R), random (Rd) or liable (L) to primary infection with Nematospiroides dubius were significantly different, but the antibody titres (generation 8 mice) after 21 days infection were similar, demonstrating that selection had separated populations of mice which differed in their innate immunity. Variations in adaptive immunity were also shown between the three colonies in terms of protection after challenge infections, self-cure reactions, humoral antibody titres and ability of immune serum from R, Rd and L donors to passively protect recipient Quackenbush (Q) strain mice. R mice were more refractory to primary infection and more proficient in acquiring protective levels of adaptive immunity than L colony mice. Correlation of the faecal parasite egg count after primary with that after secondary infection supported the conclusion that the genetic control of liability to primary infection and of the adaptive immune response following challenge infections were at least partially linked.

The relative importance of rotavirus and other pathogens in the etiology of gastroenteritis in Trinidadian children.

Over a 2-year period, 300 infants less than 3 years old with gastroenteritis admitted to hospitals in Trinidad were investigated for the presence of certain microorganisms in the feces, along with an equal number of age- and sex-matched controls. Rotavirus was detected in 23% of cases and 1% of controls; Salmonella in 7% of cases and in 1% of controls; Shigella in 4% of cases and in no controls and two serotypes of enteropathogenic E. coli in 7% of cases and in 2% of controls. Campylobacter fetus subspecies jejuni was cultured from 7 out of 60 cases and from 1 of 60 controls. Enterotoxigenic E. coli, most strains of enteropathogenic E. coli, cytopathic enteroviruses and adenoviruses and fecal parasites were not significantly associated with diarrhea. Rotaviruses were detected throughout the year but were more prevalent in the dry than in the rainy season. They were found less often in children younger than 6 months than in those aged 6 to 35 months and were present in 6 of the 20 children who died.

Nutritional status, globulin titers, and parasitic infections of two populations of Tanzanian school children

Two schools in rural Tanzania were surveyed regarding the pupils' nutrition (weight and height), serum immunoglobulins (IgA, IgG, IgM, and IgE), autoantibodies, malaria antibodies, hepatitis B antigenemia, and fecal and urinary parasites. The survey attempted to quantify the relative importance of undernutrition and parasitic infestation in determining the serological abnormalities found. Of all the children surveyed 69% were undernourished (less than 80% of expected weight for age); 63% had fecal parasites and 38% had urinary schistosomiasis. Serum IgG and IgM concentrations were raised and the serum IgE concentration was strikingly raised (mean 4990IU/ml). Elevated serum IgE was associated with ascariasis. Autoantibodies were common but no autoimmune disease was detected. Notably there was a 35% prevalence of reticulin antibody. This reticulin antibody positivity correlated with increased malaria antibody concentrations. Reduced malaria antibody concentration was significantly associated with hepatitis B antigenemia. The study illustrates that parasites, notably malaria, are important determinants of the serum antibodies of children in the tropics and suggests that mild undernutrition has little effect.

Studies on cross-transmission and pathogenicity of Haemonchus contortus in white-tailed deer, domestic cattle and sheep.

Experiments were conducted to compare the relative pathogenicity and infectivity of deer- and cattle-derived Haemonchus contortus for three hosts, viz., white-tailed deer, cattle and domestic sheep. Parameters evaluated for all animals were: general physical condition, basic hematologic values, fecal egg counts and parasite infectivity rates. Clinical signs attributable to H. contortus infections were not observed in any of the experimental animals. Deer harboring H. contortus burdens greater than 70 worms/kg body weight had decreased packed cell volume, hemoglobin and total serum protein values. Statistical analyses indicated there was not a significant difference (P greater than .05) in infectivity of deer-derived H. contortus in these hosts. No significant difference (P greater than .05) in infectivity for deer was noted between deer-derived H. contortus and cattle-derived H. contortus. Morphometric comparisons of helminths recovered indicated that parasites of deer and cattle origin were both compatible with the description for H. contortus. Results suggest that cross-transmission of H. contortus occurs between deer and domestic livestock.

Distribution and abundance of intestinal helminths in man in western Papua New Guinea with special reference to Strongyloides.

A faecal parasite survey was conducted in 32 isolated villages in six regions of western Papua New Guinea. Of 1023 samples, only 155 were without helminth eggs. Strongyloides cf. fuelleborni, the causative agent of an acute fatal infection in infants in a localized area, was found to be widely distributed in western Papua New Guinea, but has not, as yet, been found north of the dividing range. The infection is largely restricted to forested areas within the 4000 mm isohyet, but ranges in altitude from near sea level to 1500 m. Hookworm infection is almost universal but infections are rarely heavy. Ascaris and Trickuris have anomalous distributions, being inexplicably extremely rare or absent in many isolated areas. There is a marked scarcity of occasional infections of zoonotic origin.

Relationships between hemoglobin type and reproduction, lamb, wool and milk production and health-related traits in crossbred ewes.

Relationships among hemoglobin (Hb) types and production traits were examined in 294 crossbred ewes from North Country Cheviot, Dorset, Finnsheep and Romney rams, and Suffolk and Columbia-type ewes. Hb BB ewe lambs were youngest at first estrus, while Hb AA ewe lambs were oldest. Ewe lamb fertility was similar for Hb AB and Hb BB ewes, and both were superior to Hb AA ewes. When Finnsheep crossbreds were excluded, from which Hb BB was absent, Hb BB ewes had higher ewe lamb fertility than did Hb AB ewes. There was a minor advantage of the A over the B allele in ewe lamb prolificacy. Hb BB ewes were highest, Hb AB ewes were intermediate and Hb AA ewes were lowest for average fertility, prolificacy per ewe lambing, lambs born per ewe exposed to mating, total number of lambs weaned and total kilograms of lamb weaned. Grease wool production, staple length, fiber diameter grade, incidence of medullated fibers and incidence of cotted fleeces all were similar across Hb types. Likewise, Hb type did not affect milk production or composition. Ewes with Hb AB had the lowest incidence of footrot; Hb AA and Hb BB ewes were similar. Ewes with Hb AA had the lowest fecal parasite egg counts, while ewes with Hb AB or Hb BB were similar. Ewes with Hb AA also had the lowest incidence of mastitis, Hb BB ewes were intermediate and Hb AB ewes were highest. The combination of overdominance (as for footrot resistance), beneficial effects of the A allele on health-related traits (as for mastitis and parasite resistance) and the beneficial effect of the B allele on reproductive traits, if real, could partly explain the genetic polymorphism commonly reported at the Hb locus in sheep.

Gastroenteritis in Auckland: An aetiological and clinical study

SummaryFaecal specimens from 60 patients (under six years old), most of whom were Maoris and Pacific Islanders admitted to Auckland Hospital with gastroenteritis during the months of June and July 1977, were examined for the presence of faecal viruses, bacterial pathogens and parasites. Faecal specimens from 18 non-diarrhoeal control patients were also examined, of which three contained rotavirus. Forty-three (72 per cent) gastroenteritis patients had rotavirus detectable in stools by electron microscopy or immune electron microscopy. Of the remainder, 17 patients were regarded as having non-rotavirus diarrhoea. Enterotoxigenic Esch. coli. was isolated from seven patients of whom six yielded stable toxin producers (ST+), four labile toxin producers (LT+) and two dual toxigenic strains (ST+/LT+). All ST+ isolates appeared to be of low enterotoxigenicity as indicated by low gut weight/carcass weight ratios in the infant mouse assay. Rotavirus was the commonest aetiological agent (72 per cent), bacterial pathogens (alone) accounted for only five per cent and no enteric pathogens were found in 15 per cent of cases. Non-agglutinable rotavirus, presumably a different serotype, was seen in both gastroenteritis and control patients. Rotavirus ‘satellite’ particles previously undescribed were demonstrated in a number of stool samples.

Periparturient and seasonal rise in the trichostrongylid egg output of infected ewes during the dry season in Northern Nigeria

The faecal parasite egg output of lambing and non-lambing ewes in two sheep flocks in the dry season of 1975/1976 and 1976/1977 was determined. Ewes wormed at the end of the rainy season showed a very low parasite egg output during the dry season of 1975/ 1976. No periparturient rise of parasite eggs was detectable in the ewes which lambed in December or January. Towards the end of the dry season the parasite egg counts in the faeces increased and the highest counts were observed in lactating ewes. The parasite egg output at the beginning of the dry season was apparently due to recently acquired infections, mainly Trychostronglus sp. The increase in egg output at the end of the dry season was related to the development of inhibited larvae mainly of Haemonchus sp. This development was detectable from the end of February onwards. The differences in parasite egg output during the two seasons was associated with different rainfall patterns during 1975 and 1976.

IgE, parasites and asthma in Tanzanian children

Two rural Tanzanian primary schools were surveyed to test the hypothesis that parasitic infestation prevents the development of asthma. 242 pupils were interviewed to determine the prevalence of pupils with recurrent episodes of wheezing. The nineteen pupils so discovered had more exercise-induced bronchial lability than equivalently exercised controls. More girls (12.8%) than boys (3.3%) had asthma. In one school, 77% of the controls had faecal parasites, mainly Ascaris spp., and in the other school 55% of the controls had Schistosoma haematobium in their urine. Parasites were found in similar proportions in the asthmatics. The mean serum IgE for the whole population was 3174 u/ml with no demonstrable difference between the asthmatics and controls. There was no difference in immediate cutaneous hypersensitivity to twenty-two allergens between the asthmatics and controls. These findings suggest that parasitic infestation does not prevent the development of asthma.

Further observations on the formol-ether concentration technique for faecal parasites.

Further observations on the formol-ether concentration technique for faecal parasites.

Gastrointestinal nematodes of donkeys in and around Alage, South Western Ethiopia

Gastrointestinal parasites are one of the most common factors that constrain the health and working performance of donkeys. The present study was aimed to estimate the prevalence and identify major risk factors associated with donkey’s gastrointestinal nematode infection in and around Alage, South Western Ethiopia. A total of 384 randomly selected donkeys were sampled from 4 peasant associations for coprological examination of gastrointestinal nematode infection. The direct fecal smear, flotation and fecal culture methods were utilized to identify the eggs and larvae of parasites in feces, respectively. The overall prevalence of gastrointestinal nematodes recorded in donkeys examined was 99.5%. The study showed that the prevalence of Parascaris equorum, Oxyuris equi and Strongyle were 53.6%, 4.9% and 99.5%, respectively. Significantly (P<0.05) higher prevalence was observed for Oxyuris equi and Parascaris equorum in young donkeys than in both adults and old donkeys. The study showed that the prevalence of Strongyle was significantly higher than both Parascaris equorum and Oxyuris equi in all age groups of donkeys. There was also statistically significant difference in prevalence of gastrointestinal nematodes between sex, age, body condition and among peasant associations in different species of the parasites. Identification of third stage larvae of Strongyle species from 40 samples revealed high prevalence of Strongylus vulgaris (100%) followed by Cythostomes (97.5%) and Strongylus edentates (70%). The current study demonstrated that gastrointestinal nematodes are the major health challenges of donkeys in the study area. Therefore strategic dewrming and other nematode control options were recommended to be considered in order to improve the health, productivity and welfare of donkeys in the study area.Keywords: Donkeys; Ethiopia; Gastrointestinal; Nematodes; Prevalence

Protozoan infection in archaeological material

The identification of parasites in ancient human feces is compromised by differential preservation of identifiable parasite structures. However, protein molecules can survive the damage of the environment. It was possible to detected antigen of Entamoeba histolytica and Giardia duodenalis in historic and prehistoric human fecal remains using two enzyme immunoassay (ELISA) kits with monoclonal antibodies specific for E. histolytica and G. duodenalis, respectively. Specimens of desiccated feces and ancient latrine sediment from the New and the Old World were examined. The ELISA detected E. histolytica antigen in samples from Argentina, USA, France, Belgium, and Switzerland, dated to about 5300 years BP to the 19th Century AD. G. duodenalis antigen was detected in samples from USA, Belgium, and Germany, dated to about 1200 AD, 1600 AD, and 1700 AD. The detection of protozoan antigen using immunoassays is a reliable tool for the study of intestinal parasites in the past.

A Simple Method for Differential Staining of Fecal Smears Containing Protozoan Parasites

A Simple Method for Differential Staining of Fecal Smears Containing Protozoan Parasites

A Critical Study of Clinical Laboratory Technics for the Diagnosis of Protozoan Cysts and Helminth Eggs in Feces

Summary In summary, as a result of inquiry into the basic factors governing these 5 technics, the iodine-dilution technic has been found to be slightly more efficient in the actual quantitative recovery of diagnosable Endamoeba coli and E. histolytica cysts from a given amount of fecal material than is the hematoxylin-film technic or centrifugal floatation. It is considerably more efficient than centrifugation and superior to sedimentation. However, when the factors of concentration are considered, the apparent enrichment by centrifugation may be 4- or 5-fold that of the iodinedilution technic, while centrifugal-floatation, using zinc sulphate solution (sp. g. 1.180) as the diluent, provides a concentration which may be as high as 1000-fold. We are now testing the centrifugal-floatation technic, with zinc sulphate as the levitating medium, for comparison with the iodine-dilution technic in routine fecal diagnosis. As soon as an adequate series of specimens has been examined and the results have been analyzed, we expect to be in a position to recommend a simplified, practical method for clinical laboratory diagnosis of parasites in feces.