Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TAPEWORM INFECTION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1997

Tapeworm infection decreases intestinal transit and enteric aerobic bacterial populations.

Intestinal myoelectric patterns in rats are altered after chronic luminal infection with the tapeworm Hymenolepis diminuta. This study evaluates whether these altered patterns were associated with changes in intestinal fluid transit and endogenous enteric microbe levels. Luminal transit, measured throughout the small intestine during the interdigestive state, was significantly decreased during tapeworm infection. Reduced transit was regional, occurring in the same location as that of the tapeworm and maximal myoelectric alterations. In other experimental systems, aerobic and anaerobic bacterial overgrowth is associated with decreased transit; however, reduced transit during tapeworm infection was unexpectedly associated with decreased numbers of aerobic bacteria, whereas anaerobic bacterial populations remained unchanged. The lack of overgrowing endogenous microflora suggests that overgrowth is not responsible for tapeworm-stimulated alterations in host myoelectric patterns. We speculate that a tapeworm secretion could be responsible for both transit and motility changes while delayed intestinal transit could prevent tapeworm expulsion, aid the tapeworms' migration, and contribute to the digestion and absorption of nutrients by hosts and/or parasites.

Animals↗
PubMed1998

Hymenolepsis diminuta: mucosal mastocytosis and intestinal smooth muscle hypertrophy occur in tapeworm-infected rats.

The mechanisms mediating motility changes during noninvasive tapeworm infection have not been characterized. In contrast, host intestinal motility changes during invasive nematode infection are mediated by mucosal mast cells (MMC). The purpose of this study was to examine and the correlate onset of myoelectric alterations 8 days after initial tapeworm infection with changes in intestinal morphology, MMC numbers, and MMC secretory activity. Segments of the small intestine, the tapeworms normal habitat, along with stomach, colon, and bladder were taken from tapeworm-infected and control rats. Tissues were fixed and stained to identify MMC and for morphologic measurement. Tapeworm-infected and uninfected rats with chronically implanted intestinal electrodes were treated with ketotifen, a mast cell stabilizer, and in vivo myoelectric activity monitored. In tapeworm-infected rats, the muscularis externa, on day 20 postinfection, and crypts of Lieberkuhn, on day 26 postinfection, from the entire small intestine appeared thickened or deeper, respectively. Increased muscularis thickness was due to smooth muscle hypertrophy in both the circular and the longitudinal muscle layers. Mucosal mastocytosis was first observed on day 26 postinfection and occurred only in the ileum of tapeworm-infected rats. Pharmacologic stabilization of mast cells with ketotifen did not prevent onset of enteric myoelectric alterations during tapeworm infection. Stomach, colon, and bladder MMC numbers and tissue dimensions were not different between Hymenolepis diminuta-infected rats and uninfected controls. Initiation of myoelectric alterations 8 days after infection precedes and may be a contributing factor to the onset of both smooth muscle hypertrophy and mucosal mastocytosis. Taken together, our data indicate that mast cells are not an initiating factor nor chronic stimulus maintaining intestinal myoelectric alterations during H. diminuta infection.

Animals↗
PubMed2003

Effects of tapeworm infection on male reproductive success and mating vigor in the red flour beetle, Tribolium castaneum.

Parasites may exert negative effects on host survivorship and reproductive success. The effects of parasites on female host fitness have been well documented; however, the effects of parasites on the reproductive success of male hosts and particularly the underlying mechanisms that alter male fitness are not well understood. Previous studies demonstrated that infection by rat tapeworm (Hymenolepis diminuta) reduced the fitness of male red flour beetles (Tribolium castaneum) in an environment of female mate choice and strong male-male competition. The present study determined the role of female mate choice and male insemination capacity on observed fitness reduction of male beetles by the tapeworm parasites. We found that infected males showed reduced mating vigor and consequently inseminated fewer females than did uninfected males. Specifically, tapeworm infection reduced the number of offspring sired by a male by 14-22% even when male-male competition and female mate choice were absent. Further, the insemination capacity of males diminished by 30% because of infection. Female beetles did not discriminate against infected males in precopulatory mate choice experiments. Copulatory courtship, a determinant of postcopulatory female choice, was not significantly different between infected and uninfected males. Hence, we concluded that female beetles did not show either pre- or postcopulatory choice against tapeworm-infected males. Therefore, tapeworm-induced reduction in the reproductive success of male beetles possibly results from altered reproductive biology, such as lower mating vigor and decreased sperm quantity or quality.

Animals↗
PubMed1984

Fish tapeworm infections (diphyllobothriasis) in Canada, particularly British Columbia.

Although the risk of diphyllobothriasis is generally low in Canada, fish tapeworm infections seem to have become more frequent in recent years. This increase is probably a consequence of the growing popularity of raw or inadequately cooked ethnic fish dishes or of a preference for lightly cooked fish, especially salmon. Only freshwater fish become infected with the larvae, but not everyone may realize that salmon can acquire the parasites before they leave their native lakes and rivers for the sea. If fish known to be sources of the tapeworms are to be eaten raw they should first be well frozen or salted to kill the larvae. Physicians should regard fish tapeworm infection as a notifiable disease. In Canada niclosamide, the drug of choice, is available from the manufacturer on a patient-by-patient basis.

Animals↗
PubMed1981

Effect of mebendazole against Echinococcus granulosus and Taenia hydatigena cysts in naturally infected sheep and relevance to larval tapeworm infections in man.

The ability of three treatment schedules of mebendazole to kill well-established hydatid cysts was studied. Pregnant sheep, naturally infected with Echinococcus granulosus and/or Taenia hydatigena, were treated daily with mebendazole at a dose rate of 50 mg/kg body weight for either five days, one month, or three months. At autopsy, seven months after the commencement of treatment, no evidence was found that the 5-day treatment schedule had any damaging effect on E. granulosus cysts. The effects of the one month treatment were equivocal. There was evidence of a damaging effect from the 3-month treatment schedule and protoscoleces were not infective to dogs. No T. hydatigena cysts survived the 1- and 3-month treatments, but organisms from the 5-day treatment were infective to dogs. These results for E. granulosus in sheep suggest that long-term treatment with mebendazole may be required in hydatid disease in man. The results obtained for T. hydatigena in sheep are discussed in relation to the treatment of cysticercosis from T. solium in man. Mebendazole showed no untoward effect on the sheep or their lambs.

Animals↗
PubMed1976

Comparative effects of uredofos, niclosamide, and bunamidine hydrochloride against tapeworm infections in dogs.

A single dose of a new broad-spectrum anthelmintic, uredofos, was more effective than single doses of either bunamidine hydrochloride (HCI) or niclosamide in removing natural infections of Dipylidium coninum from pound dogs, as determined by necropsy examination for scolices. The efficacy of uredofos was equal to that of bunamidine HCI and exceeded that of niclosamide in removing Taenia spp from his host. All of 12 dogs harboring D caninum and all of 5 dogs harboring Taenia spp were completely cleared of tapeworm infection following treatment with uredofos at 50 mg/kg of body weight. Bunamidine HCl cleared 9 of 11 dogs (82%) of D caninum and 5 of 5 dogs of Taenia spp. Niclosamide had the least anticestodal activity of the 3 drugs; 2 or more scolices of D caninum were found at necropsy in each of 12 dogs treated with this drug. Four of 5 dogs were cleared of Taenia spp following niclosamide therapy. Untreated control dogs did not shed tapeworms of either species during a 3-day period of posttreatment fecal collections, but did have tapeworms at the time of necropsy.

Amidines↗
PubMedDate not supplied

Serology as an indicator of Taenia solium tapeworm infections in a rural community in Mexico.

Serial stool examinations were carried out on a sample of 516 persons living in the town of El Salado (1993 inhabitants). In a group of 40 families (198 individuals), selected by random sampling, there were 2 cases of Taenia solium infection (1.2%); an additional group of 67 families (318 individuals), who volunteered for the study, had 4 cases (1.1%). 5 of the 6 T. solium cases were clustered in 4 neighbouring households. Serum antibodies to the larval stage of T. solium were detected by ELISA using bladder fluid as antigen. 22 members of the random sample group were positive (11%); 58 persons of the total sample of 478 were positive (12%). 43% of individuals living in the same household as a T. solium-infected person were positive, compared to 8.6% seropositive individuals among those not known to have been in daily contact with a T. solium carrier. Odds ratio analysis of the random and total samples showed that the risk of being seropositive when living in the same household as a tapeworm carrier was 9.05 and 6.85 respectively. The results showed a significant correlation between T. solium tapeworm clusters and higher seropositivity rates among contacts rather than among non-contacts. The immune response is a sensitive indicator of a tapeworm infection in a household or family, and is easier to determine than the traditional search for taeniid eggs in stool, a method which is difficult to apply in developing countries due to lack of trained personnel.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Two cases of dipylidiasis (dog tapeworm infection) in children: update on an old problem.

Children in households with dogs and cats may become infected with the dog tapeworm more frequently than suspected. Because of age-appropriate hand-to-mouth exploration, young infants and toddlers, through contact with fleas on pets, floors, and furnishings, are particularly susceptible. Knowledge of the life cycle of this animal parasite and the manner in which children acquire and demonstrate infection can lead to early diagnosis and effective treatment.

Animals↗
PubMed1998

Hymenolepis diminuta fractions but not previous tapeworm infection stimulate intestinal myoelectric alterations in vivo in the rat.

Infection of rats with the enteric, lumen-dwelling tapeworm Hymenolepis diminuta causes electric changes in host intestinal smooth muscle and decreased luminal transit. The mechanisms that stimulate host intestinal alterations during this nontissue invasive infection may include the tapeworm's biomass, its diurnal migratory behavior, a host immune-mediated response, or direct parasite stimulation of host motor activity. In vivo intestinal myoelectric activity was monitored to evaluate the following: (1) that reinfection with H. diminuta is influenced by host immune regulation and (2) that administration of tapeworm fractions to never-before-infected rats initiates an alteration of enteric smooth muscle activity. To address the first hypothesis, we determined that altered intestinal myoelectric activity patterns were no different and did not occur earlier in a second infection with H. diminuta than in a primary infection. The lack of either a change in myoelectric pattern or an earlier onset of intestinal myoelectric changes indicates that tapeworm-induced myoelectric activity is not anamnestically stimulated by host immunomodulatory mechanisms. Consistent with the second hypothesis, administration of either H. diminuta carcass homogenate or tegument-enriched fractions directly into the intestinal lumen of tapeworm-naive rats initiated myoelectric patterns previously characteristic of chronic H. diminuta infection. Additionally, the appearance of characteristic nonmigrating myoelectric patterns in uninfected rats administered tapeworm fractions indicates that a substance from H. diminuta acts as the triggering signal molecule for intestinal myoelectric alterations. These findings also indicate that neither the tapeworm's biomass nor its diurnal movement is required for initiation of H. diminuta-altered myoelectric patterns. We have shown that H. diminuta possess a signal molecule(s) that alters host enteric electric activity, and we suggest that these alterations may play an important role in the symbiotic rat-tapeworm interrelationship.

Action Potentials↗
PubMed2001

Intestinal regrowth is amplified after jejunal but not ileal resection during tapeworm infection in the rat.

The ileum possesses functions required by a healthy individual that are not fully supplanted by the duodenum or jejunum. Evidence suggests that the ileum may also be necessary to maintain an enteric parasite-host interaction. We hypothesized that the ileum is essential to the survival of the lumen-dwelling, rat tapeworm, H. diminuta. Male rats were divided into three groups: those with ileal or jejunal resections and nonresected controls. Half of each rat group was infected with the tapeworm. After jejunal resection, the weight but not length of intestinal remnant (duodenum + ileum) in infected rats returned to that of control, nonresected intestine 29 days after surgery and tapeworm numbers were fully maintained. In contrast, after ileal removal intestinal length and weight of the remaining duodenum and jejunum in infected rats were significantly decreased and tapeworm survival diminished. Data indicates that intestinal growth following resection is amplified by tapeworm infection when the ileum remains but diminished when the ileum is removed. Furthermore, loss of the ileum results in decreased infection intensity and dry weight of the tapeworm.

Animals↗
PubMed1992

Inflammatory responses in the intestine during tapeworm infections. Mucosal mast cells and mucosal mast cell proteases in Sprague-Dawley rats infected with Hymenolepis diminuta.

Comparative studies were made of two populations of Sprague-Dawley rats infected with Hymenolepis diminuta. The time course of infection, the development of mucosal mastocytosis and the levels of rat mucosal mast cell (MMC) protease (RMCP II) in serum and in jejunal mucosal tissues were monitored at intervals after infection with 40 cysticercoids of the tapeworm. Worm expulsion patterns differed markedly between the two populations, rats of New Zealand origin showing an abrupt and clear-cut loss of worms, rats of English origin showing a more gradual decline over a longer time period. In both populations, however, numbers of MMC and levels of tissue RMCP II were positively correlated with time after infection and negatively correlated with worm numbers. In only one of the three experiments (using English strain rats over a short time period) did levels of serum RMCP II change with time. In the other two experiments, in which English-strain and New Zealand-strain rats were used, there were no correlations between serum RMCP II and time, numbers of MMC, numbers of worms or levels of tissue RMCP II. The absence of correlation between serum RMCP II and worm loss in these experiments implies that MMC have no direct role in expulsion of H. diminuta. The data do show, nevertheless, that this purely luminal tapeworm is fully capable of activating the mucosal T lymphocyte-MMC precursor axis to elicit a mucosal mastocytosis.

Animals↗