Transmission Of Cysts Research Articles

Prevalence and fertility Status of hydatid cysts in Sheep and Goats slaughtered in selected abattoirs in Adamawa State, Nigeria

Hydatidosis is one of the neglected zoonotic diseases of unrecognised importance that is caused by the dog tapeworm of thegenus Echinococcus. A study on the prevalence and fertility of hydatid cysts was conducted in sheep and goats slaughtered insome abattoirs in Adamawa State, Nigeria. A total of 1,603 animals comprising 760 sheep and 843 goats were examined forhydatid cysts by visual inspection, palpation and incision. A total of 31 (1.93%) of the study population harboured hydatidcysts, comprising 72 hydatid cysts in 13 (1.71%) sheep and 116 hydatid cysts in 18 (2.14%) goats. There was no significantdifference (p>0.05) in prevalence of hydatid cyst infection among sheep and goats. Age –specific prevalence of hydatid cystswas higher in goats 18(2.1%) than Sheep 13(1.7%), goats and sheep that were >3years old recorded highest prevalence(3.25%; 2.32%). There was no significant difference (p>0.05) in prevalence of cysts in different age groups. Prevalence ofcysts was higher in female sheep (1.96%) and goats (2.98%) than male sheep (1.49%) and goats (1.66%), the difference wasnot statistically significant (p>0.05). The number of hydatid cysts recovered in infected sheep was 72(25.0% fertile, 31.9%sterile and 43.0% calcified cysts) and 116 (47.4% fertile, 15.5% sterile and 25.9% calcified cysts) in goats. Highest number offertile cysts were recovered in lungs of sheep and goats (41.7%; 83.7%) than in their liver ( 16.7%; 37.8%). The differencewas not statistically significant (p>0.05). The most commonly infected organ was liver (66.7%) in sheep and lungs (68.1%)in goats. In conclusion, fertility of cysts in sheep and goats may serve as a potential source of transmission of hydatidosis todogs and continuation of its lifecycle. Strict regulation of slaughtering process including proper disposal of infected offalwould minimize transmission of cysts from intermediate to definitive hosts.
 Keywords: Prevalence, Hydatid cysts, fertility, Sheep, Goat, Adamawa State

Retrospective and Comparative Study of Giardia sp. Prevalence in Dogs, Cats, and Small Ruminants in Endemic Areas in Different Brazilian States

Background: Giardia, an intestinal parasite of asexual reproduction, is an important etiologic agent of diarrhea in animals and humans, transmitted by orofecal route. The disease caused by this agent, giardiasis, is endemic in the world and representing an important public health problem. The aim of the present study was do a retrospective study to determine the prevalence of Giardia sp. in fecal samples from dogs, cats, sheep and goats (small ruminants) evaluated at FMVZ Unesp, Botucatu, SP. In addition, this study presents a review of the literature on the prevalence of this protozoan in dogs, cats and small ruminants in different states of Brazil, according to the environmental of these animals.Materials, Methods & Results: During 2011 to 2017, 2,698 fecal samples of dogs, 359 fecal samples of cats and 320 fecal samples of goats and sheep were analyzed. A total of 18.9% of the dogs, 24.8% of the cats, and 6.6% of the goats and sheep were positive for Giardia sp. Only previous studies that used the zinc sulphate centrifugal flotation (Faust technique) were included for comparation of prevalence. The prevalence of Giardia sp. in samples of centrifugation-fluctuation in zinc sulfate was similar in dogs, higher in cats and lower for small ruminants when compared to previous investigations. 4.4% and 6.7% of the positive samples from dogs and cats, respectively, were associated with some co-infection. Co-infections by Cystoisospora spp., Ancylostoma spp. and/ or Toxocara spp. were the most common for dogs and cats.Discussion: This study reveals the presence of Giardia sp. in different animal species in an endemic área. The results are similar to the prevalence previous reported in dogs, and higher in cats using the same diagnostic technique (Faust technique). Co-infections by Cystoisospora spp., Ancylostoma spp. and/ or Toxocara spp. were the most common for dogs and cats, as well-known in previous studies. Investigations with household, shelter and stray dogs found a significantly lower occurrence of Giardia sp. in the group of household dogs. However, for cats these comparisons should made with caution. Despite having a owner, some of these cats have free access to the streets, so they might be more expose to the sources of infection. There are few previous reports of the presence of Giardia sp. in goats and sheep, which presented much higher prevalence when compared with this study. This variation in prevalance of Giardia sp. in small ruminants can occur due to differences inherent to each region in Brazil, as well as the presence of risck factors regarding animal age, type of raising of the animals, hygienic-sanitary and management conditions, and the presence of domestic animals inside sheep and goat installations, which can potentially favor the mechanical transmission of cysts our reservoirs of this parasite. Therefore, due to regional variations in this parasite prevalence, this information is more value in regional areas, reaffirming the importance of this kind of studies in brazilian states and cities. The intermittent elimination of cysts in feces, the low number of cysts in the samples and asymptomatic infections are relevant points to the diagnosis of giardiasis, making it a challenge. The technique of centrifugation-flotation technique in zinc sulfate gives the best results when compared to other techniques available for the diagnosis of Giardia infections, justifying the choice of this technique by this study. These evidences associated to molecular diagnoses are necessary to determine the real role of these animals in the epidemiology and zoonotic transmission, due to the close contact with humans. This may be considering as a start for further investigations of Giardia sp. at municipality of Botucatu.

Do Cysts of Endamoeba histolytica Formed in the Intestine Excyst Before Evacuation and Cause Internal Autoinfection?

The following study was designed to determine whether internal antoinfection from cysts of Endamoeba histolytica occurs. By internal autoinfection is meant the excystation of cysts formed in the intestine and their invasion of the tissues of the host without leaving the body. The term does not refer to “anus to mouth” transmission of cysts nor to reinvasion of the gut by the trophozoites. Sellards and Theiler claim to have infected 6 of 8 kittens by injecting material containing cysts only into the colon following laparotomy. In each case a silk ligature was tied around the large bowel and the inoculum injected above the point of ligation. Hoare exhibited sections of the intestine of a kitten, presumably infected with Endamoeba histolytica by the rectal injection of cysts alone. According to Wenyon, Drbohlav has stated that he was able to confirm these observations. However, these results are open to question, since the information for the most part is incomplete, there was a possibility of trophozoites being in the inoculum or the results were obtained under abnormal conditions. Negative results were obtained by Izar, who, in a single instance, inoculated one adult cat per rectum with a patient's stool containing cysts and presumably no trophozoites. No symptoms developed. Hegner, Johnson and Stabler failed to produce infection in a brown howler monkey after injection of a human strain of cysts per anum into the colon. In the present study 24 healthy young dogs, in addition to controls, were used. All animals were carefully examined before use to insure that none were naturally infected with ameæ. Precautions were taken to eliminate the possibility of the inoculum's reaching the mouth and thus causing infection by the normal route.