Benefit of the control of gastrointestinal nematode infection in goats in the dry zone of Sri Lanka

The benefit of gastrointestinal nematode control in cross-bred goats in the dry area of Sri Lanka was studied throughout 1 year by comparing the performances of three groups: group 1 animals (n = 11) were left untreated against gastrointestinal nematodes; group 2 animals (n = 11) were given monthly anthelmintic treatment. doramectin, at the dose rate of 300 microg/kg bodyweight during the entire study period; group 3 animals (n = 11) were also given monthly doramectin treatment at the dose rate of 300 microg/kg bodyweight but only during the rainy months, October to January and again once in April. All three groups were turned out together on to communal pasture. Tracers were used for the monthly estimation of gastrointestinal nematode burdens. Four untreated animals and a group 3 animal suffered from parasitic gastroenteritis during the study period. When compared with the controls, the treated groups had significantly lower gastrointestinal nematode infection as indicated by faecal egg counts (P<0.01). Faecal egg counts in group 3 were significantly higher than those in group 2 (P < 0.01). When compared with the controls, the treated groups had significantly greater weight gains (P< 0.05). Haemonchus contortus and Trichostrongylus colubriformis were the predominant gastrointestinal nematodes identified from tracers. The worm burden varied according to the rainfall pattern, with very minimal transmission during the dry period which extends from May to August. Under the conditions of this study, the monthly anthelmintic treatments increased weight gains and prevented parasitic gastroenteritis of goats in the dry zone of Sri Lanka.     

Prevalence of Cryptosporidium infection in goats in selected locations in three agroclimatic zones of Sri Lanka

The prevalence of Cryptosporidium oocysts in the faeces of 1020 goats in three age categories was examined during 1999 in selected locations of three agroclimatic zones of Sri Lanka. The oocysts were demonstrated using the Sheather's sucrose flotation method followed by staining with the modified Ziehl Neelsen technique. Cryptosporidium oocysts were detected in animals from all agroclimatic zones with the highest prevalence of infection in the dry zone (33.6%) compared with 24.7 and 21.7% in the intermediate zones and wet, respectively (P<0.001). Overall, Cryptosporidium oocyst counts were significantly higher in goats of <6 months and 7-12 months of age groups compared with goats of >12 months of age (P<0.001). Cryptosporidium oocysts were detected in 291/1020 (28.5%) animals, while 194/1020 animals (19%), 84/1020 animals (8.2%) and 13/1020 animals (1.3%) excreted low (1-1000 oocysts per gram of faeces), moderate (1000-5000 oocysts per gram of faeces) and high (>5000 oocysts per gram of faeces) counts, respectively. The mean Cryptosporidium count was 383 oocysts per gram of faeces. The majority of the infected goats were asymptomatic. These animals are likely to play an important role in the epidemiology of cryptosporidiosis in goat kids and humans.     

Detection of Cryptosporidium oocysts in soil samples by enzyme-linked immunoassay

An ELISA protocol was adapted for detection of Cryptosporidium parvum oocysts in soil samples and the limit of detection of the test was determined. A modified indirect antigen capture ELISA protocol was developed using monoclonal antibodies against the oocyst outer wall. The accuracy of the ELISA was compared to spiked soil samples and measured in terms of sensitivity and specificity of the test. The performance of the ELISA was evaluated in field soil samples and measured using the kappa-statistics. Similarly, the performance of the ELISA was compared to the concentration flotation method, to a modified concentration flotation method and to a commercial ELISA (ProSpecT) in field fecal and soil samples.The limit of detection of the test was selected to be 10,000 oocysts/g. At this limit of detection, the ELISA had a sensitivity of 95% and specificity of 100%. The agreement between the ELISA and the modified flotation-concentration method in detecting Cryptosporidium oocysts in soil samples was 32% (kappa=0.32). The ELISA had the same relative sensitivity (82%) in comparison to both the flotation and ProSpecT in determining Cryptosporidium-infection status of an animal. The kappa-statistics was 0.26 for both tests. The developed ELISA proved to be a valuable diagnostic test for detecting oocysts in soil samples and has a potential application in determining the infection status of animals.     

Seroprevalence of Sarcosystis spp. in cattle and buffaloes from the wet and dry zones of Sri Lanka: a preliminary study

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibodies to Sarcosystis infection in cattle and buffaloes. Crude antigens derived from cystozoites of Sarcosystis cruzi and antibodies from the sera of naturally infected cattle and buffaloes were used. The assay was validated by determination of the specificity, sensitivity and negative and positive predictive values. Using ELISA, a sero-epidemiological survey for sarcosystosis was carried out in cattle (n = 215) and buffaloes (n = 123) from the wet and dry zones of Sri Lanka. The prevalence of infection in cattle was 69.3%. Prevalence of the infection collectively in both cattle and buffaloes in the dry zone was significantly higher (P < 0.001) than that in the wet zone. The number of sero-positive cattle and buffaloes in the dry zone was significantly higher than that in the wet zone (P < 0.05). Buffaloes in the dry and wet zones showed a greater prevalence of infection (P < 0.05) than cattle.     

Asymptomatic shedding of Cryptosporidium oocysts by red deer hinds and calves

Levels of Cryptosporidium infection in a group of red deer were monitored over a period of 1 year. Faecal samples were examined on an approximate monthly basis from adult hinds and calves for the presence of Cryptosporidium oocysts. The water-ether sedimentation method followed by sucrose flotation and a monoclonal antibody identification procedure were used. It was found that apparently healthy adult deer were shedding low numbers of oocysts in their faeces throughout the year and that there appeared to be a periparturient increase in the numbers of oocysts shed. Samples taken from 6-month-old deer calves, both in-house and on pasture, had low numbers of Cryptosporidium oocysts, indicating that the calves were also asymptomatically shedding oocysts.     

Anatomical studies into the ruminal mucosa of pygmy goats in relation to their age

The ruminal mucosa of 15 pygmy goats of different age (Z1 approximately 4-5 months, Z2 approximately 1 year, Z3 approximately 1.5-5 years) were studied gross-anatomically concerning their colour, clumping of papillae, fodder precipitations on the papillae, areas poor in papillae or devoid of them and the development of papillae. The density of papillae/cm2 in the 3 groups investigated was 79.4; 67.3; 58.0; the mean length of the papillae (mm) 1.75; 1.86; 2.96; the mean breadth of the papillae (mm) 1.3; 1.2; 2.0; the area of the ruminal mucosa (cm2) 799; 943; 1 195; the area of the ruminal pillars (cm2) 38; 41; 69; the number of the papillae/rumen 59,940; 58,022; 64,782; the total absorptive area (cm2) 3,802; 3,854; 11,268; the surface magnifying factor 4.0; 3.4; 8.4.     

Histological studies into the ruminal mucosa of pygmy goats in relation to their age

Ruminal mucosae of 15 pygmy goats of different age (Z1 approximately 4-5 months, Z2 approximately 1 year, Z3 approximately 1.5-5 years) and sex were investigated histologically. The thickness of the Stratum corneum of the 3 experimental groups was in the Atrium ruminis 23.0, 23.0 and 29.1 microns, in the Recessus ruminis ventralis 22.8, 28.0 and 30.0 microns, that of the Stratum germinativum and Stratum granulosum in the Atrium ruminis 74.8, 78.4 and 82.3 microns and in the Recessus ruminis ventralis 87.4, 84.7 and 87.7 microns, that of the Corpus papillare in the Atrium ruminis 75.3, 75.2 and 74.4 and in the Recessus ruminis ventralis 85.0, 78.9 and 71.6 microns. The cell nuclear volumes of the basal and parabasal cells of papillae originating from the Atrium ruminis (a) and the Recessus ruminis ventralis (b) in the individual experimental groups were in case of a 103.2; 100.2 and 117.3 microns3 resp. in case of b 93.4; 96.4 and 119.7 microns3.     

猪源隐孢子虫卵囊的分离及基因型鉴定

应用RT-PCR方法对南京、上海和合肥猪源隐孢子虫卵囊SSU rRNA部分序列进行扩增,产物测序后提交GenBank,收录号为DQ855266、DQ855267;用BLAST和DNAStar软件与GenBank参考序列进行比较,分析其同源性,绘制系统发育进化树,结合卵囊形态学观察和对小鼠、大鼠、兔、山羊和鸡的传染性试验确定隐孢子虫种类或基因型。结果表明,3地区猪源隐孢子虫分离株与微小隐孢子虫(C.parvum)同源性达94%~100%,与C.parvummouse型有99.8%~100%的同源性,并处于进化树的同一分支。因此,3地区猪源隐孢子虫是C.parvummouse型,提示猪和鼠之间存在交叉传播的可能。     

Knowledge,attitudes, and practices (KAP) related to brucellosis and factors affecting knowledge sharing on animal diseases: a cross-sectional survey in the dry zone of Sri Lanka

Farmers’ lack of knowledge is assumed to have affected the presence of brucellosis in Sri Lanka for decades. This study, carried out in the Ampara district in the dry zone of Sri Lanka, revealed that there is a significant knowledge gap for brucellosis compared to foot and mouth disease (FMD) (p?<?0.001). Only 8.3% of farmers knew that brucellosis causes cattle abortions. Only 2.6% knew that it is zoonotic. The difference in knowledge of the symptoms and transmission of brucellosis and FMD was significant (p?<?0.001). Farmers’ attitudes and practices related to the spread of the disease were poor. Farmers’ education and spoken language had a negative influence on knowledge. Young people and those with strong social relationships were efficient in knowledge sharing. It can be concluded that brucellosis knowledge, attitudes, and practices are poor; thus, there is a need for more attention in disease control policymaking. Backward farmer groups should be the focus in animal health extension programs.     

Experimental Cryptosporidium baileyi infections in chickens and turkeys produced by ocular inoculation of oocysts

Developmental stages of Cryptosporidium baileyi were observed on the conjunctival epithelium of 3 of 14 chicks and none of 7 turkeys following ocular inoculation of oocysts. No clinical signs of disease were observed in chicks or turkeys. All 14 chicks had developmental stages of C. baileyi in the cloaca, whereas 4 of the 7 turkeys were infected at this site.     

Excretion of Eimeria alabamensis oocysts in grazing calves and young stock

The aims of the present study were to investigate the excretion of Eimeria alabamensis oocysts by young cattle during their first grazing season and during the first 16 days of their second grazing period. In trial 1, nine first-season grazing heifers were studied and found to have become infected with E. alabamensis shortly after turnout. The next grazing period they were turned out on to a permanent pasture together with two first-season grazing calves. Faecal samples were collected before turnout and then daily from day 3 to day 16. The second-season grazing heifers excreted insignificant numbers of E. alabamensis oocysts, whereas one of the two first-season grazing calves excreted up to 703,000 oocysts/g of faeces (OPG), indicating that the pasture was contaminated. In trial 2, faecal samples were collected from 12 calves before their first turnout in May, daily from day 2 to day 20 after turnout and then once a week until the end of September. The calves grazed pastures used in previous years by first-season grazing calves. Nine of the calves developed clinical E. alabamensis coccidiosis 4-7 days after turnout and excreted more than 950,000 OPG on days 9-10. By day 17 the oocyst excretion had decreased below 900 OPG and remained low throughout the rest of the grazing season. The results of the two studies indicate that reinfections with E. alabamensis are of little clinical importance in calves grazing contaminated pastures, and that young stock infected with E. alabamensis during their first grazing season may be used to cleanse contaminated pastures without risk of developing clinical coccidiosis.     

Observations on the pathogenicity for sheep and goats and the transmissibility of the strain of virus isolated during the rinderpest outbreak in Sri Lanka in 1987

The pathogenicity for sheep and goats of the virus strain that caused acute rinderpest in cattle and domestic buffalo in Sri Lanka after an interval of over 40 years has been examined. The results show that it can cause overt clinical disease in goats, but only mild or unapparent infection in sheep. The disease was transmitted from infected sheep to in-contact susceptible sheep and calves.     

Comparison between Sri Lankan and Australian strains ofBabesia bovis in the vaccination of imported cattle in Sri Lanka

Summary A Sri Lankan strain ofBabesia bovis (designated A strain) was isolated from larval ticks and prepared for use as vaccine by syringe-passage in 20 splenectomised calves followed by irradiation. The A strain and a vaccine strain ofBabesia bovis (designated K strain) brought in frozen form from Australia were used to vaccinate 37 susceptible bulls imported from southern Australia. Rectal temperatures, packed cell volumes, parasitaemias and overt clinical signs were monitored for three weeks following vaccination. The results indicated that the A strain was slightly more virulent than the K strain but suitable for the vaccination of well-supervised cattle.

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Comparacion Entre Las Cepas Sri Lankan Y Australiana DeBabesia Bovis En La Vacunacion De Ganado Importado A Sri Lanka

Resumen Se aisló en Sri Lanka, una cepa deBabesia bovis (denominada cepa A), de larvas de garrapatas. Esta se preparó, para ser utilizada como vacuna, mediante el pasaje a través de 20 terneros esplenectomizados e irradiándola posteriormente. La cepa A y la cepa vacunal (cepa K) traída congelada de Australia, se utilizaron para inmunizar 37 toros susceptibles importados del Sur de Australia. Se tomó la temperatura rectal, el volumen corpuscular, la parasitémia y se registraron los síntomas clínicos de los animales vacunados, por un período de tres semanas. Los resultados indican, que la cepa A fue un poco más virulenta que la K, pero efectiva para la inmunización de animales bajo buena supervisión.

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Comparaison Entre Des Souches Sri-Lankaises Et Australiennes DeBabesia Bovis Pour La Vaccination Du Betail Importe A Sri-Lanka

Résumé Une souche sri-lankaise deBabesia bovis (dénommée souche A) a été isolée de larves de tiques puis préparée comme vaccin par passage à la seringue chez 20 veaux splénectomisés, suivi d'irradiation. On a utilisé la souche A, ainsi qu'une souche vaccinale deB. bovis apportée congelée d'Australie (dénommée souche K), pour vacciner 37 taureaux réceptifs importés d'Australie méridionale. Les températures rectales, les hématocrites, les parasitémies et les signes cliniques patents ont été consignés pendant les 3 seamines aprés la vaccination. Les résultats montrent que la souche A est légèrement plus pathogène que la souche K, mais cependant utilisable pour la vaccination de bovins bien surveillés.

     

Association of herd composition, stocking rate, and duration of calving season with fecal shedding of Cryptosporidium parvum oocysts in beef herds

OBJECTIVE: To evaluate the association of herd demographics, parturition variables, stocking rate, and rotational grazing practices with the probability of fecal shedding of Cryptosporidium parvum from beef cow-calf herds in California. DESIGN: Cross-sectional study. SAMPLE POPULATION: 38 beef cow-calf operations. PROCEDURE: Fecal specimens were collected and examined for C parvum oocysts, using immunofluorescent microscopy. Association between various demographic and management factors and the probability of shedding C parvum were statistically evaluated. RESULTS: Adjusted for age and month of collection of a fecal sample, cattle from herds with a high number of young calves (< or = 2 months old) on the day of sample collection, a high stocking rate (No. of cattle/acre/mo), or a longer calving season were more likely to shed C parvum oocysts, compared with cattle from herds with fewer young calves, a lower stocking rate, or a shorter calving season. Cattle from herds with a higher number of older calves (> 2 months old) on the day of sample collection were less likely to shed C parvum oocysts, compared with cattle from herds with fewer older calves. Using our multivariate model, rotational grazing systems or season of onset of calving were not associated with shedding status for C parvum oocysts. CONCLUSIONS AND CLINICAL RELEVANCE: Reproductive management that would result in a shorter calving season and use of a lower stocking rate for cattle may be associated with reduced risk of C parvum shedding. Intensive rotational grazing systems and time of year for onset of calving season apparently have little effect on reducing prevalence of oocyst shedding.     

Infectivity of Cryptosporidium parvum isolated from asymptomatic adult goats to mice and goat kids.

An experimental study was carried out in neonatal goat kids to examine the infectivity of Cryptosporidium oocysts, pattern of oocyst shedding and morphological changes in the intestine during the infection. Cryptosporidium oocysts isolated from adult asymptomatic goats, and identified as C. parvum by polymerase chain reaction (PCR) were used in this study. Of three 4-day-old goat kids, two were orally infected with C. parvum oocysts (10(5) oocysts in 10 ml PBS/kid). One goat kid given 10 ml PBS only by the oral route served as a control. Cryptosporidium oocysts were detected in the faeces of one infected kid on day 3 post-inoculation (pi) whereas in the other 6 days pi. The faecal oocyst counts gradually increased and the peak counts in the two kids were 2 x 10(6)g(-1) (on day 12 pi) and 3.2 x 10(6)g(-1) (on day 14 pi). The increase in faecal oocyst output coincided with diarrhoea in an infected kid from days 10-17 pi. Although the oocyst excretion declined gradually after the peak, both infected kids excreted oocysts until euthanized on days 20 and 22 pi. Light and scanning electron microscopic investigations of the ileum revealed the endogenous stages on the brush border of the enterocytes, infiltration of neutrophils and mononuclear cells into the lamina propria, atrophy, stunting and fusion of villi. For purposes of comparison, goat Cryptosporidium oocysts were inoculated orally (10(3) oocysts/mouse) to eight, 1-week-old mice. All experimental mice excreted oocysts from day 3 pi, and four infected mice continued to excrete oocysts up to day 42 pi. The experimental infection described in goat kids resembled the natural disease in terms of oocyst excretion, clinical signs and intestinal pathology. The ability of oocysts excreted by asymptomatic goats, to infect goat kids and mice is likely to have a major impact on the epidemiology of cryptosporidiosis in livestock and man.     

Fecal shedding of Cryptosporidium oocysts in healthy alpaca crias and their dams

Objective-To determine the apparent prevalence of shedding of Cryptosporidium spp in healthy alpaca crias and their dams on 14 farms in New York and 1 farm in Pennsylvania. Design-Cross-sectional study. Animals-110 alpaca crias and their 110 dams. Procedures-Fecal samples were obtained from 220 alpacas at 14 alpaca farms in New York and 1 farm in Pennsylvania. For each animal, age, sex, and health condition were recorded. A fecal score (1 = normally formed; 2 = soft or loose; 3 = diarrhetic) was recorded for each cria. Cryptosporidium oocysts were identified in fecal samples by a direct immunofluorescence assay. Results-Apparent prevalence of fecal shedding of Cryptosporidium oocysts was 8% (95% confidence interval, 4% to 15%) in dams and was 7% (95% confidence interval, 3% to 13%) in crias. There was no significant difference in age between dams with positive fecal test results for Cryptosporidium oocysts (median age, 4 years; range, 3 to 8 years) and dams with negative results (median age, 4 years; range, 2.5 to 19 years). No significant difference was found in age between crias with positive fecal test results (median age, 20 days; range, 7 to 53 days) and those with negative results (median, 36 days; range, 2 to 111 days). No significant difference in fecal scores was found between crias with positive versus negative fecal test results. Conclusions and Clinical Relevance-A higher than previously reported apparent prevalence of fecal shedding of Cryptosporidium oocysts in healthy alpacas was found. A zoonotic risk should be considered, especially for Cryptosporidium parvum.