Prevalence and diversity of cystic echinococcosis in livestock in Maasailand, Kenya

Cystic echinococcosis (CE) is a zoonotic disease caused by several members of the Echinococcus granulosus species complex. In East Africa, several species/strains are known to occur in livestock and humans, but host preferences, relative frequencies and spatial distribution of these taxa are poorly known. Here, we contribute livestock data for Maasailand of southern Kenya. Total CE prevalence was 25.8?% in cattle (151/587), 16.5?% in sheep (71/430) and 10.8?% in goats (21/194), which is a significant increase compared to surveys done about three decades ago. The majority of cysts occurred in the liver (56?% in cattle, 70?% in sheep and 65?% in goats). Molecular characterization by PCR?CRFLP and sequencing of parts of the mitochondrial nad-1 gene was done for a subsample of 285 cysts. E. granulosus G1 was dominant in all host species (200 of 201 cysts from cattle, 68 of 69 from sheep and 11 of 15 from goats); the remaining taxa were Echinococcus canadensis G6 (one cyst from sheep, four from goats) and Echinococcus ortleppi (one cyst from cattle). Considering cyst fertility, sheep appear to be the most important hosts for E. granulosus G1, while goats were found to be suitable hosts for E. canadensis G6 (three of four cysts were fertile). For the first time, E. ortleppi was found in cattle from southern Kenya. Our data show an intense and possibly increasing level of CE transmission in southern Kenya, and the predominance of E. granulosus G1, which appears to be particularly pathogenic to humans, calls for urgent control measures.     

Development of an epitope-blocking-enzyme-linked immunosorbent assay to differentiate between animals infected with and vaccinated against foot-and-mouth disease virus

An epitope-blocking ELISA (EB-ELISA) was developed to distinguish animals infected with foot-and-mouth-disease (FMDV) from those immunized with commercial vaccines. The assay used monoclonal antibodies to target the 3B core repeat motif (QKPLK) and purified recombinant 3AB proteins from the major B cell line epitopes of FMDV. Sera from uninfected and regularly vaccinated cattle, pigs, goats, and sheep (raised in FMDV free areas) were screened to evaluate the specificity of the EB-ELISA. The specificity scores of the assays were 99.8-100% and 100%, respectively. Reference sera from cattle, pigs, goats, and sheep experimentally infected with FMDV tested positive, with only a single exception. Antibodies formed in response to FMDV 3B appeared 1 week after infection and persisted at high levels for more than 8 weeks within the sera collected from serial bleeding of animals infected with FMDV O/SKR/2000. The EB-ELISA was used to differentiate between farms vaccinated against and those infected with FMDV (FMDV Asia serotype) during the 2005 epidemic in Mongolia by detecting antibodies against the FMDV Asia serotype in outbreak farms. This EB-ELISA method shows promise as an effective tool for FMDV control and eradication.     

Immune responses of sheep to quadrivalent double emulsion foot-and-mouth disease vaccines: rate of development of immunity and variations among other ruminants

Despite representing the majority of the world's foot-and-mouth disease (FMD)-susceptible livestock, sheep and goats have generally been neglected with regard to their epidemiological role in the spread of FMD. In the present investigations, FMD virus quadrivalent double emulsion (Montanide ISA 206) vaccines were tested in sheep. The oil adjuvant elicited a better immune response at any time than did aluminum hydroxide gel vaccine, and the response developed quicker. The animals maintained their neutralizing antibody titers at >3 log(10) for the duration of the trial (90 days). Sheep were found to be late responders to serotypes A, C, and Asia-1; a clear upward shift in titer was observed at 60 days postvaccination. However, development of the immune response to serotype O in sheep was superior to that in cattle and goats.     

PCR-restriction endonuclease analysis of Mycobacterium avium subsp. paratuberculosis isolates from goats, sheep, and cattle in Jordan

Paratuberculosis is an endemic disease and induces high economical losses in Jordan. There is no information available on genotypic variation of Mycobacterium avium subsp. paratuberculosis (MAP) isolated from animals in Jordan. In this study, we investigated 150 fecal samples from sheep, goats, and cattle for the presence of paratuberculosis using bacterial culture and polymerase chain reaction (PCR)-RFLP analysis of insertion sequence IS1311. Analysis of the results revealed that genotypic information from sheep, goat, and cattle could classify them into cattle or sheep strains. All culture isolates from cattle, 12.5% of the isolates from sheep, and 50% of the isolates from goats were cattle strain, while 87.5% of the isolates from sheep and 50% of the isolates from goats were sheep strain. Sequencing of the IS1311 268?bp PCR product from the three animal species confirmed the different MAP patterns.     

Toxoplasma gondii infections and oocyst shedding in domestic cats and the significance of this for the epidemiology and epizootiology of toxoplasmosis

Because of the dissemination of oocysts the cat and other felines have a central position within Toxoplasma gondii epidemiology and epizootiology. From 1984 to 1986, 267 cats between 2 months and 15 years old were serologically examined (SFT) for Toxoplasma antibodies. The rate of infection was 59.9 per cent. The infection rate of stray cats (72.5%) was significantly higher than that of domestic cats (40%). The high infection rate of herbivores results from behaviour of stray cats. In faeces of 264 animals Toxoplasma oocysts could not be proved by flotation technique. But in 39 samples of faeces Toxocara mystax eggs were found, in one sample Toxascaris leonina eggs. Coproscopical examinations did not reflect the real degree of parasitization of cats. The rate of disseminators of oocysts is drainable by Toxoplasma gondii infection found serologically. About 40% of the animals at the age of up to one year were found to excrete Toxoplasma oocysts.     

Vaccination against paratuberculosis

Johne's disease, or paratuberculosis, is a chronic granulomatous enteritis in ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP) affecting principally cattle, sheep and goats. Primarily, there are two clinical signs: cachexia and chronic diarrhea (less common in goats and sheep). This disease results in considerable economic losses in livestock industry, particularly the dairy sector. The route of transmission is mostly by the fecal-oral route, but hygienic measures and culling of shedding animals are not sufficient to eradicate this disease. Moreover, diagnostic tools available at this moment are not powerful enough to perform early and specific diagnosis. Existing vaccines, based on whole killed or live-attenuated bacteria, can delay the onset of clinical symptoms but do not protect against infection. Moreover, vaccinated animals develop antibodies that interfere with existing serodiagnostic tests for paratuberculosis and they become reactive in the tuberculin skin test, used for the control of bovine tuberculosis. This review summarizes the current knowledge of the immune responses induced by MAP infection, with focus on cattle studies. It provides an overview of the existing MAP vaccines and comments on the development of second-generation subunit vaccines based on new technologies.     

Depressed antibody responses to a thymus-dependent antigen in toxoplasmosis.

The immunodepressive effect of Toxoplasma gondii infection in mice was studied, using sheep erythrocytes (SRBC) as the testing antigen and serum hemagglutinins, hemolysins, and both direct and indirect splenic plaque-forming cells (PFC) to SRBC as assays. In the primary antibody response, immunoglobulin M (IgM), hemagglutinins, and hemolysins and both IgM- and IgG-secreting PFC were depressed in animals immunized after infection. Maximum immunodepression occurred during the first 3 weeks of Toxoplasma infection. When the secondary antibody response was studied, results varied. Mice immunized with SRBC after being infected with T. gondii had a depression in both IgM and IgG PFC. Mice immunized with SRBC before being infected with T. gondii and then given a challenge dose of SRBC had a delay, but no an actual depression, in IgG hemagglutinins and hemolysins and IgG-secreting PFC. These studies show that the immunodepression associated with Toxoplasma infection is complicated, and they provide no definitive explanation for the mechanism.     

The hard ticks (Ixodidae) fauna of livestock in Sari suburb, Northern Iran

Ticks are very important pests of wildlife, domestic animals, and humans in tropical and subtropical areas. Ticks transmit a number of pathogenic organisms to livestock and humans. This study was carried out to investigate the fauna of hard ticks in domestic animals in Sari suburb. Ticks were collected from 2,356 animals including cattle, goat, and sheep and then preserved in 70% alcohol. They were removed through different grades of ethanol, after dehydration, and fixed with Canada balsam and were examined under binocular for identification of ticks based on diagnostic keys. A total of 2,356 animals (cattle, goat, and sheep) were examined from September 2009 to August 2010 randomly to determine the prevalence of ticks. Among these animals, maximum infection was found in goats (46.16%) followed by cattle (32.49%) and sheep (21.35%). Totally, six species were identified. The most frequent species were Hyalomma marginatus (41.20%) followed by Hyalomma anatolicum (21.35%) and Ixodides ricinus (17.78%). Boophilus annulatus, Rhipicephalus bursa, and Hyalomma asiaticum were less frequent species. The result shows that the maximum number of ticks was collected from udder and testis (38.90%), followed by under the tail (21.33%). The minimum number of ticks was found on the chest (9.80%). The goat and sheep were infested with the maximum numbers of ticks under the tails. A total of 1,068 ticks including 578 males, 393 females, and 97 nymphs were collected from these infested animals. Our results showed that H. marginatus is the main tick species on the infested livestock in the Sari suburb. Consequently, further studies are needed to estimate what economic losses are caused by these species and to establish measures for their control of the ticks.     

2005年湛江市、韶关市、汕头市人兽弓形虫感染状况调查

目的了解广东省湛江市、韶关市、汕头市的人兽弓形虫感染情况。方法收集3个地区人、猪、鼠血清，采用酶联免疫吸附试验（ELISA）间接法检测弓形虫IgG抗体。结果湛江市检测猪血清279份，阳性13份，阳性率为4．66％，检测鼠血清93份，阳性7份，阳性率7．53％；韶关市检测人血清42份，阳性0份，检测鼠血清95份，阳性3份，阳性率3．16％；汕头市检测人血清50份，阳性6份，阳性率为12．00％，检测鼠血清100份，阳性3份，阳性率为4．00％。结论汕头市人群存在弓形虫感染，湛江市、韶关市、汕头市兽类存在弓形虫感染，3个地区的鼠类弓形虫感染率无统计学意义，家鼠、野鼠的弓形虫感染率也无统计学意义。     

Humoral immune responses of Brucella-infected cattle, sheep, and goats to eight purified recombinant Brucella proteins in an indirect enzyme-linked immunosorbent assay.

Brucellosis research is currently focused on the identification of nonlipopolysaccharide (LPS) antigens which could potentially be useful for the specific serologic diagnosis of brucellosis as well as for vaccinal prophylaxis. On the basis of previous reports, we selected eight Brucella proteins (OMP36, OMP25, OMP19, OMP16, OMP10, p17, p15, and p39) as candidate antigens to be further evaluated. The genes encoding these proteins were cloned, sequenced, and overexpressed in Escherichia coli. The recombinant proteins were purified with a polyhistidine tag and metal chelate affinity chromatography and evaluated in an indirect enzyme-linked immunosorbent assay (iELISA). The specificity of the iELISA was determined with sera from healthy cattle, sheep, and goats and ranged from 95 to 99%, depending on the recombinant antigen and the species tested. Sera from experimentally infected, and from naturally infected, animals were used to evaluate the sensitivity of the iELISA. The antiprotein antibody response was often delayed when compared to the anti-smooth LPS (S-LPS) response and was limited to animals which developed an active brucellosis infection (experimentally infected pregnant animals and sheep and goats from areas where brucellosis is still endemic). Among the recombinant antigens, the three cytoplasmic proteins (p17, p15, and p39) gave the most useful results. More than 80% of the animals positive in S-LPS serology were also positive with one of these cytoplasmic proteins alone or a combination of two of them. None of the recombinant antigens detected experimentally infected nonpregnant cows and sheep or naturally infected cattle. This study is a first step towards the development of a multiprotein diagnostic reagent for brucellosis.     

Evaluation of two Neospora caninum recombinant antigens for use in an enzyme-linked immunosorbent assay for the diagnosis of bovine neosporosis.

Neospora caninum is a recently described apicomplexan parasite which causes paralysis and death in dogs. Neospora parasites also cause abortion and neonatal morbidity in cattle, sheep, goats, and horses, and neosporosis is emerging as an important cause of bovine abortion worldwide. The purpose of this study was to identify N. caninum cDNA clones encoding antigens that would be useful for the immunodiagnosis of bovine neosporosis. Two N. caninum tachyzoite cDNA clones expressing antigens that were recognized by serum from naturally and experimentally infected cattle were identified. The DNA sequences of these clones were determined, and the inserts were subcloned into the plasmid expression vector pTrcHisB. Both recombinant antigens, expressed as fusion proteins with a His6 tag, were purified on a nickel-chelating affinity column and evaluated in separate enzyme-linked immunosorbent assays (ELISAs). Both recombinant antigen ELISAs were capable of distinguishing between sera from Neospora-infected cows and sera from uninfected control cows. Furthermore, both assays were able to detect an antibody response in animals that were experimentally inoculated with N. caninum. Neither antigen showed evidence of cross-reactivity with serum from animals inoculated with the closely related parasites Toxoplasma gondii, Sarcocystis cruzi, Sarcocystis hominis, and Sarcocystis hirsuta.     

Bovine respiratory syncytial virus antibodies in non-bovine species

Summary To study the role of non-bovine species in the epidemiology of bovine respiratory syncytial virus (RSV) infections, sera obtained from 9 non-bovine animal species and from humans were examined for bovine RSV specific antibodies. Sera were mainly from animals and humans which had been in contact with cattle. Forty sera of each species were tested in an RSV specific whole virus ELISA as well as in a peptide based ELISA, that was developed to measure antibodies specific for bovine RSV. Antibodies directed against RSV were detected in over 50% of sera obtained from sheep, goat, cattle and human beings, and anti-RSV activity was also found in some roe and dogs and one horse. Antibodies to bovine RSV were found in sera of all tested cattle, 11 (27.5%) goats and in some other individual animals: 3 horses, 2 roe, 1 cat and 1 dog. These results indicate that of the investigated species, besides cattle only goats might play a role in the epidemiology of bovine RSV.     

Molecular characterization of Echinococcus granulosus in a hyperendemic European focus,the Republic of Moldova

Cystic echinococcosis is a zoonosis caused by the tapeworm Echinococcus granulosus sensu lato. The lifecycle of the parasite is mainly domestic, requiring dogs as definitive hosts and livestock species as intermediate hosts. Although human cystic echinococcosis is a high public health priority in the Republic of Moldova, the rare animal data available concerns only infection in cattle. A preliminary slaughterhouse survey was conducted to assess prevalence and perform the first molecular characterization of E. granulosus sensu lato in sheep and cattle. For the survey, 40 sheep and 19 cattle were inspected. Very high prevalence in sheep (82.5 %) and in cattle (78.9 %) was found. Molecular analyses identified genotypes G1 and G3 of E. granulosus sensu stricto in all the liver and lung samples. Based on the concatenated sequences of cox1?+?nad3 (701 bp), 23 different haplotypes were obtained. Mixed infections by different haplotypes/genotypes were frequently identified in both sheep and cattle. The relatively high (20.0 %) cyst fertility observed in cattle argues for the potential contribution of cattle to the lifecycle of E. granulosus sensu stricto, unlike previous observations in Europe. The hyperendemic situation of Moldova can be explained by a high majority of animals slaughtered at home usually without veterinary inspection. Further extensive slaughterhouse surveys with molecular identification also involving pigs and goats are needed to obtain a better overview of the epidemiological situation of E. granulosus sensu lato in this hyperendemic focus in the Republic of Moldova.     

Molecular evidence for bovine immunodeficiency virus infection in Iranian sheep and cattle population

Bovine immunodeficiency virus (BIV), a member of the lentivirus subfamily of retroviridae, was originally isolated from a dairy cow with persistent lymphocytosis, lymphoid hyperplasia, and prevascular cuffing in the brain. Serological studies indicated that BIV has worldwide distribution, but its prevalence in Iran is not clearly known. In this investigation, we report the detection of proviral DNA sequence of BIV in 300 blood samples of cattle and 150 blood samples of sheep by polymerase chain reaction (PCR) using oligonucleotiode primers specific for the gag gene region of the virus. Blood samples of cattle and sheep were taken from Chaharmahal Bakhtiary province, Iran. According to the PCR results, infection rate in the cattle and sheep population were 60% and 30%, respectively. This is the first report for the presence of BIV in cattle and sheep population of Chaharmahal Bakhtiary province.     

Detection of antibodies specific for sheeppox and goatpox viruses using recombinant capripoxvirus antigens in an indirect enzyme-linked immunosorbent assay

Viruses in the genus Capripoxvirus, family Poxviridae, cause sheeppox, goatpox and lumpy skin disease, which are the most serious poxvirus diseases of production animals. Despite the considerable threat that these viruses pose to livestock production and global trade in sheep, goats, cattle and their products, convenient and effective serodiagnostic tools are not readily available. To develop a more effective antibody detection capability, selected open reading frames from capripoxvirus DNA were amplified and expressed in Escherichia coli as His-tagged fusion proteins. By screening 42 candidate antigens, two sheeppox virus virion core proteins that were expressed efficiently, purified readily using affinity chromatography and reactive against capripoxvirus immune sera in an indirect enzyme-linked immunosorbent assay (ELISA) were identified. The ELISA performed favourably when sera from sheep and goats infected experimentally with virulent capripoxvirus isolates were tested, with sensitivity and diagnostic specificity ranging between 95 and 97%, but it was unable to detect antibodies reliably in vaccinated sheep or goats. Furthermore, no cross-reactivity with antibodies against orf virus was detected. This assay offers the prospect of a convenient and standardised ELISA-based serodiagnostic test, with no requirement for infectious reagents, that is well suited to high-throughput capripoxvirus surveillance on a flock or herd basis.     

Anticoagulation of juvenile sheep and goats with heparin, warfarin, and clopidogrel

Little data exist on anticoagulation of young sheep and goats. We tested the effect of heparin, warfarin, and clopidogrel in two sheep and two goats weighing 17-35 kg. Each animal received heparin boluses of 80, 100, and 200 units/kg; goats also received 300, 350, and 400 units/kg. All animals received continuous heparin 40, 60, and 80 units/kg/hour; oral warfarin 0.3, 0.6, and 0.9 mg/kg/day; and oral clopidogrel 75 and 150 mg/day (2.8-3.4 and 5.6-6.9 mg/kg/day). Results were in the form of complete blood counts, activated clotting times (ACT), partial thromboplastin times, prothrombin times, thromboelastograms, and whole-blood lumiaggregometry. After heparin boluses of 200 units/kg, sheep and goats reached mean peak ACTs over 400 seconds. After continuous infusions of 40, 60 and 80 units/kg/hour, sheep and goats exceeded our therapeutic range for ACTs (195-215 seconds for sheep, 155-175 seconds for goats). For warfarin therapy, both sheep and goats required treatment with >0.6 mg/kg/day to achieve INRs over 2.5. Clopidogrel treatment, after 14-17 days of 75-150 mg/day, inhibited sheep platelets by 25-36% and goat platelets by 35-46%. We conclude that young sheep and goats can be safely and effectively anticoagulated with heparin and warfarin, and can also show a modest antiplatelet response to clopidogrel. Doses for each drug were generally higher than those used for humans, and warfarin therapy in sheep may be unpredictable. These results should be useful for developing anticoagulation protocols to test pediatric mechanical circulatory support devices.     

Bacteriological and molecular investigation of B. melitensis in dairy cows in Iran

It is extremely important to investigate the presence of Brucella melitensis as a nonspecific and heterogeneous agent in dairy cows in Iran due to mixed populations of sheep, goats, and cattle. B. melitensis from infected sheep or goat herds may be introduced into the cattle population in this area. Hence, it is essential to obtain epidemiological data on the probable existence of B. melitensis as a different source of the infection or new exotic Brucella phenotypes development in dairy cow herds in Iran. The purpose of this study was to investigate the presence of B. melitensis infection in cows, using both traditional bacteriological tests and polymerase chain reaction (PCR)-based assay. Traditional biotyping and PCR results of 42 Brucella spp. isolates from Tehran and Fars (northern and southern) provinces of Iran identified five (11.9%) and 37 (88.1%) as B. melitensis (four biovar 1 and one biovar 2) and 37 (88.1%) Brucella abortus biovar 3. This study demonstrated that B. melitensis infection in dairy cows of Iran is still present at a low level. However, the Iranian Veterinary Organization should be careful to have dairy cow herds free of B. melitensis infection as a nonspecific agent of brucellosis, since this type of brucellosis may be extended and act as a potential source of severe infection in humans.     

Prevalence of hydatidosis in slaughtered sheep and goats by season,sex, age,and infected organ at Amol abattoir,Mazandaran Province,Iran

Hydatidosis is one of the zoonotic diseases with special importance for public health and causing financial problems in developed and developing countries. This infection is the most prevalent disease in the Middle East especially in Iran. In this survey, internal organs of 1,200 sheep and 1,200 goats, including liver, lung, heart, and kidney, were randomly inspected to estimate prevalence rate of hydatidosis and its relationship with season, sex, age, and infected organs. It was found that a total of 335 (27.9 %) of the 1,200 slaughtered goats and a total of 546 (45.5 %) of the 1,200 slaughtered sheep were infected with the hydatid cysts. Prevalence of hydatidosis in females was significantly (p?<?0.05) more than males, and the infection rate was significantly (p?<?0.05) increased by age. The most infected organs were liver and lung, respectively, and the least infected organs were kidney and heart, respectively. High prevalence of hydatidosis in Iran can be a result of conventional slaughtering of sheep and goats, availability of carcass wastes and offal for scavenging stray dogs and other wild carnivores, and close relation between shepherd dog and these animals. The prevalence rate can be decreased by interrupting Echinococcus granulosus life cycle, stopping illegal slaughtering, and increasing public awareness about the infection.     

Experimental foot-and-mouth disease in sheep and goats: An epizootiological model

Summary Observations were made on the appearance and spread of foot-and-mouth disease (FMD) in groups of sheep and goats after either intranasal inoculation of virus or contact with an infected steer. Viremia was used as the primary indicator of the spread of infection. Of 91 goats exposed to virus, 88 (97%) became infected and 92% of the infected ones had demonstrable viremia. Comparable figures for sheep were 33 of 43 (77%) infected and 72% of these with viremia. It was concluded that goats, being less expensive than cattle to purchase and house, could be suitable experimental subjects for studies of the epizootiology of FMD under laboratory conditions.