宠物弓形虫的感染及其防控

弓形虫病是一种世界性分布的人兽共患寄生虫病,对人类,尤其是妇女、儿童危害很大,估计全世界有1/3人受到该病的威胁。孕妇感染弓形虫后导致早产、流产、胎儿发育畸形;弓形虫是免疫功能低下患者的主要死亡原因之一。犬、猫是弓形虫的中间宿主和终末宿主,是人类感染弓形虫的主要来源。随着我国经济的迅速发展和人民生活水平的不断提高,城市中饲养犬、猫作为宠物的人越来越多,人、宠物间的亲密接触增加了弓形虫病传播给人的机会。加强对宠物犬、猫弓形虫病的研究及防控势在必行。本文就弓形虫的危害、宠物犬猫弓形虫感染及其防控措施作以综述。     

Diverse and atypical genotypes identified in Toxoplasma gondii from dogs in São Paulo, Brazil

The prevalence of Toxoplasma gondii in 118 unwanted dogs from S?o Paulo City, S?o Paulo State, Brazil, was determined. Antibodies to T. gondii were assayed by the modified agglutination test and found in 42 (35.8%) dogs, with titers of 1:20 in 10, 1:40 in 6, 1:80 in 5, 1:160 in 5, 1:320 in 6, 1:640 in 7, and 1:1,280 or higher in 3. Hearts and brains of 36 seropositive dogs were bioassayed in mice, or cats, or both. Tissues from 20 seropositive dogs were fed to 20 T. gondii-free cats. Feces of cats were examined for oocysts. Toxoplasma gondii was isolated from 15 dogs by a bioassay in mice, from the brain alone of 1, from the heart alone of 4, and from both brains and hearts of 10. All infected mice from 5 of 15 isolates died of toxoplasmosis during primary infection. Four additional isolates were obtained by bioassay in cats. Genotyping of these 19 T. gondii isolates using polymorphisms at 10 nuclear markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and a new SAG2 (an apicoplast marker Apico) revealed 12 genotypes. One isolate had Type III alleles at all 11 loci, and the remaining 18 isolates contained a combination of different alleles and were divided into 11 genotypes. The absence of Type II in Brazil was confirmed. The result supports previous findings that T. gondii population genetics is highly diverse in Brazil.     

Prevalence of Blastocystis in Shelter-Resident and Client-Owned Companion Animals in the US Pacific Northwest

Domestic dogs and cats are commonly infected with a variety of protozoan enteric parasites, including Blastocystis spp. In addition, there is growing interest in Blastocystis as a potential enteric pathogen, and the possible role of domestic and in-contact animals as reservoirs for human infection. Domestic animals in shelter environments are commonly recognized to be at higher risk for carriage of enteropathogens. The purpose of this study was to determine the frequency of infection of shelter-resident and client-owned domestic dogs and cats with Blastocystis spp in the Pacific Northwest region of the USA. Fecal samples were collected from 103 shelter-resident dogs, 105 shelter-resident cats, 51 client-owned dogs and 52 client-owned cats. Blastocystis were detected and subtypes assigned using a nested PCR based on small subunit ribosomal DNA sequences. Shelter-resident animals were significantly more likely to test positive for Blastocystis (P<0.05 for dogs, P = 0.009 for cats). Sequence analysis indicated that shelter-resident animals were carrying a variety of Blastocystis subtypes. No relationship was seen between Blastocystis carriage and the presence of gastrointestinal disease signs in either dogs or cats. These data suggest that, as previously reported for other enteric pathogens, shelter-resident companion animals are a higher risk for carriage of Blastocystis spp. The lack of relationship between Blastocystis carriage and intestinal disease in shelter-resident animals suggests that this organism is unlikely to be a major enteric pathogen in these species.     

Prevalence of Toxoplasma gondii Infection in Stray and Household Cats in Regions of Seoul, Korea

The principal objective of this study was to investigate the prevalence of toxoplasmosis in household and stray cats in Seoul, Republic of Korea. We collected blood samples from 72 stray and 80 household cats, and all samples were examined by ELISA and nested PCR. The overall positive rates of Toxoplasma gondii in stray cats were 38.9% (28/72), with 15.3% (11/72) in ELISA and 30.6% (22/72) in PCR. The positive rate in male stray cats was slightly higher than that of female stray cats. The highest positive rate of T. gondii infection was noted in Gangnam and Songpa populations in ELISA and in Gwangjin population in PCR. In household cats, however, we could not detect any specific antibodies or DNA for T. gondii. In conclusion, we recognized that the infection rate of toxoplasmosis in stray cats in Seoul was considerably high but household cats were free from infection.     

Incidence of pyometra in Swedish insured cats

Pyometra is a clinically relevant problem in intact female cats and dogs. The etiology is similar in both animal species, with the disease caused by bacterial infection of a progesterone-sensitized uterus. Here, we studied pyometra in cats with the aim to describe the incidence and probability of developing pyometra based on age and breed. The data used were reimbursed claims for veterinary care insurance or life insurance claims or both in cats insured in a Swedish insurance database from 1999 to 2006. The mean incidence rate (IR) for pyometra was about 17 cats per 10,000 cat years at risk (CYAR). Cats with pyometra were diagnosed at a median age of 4 years and a significant breed effect was observed. The breed with the highest IR (433 cats per 10,000 CYAR) was the Sphynx, and other breeds with IR over 60 cats per 10,000 CYAR were Siberian cat, Ocicat, Korat, Siamese, Ragdoll, Maine coon, and Bengal. Pyometra was more commonly diagnosed with increasing age, with a marked increase in cats older than 7 years. The mean case fatality rate in all cats was 5.7%, which is slightly higher than corresponding reports in dogs of 3% to 4%. Geographical location (urban or rural) did not affect the risk of developing the disease. The present study provides information of incidence and probability of developing pyometra based on age, breed, and urban or rural geographical location. These data may be useful for designing cat breeding programs in high-risk breeds and for future studies of the genetic background of the disease.     

Toxoplasmosis: stages of the protozoan life cycle and risk assessment in humans and animals for an enhanced awareness and an improved socio-economic status

Toxoplasma gondii is a protozoan parasite distributed globally. It causes toxoplasmosis, which is prevalent in animals, birds, and soil. T. gondii infection leads to severe pathological impacts in immunodeficient patients and congenital cases. This review indicated that high prevalence groups had close contact with cats, dogs, consumed uncooked raw fruits, meat, or vegetables and the socio-economic level noted to be one of the crucial factors that influence toxoplasmosis. Toxoplasmosis infection is high in low-income countries and low in developed European countries. Immunosuppressed groups and pregnant women were the highly vulnerable groups. The epidemiology of the parasite enumerated various routes of infections; but consumption of T. gondii contaminated food was the major route of disease transmission. However, the role of meat and meat-producing animals on disease transmission remained unclear. Unfiltered water acts as the primary reservoir of toxoplasmosis transmission. The diagnostic methods for determining T. gondii infection are not the gold standard, and different approaches have been prescribed to analyze the infected populations based on the organs affected. Although toxoplasmosis was reported before 70 years, no appropriate solution noted to be recommended to treat this disease. Based on the present analyses, it concluded that the eradication of toxoplasmosis would be challenging from the world until people''s socio-economic level is improved. The main aim of the present study was to analyze and update the disease transmission, epidemiology, and possible clinical interventions of toxoplasmosis.     

Toxoplasma gondii antibody in patients of lepromatous leprosy

Sera from 140 lepromatous leprosy patients (test group) and 120 normal persons, who showed no clinical signs of acute or chronic toxoplasmosis (control group), were studied for the presence of Toxoplasma gondii antibody by indirect hemagglutination and indirect-immunofluorescent antibody tests. Both tests showed a high incidence of Toxoplasma antibody in the test group in comparison with the control group. IgM and IgG classes of antibody responses were observed in both the groups, which signified recent as well as past infections in them.     

Seroprevalence of <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> antibodies in the Slovak Republic

One-thousand eight-hundreds forty-five individuals were examined for the presence of Toxoplasma gondii antibodies, 31.3 % prevalence of them being found by using the complement fixation test as a screening method. The determined total antibodies were present mainly in low titers which show evidence of past or latent infection. The acute stage of toxoplasmosis by the detection of specific IgM and IgA was diagnosed. The occurrence of acute toxoplasmosis in the healthy population is very low and presents only at 0.3 %. There was no significant difference between genders (p = 0.232), but significant differences in the prevalence of toxoplasmosis depending on age (p < 0.001) and regions (p = 0.007) were found.     

Epidemiology of toxoplasmosis in Chile. V. Prevalence of the infection in humans and domestic and wild animals, studied by indirect hemagglutination reaction, in the Juan Fernández Archipelago. V Region

A serological study utilizing an indirect hemagglutination test (IHAT) for toxoplasmosis was carried out in 222 humans and in 58 domestic animals (31 dogs, Canis familiaris; 27 cats, Felis catus), and in 62 wild mammals distributed into 50 rabbits, Oryctolagus cuniculus and 12 goats, Capra hircus. This survey was performed in the Juan Fernández Archipelago, formed by three islands: Robinson Crusoe, Santa Clara and Alejandro Selkirk (80 degrees 47'-78 degrees 47' west long., and 33 degrees 36'-33 degrees 47' south lat.). Blood samples were collected in filter paper and IHAT with titres greater than or equal to 1:16 were considered positive. This survey showed a prevalence of 42.3% in humans with no difference between men (43.0%) and women (41.5%). A high prevalence was found within groups of young individuals (0 to 19 years old), men and women. Regarding the domestic animal population, 44.8% resulted positive, distributed as follows: dogs 9.7% and cats 85.2%. Twenty one percent of wild animals were positive, distributed as follows: rabbits 8.0% and goats 75.0%. The global prevalence of toxoplasmosis in animals (domestic and wild) was 32.5%. All titres in humans and animals were less than or equal to 1:512. Toxoplasmosis is well extended among the human and animal population of the Juan Fernández Archipelago.     

Prevalence of Toxoplasma gondii antibodies and DNA in dogs in Shanghai, China

The aim of this study was to estimate the prevalence of Toxoplasma gondii infection in dogs in Shanghai, China. A total of 1,736 sera (1,178 from the city center and 558 from the outskirts) was collected from healthy dogs and tested for T. gondii infection by indirect hemagglutination; 56 sera (3.2%) were considered positive, with titers > 1∶64. The seroprevalence in dogs from the outskirts of the city (town dogs, 6.0%; countryside dogs, 9.8%) was significantly higher (P > 0.05) than that in city center dogs (1.3%). The age of the dog has an apparent association with T. gondii infection; that is, the seroprevalence ranged from 1.9% (in dogs ≤ 1 year old) to 3.6% (in dogs > 5 years old). There was no significant difference in gender (P ≥ 0.05), that is, 1.4% versus 1.1% for male and female dogs in the city center, 6.2% versus 5.9% in town dogs, and 8.4% versus 11.5% in country dogs, respectively. These results suggest that T. gondii infections are common in dogs from the city center and outskirts of Shanghai, but the T. gondii seroprevalence in dogs is considerably lower than in other regions in PR China. The presence of T. gondii DNA was investigated by nested PCR on 110 blood samples from city center dogs, but no positive samples were found, which may suggest that there were no acute infections of T. gondii in the city center samples. Our results indicate that the control and treatment of toxoplasmosis in Shanghai has been effective. However, it is still essential to further implement integrated strategies to prevent and control T. gondii infection in dogs in both the city center and the outskirts.     

几种实验动物重要疫病及其防控研究

本文结合作者科研工作实际和相关文献资料,对犬、猫、猴等实验动物犬瘟热、犬细小病毒病、猫瘟热、布病、钩体病及弓形虫病等重要疫病及其防控研究进行了概述.     

Prevalence of Toxoplasma gondii in stray cats of Gyeonggi-do, Korea

Toxoplasma gondii is an obligate intracellular zoonotic protozoan with a worldwide distribution. It infects humans as well as a broad spectrum of vertebrate hosts. Cats and wild felidae play crucial roles in the epidemiology of toxoplasmosis. This study was performed to survey the prevalence of T. gondii infection among stray cats in the Gyeonggi-do, Republic of Korea. A total of 174 stray cat blood samples were collected from Gwacheon-si (n=20), Bucheon-si (82), and Yangju-si (72). Positive sera for T. gondii were identified in 14 samples (8.1%) exclusively via the latex agglutination test, 28 (16.1%) via ELISA, and 23 (13.2%) via PCR analysis. The overall infection rate of female stray cats (29.2%) presented as higher than that of male cats (24.0%). This study suggests that T. gondii is widespread in the stray cat population of Gyeonggi-do, Korea. It is urgently needed to control urban stray cat population and to reduce the risk of zoonotic transmission of toxoplasmosis to other animal hosts and humans.     

Evaluation of a Direct Agglutination Test for Detection of Antibodies Against Toxoplasma gondii in Cat,Pig and Sheep Sera

The protozoan parasite Toxoplasma gondii is the causative agent of the zoonosis toxoplasmosis. In sheep and goats, it is one of the most prevalent causes of infectious abortion. Also in pregnant women, a primary infection can result in miscarriage. Humans acquire the infection either by ingestion of oocysts excreted by cats, the definitive host of the parasite, or by eating raw or undercooked meat from latently infected animals (Dubey & Beattie 1988). In Sweden, toxoplasmosis is a notifiable disease, and cases of clinical disease in humans as well as animals must be reported. In both veterinary and human medicine serological assays based on detecting the humoral antibody response of the host against the parasite are used as diagnostic tools. So far, solid phase assays, such as the indirect fluorescent antibody test (IFAT) and the enzyme-linked immunosorbent assay (ELISA), have been widely used to diagnose T. gondii infection in many species including cats, pigs and sheep (Dubey & Beattie 1988). However, both IFAT and ELISA require appropriate anti-species specific immunoglobulins (Ig) that must be carefully evaluated for each species prior to use. This makes these assays complicated and time consuming. Consequently, alternative, simpler methods that do not require specific antisera would be of great value. The direct agglutination test (DA), which is based on the principle that formalin-treated organisms agglutinate in the presence of specific IgG antibodies, is such an assay (Fulton & Turk 1959). The DA-test is widely used in human medicine as a screening test for T gondii infection but it has not yet been thoroughly evaluated for use in veterinary medicine (Uggla & Buxton 1990).     

Observations on the development of Echinococcus multilocularis in cats

The development of a European isolate of Echinococcus multilocularis was compared in cats and dogs at the end of the prepatent period. Echinococcus multilocularis established in all dogs and cats, but worm recovery was significantly greater from dogs than from cats. Overall, worms in cats were not as advanced as those in dogs in terms of development and maturation, but there was no evidence of retarded development or stunted forms. These results confirm that dogs are highly susceptible to E. multilocularis, whereas cats have lower and more variable recovery rates. However, because cats produce thick-shelled eggs of E. multilocularis after experimental and natural infections, they have to be regarded as potential sources of infection both for intermediate and accidental hosts, including humans. However, their general role in the epidemiology of the infection has yet to be determined.     

Epidemiologic studies on human and feline toxoplasmosis.

Human serological profiles, and feline serological and fecal profiles were used to study the epidemiology of toxoplasmosis in Santa Clara County, California. The prevalence of human toxoplasmosis was determined to be 42.9% in a test population of 147 women. The prevalence of feline toxoplasmosis was indicated to be 34.8% based on serological analysis of 158 felines. Of 107 cats tested, 6.5% were shedding Toxoplasma gondii - like oocysts in their feces. Statistical analyses of questionnaire data indicated that the major infection sources for seropositive humans in this study were: (1) eating rare-medium cooked beef; (2) exposure to cats; and (3) working in an outside garden. Of these three sources, gardening represented the least risk. The data from questionnaires with reference to age, residence, and eating and toilet habits of owned felines were evaluated and found to show no significant statistical correlation with seropositivity. The infection sources for seropositive felines could not be determined. The plausible significance of feline-human interaction, human consumption of infected meat, and gardening habits is stressed.     

High Prevalence of the Liver Fluke Amphimerus sp. in Domestic Cats and Dogs in an Area for Human Amphimeriasis in Ecuador

Background

Amphimerus sp. is a liver fluke which recently has been shown to have a high prevalence of infection among an indigenous group, Chachi, who reside in a tropical rainforest in the northwestern region of Ecuador. Since it is unknown which animals can act as a reservoir and/or definitive hosts for Amphimerus sp. in this endemic area, a study was done to determine the prevalence of infection in domestic cats and dogs. This information is important to understand the epidemiology, life cycle and control of this parasite.

Methodology/Findings

In July 2012, three Chachi communities located on Rio Cayapas, province of Esmeraldas, were surveyed. A total of 89 of the 109 registered households participated in the study. Of the 27 cats and 43 dogs found residing in the communities, stool samples were collected from 14 cats and 31 dogs (total of 45 animals) and examined microscopically for the presence of Amphimerus eggs. The prevalence of infection was 71.4% in cats and 38.7% in dogs, with similar rates of infection in all three communities. Significantly more cats were infected than dogs (p = 0.042).

Conclusions/Significance

The data show a high rate of Amphimerus sp. infection in domestic cats and dogs residing in Chachi communities. It can be concluded that these animals act as definitive and reservoir hosts for this liver fluke and that amphimeriasis is a zoonotic disease. These findings provide important epidemiological data which will aid in the development and implementation of control strategies against the transmission of Amphimerus.     

Epidemiology of toxoplasmosis in Chile. VI. Prevalence of human infection, investigated by means of an indirect hemagglutination test, in regions VII, VIII and IX

In presecuting the investigations on the epidemiology of toxoplasmosis in Chile, a new series of serological surveys has been performed during 1982-1989 in 10 urban and 25 periurban-rural localities from the regions VII, VIII and IX of the country (34 degrees 41'-39 degrees 38' South lat.). In 9,758, randomly selected apparently healthy persons, and indirect hemagglutination test (IHAT) for toxoplasmosis was carried out. The age of these individuals (4,203 males and 5,555 females) varied between 4 and 84 years. The examined persons represent a 0.33% of the total population of the three studied regions. IHAT titers of 1: > or = 16 were regarded as positive. The global prevalence for positive IHAT was 45.5% (50.5% in men and 41.7% in women). A higher proportion of positive tests was observed in urban areas (47.0%) than in periurban-rural sections (33.3%). An increasing prevalence with age was also observed. Only 5 (0.05%) persons had IHAT titers higher than 1:1000.     

Isolation of Toxoplasma gondii from animals in Durango, Mexico

Little is known concerning the epidemiology of Toxoplasma gondii infection in people and animals in rural Mexico. Serum samples and tissues from 150 dogs (Canis familaris), 150 cats (Felis catus), 65 opossums (Didelphis virginianus), 249 rats (Rattus spp.), 127 mice (Mus musculus), and 69 squirrels (Spermophilus variegatus) from the Durango area were evaluated for T. gondii infection. Using a modified agglutination test and a serum dilution of 1:25, antibodies to this parasite were found in 68 (45.3%) of 150 dogs, 14 (9.3%) of 150 cats, 11 (16.6%) of 66 opossums, 2 (0.8%) of 249 rats, 4 (3.1%) of 127 mice, and 0 of 69 squirrels. Tissues (brain and heart) of dogs, cats, opossums, rats, mice, and squirrels were bioassayed in mice for the presence of T. gondii. Viable T. gondii was isolated in tissues from 3 of 28 seropositive dogs and 5 of 8 seropositive cats, but not from the other animals. The DNA obtained from the 3 T. gondii isolates from dogs, 6 isolates from 5 cats, and 4 isolates from free-range chickens from Mexico, previously isolated, were genotyped. The PCR-RFLP typing, which used 11 markers (B 1, SAGI, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico), identified 5 genotypes. One genotype (the 4 chicken isolates) belongs to the clonal Type III lineage, three genotypes were reported in previous reports, and 1 genotype is unique.     

Prevalence of antibodies to Toxoplasma gondii in horses in Riyadh Province, Saudi Arabia

The aim of the present study was to determine the seroprevalence of Toxoplasma gondii in horses used for sporting purposes in the Province of Riyadh, Saudi Arabia. In total, 266 serum samples from clinically healthy horses were analyzed for anti- T. gondii antibodies using the Sabin-Feldman dye test. Antibodies to T. gondii were found in 84 (31.6%) horses, with specific titers of 1∶16 (78 with a prevalence of 29.3%), 1∶64 (4 with a prevalence of 1.5%), and 1∶256 (2 with a prevalence of 0.8%). The number of seropositive horses in Shaqra (43.7%) was considerably higher than in other regions, with the lowest occurring in Al-Majmaah (11.0%). However, the differences in seroprevalence between the 6 locations were not statistically significant (P > 0.05). In contrast, the overall seroprevalence in Riyadh province was higher than that reported in other countries. Horses are not a direct source of infection for human toxoplasmosis in this region. Usually human infection is facilitated via cats, which are the reservoir hosts for this parasite.     

Occurrence and Population Size of <Emphasis Type="Italic">Malassezia</Emphasis> spp. in the External Ear Canal of Dogs and Cats Both Healthy and with Otitis

Malassezia yeasts are commensal organisms of human and animal skin that occasionally act as pathogens; lipid-dependent species are associated with human skin disorders. The aim of this work was to evaluate the occurrence, risk factors and population size of different species of Malassezia in the external ear canal of dogs and cats with and without otitis externa. Between 2001 and 2003, 107 healthy animals (25 cats and 82 dogs) and 123 animals with chronic otitis exteirna (48 cats and 75 dogs) were clinically examined. Sterile cotton swabs were used to collect specimens from the external ear canal and culture tests and cytological examinations were performed to detect the presence and population size of Malassezia yeasts. Malassezia yeasts were isolated from 72.9% and 40% of the cats and from 57.3% and 28.0% of the dogs, with and without otitis externa, respectively. Malassezia was frequently isolated from animals under 5 years of age. The highest prevalence of positive samples was reported in winter for cats and in autumn for dogs. Dogs with pendulous ears showed a higher incidence of infection than dogs with erect ears. More Malassezia yeasts were recovered from animals with otitis (i.e. 59.6 colony forming units – CFUs – for cats and 66.0 CFUs for dogs) than healthy animals. Out of the 413 isolates obtained from animals with and without otitis, 403 (97.6%) were identified as M. pachydermatis and 10 (2.4%) as M. globosa. A statistical evaluation of the occurrence of Malassezia yeasts in dogs and cats revealed that predisposing factors for Malassezia infections are sampling period for cats, and type of ear for dogs. The largest population of Malassezia yeasts was detected in animals with otitis, suggesting a role in the occurrence of lesions.