Methods for investigating Trichinella infections in domestic and wild animals

Trichinellosis is an important parasitic zoonosis that is caused by the intracellular nematode Trichinella spp.. Infection of humans occurs through consumption of raw (or undercooked) meat containing infectious larvae. In Europe, meat from pork, horse, and wild boar have been identified as most important sources of Trichinella infections in humans. In Switzerland, both the domestic pig and wild boar population are considered free of Trichinella. Conversely, Swiss foxes, lynxs and recently a wolf were found to be infected, the species identified in these animals was always referred to as Trichinella britovi. Although this species rarely infects pork and, compared to Trichinella spiralis, only causes reduced pathogenic effects in humans, the basic presence of Trichinella in Switzerland cannot be neglegted. This fact has gained increasing importance since the responsible authorities in the European Union (EU) are preparing regulations for the official Trichinella-control in meat in order to improve food safety for consumers. These regulations will be implemented as a consequence of the recent association of east European countries with the EU. This new legislation particularly takes into account, that in the past by far most cases of human trichinellosis in the EU were due to consumption of imported east European meat.Within the framework of the bilateral agreements of Switzerland with the EU, the Swiss veterinary public health authorities will have to comply with the foreseen EU regulations. Although diagnostic methods for the direct demonstation of Trichinella in pork meat are already routine practice in several Swiss abattoirs, the implementation of a meat control program for Trichinella for the entire slaughter pig population of the country would lead to an enormous increase in costs for the administration and will require an increased infrastructure in veterinary services. In order to find a reduced testing format for monitoring Trichinella infections in Swiss pork, an infection risk-oriented survey strategy is currently evaluated. In the present article, this minimized survey strategy is discussed regarding its compatibility with the EU regulations laying down rules for the official control of meat for Trichinella.     

The Sertoli cell nucleolus in domestic and wild animals

Sertoli cells produce special microenvironment for developing germ cells; therefore it is assumed that they play primary role in the onset and control of spermatogenesis. In this connection we extended our previous study on the ultrastructure of Sertoli cells in different domestic and wild animals with special regard to nucleolus. Sertoli cells of domestic and wild ruminants possess the typical vesicular nucleolus except for fallow deer, in this species no vesicular nucleolus occurs in Sertoli cells even during the rut. In roe.buck, another wild ruminant with seasonal spermatogenesis, cyclic changes were found in the nucleolus of Sertoli cells. If no spermatogenesis is present, the Sertoli cells have a reticular nucleolus. Membranous vesicles appear in the nucleolus of Sertoli cells of roe-buck at the onset of spermatogenesis 1-2 months before rut. In domestic ruminants with continuous spermatogenesis the vesicular nucleolus in Sertoli cells is present permanently. During postnatal development of bull and ram the vesicular nucleolus appears in Sertoli cells just before the onset of spermatogenesis. In experimental cryptorchidism of bulls a vesicular nucleolus is found in the Sertoli cells. Our observations and experiments support a hypothesis that Sertoli cells have primary role at the onset and the maintenance of spermatogenesis.     

A review of exertional rhabdomyolysis in wild and domestic animals and man.

Exertional rhabdomyolysis is a condition arising in several species of newly captured wild animals after some form of physical exertion and stress. It is characterized by muscle necrosis and myoglobinuria. Death may result from secondary renal failure, acute or chronic heart failure and progressive emaciation.     

Outbreaks of rinderpest in wild and domestic animals in Nigeria

Rinderpest, although eradicated from Nigeria in 1974 after the JP15 campaign, was reintroduced into Sokoto state in 1980 and again into Borno state in 1983. The latter outbreak spread rapidly throughout Nigeria and severely reduced the cattle population. An estimated one million cattle were lost. An outbreak occurred at the Maiduguri zoo, in Borno state, in January 1983 and killed 15 elands and six sitatungas. In March 1983, rinderpest appeared in Yankari game reserve in adjoining Bauchi state and caused mortality in several species of wildlife. A total of 207 buffalo, 20 warthog, eight waterbuck and two bushbuck carcases were recovered. Rinderpest did not occur in wildlife in Nigeria after it was eradicated from cattle. In the Nigerian situation, the rinderpest appears to have been transmitted from cattle to wildlife. Vaccination of zoo animals and valuable animals in game reserves, preferably with a killed vaccine, and ring vaccination of livestock around game reserves can help to protect wildlife from rinderpest.     

Leptospira interrogans infection in domestic and wild animals in Fiji

Clinical and serological evidence has indicated that human leptospirosis in Fiji is an important disease, and the prevalence of antibody is exceptionally high. A serological survey of the rural population showed that only 12% of the people studied did not have complement fixing (CF) leptospiral antibody. As the origin of this infection could not be explained by the known distribution of leptospiral infection in domestic and wild animals, a serological survey using the complement fixation test (CFT) was undertaken as the first stage of an epidemiological investigation into human and animal leptospirosis. Sera from domestic and wild animals were tested for CF antibody to 12 leptospiral serovars, namely: pomona, copenhageni, grippotyphosa, hardjo, ballum, tarassovi, canicola, australis, bratislava, autumnalis, pyrogenes and bataviae. Antibody was detected in 27.5% of 480 cattle, 17.1% of 70 sheep, 10.3% of 252 goats, 10.0% of 480 pigs, 57.0% of 100 dogs, 55.8% of 34 rats (Rattus rattus, R. frugivorus, R. exulans and R. norvegicus), 53.1% of 32 mongooses (Herpestes auropunctatus) and 40.0% of 10 mice (species unknown.) Cross-reactivity precluded the identification of infecting serogroups with the exception of pomona in pigs and icterohaemorrhagiae, ballum and australis in dogs. Infection of dogs with a serovar of the australis serogroup may explain the predominance of serological reactions to bratislava in man. The survey revealed a significant level of leptospiral antibody in the animal populations of Fiji and indicated that cattle, dogs, rats, mongooses and mice are probably the most important maintenance hosts. Consequently, further investigation will concentrate on the attempted isolation of leptospires from these species.     

Trichinella species circulating among wild and domestic animals in Romania

Trichinellosis is one of the most important zoonotic diseases in Romania. Even though the disease is a serious public health concern, only a limited number of Trichinella isolates have been identified at the species level; in the past, all larvae were assumed to be Trichinella spiralis. The present study was conducted to identify Trichinella spp. circulating among wild and domestic animals in Romania, using PCR-based methods. Trichinella spp. larvae originating from 54 wild and 23 domestic mammals were examined. No Trichinella spp. larvae were detected in muscle samples of 182 birds. T. spiralis and Trichinella britovi were the only two species identified in the 40 isolates that yielded a positive PCR result. Overall, T. britovi was more prevalent (n = 26; 65%) than T. spiralis (n = 14; 35%). T. spiralis was the predominant species found in domestic animals (n = 9; 75%), while T. britovi was more prevalent in wildlife (n = 24; 86%). No mixed infections were found. The highest prevalence of Trichinella infection was detected in wolves (11/35; 31%), in European wild cats (4/28; 14%), and in red foxes (5/71; 7%). The distribution of Trichinella spp. in Romania does not show a species-specific clustering; both of the two species found were present over the entire range of counties studied.     

Parasites of domestic and wild animals in South Africa. XXII. Ixodid ticks on domestic dogs and on wild carnivores

Ixodid ticks were collected from 4 dogs on smallholdings near Grahamstown, eastern Cape Province, on 1 or more occasions each week for periods ranging from 9-36 months. Fourteen tick species were recovered and the seasonal abundance of adult Haemaphysalis leachi and adult Rhipicephalus simus was determined. Complete collections of ticks were made from 50 caracals (Felis caracal) in the Cradock, Graaff-Reinet and Southwell regions in the eastern Cape Province. The animals from Cradock and Graaff-Reinet harboured 13 ixodid tick species. The caracals from Southwell were infested with 11 tick species and the seasonal abundance of Ixodes pilosus on these animals was determined. A small-spotted genet (Genetta genetta), 1 bat-eared fox (Otocyon megalotis), 1 aardwolf (Proteles cristatus) and 6 black-backed jackal (Canis mesomelas) from various localities in the eastern Cape Province were examined for ticks and 9 species were collected. Complete tick collections were made from a side-striped jackal (Canis adustus), 2 wild dogs (Lycaon pictus), a spotted hyaena (Crocuta crocuta), a several (Felis serval), 2 African civets (Civettictis civetta), 2 leopards (Panthera pardus) and a lion (Panthera leo) in the Kruger National Park in the north-eastern Transvaal. Twelve ixodid tick specis were recovered from these animals.     

三种抗原对家畜日本血吸虫病诊断价值的比较

以日本血吸虫基因重组抗原LHD-Sj23／pGEX、可溶性虫卵抗原（soluble egg antigen，SEA）及SEA经Sephadex G-200柱层析分离后得到的第一峰SEAl作为诊断抗原，应用ELISA检测人工感染日本血吸虫绵羊血清及自然感染日本血吸虫水牛血清。结果显示，三种抗原用于检测人工感染日本血吸虫绵羊血清的阳性符合率分剐为88．79％、98．15％、100％，阴性符合率均为100％；自然感染日本血吸虫水牛血清的阳性符合率分别为80％、80％、84％，阴性符合率分别为88．9％、93．3％、91．1％；三种抗原与伊氏锥虫病牛血清无交叉反应；检测感染日本血吸虫不同时间绵羊血清，发现感染6周后均被检出针对这三种抗原的特异性抗体，且SEA及SEAl在感染4周后即可检出特异性抗体。三种抗原的诊断效果差异不显著。     

Hepatitis E virus and related viruses in wild,domestic and zoo animals: A review

Hepatitis E is a human disease mainly characterized by acute liver illness, which is caused by infection with the hepatitis E virus (HEV). Large hepatitis E outbreaks have been described in developing countries; however, the disease is also increasingly recognized in industrialized countries. Mortality rates up to 25% have been described for pregnant women during outbreaks in developing countries. In addition, chronic disease courses could be observed in immunocompromised transplant patients. Whereas the HEV genotypes 1 and 2 are mainly confined to humans, genotypes 3 and 4 are also found in animals and can be zoonotically transmitted to humans. Domestic pig and wild boar represent the most important reservoirs for these genotypes. A distinct subtype of genotype 3 has been repeatedly detected in rabbits and a few human patients. Recently, HEV genotype 7 has been identified in dromedary camels and in an immunocompromised transplant patient. The reservoir animals get infected with HEV without showing any clinical symptoms. Besides these well‐known animal reservoirs, HEV‐specific antibodies and/or the genome of HEV or HEV‐related viruses have also been detected in many other animal species, including primates, other mammals and birds. In particular, genotypes 3 and 4 infections are documented in many domestic, wildlife and zoo animal species. In most cases, the presence of HEV in these animals can be explained by spillover infections, but a risk of virus transmission through contact with humans cannot be excluded. This review gives a general overview on the transmission pathways of HEV to humans. It particularly focuses on reported serological and molecular evidence of infections in wild, domestic and zoo animals with HEV or HEV‐related viruses. The role of these animals for transmission of HEV to humans and other animals is discussed.     

Development of a novel self-medicating applicator for control of internal and external parasites of wild and domestic animals

Four trials, three in the United States and one in South Africa, were conducted to evaluate the potential value of a novel self-medicating applicator in the passive control of gastrointestinal nematodes in cattle and deer, and of files and ticks on cattle using oil-based treatments. The results of the trials demonstrated that this applicator is an effective and practical device for the passive treatment of both deer and cattle for trichostrongyle infections using the endectocide, moxidectin (Cydectin. Fort Dodge Animal Health, USA), of cattle for hom fly (Haemotobia irritans) infestations using the insecticide, cyfluthrin (CyLence, Bayer AG, Germany) and of cattle for tick infestations (in particular Amblyomma hebraeum and Rhipicephalus appendiculatus) using the acaricides deltamethrin and amitraz (Delete All, Intervet, South Africa).     

Serum amyloid A and haptoglobin levels in bovine amyloidosis

Serum amyloid A (SAA) and haptoglobin (Hp) levels were determined in 25 cows suffering from amyloidosis. SAA levels in cows with amyloidosis ranged between < 0.3 and 225.8 microg/ml, with a median level of 105.1 microg/ml, and Hp levels ranged between < 20 and 1860 microg/ml, with a median level of 950 microg/ml. These levels were significantly higher than the levels observed in healthy cows (SAA levels ranged from < 0.3 to 13.5 microg/ml, with median of 1.4 microg/ml, and Hp levels were undetectable in all cases), but were not significantly different from the levels observed in control cows with chronic inflammation. There was a significant correlation between SAA and Hp levels in cows with chronic inflammation , but not in cows with amyloidosis. It was concluded that the serum SAA levels in cows with amyloidosis might be changed by some factor other than inflammation.     

家畜痹症的辨证治疗

家畜痹症多由体虚感邪等原因引起 ,因其病邪风、寒、湿、热的偏重不同 ,其表现形式亦有差异。自1 980年以来 ,笔者运用中兽医辨证治疗马、牛、猪各种痹症 1 0 0余例 ,治愈率达 90 %以上。1　痛痹 (风寒型 )1 .1　临床症状患畜多表现为毛焦体瘦 ,耳鼻发凉 ,四肢、颈、腰、背等部位肌肉僵冷板硬 ,四肢关节不能弯曲 ,行走艰难 ,牵行不动。1 .2　治疗治宜温经散寒、祛风除湿。方用独活寄生汤加减 :独活 30 g,桑寄生 30 g,杜仲 2 0 g,牛膝 2 5 g,细辛 1 0 g,秦艽 30 g,茯苓 2 0 g,肉桂心 30 g,防风 30g,党参 30 g,黄芪 2 0 g,当归 30 g,白芍 2 5 …     

Presence of human Giardia in domestic,farm and wild animals,and environmental samples suggests a zoonotic potential for giardiasis

Giardia lamblia which parasitize humans belong to either of two genotypes, A or B, based on specific signature sequences in the 5' end of the small subunit (16S) ribosomal RNA (rRNA) gene. These two genotypes also were found in cysts from fecal samples of animal origin such as dogs, cats, some farm animals and wild animals. In addition, trophozoites recovered from cysts obtained from environmental samples belonged to these two genotypes as well, suggesting that the G. lamblia genotypes A and B are widespread and possibly zoonotic. Trophozoites were recovered from rats and these isolates might belong to another genotype of G. lamblia. Deer mice and one dog appeared to be parasitized by genotypes of Giardia with close affinity to G. microti. This species, therefore, also consists of a genotype complex.     

Parasites of domestic and wild animals in South Africa. X. Helminths in impala

Two to four impala in the Nylsvley Nature Reserve were culled each month from February 1975-February 1976. Two trematode species, 1 cestode species and 13 species of nematodes were recovered from these antelope. Of these, Fasciola gigantica, Gongylonema pulchrum, Haemonchus placei and Trichostrongylus falculatus are new records for impala. In general, H. placei, Longistrongylus sabie and Impalaia tuberculata exhibited a similar pattern of seasonal occurrence. Adult worms were present during November-February, while marked inhibition in the development of large numbers of 4th stage larvae occurred from April-September or October. Cooperia hungi, Cooperioides hamiltoni and Cooperloides hepaticae followed a similar pattern, but inhibition in the 4th larval stage was not as marked and lasted from June-September. No seasonal pattern of prevalence could be determined for Trichostrongylus spp. The worm burdens of young impala increased with the age of the animals and reached a peak when the impala were 1 year old.     

Enzyme-linked immunoassay in the diagnosis of leptospirosis in domestic animals using peroxidase-conjugated protein-A

The ELISA test for detection of antibodies to Leptospirosis in domestic animals was performed using Staphylococcal protein-A coupled to peroxidase in place of antisera to IgG. Genus- and type-specific antigens were extracted with SDS technique from four pathogenic serotypes and two non-pathogenic ones, and they were identified with the aid of ELISA using specific rabbit antisera. Micro-agglutination (MA) and ELISA were compared using a total of 48 positive swine sera and a 100% agreement was obtained, since with sera from 16 dogs clinically suspected of Leptospirosis the ELISA resulted highly more sensitive and precocious than MA in detecting specific antibodies.