Hepatitis E virus infection in swine workers: A meta‐analysis

Hepatitis E virus (HEV) infects both humans and animals. Swine has been confirmed to be the principal natural reservoir, which raises a concern that HEV infection would be substantially increasing among swine workers. The present study calculated the pooled prevalence of IgG antibodies against HEV among swine workers and the general population in previous cross‐sectional studies. We conducted a meta‐analysis comparing the prevalence of HEV infection between swine workers and the general population, including local residents, blood donors and non‐swine workers. Through searches in three databases (PubMed and OVID in English, and CNKI in Chinese) and after study selection, a total of 32 studies from 16 countries (from 1999 through 2018) were included in the meta‐analysis. A random‐effect model was employed in the study; an I ² statistic assessed heterogeneity, and the Egger's test detected publication bias. The comparative prevalence of anti‐HEV IgG was pooled from the studies. Compared to the general population, the prevalence ratio (PR) for swine workers was estimated to be 1.52 (95% CI 1.38–1.76) with the I ² being 71%. No publication bias was detected (p = 0.40). A subgroup analysis further indicated increased prevalence of anti‐HEV IgG in the swine workers in Asia (PR = 1.49, 95% CI: 1.35–1.64), in Europe (PR = 1.93, 95% CI: 1.49–2.50) and in all five swine‐related occupations, including swine farmers, butchers, meat processors, pork retailers and veterinarians (PR ranged between 1.19 and 1.75). In summary, swine workers have a relatively higher prevalence of past HEV infection, and this finding is true across swine‐related occupations, which confirms zoonotic transmission between swine and swine workers.     

A simpler, more sensitive competitive inhibition enzyme-linked immunosorbent assay for detection of antibody to malignant catarrhal fever viruses.

An earlier competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA) was developed for detection of specific antibody against malignant catarrhal fever (MCF) viruses (MCFV) in ruminants. In this study, the indirect CI-ELISA was improved by conjugating the monoclonal antibody 15-A directly with horseradish peroxidase and by developing a method of producing precoated, dried antigen plates. This new test is referred to as a direct CI-ELISA. The reformatted test yielded a significantly improved sensitivity, and the time required was reduced to about one-sixth of the previous time. Of 37 MCF cases in cattle that were confirmed by histopathology and polymerase chain reaction (PCR) assay, 37 (100%) were positive by the new test, whereas the indirect CI-ELISA detected only 23 (62%). The direct CI-ELISA detected antibody to MCFV in 100% of 48 sheep that had been defined as infected with ovine herpesvirus 2 (OvHV-2) by PCR, whereas the indirect CI-ELISA detected only 41 (85%). Comparison of antibody titers measured by the 2 assays for sera collected from OvHV-2-infected sheep and from cattle, bison, and deer with clinical sheep-associated MCF revealed that the direct CI-ELISA offered a 4-fold increase in analytical sensitivity over the indirect format. The number of seropositive animals detected by the direct CI-ELISA among apparently normal cattle and bison was 2-3 times greater than the number detected by the indirect CI-ELISA, indicating that a significant percentage of normal cattle and bison are subclincally infected with MCFV.     

The severely under‐recognized public health risk of strongyloidiasis in North American cities—A One Health approach

Strongyloides and other soil‐transmitted helminths represent a severely under‐recognized zoonotic public health risk, especially in North American cities. They are present throughout North America, including in urban areas, causing morbidity and mortality in human and non‐human animals. Epidemiological “masking” of strongyloidiasis due to overlapping symptoms with other systemic diseases, including allergies, and diagnostic limitations complicate our understanding of the epidemiological extent of this disease, and auto‐infection allows long‐term persistence of individual infections. Zoonotic transmission and environmental transmission are critical components in the epidemiology of strongyloidiasis, and other diseases caused by soil‐transmitted helminths. In this review, we bring together medical, veterinary and environmental expertise in a “One Health” context, to document and analyse this under‐recognized risk. We also present implementable opportunities for action with respect to diagnostics, treatment, community engagement and land management to mitigate the impact and transmission of strongyloidiasis and other diseases caused by soil‐transmitted helminths.     

科学使用ADE

最近一段时间,很多鸽友来电咨询如何使用ADE。这里的ADE就是指给信鸽使用的维生素A、维生素DSD维生素E。     

A newly recognized blood group in domestic shorthair cats: the Mik red cell antigen

BACKGROUND: Naturally occurring alloantibodies produced against A and B red cell antigens in cats can cause acute hemolytic transfusion reactions. Blood incompatibilities, unrelated to the AB blood group system, have also been suspected after blood transfusions through routine crossmatch testing or as a result of hemolytic transfusion reactions. HYPOTHESIS: Incompatible crossmatch results among AB compatible cats signify the presence of a naturally occurring alloantibody against a newly identified blood antigen in a group of previously never transfused blood donor cats. The associated alloantibody is clinically important based upon a hemolytic transfusion reaction after inadvertent transfusion of red cells expressing this red cell antigen in a feline renal transplant recipient that lacks this red cell antigen. METHODS: Blood donor and nonblood donor cats were evaluated for the presence of auto- and alloantibodies using direct antiglobulin and crossmatch tests, respectively, and were blood typed for AB blood group status. Both standard tube and novel gel column techniques were used. RESULTS: Plasma from 3 of 65 cats and 1 feline renal transplant recipient caused incompatible crossmatch test results with AB compatible erythrocytes indicating these cats formed an alloantibody against a red cell antigen they lack, termed Mik. The 3 donors and the renal transplant recipient were crossmatch-compatible with one another. Tube and gel column crossmatch test results were similar. CONCLUSIONS AND CLINICAL IMPORTANCE: The absence of this novel Mik red cell antigen can be associated with naturally occurring anti-Mik alloantibodies and can elicit an acute hemolytic transfusion reaction after an AB-matched blood transfusion.     

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.     

Isolation and selection of ionophore-tolerant Eimeria precocious lines: E. tenella, E. maxima and E. acervulina

Eimeria parasites were isolated from Nanhai Guangdong province (southern China) and studied in chickens in wire cages to evaluate their drug resistance against commonly used ionophores: monensin (100 mg/kg of feed), lasolacid (90 mg/kg), salinomycin (60 mg/kg), maduramicin (5 mg/kg) and semduramicin (25 mg/kg). Chinese Yellow Broiler Chickens were infected with 40,000 crude sporulated Eimeria oocysts at 15 days of age and prophylactic medication commenced a day prior to infection. Drug resistance was assessed for each ionophore drug by calculating the anticoccidial index (ACI) and percentage optimum anticoccidial activity (POAA) based on relative weight gain, rate of oocyst production and lesion values. Results revealed that Nanhai Eimeria oocysts comprising of E. tenella, E. maxima and E. acervulina, were resistant to monensin, sensitive to both salinomycin and lasolacid and partially sensitive to maduramicin and semduramicin. By selection for early development of oocysts during passage through chickens, the prepatent time of E. tenella, E. maxima and E. acervulina were reduced by 49, 36 and 22 h, respectively. The precocious lines are less pathogenic than the parent strains from which they were selected and conferred a satisfactory protection for chickens against coccidiosis. These ionophore-tolerant precocious lines could have wider applications in the development of anticoccidial vaccines for sustainable control of coccidiosis.     

Occupational swine exposure and Hepatitis E virus,Leptospira, Ascaris suum seropositivity and MRSA colonization in Austrian veterinarians, 2017–2018—A cross‐sectional study

We investigated the prevalence of Hepatitis E Virus (HEV), Leptospira and Ascaris suum (A. suum) seropositivity, and of nasal methicillin‐resistant Staphylococcus aureus (MRSA) colonization among Austrian practising veterinarians, and assessed the association with occupational swine livestock exposure. The 261 participants completed a questionnaire on demographics, intensity of occupational swine livestock contact and glove use during handling animals and their secretions. Participants' blood samples were tested for HEV, Leptospira and A. suum seropositivity and nasal swabs cultured for MRSA. We compared swine veterinarians (defined as >3 swine livestock visits/week) to non‐swine veterinarians (≤3 swine livestock visits/week) with regard to the outcomes through calculating prevalence ratio (PR) and 95% confidence interval (CI). Furthermore, the relationship between occupational swine livestock contact and the study outcomes was examined by age (</≥55 years) and glove usage. The prevalence of nasal MRSA colonization was 13.4% (95% CI: 9.3–17.6), of HEV seropositivity 20.8% (95% CI: 15.8–25.7) and A. suum seropositivity 44% (95% CI: 37.7–50.2). The highest anti‐leptospiral antibodies titres were 1:200 (L. hebdomadis) and 1:100 (L. autumnalis, L. caicola) found in three non‐swine veterinarians. Compared to non‐swine veterinarians, swine veterinarians were 1.9 (95% CI: 1.0–3.4) and 1.5 (95%CI: 1.0–2.3) times more likely HEV seropositive and A. suum seropositive, respectively, and 4.8 (95%CI: 2.5; 9.3) times more likely nasally colonized with MRSA. Among glove‐using veterinarians, occupational swine contact was no longer a determinant for HEV seropositivity (PR 1.6; 95% CI: 0.8–2.9). Similar was found for A. suum seropositivity, which was no longer associated with occupational swine livestock contact in the subgroup of glove using, ≥55‐year‐old veterinarians (PR: 1.07; 95% CI: 0.4–3.3). Our findings indicate that >3 occupational swine livestock visits per week is associated with HEV and A. suum seropositivity and nasal MRSA colonization and that glove use may play a putative preventive role in acquiring HEV and A. suum. Further analytical epidemiological studies have to prove the causality of these associations.     

Blood and milk status of vitamin E,vitamin A,and selenium in nursing Awassi ewes injected with vitamin E and selenium

Abstract

This study investigated the effects of vitamin E and selenium (Se) injections on concentrations of vitamin E, vitamin A, and Se in blood and milk to predict when injections may improve ewes’ performance. Awassi ewes received 0 (control, 13 ewes) or 15 plus 0.05?mg/kg BW of vitamin E and Se (injected, 15 ewes) at 1 and 4 weeks postpartum. Blood and milk samples were collected weekly for 6 weeks. Injections increased vitamin E, decreased Se, and had no effects on vitamin A levels in blood. Blood vitamin E was correlated positively with vitamin A. Injections increased vitamin E, but had no effects on vitamin A or Se levels in milk. Milk vitamin A was positively correlated with vitamin E and Se levels in the control group. Milk vitamins E and A were positively correlated with their corresponding levels in blood. Milk somatic cell count was negatively correlated with blood vitamin A levels.     

A comparison of serum vitamin A and vitamin E concentrations in shelter, feral, and pet cats

Upper respiratory infection (URI) is an important cause of morbidity and mortality in shelter cats. Malnutrition, specifically vitamin A deficiency, has been associated with respiratory tract infections in humans in developing countries. The purpose of this study was to determine whether feral cats and cats in shelters have lower serum vitamin A concentrations than pet cats, because it was surmised that a vitamin A deficiency may predispose these cats to develop URI. This was a cross-sectional study in which serum retinol, α-tocopherol, γ-tocopherol and beta carotene concentrations were measured from 48 shelter cats, 56 feral cats, and 42 pet cats, using HPLC. Retinol, α-tocopherol, and γ-tocopherol concentrations were found to be significantly lower in the shelter and feral cat populations than in pet cats (p ≤ 0.0001). There was no evidence of an effect of sex or neuter status on vitamin concentrations. Sick feral cats had a higher beta carotene level than did healthy feral cats. Within shelter and feral populations, no other effect of health status was found. The lower mean serum retinol and tocopherol concentrations in the feral and shelter cat groups could be due to oxidative or other forms of stress, the amount of vitamin consumed, or combinations of these. Further studies are needed to determine whether supplementation of fat-soluble vitamins improves the health status of feral or shelter cats.     

NP-AC-1中草药添加剂抗鸡E.acervulina和E.necatrix效力试验

鸡球虫病是一种危害极其严重的全球性寄生虫病,全世界每年因球虫病造成的经济损失约20多亿美元.长期使用化合药预防所产生的耐药性、药物毒副作用和高残留已经引起了社会各界极大关注.中草药饲料添加剂具有促进家禽生长、提高机体免疫力等多种生物学效应,并因其低毒、无害、无残留、不易产生耐药性等独特优势愈来愈被我国畜牧工作者重视.鸡球虫病是由艾美耳属(Eimeria)球虫引起,其中柔嫩艾美耳(E.tenella)的致病性最为严重,本课题组开发的中草药饲料添加剂(主要由青蒿、仙鹤草等等组成)在临床试验中对E.tenella所引起的鸡球虫病有良好的预防效果.本试验观察了该添加剂对堆型艾美耳球虫(E.acervulina)、毒害艾美耳球虫(E.necatrix)的疗效,为临床用药提供更为科学依据.     

Pasteurella haemolytica cytotoxin: production by recognized serotypes and neutralization by type-specific rabbit antisera

A sterile culture supernatant from each of the 12 recognized serotypes of Pasteurella haemolytica was toxic to bovine alveolar macrophages when assayed by 51Cr release. Types appeared to differ in their ability to liberate cytotoxin, although this may have reflected strain variation rather than serotype-related differences. Toxicity was partially neutralized by type-specific rabbit antisera, with neutralization of the homologous toxin being more effective than that of the heterologous serotype.     

维生素A、E和叶酸对母猪繁殖性能的调控

维生素A、E和叶酸对母猪的繁殖性能具有重要的影响.该综述主要对维生素A、E和叶酸的添加阶段、添加方式、添加剂量及其添加形式进行分析比较,总结得出维生素的最佳使用方式,为母猪生产提供参考.