Lumpy skin disease outbreaks investigation in Egyptian cattle and buffaloes: Serological evidence and molecular characterization of genome termini

Lumpy skin disease (LSD) is an endemic highly infectious viral disease affecting cattle in Egypt. This study aimed to identify and characterize the LSD virus (LSDV) outbreaks in Egypt between 2016 and 2018 and to determine the role of Egyptian buffaloes in the epidemiology of LSD. A total of 44 skin biopsies (41 from cattle and 3 from buffaloes) and 31 blood samples from asymptomatic buffaloes in contact with clinically infected cattle were collected from 7 Egyptian governorates and tested by real-time (rt)-PCR. The positive samples were further isolated, and the isolates were analyzed by conventional PCR to amplify the LSDV001 and LSDV002 genes; three isolates were sequenced, and the phylogenetic tree was constructed. In addition, 198 serum samples (102 from cattle and 96 from contact buffaloes) were examined using ELISA. Out of 44 skin nodules analyzed by rt-PCR, 31 (70.45 %) were positive while, non of the buffalo samples were positive. Out of 31 positive rt-PCR samples, LSDV was isolated on CAM (n=19; 61.29%) and MDBK cell culture. The virus isolates were confirmed by conventional PCR where 1237 bp product size was successfully amplified. The phylogenetic analysis of LSDV002 gene revealed that three sequenced LSDV isolates were identical to each other and to LSDV isolates from different countries in Africa, Asia, and Europe with 99–100 % identity. ELISA analyses showed seroreactivity of LSDV in Egyptian cattle and buffaloes. In conclusion, the Egyptian water buffalo serves as an accidental non-adapted host for the disease and this point requires more deep investigation. In addition, the current vaccine strategy should be re-evaluated for more coverage and effectiveness.     

The detection of lumpy skin disease virus in samples of experimentally infected cattle using different diagnostic techniques

Lumpy skin disease (LSD) is a disease of cattle, primarily in Africa and Madagascar and rarely in the Middle East. It is caused by a capripoxvirus that belongs to the family Poxviridae. The disease is of economic importance in endemic areas. Effective control of LSD requires accurate and rapid laboratory techniques to confirm a tentative clinical diagnosis. Comparative studies on different diagnostic tests used at different stages of the disease have not been done. The aim of this study was to compare several of these tests. Six seronegative bulls, between 11 and 20 months of age, were infected intravenously and kept in an insect-free facility. The course of the infection was monitored. During a 3-month period blood samples and skin biopsies were collected for virus isolation and polymerase chain reaction (PCR). Skin biopsies were also examined using transmission electron microscopy (TEM). The incubation period in infected animals varied from 4-5 days. The length of the viraemic period did not correlate with the severity of clinical disease. Viraemia was detected from 1-12 days using virus isolation and from 4-11 days using the PCR, which is longer than has previously been reported. Virus was isolated from skin biopsies until Day 39 post infection (p.i.) and PCR could demonstrate viral DNA until Day 92 p.i. Transmission electron microscopy of negatively stained skin biopsies detected LSD virus only in one of the four bulls that developed skin lesions until Day 33 p.i. The PCR was a fast and sensitive method to demonstrate viral DNA in blood and skin samples. It could detect viral nucleic acid in skin lesions 53 days longer than virus isolation. Virus isolation from blood and skin samples was sensitive and reliable, but as a single test it may be too time-consuming to use although this depends on how rapidly the diagnosis must be confirmed. In conclusion, this study showed the PCR to be superior in detecting LSD virus from blood and skin samples. However, virus isolation is still required when the infectivity of the LSD virus is to be determined.     

Construction of recombinant capripoxviruses as vaccine vectors for delivering foreign antigens: Methodology and application

Goatpox (GTP), sheeppox (SPP) and lumpy skin disease (LSD) are three severe diseases of goat, sheep and cattle. Their typical clinical symptoms are characterized by vesicles, papules, nodules, pustules and scabs on animal skins. The GTP, SPP and LSD are caused by goatpox virus (GTPV), sheeppox virus (SPPV) and lumpy skin disease virus (LSDV), respectively, all of which belong to the genus Capripoxvirus in the family Poxviridae. Several capripoxvirus (CaPV) isolates have been virulently attenuated through serial passaging in vitro for production of live vaccines. CaPV-based vector systems have been broadly used to construct recombinant vaccines for delivering foreign antigens, many of which have been demonstrated to induce effective immune protections. Homologous recombination is the most commonly used method for constructing recombinant CaPVs. Here, we described a methodology for generation of recombinant CaPVs by the homologous recombination, and further reviewed CaPV-vectored vaccines for delivering foreign antigens.     

新疆伊犁州首起牛结节性皮肤病疫情的诊断及处置

2019年8月,在新疆伊犁州察布查尔县、伊宁市、霍城县的牛群中发现牛皮肤上长满大小不等的肿胀结节,伴有体温升高等临床症状,并有1头牛死亡。随后专家赶赴现场开展临床诊断和流行病学调查。根据病牛临床症状和剖检变化,初步判定为牛结节性皮肤病(LSD);采集发病牛样品,包括各种皮肤结节和血清,并采集肺脏、脾脏、淋巴结等脏器,送至省级实验室开展病原学、血清学检测,同时送至国家外来动物疫病研究中心确诊。省级实验室荧光PCR检测显示,发病牛样品为LSD病毒核酸阳性;ELISA检测显示,有16份牛血清LSD病毒抗体阳性。经国家外来动物疫病研究中心检测,送检的疑似病料确诊为LSD病毒核酸阳性,这是我国首起LSD疫情。通过做好疫源追踪、消毒灭源、疫情解封风险评估,同时在新疆伊犁州使用山羊痘疫苗紧急免疫防治LSD,后期持续临床监测显示没有新的疫情发生。     

Incidence and molecular characterisation of lumpy skin disease virus in Zimbabwe using the P32 gene

Between January, 2013 and December, 2014, there was a lumpy skin disease (LSD) outbreak that affected cattle in different localities of Zimbabwe. The outbreak resulted in severe economic losses to the livestock industry. A retrospective study was conducted by examining stored veterinary records of the LSD outbreak at the Central Veterinary Laboratory (CVL) in Harare, Zimbabwe. Over the 2-year period, a total of 10,038 cases and 880 deaths (8.77 %) were recorded. LSD was reported from all regions of the country, with the highest incidence occurring in Mashonaland West (30.95 %) and Midlands province (14.59 %). The frequency of reported outbreaks was highest in March and April, with the lowest reported cases occurring in November. A total of 25 representative specimens (skin biopsies) were collected from nodular skin lesions of infected cattle, and after viral DNA isolation, the P32 gene was successfully amplified, by using PCR, in 88 % (22/25) of all assayed specimens. Out of the 22 samples that showed amplification, 16 (73 %) were selected for DNA sequencing, and from these, 13 sequences were submitted to GenBank and assigned accession numbers: KX033494, KX033495, KX033496, KX033497, KXO33498, KX033499, KX033500, KX033501, KX033502, KX033503, KX033504, KX033505 and KX033506. Phylogenetic analyses of the 13 sequences was done by using MEGA 7 and showed that the viruses formed two major clusters implying that at least two strains of LSDV are in circulation in Zimbabwe. This study provides the first report on the incidence and molecular characterisation of LSDV in Zimbabwe.     

The isolation of lumpy skin disease virus and bovine herpesvirus-4 from cattle in Egypt

Lumpy skin disease (LSD) virus (LSDV) was isolated for the first time from cattle in Egypt in 2 disease outbreaks. Bovine herpesvirus-4 (BHV-4) and LSDV were detected in a pooled sample from the first outbreak (Suez). Only LSDV was isolated from the second outbreak (Ismalia). The capripoxviruses were identified as LSDV by neutralization with specific antiserum and by their ability to produce generalized LSD in experimentally inoculated cattle.     

Phylogenetic analysis of the lumpy skin disease viruses in northwest of Iran

Lumpy skin disease (LSD) is a devastating viral disease of cattle which has recently spread from Africa into the countries of the Middle East. The aim of the present study was to investigate the relationships among lumpy skin disease viruses (LSDV) isolated from different regions of Iran and the origin and spread of these viruses. In this study, a total of 234 blood samples from clinically affected animals from four provinces in the northwest of Iran were screened for LSDV using polymerase chain reaction (PCR). From 80 positive samples for LSDV detected by PCR, the partial P32 gene (759 bp) of 12 isolates were sequenced and phylogenetically analyzed. LSD viruses were grouped in three subclusters with an overall 97.1–100% nucleotide identity. LSDVs isolated from Gilan showed lowest nucleotide identity with the other LSDVs. Four isolates of LSDV including KO-1, EA-1, EA-3, and WA-3 showed 100% similarity with each other and also with the Neethling strain. Phylogenetic analysis indicated that the identified LSDVs were closely related to each other and had high-sequence homology with other LSDV isolates from Africa. It was concluded that LSD outbreak probably occurred in the northwest of Iran by LSDVs entering the country from Iraq and P32 nucleotide sequence information obtained in the present study is a valuable resource in understanding the genetic nature and molecular epidemiology of local LSDV isolates which can be used for future vaccine development based on the circulating strains in the region.     

牛结节性皮肤病的流行与防控

牛结节性皮肤病(LSD)是由牛结节性皮肤病病毒(LSDV)引起的一种牛急性、亚急性病毒性传染病,临床主要表现为发热,皮肤出现结节,母牛流产、产奶量下降,公牛不育。文章对牛结节性皮肤病的病原学、流行病学、临床症状及病理变化、诊断、防控措施等方面进行了较全而的阐述,以期为该病的诊断和防控工作提供参考。     

Mathematical modelling and evaluation of the different routes of transmission of lumpy skin disease virus

ABSTRACT: Lumpy skin disease (LSD) is a severe viral disease of cattle. Circumstantial evidence suggests that the virus is transmitted mechanically by blood-feeding arthropods. We compared the importance of transmission via direct and indirect contact in field conditions by using mathematical tools. We analyzed a dataset collected during the LSD outbreak in 2006 in a large dairy herd, which included ten separated cattle groups. Outbreak dynamics and risk factors for LSD were assessed by a transmission model. Transmission by three contact modes was modelled; indirect contact between the groups within a herd, direct contact or contact via common drinking water within the groups and transmission by contact during milking procedure. Indirect transmission was the only parameter that could solely explain the entire outbreak dynamics and was estimated to have an overall effect that was over 5 times larger than all other possible routes of transmission, combined. The R0 value induced by indirect transmission per the presence of an infectious cow for 1 day in the herd was 15.7, while the R0 induced by direct transmission was 0.36. Sensitivity analysis showed that this result is robust to a wide range of assumptions regarding mean and standard deviation of incubation period and regarding the existence of sub-clinically infected cattle. These results indicate that LSD virus spread within the affected herd could hardly be attributed to direct contact between cattle or contact through the milking procedure. It is therefore concluded that transmission mostly occurs by indirect contact, probably by flying, blood-sucking insects. This has important implications for control of LSD.     

Risk assessments of lumpy skin diseases in Borena bull market chain and its implication for livelihoods and international trade

Risks of introduction of lumpy skin disease (LSD) through traded Borena bulls to market chain and its consequences were assessed. The assessment used the framework that has been recommended by the World Animal Health Organization (OIE) for risk analysis. Likelihoods for release and exposure were estimated by a qualitative scale ranging from negligible to very high, whereas the consequences which resulted from disease occurrences were assessed quantitatively. The likelihood of the introduction of LSD to the market chain through traded Borena bulls is found to be high (medium uncertainty), whereas the probability of exposure is very high (medium uncertainty). From the total of 11,189 bulls observed during outbreak investigation of LSD in six sites of feedlot operation in and around Adama, 681(6.1 %) and 204 (1.8 %) bulls were found to be affected and dead with LSD, respectively. The total economic loss due to LSD was estimated to be 667,785.6 USD. The risk estimates for LSD are greater than negligible; therefore, disease prevention and control strategy along the chain should be carefully considered by the Ethiopian veterinary services.     

Assessment of an ELISA method to support surveillance of bovine tuberculosis in Albania

Background

Bovine tuberculosis (bTB) is an important bacterial infectious disease in Albania of concern to animal and human health; its prevalence is poorly documented.

Methods

In this longitudinal study, we tested by ELISA 2661 serum samples, from 154 herds, with the aim of establishing the suitability of this approach to screen the bovine population for bTB. In a follow-on survey of 87 animals in three villages, we assessed the usefulness of the Mycobacterium bovis IDEXX ELISA (IDEXX M. bovis Antibody (Ab) Test. IDEXX Europe B.V P.O. Box 1334, 2130 EK Hoofddorp, The Netherlands) assay by comparing IDEXX results with the results of the single intradermal cervical skin test. Skin tests were performed either after or at the time of collection of blood samples, and therefore cattle were not sensitized by tuberculin before serological testing.

Results

The proportion of herds in which serologically positive cattle were found was 18.2 % (95 % CI, 1.9–25.8 %) and the prevalence of seropositive cattle was 1.4 % (95 % CI, 0.8–2.1 %). In the follow-up study, two of the 87 animals reacted positively to the skin test and two produced inconclusive reactions. No overlap was found between the four animals with positive IDEXX ELISA results and the four animals with non-negative skin test results.

Conclusion

The lack of agreement between the results of the two tests may reflect different elements of the immune response (humoral and cell-mediated immunity). In future, cattle should be sensitized by the intradermal injection of tuberculin 14 days prior to the collection of blood samples, which would then be tested by the Mycobacterium bovis IDEXX ELISA Test in order to determine more accurately the prevalence of infection.

     

牛结节性皮肤病病毒研究进展

牛结节性皮肤病(LSD)在全世界范围内均有流行和记载,对我国养牛业构成了严重的威胁。接种疫苗是目前防控LSDV最有效的方法,其中减毒活疫苗在许多国家均有使用。近年研究表明,LSDV活疫苗的使用会造成疫苗重组病毒的流行,接种后会引起动物不同程度的不良反应。对LSDV的病原学特征、分离鉴定方法、流行病学的情况、检测方法以及LSDV疫苗的研究进展进行了阐述,以期为牛结节性皮肤病的免疫预防以及鉴别诊断提供研究思路。     

牛结节性皮肤病病毒实验室检测方法研究进展

牛结节性皮肤病(LSD)是由牛结节性皮肤病病毒(LSDV)引起的以发热、消瘦、皮肤水肿、局部形成坚硬的结节或溃疡、淋巴结肿大等为主要特征的急性、亚急性传染病.本病目前尚无特效治疗药物,疫苗接种是当前主要的防控措施,但我国目前并没有针对该病的疫苗,因此建立快速准确的检测方法显得尤为重要.本文从该病的病毒分离和鉴定、血清学...     

Characterization of serum lysosomal enzymatic activities. II. Effect of lumpy skin disease in Egyptian cows.

Clinical findings and lysosomal enzymes (LYE) in eight lumpy skin diseases (LSD) cows and same number of healthy ones were reported in Tal-El Baker village and Tal Alkabir centre, Ismailia province, Egypt. LSD began with fever, anorexia, skin lesions in form of nodules all over the body, which disappeared spontaneously or gathered to form large lumps. It was complicated with respiratory manifestation, corneal opacity, mastitis, dehydration and later on recumbency. It is noteworthy that the level of 3 LYE showed the same trend of significant reduction in acute stage of the disease (5 days after occurrence of LSD) probably due to injection of animals with a therapeutics dose of terramycin. Acid-phosphatase (ACP) enzyme is the sole that behaved very high significant increase in the serum in acute stage of LSD due to the damaged tissues caused by the virus. It underwent insignificant decrease in late stage of the disease (20 days after its occurrence) to restore the normal LYE level in control cows indicating recovery. Alpha-galactosidase (alpha-GAL) decreased perpetually by the progression of LSD because of the decreased bactericidal index which ist in concomitance with the secondary bacterial invader. N-acetyl-beta-glucosaminidase (beta-NAG) and beta-galactosidase (beta-GAL) in LYE had the same fluctuating manner. The activities showed very highly significant decrease in acute stage, followed by highly significant and significant increases (late LSD stage) respectively. The appreciable significant increase of beta-GAL may declare the effect of anorexia on LSD. In view of these findings, it can be postulated that LSD may be diagnosed and prognosed through LYE changes in the serum.     

Outbreaks of foot-and-mouth disease in Peninsular Malaysia from 2001 to 2007

This is a retrospective study of the outbreaks of foot-and-mouth disease (FMD) in Peninsular Malaysia between 2001 and May 2007. In total, 270 outbreaks of FMD were recorded. Serotype O virus (89.95 %) and serotype A (7.7 %) had caused the outbreaks. Significant differences on the occurrence of FMD were found between the years (t?=?5.73, P?=?0.000, df?=?11), months (t?=?4.7, P?=?0.000, df?=?11), monsoon season (t?=?2.63, P?=?0.025, df?=?10) and states (t?=?4.84, P?=?0.001, df?=?10). A peak of outbreaks observed in 2003 could be due to increased animal movement and the other peak in 2006 could be due to a compromised FMD control activities due to activities on the eradication of highly pathogenic avian influenza. Cattle (86 % of outbreaks) suffered the most. However, no difference in disease occurrence between species was observed. The populations of cattle (r?=?0.672, P?=?0.023) and sheep (r?=?0.678, P?=?0.022) were significantly correlated with occurrence of FMD. Movement of animals (66 % of outbreaks) was the main source for outbreaks. A combination of control measures were implemented during outbreaks. In conclusion, the findings of this study show that FMD is endemic in Peninsular Malaysia, and information gained could be used to improve the existing control strategy.     

一起境外输入性牛结节性皮肤病疫情

2020年11月，山东滨州市、东营市引进牛皮肤出现自限性皮肤结节、损伤以及结痂等症状，疑似发生牛结节性皮肤病（lumpy skin disease，LSD）。为确诊两地疫情及了解病原的遗传演化关系，利用荧光定量PCR方法进行诊断，以PCR方法扩增GCPR基因并进行核苷酸比对分析和遗传演化分析。检测结果显示，采集的样品中检测到牛结节性皮肤病病毒（lumpy skin disease virus，LSDV），两地疫情确诊为LSD疫情。GCPR基因核苷酸比对结果显示，China/SDBinzhou/2020、China/SDDongying/2020 GCPR基因存在12个核苷酸的插入，与疫苗毒株Neethling vaccine LW 1959株、Neethling-LSD vaccine-OBP株以及俄罗斯发现的疫苗样毒株Saratov株在GCPR基因的核苷酸插入序列相同，具备疫苗样毒株的特征。系统发育分析结果表明，China/SDBinzhou/2020、China/SDDongying/2020 GCPR基因与我国新疆发现的LSDV毒株GCPR基因处同一小分支中，亲缘关系较近。同时，我国LSDV毒株与Neethling vaccine LW 1959株、Neethling-LSD vaccine-OBP株以及Saratov株等共处于一大分支中。综上，确诊滨州市、东营市两地疫情为LSD疫情，这是山东省首次确诊输入性LSD疫情。     

Recent observations on site reactions in cattle to vaccination against contagious bovine pleuropneumonia (CBPP) using T1/44 vaccine in Zambia

Contagious bovine pleuropneumonia (CBPP), a highly infectious and fatal disease of cattle present in many countries in sub-Saharan Africa, is usually controlled by mass vaccinations. However, vaccination against CBPP is known to cause site reactions in a percentage of cattle especially in primary vaccinations. In Zambia, a record of site reactions was kept for seven consecutive years from 2005 to 2011 to establish the level of the problem. In some areas, after 3 years of consecutive vaccination campaigns, immunization could not be implemented for a period of 2 years because of logistical difficulties or owner resistance. Whereas in the three preceding years when animals were vaccinated annually, site reactions were in the range of 6.2 %; on resumption of vaccination in the herds that had not been immunized for 2 years, site reactions averaged 21.3 %. This data shows that the T1/44 vaccine may cause severe local reactions in cattle if there is any break in annual vaccinations. It is therefore important for authorities to ensure that the cattle at risk of contracting CBPP are regularly vaccinated to avoid discouraging farmers from presenting their animals.     

Seroprevalence of contagious bovine pleuropneumonia at export quarantine centers in and around Adama,Ethiopia

A cross sectional study was undertaken from October 2010 to March 2011 to determine the seroprevalence of contagious bovine pleuropneumonia (CBPP) and its related risk factors in export quarantine centers. A total of 3,111 cattle sera were collected from different export quarantine farms located in and around Adama, namely, Bekero, Jogo, Kedir, and Dera farms, and tested for the presence of Mycoplasma mycoides subsp. mycoides small colonies antibody using competitive enzyme-linked immunosorbant assay. Of the total 3,111 cattle sera examined, 124 (4 %) were found positive for CBPP. Among the potential predisposing factors assessed, origin, transportation condition, confinement level, and stay time of the animals in quarantine center were not found significantly (P?>?0.05) associated with the occurrence of the disease. Whereas age was found significantly (P?<?0.05) associated with the occurrence of the disease in which a high seroprevalence was recorded in aged (9.5 %) animals than young (3 %). Generally, this study showed that CBPP is a threat for Ethiopian livestock export market and a well established disease in Borana and Bale areas, where the animals originated.     

Evidence for bovine besnoitiosis in Egypt—first serosurvey of Besnoitia besnoiti in cattle and water buffalo (Bubalus bubalis) in Egypt

The present study evaluated the presence of specific antibodies against Besnoitia besnoiti in cattle and water buffalo (Bubalus bubalis) in Egypt. Sera from cattle (n?=?216) and water buffaloes (n?=?133) collected from five different provinces of Egypt (Behera, Alexandria, Assuit, Gharbia, and Matrouh) were analyzed. Testing for B. besnoiti antibodies by PrioCHECK® Besnoitia Ab 2.0 ELISA initially identified 13.75 % (48 out of 349) of individual sera as positive at the manufacturer’s suggested cutoff threshold, 15 percent positivity (PP). Statistically significant associations between B. besnoiti prevalence, species, sex, age, and geographical distribution were observed. Seropositive animals were distributed in all of the provinces from which animals were sampled except Gharbia province. Assuit province showed the highest percentage of infection (30.76 %) followed by Matrouh, Alexandria, and Behera provinces (25, 16.29, and 9.6 %, respectively). The highest infection rate of B. besnoiti was significantly higher in cattle (17.13 %) than in water buffaloes (9.02 %). Positive cases were observed in all age categories. While the highest infection rate (17.13 %) was recorded in the age group 5–10 years followed by the age group 1–5 years (15.38 %), and only one positive case (1.58 %) was recorded in the age group less than 1 year. The highest infection rate of B. besnoiti infection was recorded in the female animals (14.95 %) followed by the male animals (8.33). This is the first report on the detection of B. besnoiti in cattle and water buffaloes in Egypt.