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Şevik M, Doğan M. Epidemiological and Molecular Studies on Lumpy Skin Disease Outbreaks in Turkey during 2014-2015. Transbound Emerg Dis 2016; 64:1268-1279. [PMID: 27039847 DOI: 10.1111/tbed.12501] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Indexed: 11/28/2022]
Abstract
This study was carried out to explore epidemiological and molecular features of lumpy skin disease virus (LSDV) in the Aegean, Central Anatolian and Mediterranean regions of Turkey, to evaluate the risk factors associated with LSDV infection and to investigate the financial impact of LSD and potential role of the Culicoides spp. in the transmission of LSDV. Samples were obtained from 611 cattle, each from different farms, and each clinically suspected to be infected with LSDV during the months of July 2014 and June 2015. Culicoides spp. were trapped from April to June 2015. Genetic characterization of the local LSDV field isolates was conducted by sequencing G-protein-coupled chemokine receptor gene segment. Real-time PCR high-resolution melting analysis was used for distinguishing each type of capripoxviruses. Viral DNA was detected in 448 of the 611 animals and Culicoides midges. Three hundred and ninety-three of the 448 affected farms were surveyed. The morbidity and mortality rates detected were 12.3% and 6.4%, respectively. Phylogenetic analysis showed that the field isolates in this study were clustered together with other Africa and Middle East isolates. Genotyping of isolates from infected cattle has revealed the presence of LSDV. A generalized mixed linear model showed that there were positive associations between LSDV infection, European breeds, small-sized family-type farms and nearness of farm to a lake. The financial cost of disease presence in surveyed cattle farms was estimated to be 72.75 GBP per head. The sequence analysis of the mitochondrial cytochrome oxidase subunit I gene showed that the species of Culicoides in LSDV-positive pools was Culicoides punctatus. Detection of LSDV in Culicoides punctatus suggests that it may have played a role in transmitting LSDV. Furthermore, movement of infected animals into disease-free areas increases the risk of the transmission of LSD. Control strategies for LSDV infection should include consideration of the risk factors identified in this study.
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Affiliation(s)
- M Şevik
- Department of Molecular Microbiology, Veterinary Control Institute, Konya, Turkey
| | - M Doğan
- Department of Molecular Microbiology, Veterinary Control Institute, Konya, Turkey
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Alkhamis MA, VanderWaal K. Spatial and Temporal Epidemiology of Lumpy Skin Disease in the Middle East, 2012-2015. Front Vet Sci 2016; 3:19. [PMID: 26973845 PMCID: PMC4776163 DOI: 10.3389/fvets.2016.00019] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 02/18/2016] [Indexed: 11/26/2022] Open
Abstract
Lumpy skin disease virus (LSDV) is an infectious disease of cattle that can have severe economic implications. New LSD outbreaks are currently circulating in the Middle East (ME). Since 2012, severe outbreaks were reported in cattle across the region. Characterizing the spatial and temporal dynamics of LSDV in cattle populations is prerequisite for guiding successful surveillance and control efforts at a regional level in the ME. Here, we aim to model the ecological niche of LSDV and identify epidemic progression patterns over the course of the epidemic. We analyzed publically available outbreak data from the ME for the period 2012–2015 using presence-only maximum entropy ecological niche modeling and the time-dependent method for the estimation of the effective reproductive number (R-TD). High-risk areas (probability >0.60) for LSDV identified by ecological niche modeling included parts of many northeastern ME countries, though Israel and Turkey were estimated to be the most suitable locations for occurrence of LSDV outbreaks. The most important environmental predictors that contributed to the ecological niche of LSDV included annual precipitation, land cover, mean diurnal range, type of livestock production system, and global livestock densities. Average monthly effective R-TD was equal to 2.2 (95% CI: 1.2, 3.5), whereas the largest R-TD was estimated in Israel (R-TD = 22.2, 95 CI: 15.2, 31.5) in September 2013, which indicated that the demographic and environmental conditions during this period were suitable to LSDV super-spreading events. The sharp drop of Isreal’s inferred R-TD in the following month reflected the success of their 2013 vaccination campaign in controlling the disease. Our results identified areas in which underreporting of LSDV outbreaks may have occurred. More epidemiological information related to cattle populations are needed to further improve the inferred spatial and temporal characteristics of currently circulating LSDV. However, the methodology presented here may be useful in guiding the design of risk-based surveillance and control programs in the region as well as aid in the formulation of epidemic preparedness plans in neighboring LSDV-free countries.
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Affiliation(s)
- Mohammad A Alkhamis
- Environmental and Life Sciences Research Center, Kuwait Institute for Scientific Research, Kuwait City, Kuwait; Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, USA
| | - Kimberly VanderWaal
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota , St. Paul, MN , USA
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Boshra H, Truong T, Nfon C, Bowden TR, Gerdts V, Tikoo S, Babiuk LA, Kara P, Mather A, Wallace DB, Babiuk S. A lumpy skin disease virus deficient of an IL-10 gene homologue provides protective immunity against virulent capripoxvirus challenge in sheep and goats. Antiviral Res 2015; 123:39-49. [PMID: 26341190 DOI: 10.1016/j.antiviral.2015.08.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 08/27/2015] [Accepted: 08/31/2015] [Indexed: 10/23/2022]
Abstract
Sheep and goat pox continue to be important livestock diseases that pose a major threat to the livestock industry in many regions in Africa and Asia. Currently, several live attenuated vaccines are available and used in endemic countries to control these diseases. One of these is a partially attenuated strain of lumpy skin disease virus (LSDV), KS-1, which provides cross-protection against both sheep pox and goat pox. However, when used in highly stressed dairy cattle to protect against lumpy skin disease (LSD) the vaccine can cause clinical disease. In order to develop safer vaccines effective against all three diseases, a pathogenic strain of LSDV (Warmbaths [WB], South Africa) was attenuated by removing a putative virulence factor gene (IL-10-like) using gene knockout (KO) technology. This construct (LSDV WB005KO) was then evaluated as a vaccine for sheep and goats against virulent capripoxvirus challenge. Sheep and goats were vaccinated with the construct and the animals were observed for 21days. The vaccine appeared to be safe, and did not cause disease, although it induced minor inflammation at the injection site similar to that caused by other attenuated sheep and goat pox vaccines. In addition, no virus replication was detected in blood, oral or nasal swabs using real-time PCR following vaccination and low levels of neutralising antibodies were detected in both sheep and goats. Leukocytes isolated from vaccinated animals following vaccination elicited capripoxvirus-specific IFN-γ secretion, suggesting that immunity was also T-cell mediated. Following challenge with virulent capripoxvirus, vaccinated sheep and goats were found to be completely protected and exhibited no clinical disease. Furthermore, real-time PCR of blood samples at various time points suggested that viremia was absent in both groups of vaccinated animals, as opposed to capripoxvirus-related clinical disease and viremia observed in the unvaccinated animals. These findings suggest that this novel knockout strain of LSDV has potential as a vaccine to protect livestock against sheep pox and goat pox.
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Affiliation(s)
- Hani Boshra
- National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB, Canada
| | - Thang Truong
- National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB, Canada
| | - Charles Nfon
- National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB, Canada
| | - Timothy R Bowden
- CSIRO Biosecurity Flagship, Australian Animal Health Laboratory, Geelong, Australia
| | - Volker Gerdts
- Vaccine & Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada
| | - Suresh Tikoo
- Vaccine & Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada; School of Public Health, University of Saskatchewan, Saskatoon, SK, Canada
| | | | - Pravesh Kara
- ARC-Onderstepoort Veterinary Institute, Onderstepoort, South Africa
| | - Arshad Mather
- ARC-Onderstepoort Veterinary Institute, Onderstepoort, South Africa
| | - David B Wallace
- ARC-Onderstepoort Veterinary Institute, Onderstepoort, South Africa; Department Veterinary Tropical Diseases, Faculty Veterinary Science, University of Pretoria, South Africa
| | - Shawn Babiuk
- National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB, Canada; University of Manitoba, Winnipeg, MB, Canada.
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104
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Abera Z, Degefu H, Gari G, Kidane M. Sero-prevalence of lumpy skin disease in selected districts of West Wollega zone, Ethiopia. BMC Vet Res 2015; 11:135. [PMID: 26082259 PMCID: PMC4468805 DOI: 10.1186/s12917-015-0432-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 05/08/2015] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Lumpy skin disease (LSD) is an economically devastating emerging viral disease of cattle caused by a virus associated with the Neethlig poxvirus in the genus Capripoxvirus of the family Poxviridae. A cross-sectional study was conducted from October, 2012 to May, 2013 in two districts of Western Wollega of Oromiya Regional State, with the objectives to determine animal and herd level seroprevalence of lumpy skin disease in the study area. The study population comprised of indigenous and crossbred cattle. Multi-stage sampling method was applied to select cattle and herd owners for the interviews. A total of 544 sera samples were collected from 252 herds and the serological test were conducted using indirect fluorescent antibody test (IFAT). RESULT An overall individual level sero-prevalence of 6.43% (n = 35) and herd level seroprevalence of 5.95% (n = 15) were estimated. There was significant variation (P < 0.05) between the seroprevalence in Gimbi (4.41%) and Lalo Assabi (8.46%) districts at animal level. The sero-prevalence of LSD exposure among breeds (local and cross) was significantly different in that it was found significantly higher in cross breeds (OR = 2.85, p = 0.016) than in local zebu. There was statistically significant difference (p = 0.384) among the age groups (adult, young and calf) in the sero-prevalence of LSD. The average sero-prevalence according to age groups was 8.78%, 5% and 2.74% in adults, youngs and calves, respectively and this shows the prevalence was very low in calves. The current finding revealed no significant variation between male and female animals (p > 0.05). In addition, there was no significant association between seropositivity to LSD and, the agro-climatic zones (midland and highland). CONCLUSION The present study revealed a moderate distribution of sero-positive cattle in the study area and the disease observed warrants future detailed study on the spread of the disease in the area.
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Affiliation(s)
- Zelalem Abera
- College of Medical and Health Sciences, School of Veterinary Medicine, Wollega University, P. O. Box 395, Nekemte, Ethiopia.
| | - Hailu Degefu
- Colleges of Agriculture and Veterinary Medicine, Head School of Veterinary Medicine, Jimma University, P. O. Box 307, Jimma, Ethiopia.
| | - Getachew Gari
- National Animal Health Diagnostic and Investigation Center (NAHDIC), P. O. Box 04, Sebeta, Ethiopia.
| | - Menbere Kidane
- National Animal Health Diagnostic and Investigation Center (NAHDIC), P. O. Box 04, Sebeta, Ethiopia.
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Loop-mediated isothermal amplification for diagnosis of 18 World Organization for Animal Health (OIE) notifiable viral diseases of ruminants, swine and poultry. Anim Health Res Rev 2015; 16:89-106. [PMID: 25900363 DOI: 10.1017/s1466252315000018] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Loop-mediated isothermal amplification (LAMP) is a simple, powerful state-of-the-art gene amplification technique used for the rapid diagnosis and early detection of microbial diseases. Many LAMP assays have been developed and validated for important epizootic diseases of livestock. We review the LAMP assays that have been developed for the detection of 18 viruses deemed notifiable of ruminants, swine and poultry by the World Organization for Animal Health (OIE). LAMP provides a fast (the assay often takes less than an hour), low cost, highly sensitive, highly specific and less laborious alternative to detect infectious disease agents. The LAMP procedure can be completed under isothermal conditions so thermocyclers are not needed. The ease of use of the LAMP assay allows adaptability to field conditions and works well in developing countries with resource-limited laboratories. However, this technology is still underutilized in the field of veterinary diagnostics despite its huge capabilities.
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106
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Williams RAJ, Escudero Duch C, Pérez-Tris J, Benítez L. Polymerase chain reaction detection of avipox and avian papillomavirus in naturally infected wild birds: comparisons of blood, swab and tissue samples. Avian Pathol 2014; 43:130-4. [PMID: 24456300 DOI: 10.1080/03079457.2014.886326] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Avian poxvirus (avipox) is widely reported from avian species, causing cutaneous or mucosal lesions. Mortality rates of up to 100% are recorded in some hosts. Three major avipox clades are recognized. Several diagnostic techniques have been reported, with molecular techniques used only recently. Avipox has been reported from 278 different avian species, but only 111 of these involved sequence and/or strain identification. Collecting samples from wild birds is challenging as only few wild bird individuals or species may be symptomatic. Also, sampling regimes are tightly regulated and the most efficient sampling method, whole bird collection, is ethically challenging. In this study, three alternative sampling techniques (blood, cutaneous swabs and tissue biopsies) from symptomatic wild birds were examined. Polymerase chain reaction was used to detect avipoxvirus and avian papillomavirus (which also induces cutaneous lesions in birds). Four out of 14 tissue samples were positive but all 29 blood samples and 22 swab samples were negative for papillomavirus. All 29 blood samples were negative but 6/22 swabs and 9/14 tissue samples were avipox-positive. The difference between the numbers of positives generated from tissue samples and from swabs was not significant. The difference in the avipox-positive specimens in paired swab (4/6) and tissue samples (6/6) was also not significant. These results therefore do not show the superiority of swab or tissue samples over each other. However, both swab (6/22) and tissue (8/9) samples yielded significantly more avipox-positive cases than blood samples, which are therefore not recommended for sampling these viruses.
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Affiliation(s)
- Richard A J Williams
- a Department of Zoology and Physical Anthropology, Faculty of Biological Sciences , Universidad Complutense de Madrid , Madrid , Spain
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107
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Lubinga JC, Tuppurainen ESM, Coetzer JAW, Stoltsz WH, Venter EH. Evidence of lumpy skin disease virus over-wintering by transstadial persistence in Amblyomma hebraeum and transovarial persistence in Rhipicephalus decoloratus ticks. EXPERIMENTAL & APPLIED ACAROLOGY 2014; 62:77-90. [PMID: 23975563 DOI: 10.1007/s10493-013-9721-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 08/03/2013] [Indexed: 06/02/2023]
Abstract
Lumpy skin disease is a debilitating cattle disease caused by the lumpy skin disease virus (LSDV), belonging to the genus Capripoxvirus. Epidemics of the disease usually occur in summer, when insect activity is high. Limited information is available on how LSDV persists during inter-epidemic periods. Transmission of LSDV by mosquitoes such as Aedes aegypti has been shown to be mechanical, there is no carrier state in cattle and the role of wildlife in the epidemiology of the disease seems to be of minor importance. Recent studies in ticks have shown transstadial persistence of LSDV in Rhipicephalus appendiculatus and Amblyomma hebraeum as well as transovarial persistence of the virus in Rhipicephalus decoloratus, R. appendiculatus and A. hebraeum. The over-wintering of ticks off the host as part of their life cycles is well known: A. hebraeum and R. appendiculatus over-winter, for example, on the ground as engorged nymphs/unfed (emergent) adults while R. decoloratus over-winters on the ground as engorged females. In this study, transstadial and transovarial persistence of LSDV from experimentally infected A. hebraeum nymphs and R. decoloratus females after exposure to cold temperatures of 5 °C at night and 20 °C during the day for 2 months was reported. This observation suggests possible over-wintering of the virus in these tick species.
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Affiliation(s)
- J C Lubinga
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstpoort, Pretoria, 0110, South Africa,
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108
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Lubinga JC, Clift SJ, Tuppurainen ESM, Stoltsz WH, Babiuk S, Coetzer JAW, Venter EH. Demonstration of lumpy skin disease virus infection in Amblyomma hebraeum and Rhipicephalus appendiculatus ticks using immunohistochemistry. Ticks Tick Borne Dis 2013; 5:113-20. [PMID: 24287140 DOI: 10.1016/j.ttbdis.2013.09.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 08/21/2013] [Accepted: 09/18/2013] [Indexed: 11/27/2022]
Abstract
Lumpy skin disease (LSD) is caused by lumpy skin disease virus (LSDV), a member of the genus Capripoxvirus. Transmission of the virus has been associated with haematophagous insects such as Stomoxys calcitrans as well as Aedes and Culex species of mosquitoes. Recent studies have reported the transmission of the virus by Amblyomma hebraeum, Rhipicephalus appendiculatus, and Rhipicephalus decoloratus ticks and the presence of LSDV in saliva of A. hebraeum and R. appendiculatus ticks. The aim of this study was to determine which tick organs become infected by LSDV following intrastadial infection and transstadial persistence of the virus in A. hebraeum and R. appendiculatus ticks. Nymphal and adult ticks were orally infected by feeding them on LSDV-infected cattle. Partially fed adult ticks were processed for testing while nymphs were fed to repletion and allowed to moult to adults before being processed for testing. The infection in tick organs was determined by testing for the presence of the viral antigen using monoclonal antibodies with immunohistochemical staining. The viral antigen was detected in salivary glands, haemocytes, synganglia, ovaries, testes, fat bodies, and midgut. Since the virus was shown to be able to cross the midgut wall and infect various tick organs, this may indicate potential for biological development and transmission of LSDV in ticks. This study strengthens the previously reported evidence of the occurrence of LSDV in tick saliva.
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Affiliation(s)
- Jimmy C Lubinga
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, Pretoria, South Africa; Department of Veterinary and Tsetse Control Services, Lusaka, Zambia.
| | - Sarah J Clift
- Department of Paraclinical Sciences, University of Pretoria, Onderstepoort, Pretoria, South Africa
| | | | - Wilhem H Stoltsz
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, Pretoria, South Africa
| | - Shawn Babiuk
- National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, Canada; Department of Immunology, University of Manitoba, Winnipeg, Canada
| | - Jacobus A W Coetzer
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, Pretoria, South Africa
| | - Estelle H Venter
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, Pretoria, South Africa
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109
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Tuppurainen ES, Lubinga JC, Stoltsz WH, Troskie M, Carpenter ST, Coetzer JA, Venter EH, Oura CA. Evidence of vertical transmission of lumpy skin disease virus in Rhipicephalus decoloratus ticks. Ticks Tick Borne Dis 2013; 4:329-33. [DOI: 10.1016/j.ttbdis.2013.01.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 01/11/2013] [Accepted: 01/14/2013] [Indexed: 10/27/2022]
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110
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Annandale CH, Holm DE, Ebersohn K, Venter EH. Seminal Transmission of Lumpy Skin Disease Virus in Heifers. Transbound Emerg Dis 2013; 61:443-8. [DOI: 10.1111/tbed.12045] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Indexed: 11/30/2022]
Affiliation(s)
- C. H. Annandale
- Department of Production Animal Studies; University of Pretoria; Onderstepoort South Africa
| | - D. E. Holm
- Department of Production Animal Studies; University of Pretoria; Onderstepoort South Africa
| | - K. Ebersohn
- Department of Veterinary Tropical Diseases; Faculty of Veterinary Science; University of Pretoria; Onderstepoort South Africa
| | - E. H. Venter
- Department of Veterinary Tropical Diseases; Faculty of Veterinary Science; University of Pretoria; Onderstepoort South Africa
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111
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Abstract
Background In this study, we developed a SYBR Green-based real-time PCR assay for the detection of sheep pox virus using a plasmid construct carrying one of the highly conserved genes encoding the virion envelope protein (P32) as a template. Results The method was demonstrated to be highly sensitive, allowing a precise SPV DNA quantitation over a range of nine orders of magnitude (from 101 to 109 copies of standard DNA). Then, specimens from SPV suspected sheep were analyzed by conventional gel-based PCR, real-time PCR and sequence analysis. Conclusion Comparison between these different techniques revealed that real-time PCR is more sensitive than conventional gel-based PCR, allowing detection low viral titers of SPV in infected sheep.
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112
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Gari G, Grosbois V, Waret-Szkuta A, Babiuk S, Jacquiet P, Roger F. Lumpy skin disease in Ethiopia: seroprevalence study across different agro-climate zones. Acta Trop 2012; 123:101-6. [PMID: 22569562 DOI: 10.1016/j.actatropica.2012.04.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 04/10/2012] [Accepted: 04/21/2012] [Indexed: 11/17/2022]
Abstract
A cross-sectional study was conducted to estimate the seroprevalence of lumpy skin disease (LSD) in the different agro-climatic zones prevailing in Ethiopia. A total of 2368 serum samples were collected from 42 kebeles located in 15 districts and tested using indirect fluorescent antibody test (IFAT) and virus neutralization test (VNT). The herd and animal true LSD serological prevalence were estimated in each agro-climate zone using a Bayesian model. The intra-cluster correlation coefficient (ICC) was evaluated using a random-effect model. According to the serological prevalence estimations, LSD affected differently the three agro-climatic zones considered. Herd level seroprevalence was higher in the midland agro-climate zone 64% (95% CI: 53-74) as compared to the highland 26% (95% CI: 17-36) and the lowland 50% (95% CI: 40-60) agro-climates. Animal level seroprevalence in infected herds was also higher in the midland agro-climate zone 31% (95% CI: 24-40) than in the highland and lowland zones (24% (95% CI: 18-31) and 23% (95% CI: 18-29), respectively). Higher ICC value in the highland agro-climate zone implies that increased sample sizes should be particularly required for this zone in future studies to estimate LSD prevalence or incidence with a desired precision level. This seroprevalence study also suggests that the prevalence of LSD infection in Ethiopia is higher than what has been previously reported. In the light of these updated estimations, we discuss options to trigger appropriate control measures in the future.
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Affiliation(s)
- G Gari
- National Animal Health Diagnostic and Investigation Center, PO Box 04, Sebeta, Ethiopia.
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113
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Mechanical transmission of lumpy skin disease virus by Rhipicephalus appendiculatus male ticks. Epidemiol Infect 2012; 141:425-30. [DOI: 10.1017/s0950268812000805] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
SUMMARYLumpy skin disease (LSD) is an economically important, acute or sub-acute, viral disease of cattle that occurs across Africa and in the Middle East. The aim of this study was to investigate if lumpy skin disease virus (LSDV) can be transmitted mechanically by African brown ear ticks (Rhipicephalus appendiculatus Neum.). Laboratory-bred R. appendiculatus males were fed on experimentally infected viraemic ‘donor’ cattle. Partially fed male ticks were then transferred to feed on an uninfected ‘recipient’ cow. The recipient animal became viraemic, showed mild clinical signs of LSD and seroconverted. Additionally, R. appendiculatus males were found to transmit LSDV through feeding on skin lacking visible lesions, demonstrating that viraemic animals without lesions at the feeding site of ticks may be a source of infection. This is the first time that transmission of poxviruses by a tick species has been demonstrated and the importance of this mode of transmission in the spread of LSDV in endemic settings is discussed.
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114
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Development of a loop-mediated isothermal amplification assay for rapid detection of capripoxviruses. J Clin Microbiol 2012; 50:1613-20. [PMID: 22357504 DOI: 10.1128/jcm.06796-11] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Sheep pox (SP), goat pox (GP), and lumpy skin disease (LSD), caused by capripoxviruses (CaPVs), are economically important diseases of sheep, goats, and cattle, respectively. Here, we report the development of a loop-mediated isothermal amplification (LAMP) assay for rapid detection of CaPVs. LAMP primers were designed to target a conserved gene encoding the poly(A) polymerase small subunit (VP39) of CaPVs. Hydroxynaphthol blue (HNB) was incorporated to monitor assay progress by color change from violet when negative to sky blue when positive, and results were verified by agarose gel electrophoresis. The LAMP assay was shown to be highly specific for CaPVs, with no apparent cross-reactivity to other related viruses (near neighbors) or viruses that cause similar clinical signs (look-a-like viruses). The performance of LAMP was compared to that of a highly sensitive quantitative real-time PCR (qPCR) assay. LAMP and qPCR exhibited similar analytical sensitivities, with limits of detection of 3 and 8 viral genome copies, respectively. Diagnostic specificity was assessed on 36 negative specimens, including swabs and EDTA blood from control sheep, goats, and cattle. Diagnostic sensitivity was assessed on 275 specimens, including EDTA blood, swabs, and tissues from experimentally infected sheep, goats, and cattle. Overall agreement on diagnostic test results between the two assays was 90 to 95% for specificity and 89 to 100% for sensitivity. The LAMP assay described in this report is simple to use, inexpensive, highly sensitive, and particularly well suited for the diagnosis of capripox in less well equipped laboratories and in rural settings where resources are limited.
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115
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Stubbs S, Oura CA, Henstock M, Bowden TR, King DP, Tuppurainen ES. Validation of a high-throughput real-time polymerase chain reaction assay for the detection of capripoxviral DNA. J Virol Methods 2012; 179:419-22. [DOI: 10.1016/j.jviromet.2011.11.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 08/30/2011] [Accepted: 11/16/2011] [Indexed: 11/28/2022]
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116
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Mathematical modelling and evaluation of the different routes of transmission of lumpy skin disease virus. Vet Res 2012; 43:1. [PMID: 22236452 PMCID: PMC3268087 DOI: 10.1186/1297-9716-43-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 01/11/2012] [Indexed: 11/10/2022] Open
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.
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117
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Embury-Hyatt C, Babiuk S, Manning L, Ganske S, Bowden T, Boyle D, Copps J. Pathology and viral antigen distribution following experimental infection of sheep and goats with capripoxvirus. J Comp Pathol 2012; 146:106-15. [PMID: 22297076 PMCID: PMC9528194 DOI: 10.1016/j.jcpa.2011.12.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 10/27/2011] [Accepted: 12/02/2011] [Indexed: 12/02/2022]
Abstract
Current understanding of capripoxvirus pathogenesis is limited since there have been no detailed studies examining cell tropism at well-defined intervals following infection. We undertook time-course studies in sheep and goats following inoculation of sheeppox or goatpox viruses in their respective homologous hosts, and examined tissues by light microscopy. A monoclonal antibody generated to a sheeppox virus core protein was used for immunohistochemical detection of viral antigen in tissue sections. Lesions and virus antigen were observed consistently in the skin, lung and lymph nodes. Antigen was detected at 6 and 8 days post inoculation for skin and lung, respectively, within cells which appeared to be of monocyte/macrophage lineage. In sheep skin capripoxvirus immunoreactivity was detected within previously unreported large multinucleated cells. In the lung, double immunolabelling detected the simultaneous expression of capripoxvirus antigen and cytokeratin indicating the presence of virus within pneumocytes. Lung double immunolabelling also detected the expression of capripoxvirus antigen in CD68(+) cells, confirming the presence of viral antigen within macrophages. Based on early detection of infected macrophages, dissemination of virus within the host and localization to tissues likely occurred through cells of the monocyte/macrophage lineage. Histological findings revealed similarities with both monkeypox and smallpox, thus capripoxvirus infection in sheep and goats may represent useful models with which to study strategies for poxvirus-specific virus vaccine concepts and therapeutics.
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Affiliation(s)
- C. Embury-Hyatt
- National Centre for Foreign Animal Disease, 1015 Arlington Street, Winnipeg, Manitoba, Canada,Correspondence to: C. Embury-Hyatt
| | - S. Babiuk
- National Centre for Foreign Animal Disease, 1015 Arlington Street, Winnipeg, Manitoba, Canada,University of Manitoba, Department of Immunology, Basic Medical Sciences Building, 730 William Avenue, Winnipeg, Manitoba, Canada
| | - L. Manning
- National Centre for Foreign Animal Disease, 1015 Arlington Street, Winnipeg, Manitoba, Canada
| | - S. Ganske
- National Centre for Foreign Animal Disease, 1015 Arlington Street, Winnipeg, Manitoba, Canada
| | - T.R. Bowden
- CSIRO Livestock Industries, Australian Animal Health Laboratory, Private Bag 24, Geelong, Victoria 3220, Australia
| | - D.B. Boyle
- CSIRO Livestock Industries, Australian Animal Health Laboratory, Private Bag 24, Geelong, Victoria 3220, Australia
| | - J. Copps
- National Centre for Foreign Animal Disease, 1015 Arlington Street, Winnipeg, Manitoba, Canada
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118
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Tuppurainen ESM, Oura CAL. Review: lumpy skin disease: an emerging threat to Europe, the Middle East and Asia. Transbound Emerg Dis 2011; 59:40-8. [PMID: 21749675 DOI: 10.1111/j.1865-1682.2011.01242.x] [Citation(s) in RCA: 217] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lumpy skin disease (LSD) is an economically devastating emerging viral disease of cattle. Lumpy skin disease is currently endemic in most African countries and has recently spread out of Africa into the Middle East region. In this article, we review the putative mechanisms of spread of LSD into the Middle East and the risks of further spread into Turkey, Europe and Asia. We also review the latest findings on the epidemiology of LSD, its mechanisms of transmission, the potential role of wildlife in its maintenance and spread and the diagnostic tests and control methods currently available.
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119
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Awadin W, Hussein H, Elseady Y, Babiuk S, Furuoka H. Detection of lumpy skin disease virus antigen and genomic DNA in formalin-fixed paraffin-embedded tissues from an Egyptian outbreak in 2006. Transbound Emerg Dis 2011; 58:451-7. [PMID: 21699673 DOI: 10.1111/j.1865-1682.2011.01238.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
An outbreak of lumpy skin disease (LSD) was reported in 2006 in Egypt affecting 16 provinces. Biopsies and post-mortem tissue samples were collected from calves that showed typical clinical signs of LSD and fixed in formalin. These samples were collected from a private dairy farm in the Damietta province of Egypt. Formalin-fixed paraffin-embedded tissue samples were assessed using histology, and skin lesions were classified as either acute or subacute/chronic. Both lumpy skin disease virus (LSDV) DNA detected by polymerase chain reaction and LSDV antigen detected by immunohistochemistry using a capripoxvirus-specific monoclonal antibody were observed in the acute skin lesions and in some subacute/chronic skin lesions.
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Affiliation(s)
- W Awadin
- Department of Pathology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
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120
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Tuppurainen ESM, Stoltsz WH, Troskie M, Wallace DB, Oura CAL, Mellor PS, Coetzer JAW, Venter EH. A potential role for ixodid (hard) tick vectors in the transmission of lumpy skin disease virus in cattle. Transbound Emerg Dis 2010; 58:93-104. [PMID: 21114790 DOI: 10.1111/j.1865-1682.2010.01184.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Lumpy skin disease (LSD) is an economically important cattle disease. The disease is endemic in many African countries, but outbreaks have also been reported in Madagascar and the Middle East. The aim of this study was to investigate the potential role of ixodid (hard) ticks in the transmission of the disease. Cattle were infected with a virulent, South African field isolate of lumpy skin disease virus (LSDV). Three common African tick species (genera Rhipicephalus, Amblyomma and Rhipicephalus (Boophilus)) in different life cycle stages were fed on the infected animals during the viraemic stage and on skin lesions. Post-feeding, the partially fed male ticks were transferred to the skin of non-infected 'recipient' animals, while females were allowed to lay eggs that were then tested using the polymerase chain reaction (PCR) method and virus isolation. Nymphs were allowed to develop for 2-3 weeks after which time they were tested. The non-infected 'recipient' cattle were closely monitored, both skin and blood samples were tested using PCR and virus isolation, and serum samples were tested by the serum neutralization test. This is the first report showing molecular evidence of potential transmission of LSDV by ixodid ticks. The study showed evidence of transstadial and transovarial transmission of LSDV by R. (B.) decoloratus ticks and mechanical or intrastadial transmission by R. appendiculatus and A. hebraeum ticks.
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Affiliation(s)
| | - W H Stoltsz
- Institute for Animal Health, Pirbright, Surrey, UK Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa Onderstepoort Veterinary Institute, Onderstepoort, South Africa
| | - M Troskie
- Institute for Animal Health, Pirbright, Surrey, UK Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa Onderstepoort Veterinary Institute, Onderstepoort, South Africa
| | - D B Wallace
- Institute for Animal Health, Pirbright, Surrey, UK Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa Onderstepoort Veterinary Institute, Onderstepoort, South Africa
| | - C A L Oura
- Institute for Animal Health, Pirbright, Surrey, UK Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa Onderstepoort Veterinary Institute, Onderstepoort, South Africa
| | - P S Mellor
- Institute for Animal Health, Pirbright, Surrey, UK Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa Onderstepoort Veterinary Institute, Onderstepoort, South Africa
| | - J A W Coetzer
- Institute for Animal Health, Pirbright, Surrey, UK Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa Onderstepoort Veterinary Institute, Onderstepoort, South Africa
| | - E H Venter
- Institute for Animal Health, Pirbright, Surrey, UK Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa Onderstepoort Veterinary Institute, Onderstepoort, South Africa
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121
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Lamien CE, Lelenta M, Goger W, Silber R, Tuppurainen E, Matijevic M, Luckins AG, Diallo A. Real time PCR method for simultaneous detection, quantitation and differentiation of capripoxviruses. J Virol Methods 2010; 171:134-40. [PMID: 21029751 DOI: 10.1016/j.jviromet.2010.10.014] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 10/11/2010] [Accepted: 10/18/2010] [Indexed: 10/18/2022]
Abstract
The genus Capripoxvirus (CaPV) comprises three members namely, sheep poxvirus (SPPV), goat poxvirus (GTPV) and lumpy skin disease virus (LSDV) affecting sheep, goats and cattle, respectively. CaPV infections produce similar symptoms in sheep and goats, and the three viruses cannot be distinguished serologically. Since there are conflicting opinions regarding the host specificity of CaPVs, particularly for goatpox and sheeppox viruses, the development of rapid genotyping tools will facilitate more accurate disease diagnosis and surveillance for better management of capripox outbreaks. This paper describes a species-specific, real time polymerase chain reaction (PCR), based on unique molecular markers that were found in the G-protein-coupled chemokine receptor (GPCR) gene sequences of CaPVs, that uses dual hybridization probes for their simultaneous detection, quantitation and genotyping. The assay can differentiate between CaPV strains based on differences in the melting point temperature (Tm) obtained after fluorescence melting curve analysis (FMCA). It is highly sensitive and presents low intra- and inter-run variation. This real time PCR assay will make a significant contribution to CaPV diagnosis and to the better understanding of the epidemiology of CaPVs by enabling rapid genotyping and gene-based classification of viral strains and unequivocal identification of isolates.
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Affiliation(s)
- Charles Euloge Lamien
- FAO/IAEA Agriculture & Biotechnology Laboratory, IAEA Laboratories Seibersdorf, International Atomic Energy Agency, Vienna, Austria
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122
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Risk factors associated with observed clinical lumpy skin disease in Ethiopia. Epidemiol Infect 2010; 138:1657-66. [PMID: 20233495 DOI: 10.1017/s0950268810000506] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
A cross-sectional study based on a questionnaire survey was conducted to determine the distribution of lumpy skin disease (LSD) and associated risk factors in three main agro-climatic zones of Ethiopia. A total of 330 questionnaire surveys were collected from 44 peasant associations (PA) distributed in 15 districts. Across agro-climate zones, herd-level LSD prevalence in the midland agro-climate was significantly higher 55.2% [95% confidence interval (CI) 47.5-62.6] than in highland and lowland agro-climate zones. Overall observed LSD prevalence at animal-level was 8.1% (95% CI 7.3-8.9) and observed mortality was 2.12% (95% CI 1.73-2.6). The odds ratio (OR) of LSD occurrence in midland vs. highland and lowland vs. highland zones was 3.86 (95% CI 2.61-5.11) and 4.85 (95% CI 2.59-7.1), respectively. Significantly high risk of LSD occurrence was associated with communal grazing and watering management (OR 4.1, 95% CI 2.02-6.18) and introduction of new cattle (OR 8.5, 95% CI 6.0-11.0). Our findings describe the distribution of LSD in different agro-climates in Ethiopia along with associated risk factors, and can help shed light on the epidemiology of LSD in other African countries suffering from the disease.
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123
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Awad WS, Ibrahim AK, Mahran K, Fararh KM, Abdel Moniem MI. Evaluation of different diagnostic methods for diagnosis of Lumpy skin disease in cows. Trop Anim Health Prod 2009; 42:777-83. [PMID: 19882228 DOI: 10.1007/s11250-009-9486-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2009] [Indexed: 11/26/2022]
Abstract
Viral isolation, polymerase chain reaction (PCR), dot blot hybridization (DBH), and indirect enzyme-linked immunosorbent assay (iELISA) were used for the diagnosis of lumpy skin disease in clinically infected, fevered, and apparently normal dairy cows. Lumpy skin disease virus (LSDV) was isolated from skin biopsies and blood samples collected from clinically infected cows in percentages of 72% and 20%, respectively. The virus recovered from blood samples collected from fevered cows in percentage of 33.3%. Both PCR and DBH detected viral DNA in 100% of skin biopsies collected from clinically infected cows whereas the detection rates in blood samples collected from clinically infected animals were 100% and 84% using PCR and DBH, respectively. Viral DNA was detected in blood samples collected from fevered cows using PCR and DBH in percentages of 77.8% and 66.6%, respectively. Only 19.1% of blood samples collected from in-contact cows was positive for both of PCR and DBH. Detection rates of antibodies against LSDV using iELISA in serum samples collected from clinically infected and fevered cows were 56% and 11.1%, respectively, whereas all in-contact cows had no antibodies against the virus.
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Affiliation(s)
- Walid S Awad
- Department of Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Cairo University, P.O. Box 12211, Giza, Egypt.
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124
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Bowden TR, Coupar BE, Babiuk SL, White JR, Boyd V, Duch CJ, Shiell BJ, Ueda N, Parkyn GR, Copps JS, Boyle DB. Detection of antibodies specific for sheeppox and goatpox viruses using recombinant capripoxvirus antigens in an indirect enzyme-linked immunosorbent assay. J Virol Methods 2009; 161:19-29. [PMID: 19426763 DOI: 10.1016/j.jviromet.2009.04.031] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 04/25/2009] [Accepted: 04/28/2009] [Indexed: 11/19/2022]
Abstract
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.
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Affiliation(s)
- Timothy R Bowden
- CSIRO Livestock Industries, Australian Animal Health Laboratory, Geelong, Victoria 3220, Australia.
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125
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Babiuk S, Wallace DB, Smith SJ, Bowden TR, Dalman B, Parkyn G, Copps J, Boyle DB. Detection of Antibodies Against Capripoxviruses Using an Inactivated Sheeppox Virus ELISA. Transbound Emerg Dis 2009; 56:132-41. [DOI: 10.1111/j.1865-1682.2009.01067.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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