1
|
Shyaka A, Rujeni N, Kanyamibwa EI, Kagabo G, Fèvre EM, Quinnell RJ. High prevalence of porcine cysticercosis in slaughtered pigs in Rwanda: An abattoir survey. PLoS Negl Trop Dis 2024; 18:e0012598. [PMID: 39453982 PMCID: PMC11540212 DOI: 10.1371/journal.pntd.0012598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 11/06/2024] [Accepted: 10/02/2024] [Indexed: 10/27/2024] Open
Abstract
Porcine cysticercosis (PC) is an important public health problem, especially in sub-Saharan Africa, but limited information is available on the prevalence of infection in pigs entering the food chain. Existing diagnostic methods vary in accuracy and efficiency; whole carcass dissection is the most reliable method but is labour-intensive and destroys the carcass so can only be used in a research setting. Serological tests offer lower specificity, while meat inspection and lingual examination lack sensitivity, hampering accurate estimates and the removal of infected pigs from the food chain. Here, we provide the first estimates of PC prevalence in abattoirs in Rwanda. We use whole carcass dissection to determine the diagnostic accuracy of a commercial antigen-ELISA to estimate the true prevalence of infection across Rwanda and identify Taenia species affecting local pigs. We carried out a cross-sectional survey in 6 abattoirs across Rwanda (n = 744 pigs), with whole carcass dissection of a subset of 67 pigs. Cysts were detected in 20/67 (30%) of carcasses, with >1000 cysts in 9/20 (45%) of infected pigs. All cysts were identified as Taenia solium by PCR-RFLP, with no cysts of Taenia hydatigena found. The antigen-ELISA showed a sensitivity of 90% (95% CI: 68-99) and specificity of 85% (95% CI: 72-94), when compared to dissection. Using these estimates, the true prevalence was calculated as 25-43% in two abattoirs in south-west Rwanda, and 2-3% in the rest of the country. Fewer than half of infected pigs were detected by tongue palpation and post-mortem veterinary inspection. Our data indicate a high prevalence of PC in Rwandan abattoirs. Tongue palpation and veterinary inspections, as currently carried out, have little impact in removing cyst-infested pigs from the food chain. Additional interventions are needed, such as proper pig husbandry, treatment and vaccination against cysticercosis, health education, improved sanitation and hygiene, and improved processing and cooking of meat.
Collapse
Affiliation(s)
- Anselme Shyaka
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
- Center for One Health, University of Global Health Equity, Butaro, Rwanda
| | - Nadine Rujeni
- School of Health Sciences, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Eric I. Kanyamibwa
- School of Health Sciences, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Geofrey Kagabo
- School of Health Sciences, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Eric M. Fèvre
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
- International Livestock Research Institute, Nairobi, Kenya
| | - Rupert J. Quinnell
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| |
Collapse
|
2
|
Trevisan C, Mwape KE, Van Damme I, Saelens G, Mubanga C, Chembensofu M, Masuku M, O’Neal S, Zulu G, Dorny P, Gabriël S. Could a ring treatment approach be proposed to control Taenia solium transmission in a post elimination setting? A pilot study in Zambia. PLoS Negl Trop Dis 2024; 18:e0012400. [PMID: 39110770 PMCID: PMC11346962 DOI: 10.1371/journal.pntd.0012400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 08/26/2024] [Accepted: 07/25/2024] [Indexed: 08/28/2024] Open
Abstract
BACKGROUND Geographically targeted Taenia solium ring approaches consisting of treating individuals within a radius of 100-meter of a cysticercosis positive pig have been trialled in Peru. This study explored if a similar approach could be proposed to control T. solium transmission in a post elimination setting in Zambia, focussing on community members' willingness to be sampled and treated. METHODOLOGY AND PRINCIPAL FINDINGS The study was conducted in a community where elimination of active T. solium transmission was achieved. All eligible pigs and people were sampled, at 4- to 6-monthly intervals, followed by implementation of the ring treatment approach. This implied that whenever a pig was seropositive for cysticercosis during sampling, every human and pig residing in a radius of 50-meters of the seropositive pig would be treated. The results of the positive human stool samples were used to create the rings, whenever no pigs were positive. From June 2018 to October 2019, four samplings, followed by ring treatments were conducted. Between 84% and 91% of the willing people provided a stool sample, covering 46% to 59% of the total population living in the study area. Between 78% and 100% of the eligible pigs got sampled. Three ring treatments were based on porcine seropositivity and one on taeniosis results. Two to four rings were opened per sampling. During the ring treatments, between 89% and 100% of the eligible human and pig population living within a ring was treated. CONCLUSIONS Participants were willing to participate and get treatment, once the rings were opened. However, the utility of ring treatment approaches in a post elimination setting needs further evaluation, given the lack of highly accurate diagnostic tools for porcine cysticercosis and the challenges in obtaining stool samples. The ring treatment approach adopted should be further improved before recommendations to public health authorities can be given.
Collapse
Affiliation(s)
- Chiara Trevisan
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
- Laboratory of Foodborne Parasitic Zoonoses, Ghent University, Merelbeke, Belgium
| | - Kabemba E. Mwape
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Inge Van Damme
- Laboratory of Foodborne Parasitic Zoonoses, Ghent University, Merelbeke, Belgium
- Service Foodborne Pathogens, Sciensano, Brussels, Belgium
| | - Ganna Saelens
- Laboratory of Foodborne Parasitic Zoonoses, Ghent University, Merelbeke, Belgium
| | | | - Mwelwa Chembensofu
- Department of Paraclinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Maxwell Masuku
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Seth O’Neal
- School of Public Health, Oregon Health & Science University and Portland State University, Portland, Oregon, United States of America
| | | | - Pierre Dorny
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Sarah Gabriël
- Laboratory of Foodborne Parasitic Zoonoses, Ghent University, Merelbeke, Belgium
| |
Collapse
|
3
|
Zhang D, Duan R, Liu J, Wang M, Yang Y, Zhao Y, Liu M, Sun S. Development and evaluation of time-resolved rapid immunofluorescence test for detection of TSOL18 specific antibody in porcine cysticercosis infections. BMC Vet Res 2024; 20:182. [PMID: 38720329 PMCID: PMC11077887 DOI: 10.1186/s12917-024-04034-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 04/24/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND Porcine cysticercosis, a serious zoonotic parasitic disease, is caused by the larvae of Taenia solium and has been acknowledged by the World Organization for Animal Health. The current detection methods of Cysticercus cellulosae cannot meet the needs of large-scale and rapid detection in the field. We hypothesized that the immunofluorescence chromatography test strip (ICS) for detecting Cysticercus cellulosae, according to optimization of a series of reaction systems was conducted, and sensitivity, specificity, and stability testing, and was finally compared with ELISA. This method utilizes Eu3+-labeled time-resolved fluorescent microspheres (TRFM) coupled with TSOL18 antigen to detect TSOL18 antibodies in infected pig sera. RESULTS ICS and autopsy have highly consistent diagnostic results (n = 133), as determined by Cohen's κ analysis (κ = 0.925). And the results showed that the proposed ICS are high sensitivity (0.9459) with specificity (0.9792). The ICS was unable to detect positive samples of other parasites. It can be stored for at least six months at 4℃. CONCLUSIONS In summary, we established a TRFM-ICS method with higher sensitivity and specificity than indirect ELISA. Results obtained from serum samples can be read within 10 min, indicating a rapid, user-friendly test suitable for large-scale field detection.
Collapse
Affiliation(s)
- Dejia Zhang
- College of Animal Science and Technology, Inner Mongolia MinZu University, Tongliao, 028000, China
| | - Rui Duan
- College of Animal Science and Technology, Inner Mongolia MinZu University, Tongliao, 028000, China
| | - Jing Liu
- Qingdao Special Servicemen Recuperation Center of PLA Navy, Qingdao, 266071, China
| | - Mengqi Wang
- College of Animal Science and Technology, Inner Mongolia MinZu University, Tongliao, 028000, China
| | - Yi Yang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, 650201, China
| | - Yongjun Zhao
- College of Animal Science and Technology, Inner Mongolia MinZu University, Tongliao, 028000, China
| | - Mingyuan Liu
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225000, China.
| | - Shumin Sun
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, 650201, China.
| |
Collapse
|
4
|
Arroyo G, Toribio L, Garrido S, Chile N, Lopez-Urbina T, Gomez-Puerta LA, Muro M, Gilman RH, Castillo Y, Dorny P, O'Neal SE, Gonzalez AE, Garcia HH. Concordance between two monoclonal antibody-based antigen detection enzyme-linked immunosorbent assays for measuring cysticercal antigen levels in sera from pigs experimentally infected with Taenia solium and Taenia hydatigena. Parasit Vectors 2024; 17:172. [PMID: 38566124 PMCID: PMC10988810 DOI: 10.1186/s13071-024-06197-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 02/15/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Antigen detection in Taenia solium cysticercosis confirms viable infection in the intermediate host (either pig or human). The reference B158/B60 monoclonal antibody (mAb)-based Ag-enzyme-linked immunosorbent assay (ELISA) has acceptable levels of sensitivity and specificity in human neurocysticercosis with multiple brain cysts, although its sensitivity is lower in cases with single brain cysts, whereas in porcine cysticercosis the assay specificity is affected by its frequent cross-reaction with Taenia hydatigena, another common cestode found in pigs. Our group has produced 21 anti-T. solium mAbs reacting against antigens of the whole cyst, vesicular fluid, and secretory/excretory products, identifying TsW8/TsW5 as the most promising pair of mAbs for an Ag-ELISA. METHODS We report the use of the TsW8/TsW5 Ag-ELISA to measure cysticercus antigen levels [expressed as optical density (OD) values] in two panels of sera collected from day 0 (baseline) to day 90 postinfection (PI) from pigs experimentally infected with T. solium (n = 26) and T. hydatigena (n = 12). At baseline and on days 28 and 90 PI, we used Bland-Altman (BA) analysis and Lin's concordance correlation coefficients (CCC) to determine the concordance between the TsW8/TsW5 and the B158/B60 Ag-ELISA. RESULTS The TsW8/TsW5 Ag-ELISA was able to efficiently measure circulating antigen levels in T. solium-infected pigs, similar to that obtained with the B158/B60 Ag-ELISA. Almost all paired log-OD differences between assays were within the limits of agreement (LoA) in the BA analysis at baseline and on days 28 and 90 PI (92.3%, 100%, and 100%, respectively), and a high concordance of log-ODs between assays was also found (Lin's CCC: 0.69, 0.92, and 0.96, respectively, all P < 0.001). In pigs infected with T. hydatigena, almost all paired log-OD differences were within the LoA in the BA analysis, whereas the concordance of log-ODs between assays was low at baseline (Lin's CCC: 0.24) but increased on days 28 and 90 PI (Lins' CCC: 0.88 and 0.98, P < 0.001). CONCLUSIONS/SIGNIFICANCE The TsW8/TsW5 Ag-ELISA recognizes antigens in pigs with T. solium cysticercosis and is highly concordant with the B158/B60 Ag-ELISA. However, its diagnostic use is hampered by cross-reactions with T. hydatigena, as in other mAb-based Ag-ELISAs.
Collapse
Affiliation(s)
- Gianfranco Arroyo
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru.
- Direccion General de Investigacion, Desarrollo e Innovacion, Universidad Cientifica del Sur, Lima, Peru.
| | - Luz Toribio
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Sara Garrido
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Nancy Chile
- Laboratory of Infectious Diseases, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Teresa Lopez-Urbina
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Luis A Gomez-Puerta
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Miguel Muro
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Robert H Gilman
- Department of International Health, Bloomberg School of Public Health, John Hopkins University, Baltimore, MD, USA
| | - Yesenia Castillo
- Parasite Immunology Laboratory, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Pierre Dorny
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Seth E O'Neal
- School of Public Health, Oregon Health and Science University-Portland State University, Portland, OR, USA
| | - Armando E Gonzalez
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Hector H Garcia
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| |
Collapse
|
5
|
Arroyo G, Lescano AG, Gavidia CM, Lopez-Urbina T, Ara-Gomez M, Gomez-Puerta LA, Bustos JA, Jayashi CM, O’Neal SE, Gonzalez AE, Garcia HH. Antibody Banding Patterns on the Enzyme-Linked Immunoelectrotransfer Blot (EITB) Assay Clearly Discriminate Viable Cysticercosis in Naturally Infected Pigs. Pathogens 2023; 13:15. [PMID: 38251323 PMCID: PMC10820179 DOI: 10.3390/pathogens13010015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/14/2023] [Accepted: 12/19/2023] [Indexed: 01/23/2024] Open
Abstract
Enzyme-linked immunoelectrotransfer blot (EITB) detects antibodies against seven Taenia solium larvae antigens in three protein families (GP50, T24/42, and 8-kDa) with different structures and functions. EITB banding patterns against these antigens in pigs provide information about the course of infection and may discriminate viable cysticercosis. We analyzed the banding patterns and infection outcomes (presence of viable cysts, degenerated cysts, and any cysts) of 512 rural pigs. Banding patterns were grouped into homogenous classes using latent class analysis, and relationships with infection outcomes were assessed. Four classes were identified: 1 (n = 308, EITB-negative or positive for the GP50 family), 2 (n = 127, positive for GP50 (GP50 family), GP42-39 and GP24 (T24/42 family), but negative for 8-kDa antigens), 3 (n = 22, positive for GP50 and T24/42 antigens (GP42-39 and GP24), as well as to 8-kDa bands GP13, GP14, and GP18, but negative for GP21), and 4 (n = 55, positive for GP50 and T24/42 antigens, as well as to 8-kDa antigens GP21 and GP18 in combination). Pigs in classes 3 and 4 were more likely to have viable cysts (72.6% and 96.4%, respectively) than pigs in classes 1 and 2 (0.7% and 27.6%, respectively; p < 0.001). The number of infections with any cysts was higher in classes 3 and 4 (77.3% and 98.2%, respectively) and lower in classes 2 and 1 (34.7% and 4.9%, respectively; p < 0.001). Pigs with viable cysts represented >90% of pigs with any cysts in classes 3 and 4 (94.1% and 98.2%, respectively), while degenerated cysts were frequent among pigs with any cysts in classes 1, 3, and 2 (86.7%, 47.1%, and 43.2%, respectively; p < 0.001). EITB banding patterns strongly correlate with cysticercosis infection status in rural pigs, with classes 3 and 4 being more predictive of viable infections.
Collapse
Affiliation(s)
- Gianfranco Arroyo
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima 15202, Peru; (J.A.B.); (S.E.O.); (H.H.G.)
| | - Andres G. Lescano
- School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Lima 15202, Peru;
| | - Cesar M. Gavidia
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
| | - Teresa Lopez-Urbina
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
| | - Miguel Ara-Gomez
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
| | - Luis A. Gomez-Puerta
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
| | - Javier A. Bustos
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima 15202, Peru; (J.A.B.); (S.E.O.); (H.H.G.)
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima 15030, Peru
| | - Cesar M. Jayashi
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
| | - Seth E. O’Neal
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima 15202, Peru; (J.A.B.); (S.E.O.); (H.H.G.)
- School of Public Health, Oregon Health & Sciences University-Portland State University, Portland, OR 97207, USA
| | - Armando E. Gonzalez
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
| | - Hector H. Garcia
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima 15202, Peru; (J.A.B.); (S.E.O.); (H.H.G.)
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima 15030, Peru
| | | |
Collapse
|
6
|
Mananjara DEA, Rakotoarinoro M, Rakotoarison VC, Raliniaina M, Razafindraibe NP, Ravonirina C, Randriamparany T, Rasamoelina-Andriamanivo H, Rakotozandrindrainy R, Cardinale E, Lightowlers MW, Donadeu M, Mwape KE. Confirmation by necropsy of a high prevalence of porcine cysticercosis in a rural district of Madagascar. Parasitology 2023; 150:852-857. [PMID: 37496390 PMCID: PMC10478050 DOI: 10.1017/s0031182023000653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/28/2023]
Abstract
Neurocysticercosis is recognized as an important health issue in the Malagasy population. To date, investigations into prevalence of infection with the causative agent, Taenia solium, in the parasite's natural animal intermediate hosts, have relied on serological methods which have been found to be non-specific. We determined the prevalence of porcine cysticercosis among pigs from a contiguous area of the Betafo and Mandoto administrative districts, Vakinankaratra Region, Madagascar. One hundred and four slaughter-weight pigs were examined by detailed necropsy examination including slicing of the heart, tongue, masseter muscles, diaphragm and carcase musculature. Thirty-seven animals (35.6%) were found infected with T. solium, representing one of the highest rates of infection ever reported, worldwide. These findings highlight the importance of T. solium in Madagascar and support the need for increased efforts to prevent the parasite's transmission to reduce its burden on the health of the Malagasy population.
Collapse
Affiliation(s)
- Diana Edithe Andria Mananjara
- National Center for Applied Research on Rural Development (FOFIFA), BP04 Rue Farafaty Ampandrianomby, Antsirabe, Antananarivo 101, Madagascar
| | - Mihajamanana Rakotoarinoro
- National Center for Applied Research on Rural Development (FOFIFA), BP04 Rue Farafaty Ampandrianomby, Antsirabe, Antananarivo 101, Madagascar
| | - Valisoa C. Rakotoarison
- National Center for Applied Research on Rural Development (FOFIFA), BP04 Rue Farafaty Ampandrianomby, Antsirabe, Antananarivo 101, Madagascar
| | - Modestine Raliniaina
- National Center for Applied Research on Rural Development (FOFIFA), BP04 Rue Farafaty Ampandrianomby, Antsirabe, Antananarivo 101, Madagascar
| | | | - Claudia Ravonirina
- Regional Directorate of Agriculture and Livestock Vakinankaratra, Madagascar
| | - Tantely Randriamparany
- National Veterinary Diagnostic Laboratory, Anosimasina Itaosy, Antananarivo 102, Madagascar
| | | | | | | | - Marshall W. Lightowlers
- Department of Biosciences, Melbourne Veterinary School, 250 Princes Highway, Werribee, Victoria 3030, Australia
| | - Meritxell Donadeu
- Department of Biosciences, Melbourne Veterinary School, 250 Princes Highway, Werribee, Victoria 3030, Australia
- Initiative for Neglected Animal Diseases (INAND), Constantia Park, Pretoria, South Africa
| | - Kabemba E. Mwape
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka 10101, Zambia
| |
Collapse
|
7
|
Chege B, Ndambuki G, Owiny M, Kiyong’a A, Fèvre EM, Cook EAJ. Improved latrine coverage may reduce porcine cysticercosis: a comparative cross-sectional study, Busia County, Kenya 2021. Front Vet Sci 2023; 10:1155467. [PMID: 37476824 PMCID: PMC10354266 DOI: 10.3389/fvets.2023.1155467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 06/14/2023] [Indexed: 07/22/2023] Open
Abstract
Introduction Smallholder pig farming is an important economic activity for many poor, rural communities in developing countries. Porcine cysticercosis is a growing public health risk in countries where pig rearing is popular. A sanitation-based intervention to reduce the prevalence of open defecation was completed in Busia County, Kenya in 2016. We capitalized on this third party intervention to evaluate its impact on porcine cysticercosis prevalence. Methods We conducted a comparative cross-sectional survey from August through to September 2021. Household selection was done using multistage sampling. Household questionnaire data on pig production, transmission, risk factors and awareness of porcine cysticercosis were collected from 251 households. Lingual palpation was used to test for cysticerci in 370 pigs while serum was tested for circulating antigen using Ag-ELISA. We compared results of our survey to an effective baseline, which was a near equivalent cross sectional survey conducted in 2012 before the third party sanitary intervention was established. The difference in prevalence was measured using Chi-square tests. Multivariable logistic regression analysis was used to identify risk factors for lingual cysts in pigs. Results The prevalence of palpable lingual cysts was estimated to be 3.8% (95% CI 2.3-6.3%) (14/370). This was 6% (95% CI 0.8-13.9%; p-value 0.0178) lower than the prevalence reported in the pre-implementation period of 9.7% (95% CI: 4.5-17.6%). Circulating antigen was detected in 2 samples (0.54%, 95% CI: 0.2-1.9). Latrine coverage was 86% (95% CI: 81-90%), which was 11% (95% CI: 4.8-16.8%; p < 0.001) higher than the pre-implementation period coverage of 75% (95% CI: 71-79%). There was reduced prevalence of lingual cysts in pigs from households that had a latrine (OR = 0.14; 95% CI: 0.05-0.43; p < 0.001) and where pigs were confined or tethered (OR = 0.27; 95% CI: 0.07-1.02; p = 0.053). Conclusion There was a reduction in the prevalence of porcine cysticercosis in Busia County over the study period from 2012 to 2021. This was not a trial design so we are unable to directly link the decline to a specific cause, but the data are consistent with previous research indicating that improved sanitation reduces porcine cysticercosis. Programs for controlling porcine cysticercosis should include a focus on sanitation in addition to other integrated One Health approaches.
Collapse
Affiliation(s)
- Bernard Chege
- Field Epidemiology and Laboratory Training Program (FELTP), Nairobi, Kenya
- International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Gideon Ndambuki
- International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Maurice Owiny
- Field Epidemiology and Laboratory Training Program (FELTP), Nairobi, Kenya
| | - Alice Kiyong’a
- International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Eric M. Fèvre
- International Livestock Research Institute (ILRI), Nairobi, Kenya
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | | |
Collapse
|
8
|
Sanga TA, Maganira JD, Kidima WB. An epidemiological survey of porcine cysticercosis in Rungwe District, Tanzania. Prev Vet Med 2023; 213:105866. [PMID: 36736267 DOI: 10.1016/j.prevetmed.2023.105866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 01/17/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023]
Abstract
Taeniasis/cysticercosis caused by tapeworms belonging to the genus Taenia, poses serious veterinary and public health problems, resulting in economic burden in endemic low-income countries worldwide. However, little epidemiological data exist on infection status among pigs in many areas in Tanzania. We conducted a cross-sectional survey in Rungwe District, Mbeya Region, Tanzania, to define the prevalence and risk factors associated with porcine cysticercosis transmission. One-hundred sixty-nine pigs from 152 households were examined for circulating taeniid antigens by cysticercosis antigen (Ag) enzyme-linked immunosorbent assay (ELISA). Agarose gel electrophoresis was used to differentially diagnose Taenia species-specific cysticerci DNA bands. Structured questionnaires were administered in the surveyed households to collect information on risk factors for porcine cysticercosis transmission. Sera from eleven household pigs tested positive for porcine cysticercosis in the Ag-ELISA with an apparent prevalence of 6.5 % (95 % C.I. 3.8-11.3 %) and estimated true prevalence of 6.1 % (95 % C.I. 3.3-10.9 %). DNA Gel electrophoresis confirmed that 100 % of cysticerci isolated amongst pigs slaughtered in the study area belonged to T. solium. Of the five surveyed wards, positive household pigs were from Bulyaga, Kiwira, and Mpuguso. Lack of knowledge on porcine cysticercosis among household members was found to be significantly associated with positivity of Taenia species antigen in pigs sera (OR = 7.742, p = 0.017). Our results show that porcine cysticercosis is prevalent in Rungwe. There is a definite need to establish control measures against this potential zoonosis to safeguard veterinary and public health in the Rungwe District.
Collapse
Affiliation(s)
- Tusane Alatupa Sanga
- Department of Zoology and Wildlife Conservation, University of Dar es Salaam, P.O. Box 35064, Dar es Salaam, Tanzania
| | - Justine Daudi Maganira
- Department of Biosciences, Sokoine University of Agriculture, P.O. Box 3038, Morogoro, Tanzania.
| | - Winifrida Benedict Kidima
- Department of Zoology and Wildlife Conservation, University of Dar es Salaam, P.O. Box 35064, Dar es Salaam, Tanzania
| |
Collapse
|
9
|
Challenges in the Diagnosis of Taenia solium Cysticercosis and Taeniosis in Medical and Veterinary Settings in Selected Regions of Tanzania: A Cross-Sectional Study. Vet Med Int 2022; 2022:7472051. [PMID: 35815231 PMCID: PMC9262556 DOI: 10.1155/2022/7472051] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/16/2022] [Accepted: 05/19/2022] [Indexed: 12/04/2022] Open
Abstract
Background Taenia solium (neuro) cysticercosis/taeniosis (TSCT) is a zoonotic disease complex. There is a perceived inefficient diagnosis of infections by either form, the adult pork tapeworm (taeniosis) and the larval stage of it (cysticercosis), in low-income settings, including Tanzania. This study aimed at identifying potential gaps around TSCT diagnosis and knowledge of primary healthcare providers (officers in charge (OICs) of primary healthcare facilities (PHFs)) and veterinarians (meat inspectors (MIs)) on various aspects of TSCT disease complex and addressing effective disease control in Tanzania. Methodology. A cross-sectional study was conducted between January and April 2020 in Manyara, Dodoma, Ruvuma, Iringa, and Arusha regions in Babati, Mbulu, Kongwa, Mbinga, and Nyasa districts. We interviewed 152 OICs of PHFs and 108 MIs using a structured questionnaire and 33 medical and veterinary officers from level I healthcare facilities and district livestock offices, respectively, from selected study districts to the respective ministerial level using key informant interviews. Results Quantitative data revealed inadequate microscopic diagnostic facilities (54.6%) and personnel (100%) for taeniosis diagnosis in PHFs (n = 152). Approximately 81.2% of MIs compared with only 42.1% of OICs of PHFs scored above average regarding T. solium cysticerci knowledge. Nevertheless, 61.2% of OICs of PHFs compared with only 42.6% of MIs scored above average regarding the adult T. solium tapeworm knowledge. Qualitative data revealed inadequate availability of advanced diagnostic facilities (neuroimaging) and trained personnel for specific diagnosis of TSCT with a focus on neurocysticercosis (NCC) in secondary and tertiary healthcare facilities. Inadequately number of qualified MIs, slaughter slabs, and resource facilitation challenged porcine cysticercosis diagnosis. Conclusion It is concluded that diagnostic capacity and knowledge of OICs of PHFs and MIs regarding TSCT are insufficient in both medical and veterinary sectors. A One Health approach should be adopted to improve TSCT diagnostic capacity and practitioners' knowledge in both medical and veterinary sectors.
Collapse
|
10
|
Corda M, Sciurba J, Blaha J, Mahanty S, Paredes A, Garcia HH, Nash TE, Nutman TB, O’Connell EM. A recombinant monoclonal-based Taenia antigen assay that reflects disease activity in extra-parenchymal neurocysticercosis. PLoS Negl Trop Dis 2022; 16:e0010442. [PMID: 35617367 PMCID: PMC9176767 DOI: 10.1371/journal.pntd.0010442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 06/08/2022] [Accepted: 04/21/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Antigen tests for diagnosis and disease monitoring in some types of neurocysticercosis (NCC) are useful but access to testing has been limited by availability of proprietary reagents and/or kits. METHODS/PRINCIPAL FINDINGS Three previously identified IgM-secreting hybridomas whose IgM products demonstrated specificity to Taenia solium underwent variable heavy and light chain sequencing and isotype conversion to mouse IgG. Screening of these recombinantly expressed IgG anti-Ts hybridomas, identified one (TsG10) with the highest affinity to crude Taenia antigen. TsG10 was then used as a capture antibody in a sandwich antigen detection immunoassay in combination with either a high titer polyclonal anti-Ts antibody or with biotinylated TsG10 (termed TsG10*bt). Using serum, plasma, and CSF samples from patients with active NCC and those from NCC-uninfected patients, ROC curve analyses demonstrated that the TsG10-TsG10-*bt assay achieved a 98% sensitivity and 100% specificity in detecting samples known to be antigen positive and outperformed the polyclonal based assay (sensitivity of 93% with 100% specificity). By comparing levels of Ts antigen (Ag) in paired CSF (n = 10) or plasma/serum (n = 19) samples from well-characterized patients with extra-parenchymal NCC early in infection and at the time of definitive cure, all but 2 (1 from CSF and 1 from plasma) became undetectable. There was a high degree of correlation (r = 0.98) between the Ag levels detected by this new assay and levels found by a commercial assay. Pilot studies indicate that this antigen can be detected in the urine of patients with active NCC. CONCLUSIONS/SIGNIFICANCE A newly developed recombinant monoclonal antibody-based Ts Ag detection immunoassay is extremely sensitive in the detection of extra-parenchymal NCC and can be used to monitor the success of treatment in the CSF, serum/plasma and urine. The ability to produce recombinant TsG10 at scale should enable use of this antigen detection immunoassay wherever NCC is endemic. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov Identifiers: NCT00001205 - & NCT00001645.
Collapse
Affiliation(s)
- Madelynn Corda
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Joshua Sciurba
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Jiana Blaha
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Siddhartha Mahanty
- The Peter Doherty Institute for Infection and Immunity, University of Melbourne & The Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | | | | | - Theodore E. Nash
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Thomas B. Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Elise M. O’Connell
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| |
Collapse
|
11
|
Gulelat Y, Eguale T, Kebede N, Aleme H, Fèvre EM, Cook EAJ. Epidemiology of Porcine Cysticercosis in Eastern and Southern Africa: Systematic Review and Meta-Analysis. Front Public Health 2022; 10:836177. [PMID: 35372187 PMCID: PMC8966092 DOI: 10.3389/fpubh.2022.836177] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 02/16/2022] [Indexed: 11/29/2022] Open
Abstract
Taenia solium cysticercosis is the most common cause of acquired epilepsy in pig-raising and pork-consuming parts of Africa, Latin America, and Asia. This review aimed to systematically compile and synthesize data on the epidemiology of porcine cysticercosis in the Eastern and Southern Africa (ESA) region. Comprehensive searching strategies were employed to retrieve the studies published or reported between January 1,1997 and March 1, 2021, from Pub Med, Hinari, and Google Scholar databases and search platforms. The identified studies that met the inclusion criteria were then appraised for methodological quality. Finally, 44 studies obtained from nine countries were selected and included in this review. Relevant data were extracted using standardized templates for qualitative synthesis and meta-analysis. The overall pooled prevalence estimate of porcine cysticercosis in the ESA region was 17% (95% CI: 14-20%). The prevalence level between and within countries showed high variability. The pooled estimate showed high heterogeneity among the reports (the inverse variance index value (I2) of 98.99%, p < 0.05). The meta-analysis sub-grouped by the type of diagnostic test showed the pooled prevalence estimate of 27% (95% CI: 9-50) by carcass dissection; 23% (95% CI: 14-33) by Antibody-based immunodiagnostic techniques; 23% (95% CI: 18-29) by antigen detecting (Ag)-ELISA, 12% (95% CI: 7-18) by meat inspection, and 9% (95% CI: 7-11) by lingual examination. The meta-analysis sub-grouped by region showed a relatively higher pooled prevalence estimate for the Southern region 22% (95% CI: 15-30) compared to 13% (95% CI: 11-15) in the Eastern region. The highest country-based pooled prevalence was obtained from South Africa (33%, 95% CI: 20-48) and Zambia (22%, 95% CI: 16-29), whereas the lowest pooled prevalence was identified in Madagascar (5%, 95% CI: 4-5) and Rwanda (7%, 95% CI: 6-8). The lack of latrine, traditional pig husbandry practices, unprotected water sources, and increase in age were identified as significant risk factors for the occurrence of porcine cysticercosis in the pooled studies. The findings of this review will provide context-specific input to prioritize the possible intervention programs for T. solium control in the ESA region. More sensitive and specific test-based prevalence estimates, detailed risk factor investigations, and financial losses analysis are needed to establish feasible control strategies. Systematic Review Registration http://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021238931.
Collapse
Affiliation(s)
- Yewubdar Gulelat
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
- International Livestock Research Institute, Nairobi, Kenya
| | - Tadesse Eguale
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Nigatu Kebede
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Hailelule Aleme
- School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
| | - Eric M. Fèvre
- International Livestock Research Institute, Nairobi, Kenya
- Institute of Infection, Veterinary, and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Elizabeth A. J. Cook
- International Livestock Research Institute, Nairobi, Kenya
- Institute of Infection, Veterinary, and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| |
Collapse
|
12
|
Ngwili N, Thomas L, Githigia S, Muloi D, Marshall K, Wahome R, Roesel K. Co-infection of pigs with Taenia solium cysticercosis and gastrointestinal parasites in Eastern and Western Uganda. Parasitol Res 2021; 121:177-189. [PMID: 34816302 PMCID: PMC8610610 DOI: 10.1007/s00436-021-07380-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 11/10/2021] [Indexed: 11/27/2022]
Abstract
A study was carried out in Kamuli and Hoima districts in Eastern and Western regions of Uganda to determine the Taenia solium porcine cysticercosis (PCC) and gastrointestinal (GI) parasites co-infection status in pigs. One hundred sixty-one households were selected randomly and visited between November and December 2019. A household questionnaire was administered, and faecal and blood samples were collected from at least one pig older than 3 months per household. A blood sample was obtained from a jugular venipuncture, and a rectal faecal sample was obtained. Taenia spp. circulating antigen levels in the sample sera were tested using a commercial enzyme-linked immunosorbent assay kit, apDia™ cysticercosis Ag ELISA. The modified McMaster technique was used to identify and quantify the GI parasites. The apparent animal-level seroprevalence for PCC was 4.8% (95% CI 2.7–7.1) and differed across the two districts (p = 0.018). At the pig herd level, the prevalence was 9.7% (95% CI 5.5–14.4). The prevalence of the different nematode eggs and coccidian oocysts in the two districts was as follows: strongyles 79.0% (95% CI 74.3–83.6), coccidia 73.3% (95% CI 68.3–78.6), Trichuris spp. 7.4% (95% CI 4.9–10.6), Strongyloides ransomi 2.1 (95% CI 0.7–3.5) and Ascaris spp. 4.9 (95% CI 2.8–7.4). Overall, across the two districts, the arithmetic mean for the oocysts per gram (OPG) for coccidia was 2042.2 ± 5776.1, and eggs per gram (EPG) were the highest in strongyles 616.1 ± 991. Overall, 57.4% of the porcine cysticercosis seropositive pigs were also positive for at least one of the gastrointestinal helminths which included strongyles, Strongyloides ransomi, Trichuris spp. and Ascaris spp. The co-infection status of pigs with both PCC and GI parasites demonstrated by this study can provide an incentive for integrating the control and management of both parasites with oxfendazole. Further studies are required to understand the feasibility of using oxfendazole including cost–benefit analysis and the acceptability by local stakeholders for the control of T. solium cysticercosis and gastrointestinal parasites in pigs.
Collapse
Affiliation(s)
- Nicholas Ngwili
- Animal and Human Health Program, International Livestock Research Institute, Nairobi, Kenya. .,Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya.
| | - Lian Thomas
- Animal and Human Health Program, International Livestock Research Institute, Nairobi, Kenya.,Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Leahurst Campus, Neston, CH64 7TE, UK
| | - Samuel Githigia
- Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
| | - Dishon Muloi
- Animal and Human Health Program, International Livestock Research Institute, Nairobi, Kenya.,Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Leahurst Campus, Neston, CH64 7TE, UK
| | - Karen Marshall
- Animal and Human Health Program, International Livestock Research Institute, Nairobi, Kenya
| | - Raphael Wahome
- Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
| | - Kristina Roesel
- Animal and Human Health Program, International Livestock Research Institute, Nairobi, Kenya.,Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| |
Collapse
|
13
|
Arcas AS, Jaramillo L, Costa NS, Allil RCSB, Werneck MM. Localized surface plasmon resonance-based biosensor on gold nanoparticles for Taenia solium detection. APPLIED OPTICS 2021; 60:8137-8144. [PMID: 34613077 DOI: 10.1364/ao.432990] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
This paper describes, for the first time to our knowledge, a fast-response and specific biosensor for detection of Taenia solium, a parasite responsible for neurocysticercosis disease that affects the central nervous system. The biosensor is based on the localized surface plasmon resonance (LSPR) technique on gold nanoparticles (AuNPs) in colloidal suspension that were functionalized and activated with antibodies to perform an immuno-capture effect. The AuNPs were synthetized by Turkevich and seed-mediated growth methods. A variety of concentrations of T. solium antigen were added to test the detection and the dose-response profile. Small antigen concentrations were detected indicating that the limit of detection is lower than 0.1 µg/mL of antigen. The results demonstrate the potential of the AuNPs LSPR biosensor as a clinical tool for neurocysticercosis diagnostic.
Collapse
|
14
|
Shongwe NA, Byaruhanga C, Dorny P, Dermauw V, Qekwana DN. Knowledge, practices and seroprevalence of Taenia species in smallholder farms in Gauteng, South Africa. PLoS One 2020; 15:e0244055. [PMID: 33338060 PMCID: PMC7748137 DOI: 10.1371/journal.pone.0244055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 12/02/2020] [Indexed: 02/01/2023] Open
Abstract
Porcine cysticercosis and associated human infections are endemic in Sub-Saharan Africa, Latin America, and Asia. Poor agricultural practices, sanitary practices, and lack of knowledge increase the burden of the diseases in susceptible populations. This study investigates the seroprevalence of Taenia spp. in township pigs in Gauteng, South Africa and describes knowledge and farming practices of pig farmers regarding T. solium infections. Blood samples were collected from 126 pigs in three Gauteng township areas, and analyzed for active Taenia spp. infection using the B158/B60 Ag-ELISA. Farmer questionnaire surveys were conducted in four township areas to investigate the level of knowledge and practices associated with porcine cysticercosis and neurocysticercosis. Logistic regression models were used to assess the relationship between predictor variables and the outcome variable, knowledge of porcine cysticercosis or knowledge of neurocysticercosis. Overall, 7% of the pigs were seropositive for active Taenia spp. infection. 46% of farmers practiced a free-ranging system, while 25% practiced a semi-intensive system. Latrines were absent on all farms; however, 95% of farmers indicated that they have access to latrines at home. Most farmers had no knowledge of porcine cysticercosis (55%) or neurocysticercosis (79%), and this was not associated with any of the factors investigated. The prevalence of active Taenia spp. infection was reasonably low in this study, yet the knowledge level was also low, thus calling for further educational and training programmes to prevent Taenia spp. transmission in these communities.
Collapse
Affiliation(s)
- Nothando Altrecia Shongwe
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria, South Africa
| | - Charles Byaruhanga
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria, South Africa
| | - Pierre Dorny
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Veronique Dermauw
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Daniel Nenene Qekwana
- Section of Veterinary Public Health, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
- * E-mail:
| |
Collapse
|