Foot-and-mouth Disease Control Strategies Research Articles

Seroprevalence and Associated Risk Factors of Foot and Mouth Disease in Selected Woredas of the West Omo Zone, Southwest Ethiopia.

Aim and Background: Foot and Mouth Disease (FMD) is a prioritized transboundary animal disease, endemic in Ethiopia, and it has a high impact on cattle production and trade nationally and internationally. Methods: To ascertain the sero-prevalence and identify the exposure factors connected to a seropositive FMD in cattle, a cross-sectional study was conducted in three weredas of the West Omo Zone from January 2022 to February 2022. Multistage sampling was used to take one study wereda based on agroecology from the highland, midland, and lowland of the zone. Selection of cattle herd and blood samples from cattle were taken by using a simple random method. The Statistical Package for Social Science Version 25 was used to analyze the pertinent data once it had been entered and coded into Microsoft Excel. Results: The study area's FMD seroprevalence for individual cattle and at the herd level was 5.3% with a 95% confidence interval (3.51%–7.99%) and 77.78% (n= 9), respectively. The high herd level recorded during the current study was evidence that the disease has spread throughout the zone. Multinomial logistic regression analysis showed the age of the animal and study wereda are significantly(p<0.05) associated with the sero-prevalence of FMD in this study. High cattle movement to big markets and long exposure of old cattle to the disease may contribute to the significant association of the disease with these risk factors. Conclusion: This study showed that herd-level FMD seropositivity is high, necessitating the identification of specific FMD serotypes and the commencement of appropriate FMD prevention and control strategies in the zone.

Evolutionary dynamics of topotype ME-SA/Ind-2001 of foot and mouth disease virus serotype-O in Pakistan: 2017-2022.

During past few years, the Ind-2001 lineage of the Middle East-South Asia topotype (ME-SA) of the foot-and-mouth disease (FMD) virus has been implicated in FMD outbreaks in Pakistan. This work conducts a comprehensive evolutionary analysis of the Ind-2001 and Pan Asia II lineages, with a specific emphasis on their geographical distribution, lineage classification, and sub-lineage distribution within the region. Furthermore, it aims to expand our understanding of the conserved region of the VP1 protein. Total samples (n=50) were subjected to antigen detection ELISA and RT-PCR for serotype determination. Confirmed serotype-O isolates (n=17) underwent sequencing for lineage comparison, mutation impact assessment on the VP1 protein GH loop, 3D structure prediction, and further comparative analysis. Isolates collected from 2017 to 2020 were identified as serotypes O/ME-SA/Pan Asia II ANT10 and O/ME-SA/Pak14. Notably, isolates collected from 2020 to 2022 belonged to a novel FMDV serotype O/ME-SA/Ind-2001e lineage. Phylogenetic analyses indicated that these strains were distinct from dominant contemporaneous strains which may challenge Pakistan's FMD control measures. These isolates exhibited variance in the VP1 epitope, specifically in amino acid residues 135-155, known to influence neutralizing antibody generation. Observed mutations suggest potential challenges to current vaccination efficacy against FMD. This emphasizes enhanced FMD surveillance and demonstrates that tracking the emergence of the O/ME-SA/Ind-2001e lineage is important for determining FMD control strategies in Asia.

Subdistrict-Level Reproductive Number for Foot and Mouth Disease in Cattle in Northern Thailand.

Foot and mouth disease (FMD) is an important contagious transboundary disease that causes a significant economic loss for several countries. The FMD virus (FMDV) can spread very rapidly by direct and indirect transmission among susceptible animals. The complexity and magnitude of FMDV transmission at the initial stages of the epidemic can be expressed by the basic reproductive number (R0), and furthermore, control strategies can be assessed by the estimation of the effective reproductive number. In this study, we aimed to describe FMD outbreaks among smallholder cattle farms by subdistricts in the northern Thailand and compute the effective reproductive number for outbreaks caused by FMDV serotype O and overall serotypes, including serotype O, serotype A, and unidentified serotype, at the subdistrict level (Rsd) using an epidemic doubling time method. Field data of FMD outbreaks during 2015–2017 that affected 94 subdistricts in northern Thailand were assessed to estimate the Rsd. Results showed that 63.38% (90/142) of the FMD outbreak episodes in cattle were caused by FMDV serotype O. The average doubling time and the Rsd estimated of the outbreaks caused by FMDV serotype O and overall serotype were 2.80 and 4.67 months, and 1.06 and 1.04, respectively. Our results indicated that transmission of FMD in cattle at the subdistrict level in northern Thailand was not controlled (Rsd > 1), which indicates the endemicity of the disease in the region. Although control measures are in place, the results from this study highlighted the need for enhancing FMD monitoring and control strategies in northern Thailand.

Use of an automatic needle-free injection device for foot-and-mouth disease vaccination in dairy heifers

The foot-and-mouth disease (FMD) vaccination of Thai dairy cows is routinely conducted to control and prevent the disease. In Thailand, FMD control strategies include a subcutaneous route (s.c.) vaccination with 2 ml of inactivated FMD vaccine 2–3 times a year produced by the Department of Livestock Development (DLD). A new way of vaccination was introduced in the form of an automatic needle-free injection device. This technology has several important advantages, such as requiring less animal restraint, reduced time and labour with high precision, and a consistent delivery system. Here, the effectiveness of an automatic needle-free injection (ANFI) device was evaluated in 30 dairy heifers (randomly divided into three groups, 10 in each group) in the FMD vaccine delivery. The first group was subcutaneously (s.c.) vaccinated using a conventional hypodermic needle with 2 ml of the vaccine, the second group received the same, but using a CO<sub>2</sub>-powered ANFI device, and the third group received the vaccine using the same ANFI device, but administered intradermally (i.d.) with only 1 ml of the vaccine. The blood samples collected up to 120 days post-vaccination revealed that both injection methods resulted in a similar serological response. The results suggest that the i.d. and s.c. ANFI systems are effective and safe. Moreover, the i.d. use of the ANFI enabled the possibility to half the vaccination dose with the same efficacy. Therefore, the ANFI can be used as an alternative approach for FMD vaccination by s.c. or i.d. routes in dairy cows in Thailand. Ultimately, reducing the use of restraint devices and labour will improve the vaccination for the prevention and control of FMD and may improve the cows’ welfare.

Foot-and-mouth disease seroprevalence and reporting behaviours in nine northern provinces in Lao PDR: The current situation and challenges for control.

Foot-and-mouth disease (FMD), caused by the FMD virus (FMDV), is one of the most important of global livestock diseases, impacting even-toed ungulates and distributed mostly in less developed countries that are home to 75% of the human population. A progressive control pathway for FMD (PCP-FMD) was developed to assist countries to better manage FMD risks and progress towards control and eradication. This requires evidence of current FMD seroprevalence to enable the informed risk assessment and the disease control planning required to progress along the initial stages of the PCP-FMD. Despite Laos being an active member of the South East Asia and China FMD campaign, these data have been challenging to obtain. To address this gap, a cross-sectional seroprevalence study in nine northern Lao provinces was conducted in early 2019. The study sampled 602 large ruminants and 19 goats from 30 villages. Overall, the large ruminant seroprevalence was 43.7% (95% CI 39.7-47.8), and 90% of sampled villages had at least one seropositive animal. Large ruminants suspected of having had clinical FMD in their lifetime were found to have an increased risk of being seropositive (odds ratio 1.96, 95% CI 1.06-3.65, p=.03). An examination of current reporting behaviours of farmers, village veterinary workers and district and provincial officials found that individuals were using their discretion as to whether disease events required reporting along the chain of command. This, plus the lack of a computerized reporting system, contributed to a loss of historical data, potentially compromising progression on the PCP-FMD. Laos requires ongoing support from donor agencies to improve the current animal disease surveillance system and implement effective FMD control strategies that can enable progress on the PCP-FMD.

A Comprehensive Review of the Immunological Response against Foot-and-Mouth Disease Virus Infection and Its Evasion Mechanisms.

Foot-and-mouth disease (FMD) is a highly contagious viral disease, which has been reported for over 100 years, and against which the struggle has lasted for the same amount of time. It affects individuals from the order Artiodactyla, such as cattle, swine, sheep, wild animals from this order, and a few non-cloven hoofed species, such as mice and elephants. FMD causes large-scale economic losses for agricultural production systems; morbidity is almost 100% in an affected population, accompanied by a high mortality rate in young animals due to myocarditis or an inability to suckle if a mother is ill. The aetiological agent is an Aphthovirus from the family Picornaviridae, having seven serotypes: A, O, C, SAT1, SAT2, SAT3, and Asia 1. Serotype variability means that an immune response is serospecific and vaccines are thus designed to protect against each serotype independently. A host’s adaptive immune response is key in defence against pathogens; however, this virus uses successful strategies (along with most microorganisms) enabling it to evade a host’s immune system to rapidly and efficiently establish itself within such host, and thus remain there. This review has been aimed at an in-depth analysis of the immune response in cattle and swine regarding FMD virus, the possible evasion mechanisms used by the virus and describing some immunological differences regarding these species. Such aspects can provide pertinent knowledge for developing new FMD control and prevention strategies.

Multi-criteria decision analysis to evaluate foot and mouth disease control strategies with the perspectives of Chief Veterinary Officers in the Asia-Oceania region.

The objective of this study was to evaluate the effectiveness of foot and mouth disease (FMD) control strategies using multi-criteria decision analysis (MCDA). The FMD control strategies were evaluated for epidemiological, economic and social-environmental criteria, accounting for the preferences of Chief Veterinary Officers (CVOs) from the Asia-Oceania region, with the preferences quantified using a questionnaire study. Previously reported simulation results of an FMD epidemic were used to measure the epidemiological effectiveness of FMD control strategies. The simulated FMD epidemic results, such as the number of infected farms, the duration of the epidemic and the outbreak area, were compared for a number of FMD control strategies. Based on previous simulation and economic modelling results and incorporating a literature search to quantify the social and environmental outcomes of an FMD outbreak, MCDA analysis was conducted to evaluate control strategies. According to the overall score in the MCDA results, an FMD control strategy which consisted of a 3-km radius of pre-emptive slaughter, 100 days of movement restriction and vaccinating all FMD-susceptible animals (baseline strategy) was the preferred strategy, with the highest overall score of 62.99. In contrast, the same duration of movement restriction and vaccination strategy with a 0.5-km radius of pre-emptive slaughter was least preferred, with the lowest overall score of 37.05. The evaluation of the FMD control strategies presented here using MCDA has provided scientific evidence for selecting an appropriate baseline FMD control strategy, based on the preferences of CVOs.

Economic Analysis of Increasing Foot-and-Mouth Disease Vaccination Frequency: The Case of the Biannual Mass Vaccination Strategy.

Biannual mass vaccination is a routinely applied foot-and-mouth disease (FMD) control strategy in Turkey. However, because biannual mass vaccination may leave significant immunity gaps, this strategy may cause economic losses because of possible FMD infections. In high-risk areas—such as border cities, it was suggested by the government to increase the vaccination intervals in order to decrease the FMD infection risk. This study analyses and compares the economic effects of a biannual mass vaccination regime and vaccination every 4 months as an alternative strategy in border cities by using partial budgeting approach. Biannual mass vaccination was used as a baseline scenario. Data on the impact of FMD on animal health and production parameters for 2018 were obtained from the OIE-WAHIS system and complemented by literature data and expert opinion. In the partial budgeting model, weight loss was considered as a major loss of income because majority of the farming systems are based on cattle fattening in the border cities of Turkey. Results revealed that the net economic impact, which is the benefit that exceeds the losses and costs of increasing the frequency of vaccination, is 76.4 TL ($15.9) per cattle. The sensitivity analysis showed that average body weight and weight losses when infected had more effect on net impact changes than market prices. The lower and upper FMD incidence variability resulted in 19.2 TL ($4) and 190.8 TL ($39.6) of net impact per cattle, respectively. The new FMD control strategy would make a total net economic impact of 5,274,836 TL ($1,094,250) for a population of 800,970 fattening cattle in border cities. The results of this study indicated that intense FMD control strategies may be more cost effective than the current control strategies, especially in high-risk areas. Future studies with more comprehensive epidemiological and economic data must be conducted to analyze and compare alternative FMD control strategies in Turkey.

Detection of an emerging novel sublineage Ind2001BD1 and lineage PanAsia of foot-and-mouth disease virus serotype O in cattle in Manikgonj district of Bangladesh, 2018

Background:Foot-and-mouth disease (FMD) is an endemic disease of cloven-hoofed animals in Bangladesh and multiple outbreaks occur every year because of the FMD virus (FMDV).Aim:The aim of the present investigation was to determine the molecular characterization of the VP1 coding region of FMDV serotype O outbreak in cattle.Methods:A total of four tongue epithelial specimens were collected from clinically FMD-positive cattle during June 2018 in Manikgonj district of Bangladesh.Results:All four isolates were recorded positive for FMDV serotype O. The phylogenetic analysis showed that two isolates were clustered within an emerging novel sublineage Ind2001BD1 under lineage Ind2001 of FMDV serotype O, which was identified during 2012–2016 in Bangladesh. One isolate was clustered within the lineage PanAsia of FMDV serotype O and was closely related to an isolate identified in Nepal in 2009. The phylogenetic reconstruction revealed that all the four isolates belong to the Middle East–South Asia topotype.Conclusion:Therefore, multiple lineages of the FMDV serotype O are circulating among the cattle in the outbreak area, which make it more complex for the FMD control program in Bangladesh. A comprehensive study on the genetic characteristics of FMDV across the country is required for effective FMD prevention and control strategy.

Foot-and-mouth disease in Southern Ghana: occurrence and molecular characterization of circulating viruses.

Foot-and-mouth disease (FMD) is considered to be endemic in Ghana. However, our knowledge of the local epidemiology of the disease is restricted by a lack of serological information and data for characterized viruses causing field outbreaks. In order to improve our understanding of the prevailing situation, this study was initiated to establish the FMD viruses (FMDV) circulating in the country. During 2016, sera (n = 93) and epithelia/oral swab (n = 20) samples were collected from cattle from four districts in Southern Ghana that experienced FMD outbreaks. Sera were analyzed using the PrioCHECK® FMDV non-structural protein (NSP) ELISA whereas the epithelia/oral swab samples were examined by virus isolation, antigen ELISA, reverse transcription polymerase chain reaction (RT-PCR), and sequencing of VP1 followed by phylogenetic analysis. Assay for antibodies against FMDV NSPs provided evidence of exposure to FMDV in 88.2% (82/93) of the sera tested. Serotypes O and A viruses were detected from clinical samples by RT-PCR and sequencing of VP1. Phylogenetic analysis of VP1 coding sequences revealed that the serotype O viruses belonged to the West Africa (WA) topotype and were most closely related to viruses from Niger and Benin, while the serotype A viruses clustered within genotype IV (G-IV) of the Africa topotype and were most closely related to viruses from Nigeria. This study provides useful information on FMDV serotypes and viral lineages that circulate in Ghana and West Africa that may aid in the formulation of effective FMD control strategies.

Deciphering foot-and-mouth disease (FMD) virus–host tropism

The pattern of interactions between foot and mouth disease (FMD) viral protein 1 (VP1) with susceptible and resistant host integrins were deciphered. The putative effect of site-directed mutation on alteration of interaction is illustrated using predicted and validated 3D structures of VP1, mutated VP1 and integrins of Bos taurus, Gallus and Canis. Strong interactions were observed between FMDV-VP1 protein motifs at conserved tripeptide, Arg-Gly-Asp 143RGD145 and at domain 676SIPLQ680 in alpha-integrin of B. taurus. Notably, in-silico site-directed mutation in FMDV-VP1 protein led to complete loss of interaction between FMD-VP1 protein and B. taurus integrin, which confirmed the active role of arginine-glycine-aspartic acid (RGD) domain. Interestingly, in-vitro analysis demonstrates the persistence of the putative tropism site ‘SIPLQ’ in different cattle breeds undertaken. Thus, the attempt to decipher the tropism of FMDV at host receptor level interaction might be useful for future FMD control strategies through development of mimetic marker vaccines and/or host receptor manipulations.Communicated by Ramaswamy H. Sarma

The Effectiveness of a Foot and Mouth Disease Outbreak Control Programme in Thailand 2008–2015: Case Studies and Lessons Learned

Three Foot and Mouth Disease (FMD) outbreaks in northern Thailand that occurred during the implementation of the national FMD strategic plan in 2008–2015 are described to illustrate the lessons learned and to improve the prevention and control of future outbreaks. In 2008, during a FMD outbreak on a dairy farm, milk delivery was banned for 30 days. This was a part of movement management, a key strategy for FMD control in dairy farms in the area. In 2009, more than half the animals on a pig farm were affected by FMD. Animal quarantine and restricted animal movement played a key role in preventing the spread of FMD. In 2010, FMD infection was reported in a captive elephant. The suspected source of virus was a FMD-infected cow on the same premises. The infected elephant was moved to an elephant hospital that was located in a different province before the diagnosis was confirmed. FMD education was given to elephant veterinarians to promote FMD prevention and control strategies in this unique species. These three cases illustrate how differences in outbreak circumstances and species require the implementation of a variety of different FMD control and prevention measures. Control measures and responses should be customized in different outbreak situations.

Spatiotemporal analysis of foot-and-mouth disease outbreaks in the Republic of Kazakhstan, 1955 - 2013

Foot-and-mouth disease (FMD) poses a significant obstacle to international trade and economic development, and for that reason, FMD prevention, control and eradication are major goals guiding animal health policy in most countries. The purpose of this study was to conduct a retrospective spatiotemporal analysis of FMD outbreaks among livestock in the Republic of Kazakhstan (RK) from 1955 to 2013. During that time, several FMD control strategies were implemented in RK, which culminated with the World Organization for Animal Health (OIE) recognition of RK as a country that is FMD-free with partial vaccination (2015). Here, we describe and analyse the changes in spatial and temporal dynamics of FMD under different control strategies that were utilized as the country progressively moved towards eradication of the disease. A total number of 5,260 FMD outbreaks of serotype O and A (including the A22 lineage) were recorded in the cattle, pig and small ruminant populations of RK during that period. We found that outbreaks occurred in spatiotemporal clusters only prior to 1970, which is before ring vaccination around outbreaks was first employed. This finding suggests that ring vaccination substantially reduced local spread and prevented large FMD epidemics in the country. Disease incidence steadily decreased after the implementation of ring vaccination and culling of infected animals, with spatiotemporal clusters only occurring as a result of an introduction of an antigenically distinct variant of serotype A. From 1955 to 1984, FMD outbreaks demonstrated two seasonal peaks of incidence in the spring and fall. In contrast, only the peak in spring was observed between 1984 and 2013. Quantitative knowledge on how different policy and alternative control strategies contributed to RK achieving FMD-free status could improve prospects for continued control in RK and inform control strategies in other FMD-endemic regions.

Serological evidence of foot-and-mouth disease virus infection in goat breeds in the Samsun province of Turkey

Foot-and-mouth disease (FMD) is one of the major endemic trans-boundary livestock diseases of socio-economic importance in Turkey and worldwide. Goats constitute the third largest susceptible population of domestic livestock in Turkey. FMD surveillance and control strategies in the country largely ignore small ruminants, known to be critical in the epidemiology of the disease. In this study, blood samples were randomly collected from different domestic goat breeds (Anatolian black goat, Maltese and Saanen). The material consisted of 368 domestic goats, including 121 Anatolian black, 125 Maltese and 122 Saanen goats from Samsun province. The serum samples were examined for the presence of antibodies to foot and mouth disease virus using non structural proteins (NSPs) competitive enzyme-linked immunosorbent assay (ELISA). Out of 368 serum samples examined, 12 (3.26%) were positive for FMD. Seropositivity rates in Anatolian black, Saanen and Maltese breeds were 0.83%, 0.82% and 8.00% for FMD, respectively. Although, seropositivity rate in Maltese goat breed was higher than others, this result was not attributed to breed susceptibility. The results of the investigation indicate that FMD is less widespread in goats than sheep and cattle in Samsun province. The results, supported for the first time in Turkey the hypothesis that goats act as a potential reservoir of FMD virus and thus have a role in the epidemiology of FMD.

Transmission of Foot-and-Mouth Disease Virus during the Incubation Period in Pigs.

Understanding the quantitative characteristics of a pathogen’s capability to transmit during distinct phases of infection is important to enable accurate predictions of the spread and impact of a disease outbreak. In the current investigation, the potential for transmission of foot-and-mouth disease virus (FMDV) during the incubation (preclinical) period of infection was investigated in seven groups of pigs that were sequentially exposed to a group of donor pigs that were infected by simulated-natural inoculation. Contact-exposed pigs were comingled with infected donors through successive 8-h time slots spanning from 8 to 64 h post-inoculation (hpi) of the donor pigs. The transition from latent to infectious periods in the donor pigs was clearly defined by successful transmission of foot-and-mouth disease (FMD) to all contact pigs that were exposed to the donors from 24 hpi and later. This onset of infectiousness occurred concurrent with detection of viremia, but approximately 24 h prior to the first appearance of clinical signs of FMD in the donors. Thus, the latent period of infection ended approximately 24 h before the end of the incubation period. There were significant differences between contact-exposed groups in the time elapsed from virus exposure to the first detection of FMDV shedding, viremia, and clinical lesions. Specifically, the onset and progression of clinical FMD were more rapid in pigs that had been exposed to the donor pigs during more advanced phases of disease, suggesting that these animals had received a higher effective challenge dose. These results demonstrate transmission and dissemination of FMD within groups of pigs during the incubation period of infection. Furthermore, these findings suggest that under current conditions, shedding of FMDV in oropharyngeal fluids is a more precise proxy for FMDV infectiousness than clinical signs of infection. These findings may impact modeling of the propagation of FMD outbreaks that initiate in pig holdings and should be considered when designing FMD control strategies.

Potential impact of species and livestock density on the epidemic size and effectiveness of control measures for foot-and-mouth disease in Japan.

The characteristics of a livestock area, including farm density and animal species, influence the spread of foot-and-mouth disease (FMD). In this study, the impact of livestock area on FMD epidemics was examined using an FMD transmission model. For this simulation, three major livestock areas were selected: the 2010 FMD epidemic area in Japan as the baseline area (BS), a cattle and pig mixed production area (CP) and a cattle production area (C). Simulation results demonstrated that under the 24-hr culling policy, only 12% of epidemics among 1,000 simulations were abated within 100 days in the CP area, whereas 90% of the epidemics ceased in the BS area. In the C area, all epidemics were successfully contained within 100 days. Evaluation of additional control measures in the CP area showed that the 0.5-km pre-emptive culling, even when only targeting pig farms, raised the potential for successful containment to 94%. A 10-km vaccination on day 7 or 14 after initial detection was also effective in halting the epidemics (80%), but accompanied a large number of culled or vaccinated farms. The combined strategy of 10-km vaccination and 0.5-km pre-emptive culling targeting pig farms succeeded in containing all epidemics within 100 days. The present study suggests the importance of preparedness for the 24-hr culling policy and additional control measures when an FMD outbreak occurs in a densely populated area. Considering the characteristics of the livestock area is important in planning FMD control strategies.

Food and biosecurity: livestock production and towards a world free of foot-and-mouth disease

A key challenge for global livestock production is the prevalence of infectious animal diseases. These diseases result in low productivity in meat and dairy production, culled animals, and significant barriers to trade and lost income from meat and meat products. Foot-and-mouth disease (FMD) affects both developing countries, where it is often endemic and very costly, and developed countries where incursions result in considerable economic losses in the order of billions of dollars per year. In some cases, production levels of pork meat in developed countries have still not recovered to levels prior to past disease incursions, more than a decade ago. In developing countries, the export of animal products has exhibited sluggish growth for decades, constrained by ongoing animal disease problems. We make three contributions. First, we provide an overview of worldwide meat production, consumption and trade in the context of FMD. Second, we provide insights into the economics of biosecurity measures and how these activities should be optimally designed to enhance livestock production. Third, we analyse a case study of an FMD-endemic country, Vietnam, which has been trying to achieve FMD-free status for some time. Lessons learnt from this case study shed light on the challenges in achieving FMD-free status in developing countries, which is useful for a global FMD control strategy and the promotion of world food security.

Serosurveillance of foot-and-mouth disease virus in selected livestock-wildlife interface areas of Tanzania.

Foot-and-mouth disease (FMD) is caused by a virus of the genus Aphthorvirus of the family Picornaviridae. There is great scientific need for determining the transmission dynamics of FMD virus (FMDV) by drawing more attention to the livestock-wildlife interface areas. A variety of literature suggests that buffalo could serve as reservoir of FMDV in wildlife and cattle. However, many FMDV research studies conducted on experimentally infected cattle as carriers and groups of animal highly susceptible to FMDV (i.e. bovine calves) have shown lower chances of transmission of the virus between carriers and the susceptible groups. These findings underscore the importance of continued research on the role played by carrier animals on FMDV transmission dynamics under natural conditions. The aim of this research study was to determine FMDV infection status among buffalo and cattle herds in selected livestock-wildlife interface areas. The sampled areas included Mikumi, Mkomazi and Ruaha national parks, where a total of 330 buffalo and bovine sera samples were collected. Laboratory analysis of the samples was done through the NSP ELISA technique using the PrioCHECK® FMDV NS Kit for detection of antibodies directed against 3ABC non-structural proteins and confirming natural infections. Results showed that 76.3% of tested sera samples were positive for FMDV. However, serotyping of NSP ELISA seroreactors with LPBE is yet to be done. This information is important for further epidemiological studies towards developing effective FMD control strategies.

Laboratory capacity for diagnosis of foot-and-mouth disease in Eastern Africa: implications for the progressive control pathway.

BackgroundAccurate diagnosis is pertinent to any disease control programme. If Eastern Africa is to work towards control of foot-and-mouth disease (FMD) using the Progressive Control Pathway for FMD (PCP-FMD) as a tool, then the capacity of national reference laboratories (NRLs) mandated to diagnose FMD should match this task. This study assessed the laboratory capacity of 14 NRLs of the Eastern Africa Region Laboratory Network member countries using a semi-structured questionnaire and retrospective data from the World Reference Laboratory for FMD annual reports and Genbank® through National Centre for Biotechnology Information for the period 2006–2010.ResultsThe questionnaire response rate was 13/14 (93%). Twelve out of the 13 countries/regions had experienced at least one outbreak in the relevant five year period. Only two countries (Ethiopia and Kenya) had laboratories at biosecurity level 3 and only three (Ethiopia, Kenya and Sudan) had identified FMD virus serotypes for all reported outbreaks. Based on their own country/region assessment, 12/13 of these countries /regions were below stage 3 of the PCP-FMD. Quarantine (77%) and vaccination (54%) were the major FMD control strategies employed. The majority (12/13) of the NRLs used serological techniques to diagnose FMD, seven used antigen ELISA and three of these (25%) also used molecular techniques which were the tests most frequently requested from collaborating laboratories by the majority (69%) of the NRLs. Only 4/13 (31%) participated in proficiency testing for FMD. Four (31%) laboratories had no quality management systems (QMS) in place and where QMS existed it was still deficient, thus, none of the laboratories had achieved accreditation for FMD diagnosis.ConclusionsThis study indicates that FMD diagnostic capacity in Eastern Africa is still inadequate and largely depends on antigen and antibody ELISAs techniques undertaken by the NRLs. Hence, for the region to progress on the PCP-FMD, there is need to: implement regional control measures, improve the serological diagnostic test performance and laboratory capacity of the NRLs (including training of personnel as well as upgrading of equipment and methods, especially strengthening the molecular diagnostic capacity), and to establish a regional reference laboratory to enforce QMS and characterization of FMD virus containing samples.

Foot-and-Mouth Disease Virus Serotype O Phylodynamics: Genetic Variability Associated with Epidemiological Factors in Pakistan

One of the most challenging aspects of foot-and-mouth disease (FMD) control is the high genetic variability of the FMD virus (FMDV). In endemic settings such as the Indian subcontinent, this variability has resulted in the emergence of pandemic strains that have spread widely and caused devastating outbreaks in disease-free areas. In countries trying to control and eradicate FMD using vaccination strategies, the constantly evolving and wide diversity of field FMDV strains is an obstacle for identifying vaccine strains that are successful in conferring protection against infection with field viruses. Consequently, quantitative knowledge on the factors that are associated with variability of the FMDV is prerequisite for preventing and controlling FMD in the Indian subcontinent. A hierarchical linear model was used to assess the association between time, space, host species and the genetic variability of serotype O FMDV using viruses collected in Pakistan from 2005 to 2011. Significant (P<0.05) amino acid and nucleotide variations were associated with spatial distance, but not with differences in host species, which is consistent with the frequent multi-species infection of this serotype O FMDV. Results from this study will contribute to the understanding of FMDV variability and to the design of FMD control strategies in Pakistan. Viruses sequenced here also provide the earliest reported isolate from the Pan Asia II(ANT-10) sublineage, which has caused several outbreaks in the Middle East and spread into Europe (Bulgaria) and Africa (Libya).