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

SummaryEffective control and monitoring of foot‐and‐mouth disease (FMD) relies upon rapid and accurate disease confirmation. Currently, clinical samples are usually tested in reference laboratories using standardized assays recommended by The World Organisation for Animal Health (OIE). However, the requirements for prompt and serotype‐specific diagnosis during FMD outbreaks, and the need to establish robust laboratory testing capacity in FMD‐endemic countries have motivated the development of simple diagnostic platforms to support local decision‐making. Using a portable thermocycler, the T‐COR™ 8, this study describes the laboratory and field evaluation of a commercially available, lyophilized pan‐serotype‐specific real‐time RT‐PCR (rRT‐PCR) assay and a newly available FMD virus (FMDV) typing assay (East Africa‐specific for serotypes: O, A, Southern African Territories [SAT] 1 and 2). Analytical sensitivity, diagnostic sensitivity and specificity of the pan‐serotype‐specific lyophilized assay were comparable to that of an OIE‐recommended laboratory‐based rRT‐PCR (determined using a panel of 57 FMDV‐positive samples and six non‐FMDV vesicular disease samples for differential diagnosis). The FMDV‐typing assay was able to correctly identify the serotype of 33/36 FMDV‐positive samples (no cross‐reactivity between serotypes was evident). Furthermore, the assays were able to accurately detect and type FMDV RNA in multiple sample types, including epithelial tissue suspensions, serum, oesophageal–pharyngeal (OP) fluid and oral swabs, both with and without the use of nucleic acid extraction. When deployed in laboratory and field settings in Tanzania, Kenya and Ethiopia, both assays reliably detected and serotyped FMDV RNA in samples (n = 144) collected from pre‐clinical, clinical and clinically recovered cattle. These data support the use of field‐ready rRT‐PCR platforms in endemic settings for simple, highly sensitive and rapid detection and/or characterization of FMDV.

Section: Discussionmentioning

confidence: 99%

Direct detection and characterization of foot-and-mouth disease virus in East Africa using a field-ready real-time PCR platform

Howson

Armson

Lyons

et al. 2017

“…Apart from serotype O, other serotypes including A, SAT 1 and SAT 2 have also been recently in circulation (Namatovu et al, 2013), while previously, serotype C has also been identified within the region (Vosloo et al, 2002). However, serotype C was last isolated from Kenyan cattle in 2004 (Roeder and Knowles, 2009;Sangula et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Analysis of Recent Serotype O Foot-and-Mouth Disease Viruses from Livestock in Kenya: Evidence of Four Independently Evolving Lineages

Wekesa

Muwanika

Siegismund

et al. 2013

Citation (APA):Wekesa, S. N., Muwanika, V. B., Siegismund, H. R., Sangula, A. K., Namatovu, A., Dhikusooka, M. T., ... Belsham, G. (2015 from Eastern Africa, it was apparent that the outbreaks were caused by viruses from three different lineages of topotype EA-2 and a fourth virus strain belonging to topotype EA-4. The topotypes EA-1 and EA-3 were not detected from these outbreaks. Implications of these results for FMD control in Eastern Africa are discussed.

“…A clear global picture of the distribution and movements of FMD strains within and between regions and countries is lacking. This is partly due to limited diagnostic capacity and limited sampling in many endemic countries (Namatovu et al., ). Cost, complexity and biosafety requirements of current tests (antibody and antigen) present a barrier to some countries wishing to perform more FMD diagnostics.…”

Section: Introductionmentioning

confidence: 99%

Global Foot-and-Mouth Disease Research Update and Gap Analysis: 4 - Diagnostics

Knight-Jones

Robinson

Charleston

et al. 2016

SummaryThis study assessed knowledge gaps in foot-and-mouth disease (FMD) research in the field of diagnostics. The study took the form of a literature review combined with research updates collected in 2014 from 33 institutes from around the world. Findings were used to identify priority areas for future FMD research.Molecular and genetic technologies, including sequencing, are developing at an increasing rate both in terms of capability and affordability. These advances potentiate progress in many other fields of research, from vaccine development to epidemiology. The development of RT-LAMP represents an important breakthrough allowing greater use and access to molecular diagnostics. It is now possible to determine virus serotype using PCR, although only for certain virus pools, continued progress is needed to cover the global spectrum of FMD viruses. Progress has also been made in the development of pen-side rapid diagnostics, some with the ability to determine serotype. However, further advances in pen-side serotype or strain determination would benefit both FMD-free countries and endemic countries with limited access to wellresourced laboratories.Novel sampling methods that show promise include air sampling and baited ropes, the latter may aid sampling in wildlife and swine. Studies of infrared thermography for the early detection of FMD have not been encouraging, although investigations are ongoing. Multiplex tests have been developed that are able to simultaneously screen for multiple pathogens with similar clinical signs. Crucial for assessing FMDV freedom, tests exist to detect animals that have been infected with FMDV regardless of vaccination status; however, limitations exist, particularly when testing previously vaccinated animals. Novel vaccines are being developed with complementary DIVA tests for this purpose. Research is also needed to improve the current imprecise approaches to FMD vaccine matching.The development of simple, affordable tests increases access to FMD diagnostics, greatly benefiting regions with limited laboratory capacity.