Abstract:
Lumpy skin disease virus is a poxvirus in the genus Capripoxvirus and is closely related to sheeppox
virus and goatpox virus. It’s economically important in cattle and a notifiable disease by World
Organization for Animal Health. Lumpy skin disease (LSD) is endemic in most parts of Africa with
small-scale farmers experiencing the highest loss during outbreaks due to restricted animal trade
and costly control and eradication measures. Serological methods of LSD detection are sensitive,
inexpensive but can be laborious and time-consuming while, molecular methods such as
Polymerase chain reaction (PCR), and real-time PCR/quantitative PCR (qPCR) are sensitive but
require expertise and sophisticated laboratories. Loop-mediated isothermal amplification (LAMP)
molecular method is advantageous, as it does not require expertise or sophisticated equipment.
Thisstudy aimed to develop a rapid, simple, specific, and sensitive detection method for LSD. Sixtytwo samples that included skin biopsies, whole blood, serum, and cell cultures were used. New
LAMP primer (10_LSD) that could detect lumpy skin disease virus, was designed using Genome
based LAMP primer designer (GLAPD) software. Samples were analyzed by LAMP assay and a gold
standard (real-time PCR). A LAMP field-based extraction method using polyethylene glycol (PEG)
was developed and used for the detection of lumpy skin disease virus. The 10_LSD had a kappa
value of 0.32 against the qPCR gold standard. In terms of limit of detection, qPCR had a detection
limit of 10-3 ng/µl while 10_LSD had a limit of detection of 1 ng/µl and. The 10_LSD assay showed
sensitivity of 60% and a specificity of 86 %. The LAMP assay did not cross-react with closely related
viruses like camelpox, Orf virus, and Pestes des Petit Ruminants but could amplify sheeppox virus
and goatpox virus. The average time to positivity was 14-28 minutes. The study supports the
adoption of the LAMP assay for rapid Capripoxvirus diagnosis as a simpler, effective, and rapid
method of detection, monitoring, and controlling outbreaks and the spread of disease in a field
set up.
