Classical Swine Fever (CSF) is a highly contagious viral disease of swine that causes major
losses to pig production. CSF virus is a member of the genus Pestivirus of the family
Flaviviridae and is closely related antigenically to other Pestiviruses, Bovine Viral Diarrhoea
(BVD) virus and Border Disease (BD) virus. In the Lao People’s Democratic Republic (Laos),
CSF has been recognised as a disease that causes significant loss to the smallholder pig sector.
However, there exists in Laos a deficiency in fully understanding the epidemiology and impact
of CSF, together with limitations in being able to reliably detect CSF outbreaks in a timely
manner.
The research presented in this thesis is divided into three components. The first component
describes the smallholder pig sector in general and seeks to address the impact CSF has on
production. In comparison to accepted standards of international and tropical pig production,
the performance of the smallholder pig sector of Laos was quite poor. Classical Swine Fever
was found to be an important disease impacting on pig production, where the incidence of CSF
in Bolikhamxay province was 18 outbreaks per 100 village years.
The second and major component describes the development of a new diagnostic test to
improve the rapid identification of CSF outbreaks. This thesis describes the development and
assessment of a rapid and sensitive ELISA-based test for the diagnosis of CSF virus using
immunomagnetic beads (IMBs) as the solid phase. The majority of the research was conducted
in Laos where the IMB-ELISA for CSF virus was developed and compared to an antigen
capture (AC)-ELISA. Initial estimates of diagnostic specificity and sensitivity show 100 %
agreement with the AC-ELISA and the IMB-ELISA has up to 64-fold greater analytical
sensitivity. The rapid test is a highly robust and stable test format and much simpler to perform
than the AC-ELISA. The IMB-ELISA has the added advantage that the test can be read by eye,
lending it to the possibility of adaptation to a near-to-field test with minimal equipment needed.
The new test is comparable in cost to the current AC-ELISA; however it can be performed in
approximately 3 hours upon receipt of specimens compared to 1 to 2 days for the AC-ELISA.