A Study Of Domestic Pigs, Wild Suids And Ticks As Reservoirs For African Swine Fever Virus In Uganda.pdf

Background
African swine fever (ASF) is a contagious viral disease that affects domestic pigs and can cause up to 100% mortality. The disease is endemic in Uganda and causes significant economic and personal losses for farmers. Outbreaks occur frequently, and the source of infection is often unknown.

African swine fever
Distribution and history
ASF has been present in Africa for over 100 years and has been reported in several countries, including Uganda. The disease has a complex history, with multiple introductions and re-introductions.

Aetiology
ASF is caused by the African swine fever virus (ASFV), a member of the Asfarviridae family. The virus is highly contagious and can be transmitted through direct contact with infected animals, contaminated feed or water, or through the bite of infected ticks.

Pathogenesis
The pathogenesis of ASF involves the replication of the virus in the host's cells, leading to cell death and tissue damage. The virus can cause a range of clinical signs, from peracute to chronic, depending on the severity of the infection.

Clinical signs
Peracute ASF
Peracute ASF is a rare and severe form of the disease, characterized by sudden death in infected animals.

Acute ASF
Acute ASF is a more common form of the disease, characterized by fever, lethargy, and loss of appetite.

Subacute ASF
Subacute ASF is a milder form of the disease, characterized by a prolonged course of illness.

Chronic ASF
Chronic ASF is a rare form of the disease, characterized by a prolonged course of illness and a high mortality rate.

Pathology
The pathology of ASF involves the replication of the virus in the host's cells, leading to cell death and tissue damage. The virus can cause a range of lesions, including necrosis, hemorrhage, and inflammation.

Immunity
Immunity to ASF is not well understood, but it is thought to be related to the host's ability to mount an immune response to the virus.

Epidemiology
The epidemiology of ASF is complex, with multiple cycles of transmission. The domestic cycle involves the transmission of the virus between domestic pigs, while the intermediate cycle involves the transmission of the virus between domestic pigs and wild suids. The sylvatic cycle involves the transmission of the virus between wild suids and ticks.

Uganda
Pig production in Uganda
Pig production is an important source of income for many people in Uganda, particularly in rural areas.

African swine fever in Uganda
ASF is endemic in Uganda and causes significant economic and personal losses for farmers.

Objective
The objective of this study was to investigate the dynamics of ASF in Uganda, including the possible reservoirs of the virus and the prevalence of the disease in one district, Rakai.

Methods and material
The study involved the sampling of domestic pigs and interviewing local pig farmers, as well as collecting wildlife data and conducting laboratory analyses.

Results
The study found that DNA from ASFV was present in nine of 239 domestic pigs with no clinical signs, and in three of four sampled soft ticks. Antibodies against ASFV were found in two of four sampled bushpigs, the only warthog sampled in the study, and in five of the 239 domestic pigs. The prevalence of ASFV in Rakai was 3.3%, while the seroprevalence was 2.1%.

Discussion
The study suggests that domestic pigs, bushpigs, warthogs, and soft ticks can act as reservoirs for ASFV. The study also found that domestic pigs and bushpigs can interact, which may facilitate the transmission of the virus.

Future aspects
The study highlights the need for further research on the dynamics of ASF in Uganda, including the possible reservoirs of the virus and the prevalence of the disease in different districts.

Acknowledgement
The study was supported by the Swedish International Development Cooperation Agency (Sida).

Reference
The study references several previous studies on ASF, including a study on the epidemiology of the disease in Uganda.