Background information
African swine fever (ASF) was first reported in the United Republic of Tanzania in 1914. Another outbreak followed in 1962, yet the years 1963-1972 registered no incidents, according to the country's Veterinary Department reports.
In 1987 and 1988, major epidemics with their attendant economic losses in the Mbeya region and in Arusha and Kilimanjaro regions, respectively, were certified as ASF positive by the Animal Disease Research Institute Laboratory (ADRI) in Dar-es-Salaam.
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The recent (May 2001) ASF outbreak in the capital city, Dar-es-Salaam, is currently a top priority for the Tanzanian authorities. The reasons are twofold: first, the pig population in Dar-es-Salaam has recently increased to an estimated 7 200; second, and more importantly, pig production is fast becoming a profitable means of household income and family subsistence. This is particularly true in Dar-es-Salaam. It should also be noted that the pig population in Dar-es-Salaam consists predominantly of exotic breeds.
All the pig farms in the area have good housing, ranging from permanent to semi-permanent, mainly wooden, structures. Feeding practices vary widely, with maize meal being the most common feed. Untreated swill feeding can also be found in some farms.
FAO has been providing assistance to the Tanzanian Government through a project entitled "Emergency surveillance of rinderpest and other transboundary animal diseases" (TCP/URT/0067). In order to control the ASF outbreak and assist in determining the extent of spread and the exact areas at risk, approval has been given to extend the project to cover the ASF incidence.
The target: control as against stamping out
Since no stamping-out exercise was carried out during the current outbreak, nor is now envisaged, other alternative control measures such as a rapid response approach are being encouraged. These measures aim to control and contain ASF by removing the chances of susceptible pigs becoming infected and eliminating the spread of infection within and between pig holdings. This ASF action plan will benefit from the intensive pig production system in Dar-es-Salaam.
The implementation of the project has just started and is proceeding in earnest. The project will undertake to realize an epidemiological survey to ascertain the source of infection and its possible spread, and boost ASF surveillance capacity and the designation of infected areas. Other activities include facilitating slaughter mechanisms and carcass disposal, bringing the central laboratory's diagnostic capacity to an optimal level and training veterinary staff in ASF control. To maximize results through greater public awareness, a robust and effective public education programme is planned.
Issues at stake
Reports indicate four ASF outbreaks in March, in the Mbeya region, none for April, two in May and five in June. Information on the status of ASF was not published during the months of July and August.
In terms of emergency preparedness, it is hoped that the initiatives taken so far in response to the ASF outbreak will lead to the formation of an interministerial disease emergency committee and the creation of a contingency plan.
So far, 12 reaction teams have been trained and equipped with the necessary materials required to mount a rapid response when an ASF case is suspected. The teams are based at the three districts in ASF-affected areas of Dar-es-Salaam, six veterinary investigation centres (VICs), the Epidemiology Unit and the Laboratory at ADRI. The training and supply of materials having been implemented, it is now hoped that the concepts and practical details will be put into action.
A major workshop, "Training of Trainers" (TOT), with a discussion session, was recently organized in Dar-es-Salaam. During the workshop, an EMPRES guide on transboundary animal disease, Recognizing African swine fever: a field manual, was discussed and an FAO video on ASF shown before being distributed to each participant. The participants will share their knowledge with other people in their districts and investigation centres. Other information materials such as pamphlets and posters were also produced and distributed.
In recognition of the vital importance of local languages in the project implementation, the information materials described above were translated into Swahili, the official language of the United Republic of Tanzania. This work enjoyed the support and active participation of the end users, i.e. field staff and farmers. During the course of the TOT workshop, a plan of action against ASF was elaborated, based on sanitary measures, confinement and disinfection as means of controlling the spread of disease. It is against this background that the reaction teams are expected to act in response to ASF outbreaks.
On the other hand, a survey identified the reporting system in use as a critical factor in ASF control. Accordingly, efforts were targeted towards strengthening the disease reporting system. The key elements envisaged are enhancing the speed and detail of reports to the Epidemiology Unit. The absence of an organized farmers' forum was also noted, which could militate against the sensitization programme.
ASF has been confirmed in the eastern province of Zambia and is said to be endemic, with occasional outbreaks in the midlands (commercial sector).
On 6 August, two ASF outbreaks were recorded. In all, 20 cases have been reported, with 16 deaths, while 431 pigs have been destroyed. Movement control and surveillance are being enforced.
Source: International Office of Epizootics (OIE) information bulletin.
A report from Kenya indicates that 430 pigs have died in an outbreak of ASF in the Kenyan districts of Kiambu, Nairobi and Thika. The incidents occurred in September. Although the disease was not immediately recognized, the respective districts' veterinary authorities have identified the disease as ASF. The laboratory tests were conducted at the Onderstepoort Veterinary Institute, using polymerase chain reaction (PCR), virus isolation and enzyme linked immunosorbent assay (ELISA). So far, 460 animals have been destroyed. The source of infection is yet undetermined but an investigation is under way.
The veterinary department has instituted a quarantine in four of the five divisions in Kiambu district and the other districts affected. It has also banned the movements of pigs and their products in the affected areas.
Farmers in the area have been advised to avoid rearing pigs in the coming months. Earlier, measures such as the disinfection and slaughter of infected pigs were introduced.
The movement of pigs from uninfected areas is also being checked, through the issuance of movement certificates.
Source: OIE information bulletin.