1. Livestock virology sub-programme

Traditionally the division conducted research on rinderpest and rinderpest-like diseases, malignant catarrhal fever, lumpy skin disease and rabies. The Plowright tissue-culture based rinderpest virus vaccine that was used to control the killer disease in Africa was developed at the centre. The sub-programme has isolation facilities for contained virus diseases research, large animal houses and a wildlife holding facility in addition to equipped laboratories. With the eminent eradication of rinderpest focus is now on PPR which was hitherto unknown in Kenya. There are efforts to also take Rift Valley fever on board in collaboration with other institutes.
The laboratory also serves as a national and regional reference laboratory for rinderpest and PPR.

2. Ticks and tick-borne diseases research sub-programme

The protozoology division carries out research aimed at controlling ticks and tick-borne diseases of livestock especially East Coast Fever (ECF). It pioneered the infection and treatment method of immunising against ECF, a method that has now been widely adopted in East Africa. The current activities include:

• Evaluation of an inactivated vaccine against heartwater using Kenyan isolates of the causative agent
• Commercialisation of the infection and treatment method of immunising against ECF
• Evaluation of T. parva parasites that can be used to immunise cattle against corridor disease
• Evaluation of the effect of relaxed tick control after ECF immunisation

3. Livestock helminthology sub-programme

This sub-programme carries out research on worms – roundworms’ tapeworms and flukes. The majority of nematodes occur in the gastrointestinal tract of cattle, sheep and goats. The flukes have life cycles that alternate between the ruminant final host and a snail intermediate host. Worm infections tend to be sub-clinical, thus causing insidious production losses. Some infections due to the stomach wireworm of sheep (Haemonchus contortus) and liverfluke can however present in acute forms. Currently the focus is on:

• Designing, validating and updating worm control strategies for different ecological zones in Kenya on the basis of epidemiological information
• Packaging of developed worm control technologies
• Establishing the necessary uptake pathways for worm control
• Investigating the efficacy of ethno-veterinary products in the control of worms and their vectors (eg Eucalyptus leaves to control snail vectors of liverflukes)
• Surveillance of zootic helminth diseases
• Conducting seminars for farmers and extension staff to disseminate key messages
• Testing new anthelmintics or combinations thereof and examining medicated and non-medicated urea molasses blocks for supplementation and worm control
• Exploring ways of reversing anthelmintic resistance where it has occurred already

4. Bacterial diseases sub-programme

In the last five years, the bacterial diseases sub-programme has focused on two of the important bacterial diseases of livestock: contagious bovine and caprine pleural pneumonias (CBPP and CCPP). The two diseases are caused by mycoplasmas and are widespread in Africa. CBPP vaccines which are currently in use in Africa are manufactured with two vaccine strains, T1/44 and T1sr which is a streptomycin resistant derivative of T1/44. T1/44 is a vaccine strain that yields an immunity lasting about one year. However these T1/44 strains sometimes induce reactions (Willems reaction) at the site of injection about two weeks post-vaccination. These reactions may lead to the death of the animals if no antibiotic treatment is given. T1sr is completely devoid of residual virulence and yields a similar level of protection as T1/44. However the duration of immunity induced by T1sr is believed to be shorter than that induced by T1/44. CBPP is controlled through vaccination, movement control and slaughter of (serologically) positive cattle. The disease had been controlled by annual vaccination campaigns in the 1960s and 1970s. However, it re-emerged in the 1990s because of political upheavals and economic hardships in some African countries. Re- vaccinations were unable to contain it, offering only 30-60% protection. The objectives of this work are to:

1. re-evaluate the efficacy of T1/44 and T1 sr strains of the CBPP vaccine following some modifications. Current freeze-dried vaccines are limited in efficacy due to low levels of protection, short duration of immunity, and poor stability. However, relatively simple and inexpensive changes may result in marked improvement of the vaccine and also increase vaccine yield. Changes include altered buffer formulations, the inclusion of pH indicators and better protein estimation methods.
2. find out whether or not the vaccine strain can revert to virulence after cattle passage.

Experimental tests on use of antibiotics. Currently the use of antibiotics in the control of the pleuropneumonias is not allowed. Studies were initiated to investigate how tetracyclines can be used prophylactically with vaccination. Concrete studies on whether the drugs can be used in a sick animal to mitigate against the disease and after recovery, investigate if the animal is suitable for human consumption are in the pipeline. Other works include

• Field testing of improved live vaccine formulations.
• Mastitis control.

5. Epidemiology and socio-economics sub-programme

This sub-programme focuses on the development of methods for participatory research, technology transfer, assessment of adoption and impact of technology transfer. It also offers expertise in offering appropriate statistical methods in research. It provides epidemiological information on diseases during the formulation of control and other intervention studies. A further engagement of the unit is in the analysis and provision of market and policy information.