Tick resistance needs integrated intervention

Livestock production is an important component of Uganda’s agricultural sector and plays a key role in the development of the economy. It plays a significant role in uplifting the socio-economic status of the more than 2.2 million Ugandans employed in this sector.

Despite its importance, the sub-sector suffers low rates of productivity, largely due to ticks and associated tick-borne diseases (TBDs). The control of ticks and TBDs causes further economic strain, as it makes up more than 60 percent of expenditure on farms and businesses.

Previously, our livestock farmers only kept indigenous cattle breeds known for tolerance to diseases. However, in an effort to improve dairy production, they opted for exotic breeds and their crosses that are highly susceptible to TBDs.

Currently, the most recommended control method for ticks is use of acaricides in the appropriate concentrations by dipping or spraying at weekly intervals. However, many farmers cannot afford the costs of establishing and maintaining the dip tank. Therefore, spraying is the most commonly used method of acaricide application.

Currently, cattle corridors in Uganda are battling tick resistance to acaricides which was first registered in 2012.

The National Drug Authority (NDA) and its partners led by Ministry of Agriculture, Animal Industry and Fisheries (MAAIF) commissioned a study to establish the extent of the challenge and its causes. Several other studies have revealed that we need a holistic approach to have a sustainable solution.

Uganda is now facing the third wave of tick resistance to acaricides, which is yet to be characterised. The situation seems to be complex as there is confirmed multiple tick resistance to almost all acaricides molecules on some farms.

Acaricides are grouped in classes depending on their formulation and it is recommended that a farmer uses appropriately a particular acaricides for not more than two years. Currently, NDA has more than 25 products in five different classes approved for use.

NDA’s farm audits and profiling together with the Kiruhura District Local Government confirm that farm practices in acaricide application have largely contributed to the tick-resistance problem. 

Farmers are doctors of their animals, they stock all classes of drugs, administer any drug based on guesswork. It is important to note that a good drug has to be handled and used well in order to be effective.

Additionally, there is need for good infrastructure like a proper cattle crush appropriate spray pump/spray race with right nozzles and suitable pressure to push the acaricides through the fur.

NDA controls the manufacture, importation, distribution and use of both human and veterinary drugs in the country.   Acaricides in Uganda are registered by NDA following well laid procedures that conform to international standards and following recommendation from MAAIF.

The NDA also constantly monitors compliance to quality standards by random sampling and testing of acaricides on market. Whereas the authority undertakes in-depth regulatory controls before any drug is allowed on the market, the outcry about the ineffectiveness of veterinary drugs is high.

Farmers have resorted to mixing acaricides with fumigants and agrochemicals which have grave effects such as causing blindness.

Tick resistance is a growing challenge and researchers have called for integrated tick management; combining a series of complementary control measures including pasture management, paddocking, proper animal bleeding, use of herbs among others.

NDA and MAAIF have initiated several interventions including vaccination against East Coast Fever, evidence based prescription of acaricides where ticks are tested against all acaricides to see the effective ones.

NDA also continues to recommend accurate rotation of acaricides as advised by veterinary professionals.  We remain committed to ensuring access to safe, good quality and effective drugs.

By Dr Medard Bitekyerezo

The writer is the Board Chairman – National Drug Authority