Dr. Muhammad Usman Naseer, Dr. Zia ud Din Sindhu
Department of Parasitology, University of Agriculture, Faisalabad
Ticks were the first arthropods to be established as vectors of pathogens and currently they are recognized, along with mosquitoes, as the main arthropod vectors of disease agents to humans and domestic animals globally. Moreover, the incidence of tick-borne diseases (TBDs) is increasing worldwide. Hence, the need for a comprehensive approach towards a better management of these diseases is evident. The spectrum of TBDs affecting domestic animals and humans has increased in recent years; many important zoonotic TBDs, such as anaplasmosis, babesiosis, ehrlichiosis, and Lyme borreliosis are increasingly gaining more attention from physicians and veterinarians.
The integrative thinking on human and animal health comes from ancient times, but it was in the 20th century that the American epidemiologist C.W. Schwabe comprehensively revisited the concept of ‘One Medicine’ (commonly referred to as ‘One Health’), proposing to unify human and veterinary medicine against zoonotic diseases. More recently, the role of companion animals and the vector-borne diseases they share with humans have been conceptualized with a One Health approach. Similarly to other vector-borne diseases (e.g., malaria, leishmaniasis), TBDs may be difficult to control due to their complex epidemiology that may involve different tick vectors and animal hosts. Veterinarians and physicians have long dealt with TBDs in their daily routine, following parallel, but often non-convergent pathways. It is now clear that an integrated approach is required for the control of TBDs, particularly for those of zoonotic concern. It is necessary to unify the animal and human branches of medicine towards a better management of this important group of diseases, filling the gaps of communication between physicians and veterinarians to accelerate diagnosis, to expedite treatment decisions and the implementation of preventive measures.
The principle of the One Health approach for the management of TBDs is to increase the level of communication between physicians and veterinarians dealing with patients with past or present history of tick bites, particularly those with unexplained febrile illness in areas where TBDs are endemic. Specific procedures regarding patient’s management (e.g., referral to a reference hospital or treatment center) should respect the organization and infrastructure of local healthcare systems and follow the recommendations and rules of local public health authorities. The core principle is to increase the communication and exchange of information between physicians and veterinarians concerning all aspects of TBDs at local, regional, and national levels.
The risk of TBDs is increasing worldwide, and this situation seems to be driven by several interacting factors. Wildlife populations can naturally migrate, bringing ticks and tick-borne pathogens from one area to another. Human travelers may also play a role in the translocation of wildlife species and in the introduction of exotic tick species into previously free areas, which may eventually carry relevant pathogens. TBDs are increasingly being diagnosed in travelers returning from endemic areas, which might represent a diagnostic challenge for less-experienced physicians in non-endemic areas. Humans often become infected by tick-borne pathogens (e.g., Anaplasma phagocytophilum, Babesia microti, B. burgdorferi sensu lato, and R. rickettsii) by entering wooded areas infested by ticks that are usually parasitic on wildlife. There is also an increased risk of being inoculated with several agents at once from a single tick bite, as questing ticks may often be co-infected by several pathogens. However, the actual risk of contracting TBDs by pet owners and farmers is uncertain. For instance, cattle are the main reservoirs of B. divergens, but the risk of acquiring B. divergens by farmers during daily work with animals has not yet been quantified.
It is a fact that TBDs are on the rise and the unification of health professional efforts is vital to rectify this situation and to reduce their current burden in terms of morbidity and mortality. Attitude change and increased communication between physicians and veterinarians could play a pivotal role in this process, and it is evident that there is a need for a One Health approach towards a better management of TBDs. The diagnosis of TBDs is challenging, and information exchange from physicians to veterinarians and vice versa is beneficial for both sides, but mainly for patients. In this changing scenario of TBDs, continuous education is essential. Physicians and veterinarians must be aware of new discoveries and developments to improve their clinical practice. National and local conferences on One Health, where veterinarians and physicians could sit around the same table, should be promoted worldwide. Because dogs and cats can act as sentinels for certain human diseases, veterinarians may play a decisive role by notifying public health authorities when appropriate and implementation of national integrated information systems, coupling animal and human disease data, would be valuable. It is imperative to emphasize that pet owners should be advised to keep their animals protected against ectoparasites.
Finally, researchers should endeavor to generate novel research-based information on traditional and emerging TBDs, which should be translated into practice. Education is key to controlling TBDs, and beyond a shadow of doubt, public health decision makers, researchers, physicians, veterinarians, dog owners, farmers, travelers, etc., should be aware of TBDs and how they should be dealt with. The immediate removal of a tick from the skin of a patient might save a life; this is a small step for a physician, but significant action for the prevention of TBDs.
