THIS is an urgent clarion call to every Zimbabwean who is passionate and cares about the fate of our cattle, food security and the economy.
“What is January disease?” has been the question uppermost in people’s minds; especially communal farmers affected by it.
Recent press reports country-wide point to a disease that is seriously affecting cattle throughout Zimbabwe; with over 2 000 herd of cattle reported dead in January 2018.
The fatal livestock disease is known as Theileria; it is caused by ticks and 80 percent of cattle worldwide are exposed to tick infestations.
These infestations include: redwater (babesiosis) — both African and Asiatic; heartwater, East Coast fever, brucellosis, and turning sickness — an unusual form of Theileriosis, among several others.
Theileria is no stranger to sub-Saharan countries, Zimbabwe included, and had been brought under control – why has it re-emerged?
Speaking to several communal cattle farmers from various regions, especially Mashonaland Central and Mashonaland West, regarding the contagion, all cited the prohibitive, arbitrary charges, costs of veterinary products, dipping fees and ancillary charges currently hampering farmers from dipping their cattle.
An outline of charges includes:
– Police clearance US$10
– Dipping fees @US$2/$5/head US$50 for 10 cows (herd)
– 5ml dipping chemicals US$18,20
– Veterinary card US$5
– Fee for herder US$ 10
– Unspecified fee for dipper US$ 20
There is usually an errant headmaster/teacher who finds dipping cattle more profitable than teaching
Many also cited lack of water, broken-down infrastructure, stolen pumps and a general lack of supervised veterinary services in the rural areas.
Little wonder the disease is out of hand and rampant.
In Zimbabwe, the disease occurs mainly in the summer when the hot and wet climate is especially conducive for the increase and rapid progression of ticks; although even a single tick can cause fatal infection.
Viruses in the Theileria species infect a wide range of both domestic and wild animals, including (African) buffalo, water buffalo (in India) and waterbucks.
The control of ticks and tick-borne diseases (TBDs), in Eastern and southern Africa has been largely wrought by the traumatic experiences during the outbreaks of cattle diseases in the early part of the 20th Century, among them Rinderpest and East Coast Fever (ECF), as the result of the introduction of exotic European livestock.
In order for the colonialists to sustain their newly-introduced, highly susceptible European stock and their cross-breeds, control measures were introduced by governments throughout the region.
Special tick control units were formed and restriction of cattle movements, quarantine, slaughter of infected animals and short-interval chemical application were exercised.
A combination of these measures made the eradication of East Coast Fever in southern Africa possible by 1954.
However, two sub-species remained – Theileria parva bovis, causing January disease and Theileria parva lawerncei, which caused Corridor Disease/ECF; together these two are responsible for about 2 000 cattle deaths each year.
East Coast Fever is known as Corridor Disease in eastern and southern Africa and as ‘January disease’ in Central Africa, including Zimbabwe, for which the agent is Theileria parva bovis.
Corridor Disease is more acute than classical East Coast fever, with death, at times, occurring within four days.
In Zimbabwe, outbreaks of T. parva bovis follow a seasonal pattern — normally between January and March; coincides with the rains and the active period of the adult stage of the brown ear tick — rhipicephalus appendiculatus — that usually infest the Highveld areas of Zimbabwe in great numbers.
Outbreaks of T. parva lawrencei, on the other hand, occur mostly in the southern Lowveld, where the main vector, R. zambeziensis, are usually carried by buffalo active in that area.
Ticks are regarded as the most significant ectoparasites of livestock, and tick-borne diseases are the major vector-borne diseases of ruminants worldwide; except in some parts of Africa where tick-borne diseases are overshadowed by trypanosomiasis, that is caused by tsetse flies.
Tick and tick-borne diseases, especially East Coast fever, caused by Theileria parva, are currently among the most significant aspects restricting cattle production in Eastern, Central, and southern Africa today and are thus a grave threat to food security in the region.
Theilerial diseases are tick-borne diseases, which means that they are spread between animals by the bites of infected ticks; Theileriosis caused by the hemoprotozoan pathogen Theileria parva ranks foremost among the tick-borne cattle diseases in sub-Saharan Africa, making systematic dipping of cattle vital and mandatory.
Theileria have complex life cycles involving both vertebrate and invertebrate hosts. Some vector-borne diseases can also infect small ruminants.
The general lifecycle for the genus Theileria includes the secretion of infective sporozoites into the animals’ feeding spot during tick feeding.
The Theileria sporozoites enter their bovine host during feeding and rapidly invade mononuclear leukocytes, where they mature into macroschizonts and encourage the spread in host cells.
It is a febrile, highly fatal disease with an almost 100 percent morbidity rate among susceptible cattle and a 95 percent mortality rate – “Chirwere ichi chinonzi Theileria, chinokonzerwa nezvishambwa, uye chino uraya mombe mumavhiki maviri.”
Theileriosis, an economically devastating tick-borne hemoprotozoan cattle disease is caused by several Theileria species; among them, the most pathogenic are T. parva, the cause of East Coast fever and T. annulata, that causes Tropical Theileriosis.
Because T. parva and T. annularis only migrate to the acinar cells of the tick salivary gland and mature after the tick attaches to a host, ticks have to stay attached for a number of days to the host prior to infecting it.
Protozoal parasites are excreted in the saliva between three to five days after ticks start feeding.
Theileriosis, common in tick-infested areas throughout the world, refers to diseases caused by Theileria which are very small parasites called protozoa.
Although all tend to be called Theileriosis, there are, in fact, many different types of Theileria which cause different diseases in animals.
The prevalence of Theileriosis is dependent upon several factors, that is, the geographical region and tick density, climatic conditions, age, gender, management practices and the cattle breed’s immunity, as cattle typically differ in tick resistance and innate susceptibility to infection.
Tropical Theileriosis is more severe in exotic and cross-bred cattle where fatality rates can exceed 80 percent compared to 20 percent in indigenous African breeds, such as the Mashona cattle breed, with natural resistance and some with immunity. However, once the disease is endemic, no cattle breed is spared.
However, since innate immunity in calves is not developed enough to combat Theilerial diseases, recent studies showed the prevalence of Tropical Theileriosis in young animals to be as high as 23,4 percent, compared to 15 percent in adult cattle.
Furthermore, the prevalence of Theilerial diseases was found to be higher – at 24,6 percent in females, against 13,1 percent in males.
Since cattle for most Zimbabweans, especially for the majority of smallholder rural farmers, represent an important source of livelihood in the form of draught power, fertiliser, fuel and transportation; assuring food security in the form of proteins for their families in the form of milk, meat and their byproducts; the loss of a single animal for any livestock farmer is devastating.
Managing diseases can be a frustrating and costly proposition, but prevention if, and whenever possible, is always best.
In these days of advanced veterinary science knowledge, such a contagion is largely a result of ignorance and/or negligence on our part, due to failure to dip or spray cattle regularly at the stipulated intervals, especially during the rain season we are currently experiencing.
Unfortunately, many subsistence farmers are unable to raise the US$2/animal/year or US$10/herd of cattle being demanded, which is excessive for most rural farmers, for the requisite vaccinations; it requires Government intervention under the Command Livestock programme.
Although the onset of the current incessant rains in most parts of the country spell good tidings for crop farmers, for cattle ranchers, the rain season is a worrying time since it is a time when many diseases are rife.
There have been numerous reports of Theileriosis in Domboshava, Mashonaland East and Central, parts of the Lowveld, Masvingo, including in the south-east of the country.
Reports of outbreaks of Theileriosis have also come from cattle owners in Rushinga, Muzarabani, Kaitano, Kanyemba, Mount Darwin, Gwanda and West Nicholson; most are within natural safari areas and could be buffalo-derived.
Occasional outbreaks of buffalo-derived T. parva disease still occur in SA, where the disease has mostly been eradicated through strict controls of cattle movement, stringent observation of the slaughter of infected cattle and fencing, used to restrict buffalo to game parks while keeping cattle out.
In countries where measures for sustainable methods of disease control have not been implemented or enforced, diseases remain acute and usually lethal.
When nothing is done to control the tick-vectors or their diseases, a stable enzootic disease situation develops with a high prevalence of infection in the animal population caused by a high transmission rate between vector-tick and the vertebrate host.
Once normal enzootically-stable situations are disrupted, such as with the current heatwave and heavy rains in Zimbabwe, cattle become unprotected by irregular tick control programmes and they immediately become susceptible to all forms of tick-borne diseases.
We face the annihilation of our herds as experienced in the early 1900s, when the colonial settlers first introduced T. parva in the form of East Coast Fever (ECF) disease into the country.
In the early 1900s, Veterinary Bacteriologist, Dr Arnold Theiler (after whom the disease is named), recognised that Theileria parva was the contributing cause of East Coast Fever (ECF) in southern Africa.
He was able to distinguish East Coast Fever from Redwater caused by babesia — which is introduced into the bloodstream by the ticks, thereby invade the red blood cells where it begins to divide and finally ruptures the cells.
Dr Theiler identified the brown ear tick, also referred to as the ‘Rhodesian bush-tick’ — the prime tick vectors that transmitted T. parva, from cattle to cattle, as rhipicephalus appendiculatus.
However, in parts of Africa R. zembeziensis and R. duttoni are also vector carriers; as evidenced by the outbreaks of T.P. bovis in Zimbabwe.
Memories of the high rate of mortality witnessed in Zimbabwe, when dipping was stopped at the height of the liberation war, is an example of high cattle mortalities most cattle farmers will recall, especially those in rural areas.
Tropical Theileriosis and East Coast fever are diseases transmitted by ticks of the genus hyalomma and rhipicephalus, respectively; the sporozoites of tick origin that invade and infect host lymphocytes and macrophages, are transmitted to animals in the saliva of the feeding tick.
Symptoms of East Coast fever (ECF) and Tropical Theileriosis, are characterised by enlargement of superficial lymph nodes and sustained high fever, depression, drooling, lacrimation, diarrhoea, weight loss and anorexia as well as decreased milk production with abortions also common.
The incubation period for East Coast fever and Tropical Theileriosis ranges between eight-21 days.
The result of exposure is largely determined by the susceptibility of the cattle; where indigenous animals may have a morbidity rate of 100 percent, mortality is commonly plus five percent due to their natural resistance built overtime.
Both East Coast fever and Tropical Theileriosis are most severe when susceptible animals are introduced into endemic areas, such as areas where buffalo are present resulting in mortalities reaching 100 percent and 90 percent, respectively.
Some animals with East Coast fever may develop a fatal condition called ‘turning sickness’, characterised by neurologic signs as a result of capillary impairment by parasites in the central nervous system.
In Zimbabwe these diseases are often associated with the cattle imported from East Africa by early colonial missionaries and white settlers, which caused the initial high levels of infection hitherto unknown, among indigenous cattle, that resulted in vast numbers of cattle dying or being physically destroyed.
According to some estimates, there are about 250 million cattle worldwide at risk of Tropical Theileriosis. It threatens almost 25 million cattle on the African continent and results in the death of about one million cattle annually in Central, Eastern and southern Africa.
Tropical Theileriosis also hinders and limits the introduction of improved cattle breeds.
Other Theileria spp, spread by biological tick vectors, include T. mutans, T. velifera, T. taurotragi, T. buffeli and T. sergenti. They usually cause a symptomatic infection or can increase the severity of East Coast fever and Tropical Theileriosis.
Under high temperatures, as experienced recently in Zimbabwe, Theileria spp. matures even in unattached ticks and can enter the host animal immediately after the tick attaches to it.
Bovine Theileriosis is characterised by high fever, weakness, weight loss, inappropriate appetite, conjunctival petechia, enlarged lymph nodes and aenemia.
Tick control is one of the most important factors influencing the epidemiology of bovines in Africa.
Preventive methods are currently available for the control of Theileriosis; the most practical, widely used and economical is the methodical control of ticks and tick-transmitted pathogenic tick species either with chemical dips, sprays or vaccinations.
Dipping tanks must be covered with a roof to avoid chemical dilution by rain or evaporation.
It is important to carefully adjust dip concentration according to the recommendation.
Incorrect application of even highly effective chemicals will prove unsatisfactory, resulting in chemical resistance developing in the animal; hence vaccination, although costlier, is the most sustainable option in the long run.
Here, I must caution unsuspecting rural cattle farmers of unscrupulous individuals who are injecting cattle with diluted chemicals, often injecting multiple animals with the same needle thereby transmitting many infections from one hapless animal to another.
Unscrupulous dealers are known to be packaging and selling tea as cattle dipping chemicals.
Both these practices are unfortunate and detrimental to the farmers and the country’s national food security.
Due to the high costs of theilericidal drugs and the high costs of treatment of Theilerial infection, prevention is the best means to control the vector ticks.
Manual removal of ticks is a common practice, but must be done correctly
Tick-borne diseases (TBDs), are frequently also passed on by animals in trans-location and the introduction of additional cattle from districts where the infection is common and where cattle regulation is lax.
These, and newly purchased cattle, must first be properly examined before mixing with the existing stock.
The necessary clearance documents must be obtained when moving or buying cattle.
It is also prudent to request and keep requisite cattle health certificates or statements from a registered veterinarian.
Vehicles transporting cattle should also be kept scrupulously clean, lest a tick detaches and hides — only to attach onto another animal.
The Theileria, currently occurring in 14 countries in sub-Saharan Africa, is posing a serious threat to national food security and is a major constraint to the local dairy and beef industries as well as throughout the world.
Regionally Theileria prava-induced ECF alone kills roughly one million herd of cattle each year with annual economic losses estimated at over US$1 billion.
Ticks and tick-borne diseases know no boundaries; diseases can spread between neighbours, provinces, across regions and across countries. The diseases have serious national, regional and global economic impact on food security in view of mortality rate, reduced milk yield, weight losses, abortions as well as control and prevention costs in cattle.
Access to unadulterated, genuine vaccines and vaccination by an accredited veterinarian or accredited extension officers are therefore essential — and should not be carried out by charlatans.
Surely if Command Livestock and food security are to be a success as Government intends, and our nation deserves, communal and commercial farmers need to be adequately capacitated to prevent controllable animal diseases from depleting the national herd.
Needless to say, I will always emphasise that for Zimbabweans, our cattle are our custodial heritage and livelihood.
We cannot allow them to become an endangered species due to human mismanagement and negligence.
Our God-given stewardship of our animals needs to be taught and inculcated in our children as they are part of our ancestral heritage.
Timeous reports of disease outbreaks in our rural outposts should be mandatory.
Close state-monitoring and disease prevention measures need to be carried out diligently and judiciously from village-to-village.
Information is the most important weapon against diseases; then awareness and then action!
Perhaps a nation-wide Command Cattle Disease Control Unit (CCDCU) needs to be urgently marshalled.
“If your animals aren’t healthy, you cannot make money,” says veterinarian and managing director for the Institute for Dairy Technology in SA.
According to the Food and Agriculture Organisation (FAO): “The increased potential for new pathogens to emerge, grow and spread from animals to humans on a global scale…” is attributed to changes in livestock production “…Healthy animals are closely related to healthy people and a healthy environment.”
Professional and accessible veterinary services are indispensable to Zimbabwe if any meaningful progress is to be made in combating these and a myriad of other diseases afflicting our cattle herds in recent years.
Disclaimer: this article is an abbreviated research from a scholarly point of view. It is not an epidemiological analysis nor a clinical, veterinary consultation, nor a qualitative or quantitative report. It is merely a guide for farmers, agriculture workers and the common man to be aware of the disease’s re-emergence in Zimbabwe.
Dr Tony Monda holds a PhD in Art Theory and Philosophy and a DBA (Doctorate in Business Administration) and Post-Colonial Heritage Studies. He is a writer, lecturer, musician, art critic, practicing artist and corporate image consultant. He is also a specialist art consultant, post-colonial scholar, Zimbabwean socio-economic analyst and researcher. E-mail: tonym.MONDA@gmail.com