By Julie Murchie and Victoria Paesani Phylum Apicomplexa Caused by a tick-borne obligate intracellular parasite, Theileria parva, in subSaharan Africa, infecting ungulates Brown Ear Tick Major constraint to livestock production & food security in many developing countries Causes high morbidity & mortality, killing 1 million cattle every year Prevents introduction of very productive but disease-susceptible breeds of cattle Expensive to control Places a huge economic burden on poor smallholder farmers Costs nearly $170 million yearly Some African counties use the cattle as forms of currency T. parva has ability to induce cancer in host cell in a way that is reversible Studies have provided clear links to cancer biology in humans Studying this parasite has given researchers clues for the right direction Vaccines have the power to eradicate the disease Not hazardous to human health Threat mostly in eastern, central, & southern Africa Cattle * Indian Water Buffalo* *develop symptomatic infections Waterbuck African Buffalo 5) …divides with schizont inside 2 infected daughter cells 4) Lymphocyte lymphoblast (enlarged lymphocyte) and… 3) Sporozoite enters lymphocyte (WBC) schizont 2) Sporozoites transfer to ungulate if tick is attached for 48-72 hrs 1) Sporozoites produced in tick salivary glands Incubation Period Experimentally Infected: 8-12 days Naturally Infected: up to 3 weeks 6) 10-15 days postinfection, schizont merozoite (invades erythrocyte (RBC)) * 5-8 days post-infection: found in lymph nodes * Schizonts increase 10fold every 3 days 7) In RBC, merozoite piroplasm (infect ticks) 8) RBCs ingested by nymphs during feeding 9) Once in gut, undergoes sexual reproduction motile stage, moves to tick’s salivary gland First Signs appear 7-25 days after tick attaches Parotid gland swells Ear is preferred feeding site Fever Anorexia & decrease in overall condition Later Signs Lacrimation, corneal opacity Nasal discharge, terminal dyspnea Interlobular emphysema & sever pulmonary edema Before death, temperature falls & dyspnea intensifies Some develop neurologic disease “turning sickness” Due to affected cells blocking circulation in capillaries within the CNS Death (18-30 days after infestation by ticks) The few survivors become lifelong immune carriers. Majority of these cases, asymptomatic carriers can be recognized with little or no effect on their productivity. Minority develop chronic disease problems that result in stunted growth in calves and lack of productivity in adult cattle. Vaccination Infect animal with the sporozoite form of the parasite while at the same time treating the cattle with an antibiotic drug to lessen the severity of the infection Pasture Management Herd-Selection Tick of Resistant Animals Control & Eradication Matovelo et al. 2003 Induction of Acquired Immunity in Pastoral Zebu Cattle Against East Coast Fever After Natural Infection by Early Diagnosis and Early Treatment 1. Examine efficiency of chemotherapy of natural ECF cases to look at protective immunity against ECF in cattle. 2. Design a regimen farmers can use to help minimize cattle loss due to ECF. This is done by establishing early disease diagnosis and early treatment. Two villages in the Morogoro Rural District Two seasons (April and November) Ear tagged 280 calves Farmers were trained to monitor the animals for clinical symptoms of ECF. Qualifying clinical symptoms: enlargement of superficial lymph nodes, increase in body temperature, dullness, and respiratory distress. Animals diagnosed with ECF were treated with buparvaquone. Severity of the disease at the time of treatment was categorized based on the criteria set for ECF clinical reactions with some modifications. Indicator Variable Clinical status Rectal Temperature Lymph node status Respiratory performance Demeanor Mild Above 39.5 ºC Swollen parotid lymph-node Normal Normal Moderate Above 39.5 ºC Swollen parotid and Prescapular node Slight labored breathing Nasal discharges Normal Severe Above 39.5 ºC Swelling off all superficial lymph nodes Respiratory distress Reluctant to move/ recumbence Treatment responses were categorized as prompt/rapid, slow, or died. Examined serum antibodies to T. parva, with samples at the beginning and end of study, using ELISA. Studied blood and lymph node smears for T. Parva parasites. 100 animals were diagnosed with ECF Most prominent clinical signs were fever and lymph node enlargements. 81% of animals were positive for ECF on at least one screening method. During follow-up, only 5 individuals were diagnosed with ECF a second time. Diagnostic Means Cases Tested Missing Clinical Responses Total Cases Mild Moderate Severe Clinical signs of ECF 100 0 100(100%) 4 66 30 Lymph node smears 99 1 67(67.68%) 3 42 22 Blood Smears 98 2 41(41.84%) 1 27 13 No test detected __ __ 19(19%) 1 13 5 Majority of cattle that were treated recovered. (98% recovery rate) Shows that early diagnosis and early treatment is a reliable means to diagnose cattle with ECF on a basis of clinical signs in endemic areas. Reliable early signs of infection are fever and swollen lymph nodes. Use of chemotherapy with the early detection and early treatment approach reduced mortality and helped cattle develop immunity. In terms of immunization, the early detection and early treatment approach is a reasonable alternative to the infection and treatment. East Coast Fever is caused by Theileria parva Hosts Intermediate= cattle Definitive= ticks Incubation time is anywhere from 8 days to 3 weeks. Very expensive High morbidity & mortality rates No harm to human health Matovelo, Gwakisa, Gwamaka, Chilongola, Silayo, Mtenga, Maselle, and Kambarage. "Induction of Acquired Immunity in Pastoral Zebu Cattle Against East Coast Fever After Natural Infection by Early Diagnosis and Early Treatment." The Journal of Applied Research In Veterinary Medicine. 2003. Web. 23 Mar. 2011. <http://www.jarvm.com/articles/Vol1Iss2/Matovelo.htm>. Azeem Photos. 2010. A blue water is looking well with animal Waterbucks. <http://azeemphotos.blogspot.com/2010/09/blue-water-is-looking-well-with-animal.html>. 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