Pathogen test
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The PCR test detects the genome (DNA) of Trypanosoma evansis, the pathogen responsible for Surra.
Sample
- 5 mL - blood - K3 EDTA tube
Turnaround time
- 2 to 5 working days
What is Surra?
- Trypanosoma evansi causes a trypanosomosis known as ‘surra’.This parasite, which has been reported in domestic and wild mammals, can cause considerable economic losses.
- The trypanosomes reproduce in the blood of the vertebrate host, and the trypomastigote forms are transmitted mechanically by bloodsucking insects from infected to uninfected animals.
- Surra is the most commonly reported disease in some continents due to the favorable environment for insects. In recent years, several outbreaks or isolated cases have been reported in certain European countries, an atypical region for the disease.
Clinical signs
- The general clinical signs of evansi infections: pyrexia directly associated with parasitaemia together with a progressive anaemia, loss of condition and lassitude are not sufficiently pathognomonic for diagnosis.
- Recurrent episodes of fever and parasitaemia occur during the course of the disease.
- Oedema, particularly of the lower parts of the body, urticarial plaques and petechial haemorrhages of the serous membranes are sometimes observed in horses.
- Abortions have been reported in buffalos and camels.
- Nervous signs are common in horses.
- The disease causes immunodeficiencies that may be of high impact when interfering with other diseases or vaccination campaigns.
- Trypanosomiasis caused by evansi can be clinically confused with other diseases, including equine protozoal myeloencephalitis in the chronic stages.
- Where surra is suspected, it is important to rule out other causes of equine neurologic disease.
Transmission
- Surra is a non-contagious disease, transmitted only mechanically by several different genera of haematophagous flies.
- The efficiency of vector transmission is dependent on high intensity of fly challenge, the presence of high numbers of the parasite in the blood of horses, and the close herding of animals that maintains short intervals between successive feeds. The infectivity of a fly is highest within minutes of feeding and drops quickly thereafter, with the loss of ability to reinfect when feeding intervals exceed 8 hours.
- Wild carnivores and dogs can be infected by ingestion of meat from parasitaemic animals.
- In Central and South America, The vampire bat can also act as a vector.
- The disease can be reproduced experimentally by blood inoculation.
Prevention
- There is no vaccine against trypanosomiasis.
- Therefore, conventional disease control measures are based on the use of curative and preventive drugs to combat the parasite and interventions to control fly populations.
- Control and eradication of surra from an area is usually depends upon the detection and treatment of infected animals.
- Protection of susceptible animals from biting flies by smoking and using flies repellants.