The prevalence of surra was 25% at the farm level and 16% at the animal level, which clearly states that Trypanosoma evansi infection, also known as surra, is present not only in the institutional farms but also in small hold farms of Ubay, Bohol. This is the first time that an animal from outside a commercial farm in the province was detected to be infected with the blood parasite.

This is concluded in a research study titled “Prevalence and risk factors of Trypanosoma evansi infection in water buffaloes (Bubalus bubalis) in Ubay, Bohol, Philippines” conducted last 2018 by researchers at the Philippine Carabao Center at Ubay StocK Farm (PCC@USF).

The disease is present in the Philippines and has become a serious problem for the livestock industry due to its wide range and extensive distribution in tropical countries. It is characterized by fever, progressive anemia, weight loss, jaundice, progressive weakness and lethargy, edematous swellings of the lower parts of the body, urticarial plaques in the skin, petechial hemorrhages of the serous membranes, abortions, and deaths.

Surra has affected buffaloes, horses, and cattle resulting in serious economic losses caused by reduced productivity, mortality, and cost of treatment.

This research aimed to determine the prevalence and risk factors of Trypanosoma evansi infection in Ubay, Bohol as well as the knowledge, attitudes and practices (KAP) of water buffalo raisers regarding the infection. 

A cross-sectional study involving 85 farms and 130 water buffaloes was conducted in Ubay where outbreaks of the disease had been reported. Blood samples were collected to test for Trypanosoma evansi antibodies and DNA using CATT/Trypanosoma evansi and PCR assay, respectively. Data on KAP and risk factors were obtained using a structured questionnaire.

Risk factors identified

The study showed that water buffaloes grazed or tethered by their owners near (around 30 meters) other water buffaloes, goats and pigs were more likely to get infected with Trypanosoma evansi.

Water buffaloes given with dewormer every 6 months are less likely to be infected with Trypanosoma evansi compared to those dewormed every 12 months with 10.5 times risk. The study says that deworming of water buffaloes every 12 months only may not be enough to control intestinal helminths, which could lead to malnutrition - a is known risk factor for surra.

Also, water bufflaoes having a body condition score of 2.5 (between average and thin) have more tendencies to be infected with Trypanosoma evansi. Other risk factors identified were stress-related conditions such as physical labor, pregnancy and calving, which could result in reduced resistance and higher susceptibility to diseases such as surra. Non-specific risk factors were also identified such as the year when the animals were brought in the farm and the number of hours the water buffaloes wallowed per day.

Knowledge, Attitudes and Practices (KAP) on Surra

A huge majority (96%) of buffalo raisers in Ubay have never heard about surra. However, a great margin of them had the right attitude regarding water buffalo diseases. Most of the buffalo raisers strongly agreed on the following issues: some diseases are serious and life-threatening to water buffaloes (71%), a veterinarian or livestock technician should be consulted if a water buffalo has a disease (78%), it might be a greater risk if a sick water buffalo is left untreated (88%), information from the government about water buffalo diseases is helpful (95%), and there should be control in the movement of water buffaloes and checking for diseases before they are moved to other provinces (86%). On the other hand, a huge number of buffalo raisers did not practice fly population control measures (86%). Horse flies (Tabanus spp.) are the mechanical transmitters of surra.

Recommendations of the study

It is recommended to conduct a province-wide surra surveillance on water buffaloes, pigs and goats with a BCS of 2.5 or below (average and thin) and treat infected animals to prevent the spread of surra. Moreover, animals for dispersal should be checked for Trypanosoma evansi infection before they are distributed to farmers especially if surra was detected in the source farms. More importantly, it is suggested that a surra control program be established in the province of Bohol to prevent the disease from further spreading. The program may include components of surveillance, IEC campaigns, capacity building and provision of prophylaxis and treatment.

The researchers were Dr. Emerson Tapdasan, Dr. Loinda Baldrias, Dr. Claro Mingala, Dr. Billy Divina, Dr. Gundolino Bajenting, and Dr. Caro Salces.