Sporadic Outbreaks of Surra in the Philippines and its Economic Impact

抄録

Surra occurs in all 13 regions of the Philippines particularly Regions 2, 3, and 4 in Luzon and Regions 9, 10 and 11 in Mindanao. Based on government reports from 1989 to 1997, carabao (swamp buffalo) is the most commonly affected (3,819 cases), followed by horse (3,430 cases) and cattle (2,005 cases). Mortality rate is highest in horse (345 deaths) and least in cattle (122 deaths). These figures are far from the actual numbers of cases and deaths which have not been properly reported due to misdiagnosis and poor monitoring system.
Clinical manifestations in cattle, carabao and horse infected with Philippine strain of Trypanosoma evansi, are intermittent fever, severe anemia, progressive loss of condition despite fairly good appetite, leg weakness, incoordination, prostration, circling movement, running aimlessly, sudden collapse and death if not treated. Other clinical signs are scrotal swelling and anestrus in ruminants. Abortion and congenital transmission in cattle have been observed. Infected animals may remain negative on blood examination but positive by mouse inoculation test.
Considerable economic losses due to surra is estimated to be P44.8 M ($1,149,230.70) in nine years, excluding losses attributable to decreased meat and milk yield, poor reproductive performance, cost of labor and medication.