Setaria equina infection of Turkish equines: estimates of prevalence based on necropsy and the detection of microfilaraemia.

The research examined Setaria equina infection rate in equines (horses, donkeys, and mules) in Ankara, Turkey, using necropsy and blood sample analysis to detect microfilariae. The results indicated a 15% infection rate but only 4% showed microfilaraemia in their blood samples.

Methods Employed

• The researchers performed necropsies on a total of 80 equines (43 horses, 35 donkeys, and 2 mules) to determine the presence of adult Setaria equina parasites.
• Blood samples were also collected and examined for the presence of microfilariae, using two techniques – Knott’s method and a combination of membrane filtration followed by histochemical staining for acid phosphatase (AP).

Findings

• In 12 of the 80 animals (equivalent to 15% of the subject lot), they found adult Setaria equina during necropsy. This indicates the prevalence rate of the infection among the mammals studied.
• When examined for microfilariae using the two described methods, just three of the animals (4%) showed microfilaraemic conditions.
• Application of the AP stain showed that the S. equina microfilariae exhibited a diffused red staining pattern all over the body, which included the sheath, and a noticeably brighter staining around the anal and excretory pores.
• The classic Knott’s method was found to identify only two out of the three microfilaraemias detected using the combination of filtration and AP staining technique.

Conclusions

• The research concluded the prevalence rate of Setaria equina in the tested population of equines in Ankara, Turkey as 15%. However, the presence of microfilaraemia was comparatively lower, with an occurrence rate of only 4%.
• Considering the outcomes, the use of AP staining in combination with membrane filtration may be a more effective method to detect equine microfilaraemia as compared to the conventional Knott’s method; it detected 50% more cases in this study.