OBJECTIVES

The aim of this study is to evaluate the performances of two rapid immunomigration tests under field conditions. The two diagnostic tests are used for the detection of canine ehrlichiosis caused by Ehrlichia canis and heartworm disease caused by Dirofilaria immitis. The dog population selected for this trial was from Sudan, Africa. This study deals also with some epidemiological data.

MATERIALS

In 2000, samples were collected from 38 local dogs from the city of Barbar el Fugarra from the eastern part of Sudan (on the border of Ethiopia).

For ehrlichiosis diagnostic, sera were tested with a Rapid ImmunoMigration (RIM®) test (WITNESS® Ehrlichia) and an ImmunoFluorescent Assay (IFA) as reference technique.

For heartworm disease diagnostic, sera were tested with a Rapid ImmunoMigration (RIM®) test (WITNESS® Dirofilaria) and an Enzyme Linked ImmunoSorbent Assay (ELISA) as reference technique (DiroCHEK®).

RESULTS

The canine ehrlichiosis seroprevalence is 100% (38 dogs positive in IFA - titers  1/40). Correlation with rapid immunomigration test is very strong (r=1, minimum guarantied rm=0.90 with =5%). Only one serum with a IFA titer of 1/40 over the 38 sera tested remains negative with Rapid ImmunoMigration (RIM®) test. Therefore sensitivity is 97.3% and specificity is 100%.

The heartworm disease seroprevalence is 5.4 % (2/37 dogs positive in ELISA). Correlation with Rapid ImmunoMigration (RIM®) test is very strong (r=1, minimum guarantied rm=0.90 with =5%).The sensitivity and the specificity of this rapid test are 100%.

CONCLUSION

Rapid ImmunoMigration (RIM®) tests present very high performances. They are accurate, easy-to-use and rapid (results in 10 minutes). They can be stored at room temperature and can be easily used under field conditions. They are useful for the diagnostic of asymptomatic heartworm disease and canine ehrlichiosis as well as for the confirmation of a clinical diagnostic. For the first time this study also shows a high prevalence of canine ehrlichiosis and a low prevalence of heartworm disease occurring in Sudan.