Evaluation of the Acridine Orange Fluorescence Technique and the Indirect Fluorescent Antibody as Diagnostic Tests for Tropical Theileriosis

Omer Omer,Om Alsadrani,O H,Aa Aa,Mahmoud Mahmoud

doi:10.5455/vetworld.2011.341-344

Abstract

This study was carried out to evaluate the use of acridine orange fluorescence technique on blood slides as a rapid diagnostic test for tropical theileriosis in comparison with the Giemsa-stained thin blood film technique. Also the indirect fluorescent antibody test has been employed for the serodiagnosis of tropical theileriosis. The study was carried out on 62 young and 48 adult Friesian cattle suffering from clinical tropical theileriosis in Qassim Region, Central Saudi Arabia, during the period from August 2006 to July 2008. For control, blood samples were also obtained from 25 young and 25 adult, clinically healthy, Friesian cattle, selected at random from different dairy farms in Qassim Region. Thin blood films were fixed with methanol and stained with Giemsa and acridine orange and were examined by two independent microbiologists. There was 100% correlation in the interpretation of slides stained with Giemsa and acridine orange both with respect to positivity and negativity, between the two microbiologists. It is concluded that if facilities are available acridine orange is a valuable alternative for screening tropical theileriosis. The method may also have potential value in the diagnosis of Theileria parva, which causes East Coast fever, and also other Theileria species. Results of the present study also showed that IFA test was not found sufficiently sensitive and specific as has been reported earlier.

Highlights

Tropical theileriosis or Mediterranean Coast fever is a disease of cattle caused by the protozoan parasite Theileria annulata (Dschunkowsky and Luhs, 1904) and transmitted by species of ixodid ticks of the genus Hyalomma, principally Hyalomma anatolicum anatolicum (Robinson, 1982)
In this report we describe the comparison of the Giemsa-stained thin blood film technique with the indirect fluorescent antibody (IFA) test for diagnosis of tropical theileriosis
Prevalence of Theileria annulata antibodies in Friesian cattle in Qassim Region using the indirect fluorescent antibody technique

Summary

Introduction

Tropical theileriosis or Mediterranean Coast fever is a disease of cattle caused by the protozoan parasite Theileria annulata (Dschunkowsky and Luhs, 1904) and transmitted by species of ixodid ticks of the genus Hyalomma, principally Hyalomma anatolicum anatolicum (Robinson, 1982). The exotic breeds and cross-bred cattle are susceptible with mortality rates of 40-60% (Brown, 1990) reaching up to 80% in some areas (Gill et al, 1977; Hashemi-Fesharki, 1991). An accurate diagnosis is a prerequisite for an effective disease management of tropical theileriosis. Diagnosis of tropical theileriosis is based on clinical signs, knowledge of disease and vector distribution and examination of Giemsa-stained blood and lymph node smears (OIE, 2008)

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Results

Conclusion