The occurrence of Trypanosoma evansi in buffaloes in Indonesia, estimated using various diagnostic tests

• Published in: Epidemiology and infection Vol. 124; no. 1; pp. 163 - 172
• Main Authors: DAVISON, H. C., THRUSFIELD, M. V., HUSEIN, A., MUHARSINI, S., PARTOUTOMO, S., RAE, P., LUCKINS, A. G.
• Format: Journal Article
• Language: English
• Published: Cambridge Cambridge University Press 01-02-2000
• Subjects: Animal protozoal diseases; Animals; Biological and medical sciences; Buffaloes; Buffaloes - parasitology; Cattle; Cross-Sectional Studies; Enzyme-Linked Immunosorbent Assay; Epidemiology; Female; Incidence; Indonesia; Indonesia - epidemiology; Infections; Infectious diseases; Longitudinal Studies; Male; Medical diagnostic tests; Medical sciences; Parasitemia; Parasitic diseases; Parasitism; Parasitology; Protozoal diseases; Seroepidemiologic Studies; Trypanosoma evansi; Trypanosomiasis; Trypanosomiasis - epidemiology; Trypanosomiasis - veterinary; Veterinary medicine; Asia; Indonesia; Kinetoplastida; Protozoa; Protozoal disease; Farming animal; Parasitosis; Epidemiology; Bubalus bubalis; Infection; Trypanosoma evansi; Vertebrata; Mammalia; Artiodactyla; Veterinary; Trypanosomiasis; Ungulata; Buffalo
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268899003271

The prevalence and incidence of Trypanosoma evansi infections in village buffaloes in Central
Java were estimated using parasitological tests, two antigen-detection ELISAs (2G6 Ag-ELISA
and Tr7 Ag-ELISA), an antibody-detection ELISA (IgG ELISA) and a card agglutination test
(CATT). Of 2387 village buffaloes tested in five districts, 4% (95% confidence interval [CI]:
3%, 5%) were positive with the microhaematocrit test (MHCT), 58% (95% CI: 56%, 60%)
were positive with the 2G6 Ag-ELISA and 70% (95% CI: 68%, 72%) were positive with the
Tr7 Ag-ELISA. An increasing prevalence with age was found and the proportion of positive
buffaloes was highest in the over 84 months-old age-group (68%) with the 2G6 Ag-ELISA and
in the 37–60 months-old age-group (78%) with the Tr7 Ag-ELISA. Parasitaemic buffaloes were
found in more than half of the villages visited. Corrected village-specific prevalence values
obtained with the two Ag-ELISAs ranged from 0% to over 100%, and prevalence differed
significantly (P[les ]0·0001) between villages in four of the five districts. Overall, 10% of
buffaloes tested in markets were found to be parasitaemic and 39, 56 and 47% were found
positive with the 2G6 Ag-ELISA, IgG ELISA and CATT, respectively. Incidence rates varied
according to the test used and ranged from 0·22 (95% CI: 0·09, 0·44)
to 0·44 (95% CI: 0·24, 0·76), per animal-year at risk,
in two villages. The results highlight the importance of using
validated diagnostic tests to obtain accurate estimates of prevalence and incidence. These
parameters are needed, for example in mathematical models, for the development and
evaluation of different control strategies for T. evansi infections in buffaloes.