Comparative evaluation of antibody positive titer by ELISA and IFA in Theileria annulata vaccinated cattle in Iran.

An enzyme linked immunosorbent assay (ELISA) was used to evaluate antibody positive titer in vaccinated and non-vaccinated cattle using schizont infected myeloid cells as an antigen. The result was compared with indirect fluorescent antibody level in the same animals. For this study 116 milking cows, 95 vaccinated and 21 non-vaccinated, were bleeded in order to prepare sera. They were tested with both ELISA and IFA tests. 94 sera had positive antibody titer and 22 sera were negative through ELISA test but, with IFA test, only 89 sera showed positive antibody titer and 27 were negative. Thereby, it was concluded that the sensitivity and specificity of ELISA test in comparison with IFA test was 95.5% and 66.6% respectively. This study generally indicated that ELISA could be an effective test for sero-epidemiological investigations of bovine tropical theileriosis, and it is considered to be valid as an additional test to distinguish the vaccinated from the non vaccinated cattle in order to schedule vaccination programs.

A randomised, double-blind, controlled trial of a killed L. major vaccine plus BCG against zoonotic cutaneous leishmaniasis in Iran.

Safety and efficacy of killed (autoclaved) L. major promastigotes, ALM, mixed with BCG against zoonotic cutaneous leishmaniasis was tested in healthy volunteers (n = 2453) in a randomized double blind trial vs. BCG as control. Side-effects were similar in both groups but tended to be slightly more frequent and prolonged in the ALM + BCG group. Leishmanin skin test conversion (induration > or =5 mm) was significantly greater in the ALM + BCG than in the BCG group (36.2% vs. 7.9% on day-80 and 33% vs. 19%, after 1 year, respectively). Cumulative incidence rates for 2 years, were similar in both groups (18.0% vs. 18.5%). However, LST responders on day 80 (> or =5 mm) had a significantly lower incidence (35%) of CL during the first year than non-responders. A single dose of ALM + BCG is not sufficiently immunogenic to provide a measurable response when compared to BCG alone. A single dose of this vaccine has been shown to be safe with no evidence of an exacerbating response following natural infection; hence, multiple doses or other adjuvants should be considered to increase its immunogenicity.

Recent development in control of Theileria annulata in Iran.

During 1973-1990 cattle immunization, in Iran, was induced by two strains within an interval of one month: first the milder and then the mild strain. Although this method of vaccination rendered satisfactory results in the field, yet production, maintenance in deep-freezers and transportation in liquid nitrogen particularly to remote areas of the country proved to be uneconomical and time consuming. Therefore, in order to reduce cost and save time, a new method involving only one local and live attenuated vaccine strain was sought. Reports received from different ecological areas of the country have shown no presence of any significant abnormal side-effects in vaccinated cattle and the immunization results have been highly satisfactory.

Delayed type hypersensitivity theilerin test in cattle vaccinated against Theileria annulata infection.

Theilerin was prepared and its total nitrogen was determined at level of 1 mg/ml. Seventy-two Holstein Friesian cattle recovered from acute theileriosis or vaccinated received 0.1 ml of theilerin intradermally at normal concentration of total nitrogen or other dilutions (1 / 10 and 1 / 100). Some 60(% of calves and 66.67% of milking cows receiving normal theilerin showed more than 1 mm increase in skin thickness at the site of inoculation (mean value of 1.86 mm for calves and 3.46 mm for milking cows). The pathological examination of the inoculation site showed infiltration of lymphocytes. No changes of general condition were observed in animals under study. The result indicated that the test is positive and could be used for checking Immunity in vaccinated animals.

Tick-borne diseases of sheep and goats and their related vectors in Iran.

Haemoparasitic diseases have long been considered as a major problem to efficient sheep and goats production in Iran. Theileriosis due to Theileria hirci and babesiosis due to Babesia ovis and B. motasi are the most pathogenic protozoa. B. crassa, Anaplasma ovis and Eperythrozoon ovis are usually non-pathogenic and do not cause any apparent problem. The major tick genera found on sheep and goats are Hyalomma, Rhipicephalus, Haemaphysalis, Ixodes and rarely Dermacentor distributed in all part of Iran. Our studies indicate that only Hyalomma ticks transmit Theileria species but the others transmit Babesia, Anaplasma and Eperythrozoon. The two latter ones can also be transmitted through some biting flies and mechanical means. Control methods presently available in Iran rely almost entirely on: (i) vaccination of sheep and goats with cell culture vaccine for theileriosis; (ii) chemotherapeutic treatment for babesiosis and anaplasmosis; (iii) acaricides for control of tick vectors.

Seroprevalence of Toxoplasma gondii in cattle, sheep and goats in Iran.

Serum samples from 2000 cows, 3311 sheep and 638 goats from Iran were examined for antibodies to Toxoplasma gondii by use of the latex agglutination (LAT) and indirect hemagglutination tests (IHAT). Antibodies to T. gondii were found in 24.50% sheep and 19.25% of goats. Antibodies to T. gondii were not detected in cow sera by LAT and IHAT in 1:8 and 1:64 dilutions of bovine sera, respectively. Toxoplasma gondii was not found in tissues of 300 aborted fetuses from cows by direct microscopy and bioassay in mice.

Chemotherapeutic value of parvaquone and buparvaquone against Theileria annulata infection of cattle.

Parvaquone (BW993C), 2-cyclohexyl-3-hydroxy-1,4-naphthoquinone, and buparvaquone (BW720C) 2-(trans-4-t-butylcyclohexyl-methyl)-3-hydroxy-1,4-naphthoquinone, were evaluated to determine their therapeutic efficacy in the treatment of theileriosis caused by Theileria annulata infection in cattle in Iran. One hundred and fifty-nine pure and crossbred Bos taurus cattle, experimentally or naturally infected with T annulata, were treated. Parvaquone was injected into 86 animals with up to three doses of 20 mg kg-1 or 10 mg kg-1 at intervals of 48 hours between doses. Buparvaquone was injected into 73 animals. Up to three doses of 2.5 mg kg-1 were injected with an interval of 48 hours between doses. The recovery rate of animals treated with parvaquone was 60.7 per cent and with buparvaquone it was 88.7 per cent. No significant side effects of relapse of disease were observed following the use of either compound. It is concluded that buparvaquone at a dose of 2.5 mg kg-1 has a satisfactory therapeutic index and is a more effective treatment of T annulata infection than parvaquone. The prophylactic use of schizont tissue culture vaccine and chemotherapy with buparvaquone could be the most promising means of controlling theileriosis in Iran.

Control of Theileria annulata in Iran.

Tropical theileriosis or Mediterranean Coast Fever - caused by Theileria annulata - is a disease of cattle widely distributed across southern Europe, north Africa and central Asia. Its distribution broadly corresponds with that of its main ixodid tick vectors Hyalomma excavatum and H. detritum (Fig. 1). 'Exotic' cattle (Bos taurus) are particularly susceptible with mortalities up to 40-80% in some areas, whereas indigenous cattle (B. indicus) generally suffer much lower mortalities (about 10%) confined mainly to calves. But because imported non-immune cattle are so susceptible, T. annulata represents a major constraint to livestock improvement programmes in many parts of the middle east and Asia. Cattle that recover from T. annulata infection generally show a solid, long-lasting immunity. For many years there have been programmes to protect cattle by inoculation with blood from sick animals, and more recently using live attenuated T. annulata vaccines prepared from cultured schizont-infected lymphoid cells. This article reviews a 14 year immunization programme against T. annulata in Iran.

Theileria orientalis in Iran.

A benign species of Theileria of cattle in northern Iran proved to be indistinguishable from T. orientalis in the indirect fluorescent antibody test as well as in the morphology of its piroplasms. It was transmissible transstadially by Haemaphysalis punctata.

Babesia crassa n.sp. (Sporozoa, Babesiidae) of domestic sheep in Iran.

A large Babesia sp., isolated from a sheep in Iran, provided to be serologically and morphologically different from B, motasi and B. ovis. The parasite, designated B. crassa n. sp., is characterized by the frequent occurrence of four organisms in one erythrocyte, which is the result of quadruple division and, in other cases, of two successive binary divisions. Parasited resulting from the first of two successive binary divisions are exceptionally broad. B. crassa appears to be of low pathogenicity for sheep and goats, to which it is also infective. The vector is unknown.