Babesia bovis, cell culture-derived vaccine administered to yearling heifers, immunologic protection against challenge, immune recognition manifested by anamnestic humoral response to challenge

Babesia bovis, B. bigemina, cattle, effect of tick control on infection rates and on enzootic stability, survey of farms from 6 geographical regions, control of ticks is not justified economically as means of minimizing risks of babesiosis outbreaks unless regular dipping is necessary to limit damage done by ticks per se

The use of 1.16 mg/kg (one third) of the recommended dose of diminazene aceturate, administered indiscriminately to cattle on day seven of the unfrozen <em>Babesia bovis</em> and <em>Babesia bigemina</em> bivalent live blood vaccine reaction, was an infection and block treatment method of immunisation used successfully with no known adverse effect on the parasites or the development of protective immunity. Continuing with this practice after replacement of the unfrozen vaccine with deep-frozen monovalent <em>B. bovis</em> and <em>B. bigemina</em> live blood vaccines resulted in reports of vaccine failure. Laboratory investigation indicated the harmful effect of block treatment in preventing the development of durable immunity against <em>B. bigemina</em> as opposed to the much lesser effect it had on <em>B. bovis</em>. Consequently the practice was no longer recommended. A <em>B. bovis</em> vaccination attempt aimed at controlling the disease of dairy cows in milk (<em>n</em> = 30) resulted in 20% fatalities during the expected vaccine reaction period. The practice of block treating <em>B. bovis</em> was therefore reinvestigated, this time in a field trial using dairy cattle in milk (<em>n</em> = 11). Using 0.88 mg/kg (one quarter) of the recommended dose of diminazene administered on day 12 of the <em>B. bovis</em> vaccine reaction resulted in only two animals (<em>n</em> = 5) testing ≥ 1/80 positive with the indirect fluorescent antibody test (IFAT) although parasites could be demonstrated in three. In the untreated control group, by contrast, five of the vaccinated animals (<em>n</em> = 6) tested ≥ 1/80 positive with IFAT and parasites could be demonstrated in all. The unsatisfactory outcome obtained in this study, combined with that of the earlier investigation, indicated that there are more factors that influence successful vaccination than previously considered. It is therefore concluded that block treatment of the live frozen South African cattle babesiosis vaccines reactions is not recommended.

Babesia bovis, cattle, kinetics of specific indirect fluorescent antibody test titers and total serum IgG and IgM values after vaccination and challenge exposure, nonspecific suppression of total IgG and IgM values coinciding with period of peak parasitemia

Bovine haemoparasites are cosmopolitan in distribution and are known to cause substantial losses to the cattle industry. In spite of their economic importance, there remains a dearth of information on their molecular epidemiology in many parts of the world including Malaysia. To ascertain the molecular prevalence and species co-infection of bovine haemoparasites in the country, blood samples were collected from 1,045 heads of beef and dairy cattle on 43 farms from six geographical zones throughout Peninsular Malaysia. Samples subjected to PCR amplification of parasite species-specific genetic fragments revealed that Anaplasma marginale was the most prevalent haemoparasite (72.6%),followed by Theileria orientalis(49.8%),Candidatus Mycoplasma haemobos ( 47. 0 % ),Babesia bovis(32. 5%), Babesia bigemina (30.5%) and Trypanosomaevansi(17.9%). A high percentage (92.1%) of cattle was infected with either one or more haemoparasites. Triple haemoparasite species co-infection was the most prevalent (25.6%), followed closely by double species co-infection (25.1%). The most common (8.8%) and significantly correlated(rs= 0.250; p<0.01) combination was A. marginale+ T.orientalis. The present study constitutes the first attempt in the country to document the molecular prevalence and species co-infection of bovine haemoparasites over a wide spatial distribution. The data obtained will facilitate treatment, control and prevention measures to improve the local cattle industry.

Babesia bovis, nonviable tissue culture-derived antigens as vaccine in cattle, comparison with premunition

Blood protozoan diseases are significant to animal breeding as theyresult in economic loss due to mortality, reduction in production efficiency and increment in drugs usage. This historical retrospective study was carried out to investigate the most significant blood protozoan diseases, their trends as well as the host range diagnosed by Veterinary Research Institute (VRI) from 1931 to 2010 among Malaysian domestic animals. Conventional techniques such as stained thin blood film, whole blood buffy coatexamination and direct wet smears were utilised for diagnosis from 1931 to 2010. Five most common significant blood protozoan diseases from the domestic animals were identified namely, theileriosis,leucocy tozoonosis, pla smod ia sis, babesiosis and trypanosomiasisrespectively. The setting up of a systematic laboratory service in VRI has enabled more cases of blood protozoan infections to be diagnosed and this has inadvertently led to better understanding and control of the diseases thereby improving the livelihood and reducing economic loss of local farmers.