Pathogenesis of Trypanosoma evansi in buffaloes with high and low grade ration

Shortages and low grade of forages during the dry season and hard working during paddy cultivation are thought as phenomena triggering clinical diseases or even outbreaks of surra in Indonesia . An experiment using 12 buffaloes, 12-18 months of ages was conducted to disclose that hypothesis . The experimental animals were divided into 4 Groups of 3 animals (2 females and 1 male), Gr*l and Group2 were fed with high grade ration, while Group3 and Group4 with low grade ration. Group I and Group3 were then infected with Trypanosoma evansi Bakit 102 with the dose rate of 107 trypanosomes/head intravenously . Observations were made for 10 weeks after infection . The results indicated that buffaloes in Group I tended to have higher and persistently longer parasitaemia compared to buffaloes in Group3 (P0 .05). There were only little bitmore severe clinical signs in buffaloes in Group3 compared to those of Groupl . The mean weight gains of buffaloes in Groups with high grade ration was significantly higher compared to those buffaloes in low grade ration (P0.01), However, it was only slightly different in the weight gain differences between infected and noninfected buffaloes in each Group of ration (about 100 glhead/day)(P0.05) . The prepatent period of Groupl was 1 .2 days which was not significantly different to 2 days of Group3 (P0 .05) . There were no direct effects of low grade ration to the pathogenesis of T. evansi . Low grade ration and T. evansi infection complementary reduced the weight gain, consequently buffaloes with low grade ration infected with T. Evansi showed lower weight gain compared to those of high grade ration infected with T. evansi .   Key words : Trypanosoma evansi, pathogenesis, high grade ration, low grade ratio

An investigation of the feasibility of vaccinating against the Old World Screwworm fly Chrysomya bezziana

The problem of the Old World Screwworm fly Chrysomya bezziana and the limitations of current methods of control are discussed briefly. Any attempt to investigate the feasibility of vaccinating against the fly, as a novel control technology, demands the establishment of methods for fly culture, the production of sources of antigens and the development of assay techniques suitable for the assessment of vaccination effects. This must be coupled to a strategy for vaccine development. This strategy is described, as a prelude to a series of papers evaluating the feasibility of vaccination in detail.   Key words: Chrysomya bezziana, screwworm fly, vaccin

Review of Research in Veterinary Parasitology in the Research Institute for Veterinary Science (Rivs) Since 1983

Studies on gastrointestinal parasites and the epidemiology and pathogenesis of blood protozoa in ruminants have been undertaken during the last few years. An abattoir survey for a period of one year showed that most large ruminants slaughtered in the Bogor abattoir were infected with nematodes, about half with trematodes and few with blood parasites. Worm infections were also common in small ruminants but none were infected with blood protozoa. Some field studies on Fasciola infection in large ruminants showed that these animals were susceptible to the disease. The seasonal prevalence of fascioliasis is not yet fully determined; management systems and the local geography play an important role. Most anthelmintics were effective against worm infection in large and small ruminants. A new flukicide (triclabendazole) is highly effective against both immature and mature liver flukes. Studies on the epidemiology and pathogenesis of trypanosomiasis in cattle and buffalo have been conducted since 1982. The results indicate that T. evansi is prevalent in five regions in Java; the prevalence rates are higher in Sahiwal and Belmont Red than Ongole cattle or buffalo. ELISA values increase with increasing age of the animals. Buffaloes are more susceptible than cattle. Naganol is the drug of choice for control of trypanosomiasis in Indonesia

The Epidemiology and Control Myiasis in Indonesia

Myiasis caused by screwworm of Chrysomya bezziana fly has been widely distributed in Indoenesia for years, however myiasis as a disease problem is only reported in local cattle raised under semiextensive management system in West Nusa Tenggara, East Nusa Tenggara, South and North Sulawesi. In local cattle raised under an intensive management system in Java, Madura and Bali, disease problems caused by myiasis are unknown. Australian Brahman and Brahman cross cattle which were raised under a ranch system in South Sulawesi and East Sumba, and Merino sheep raised under intensive management system in Bogor and Jakarta are more susceptible to myiasis than local animals. Traditional medicines including tobacco extract, petrol and bettery acid are used for myiasis treatment in the villages, though the scientific background of these medicines are remained unknown. Insecticides and pesticides in the form of ointments are considered more effective against screwworm than in the form of spraying particles, the reasons for this being that C. bezziana flies do not stay long on the body of animals except whilst laying their eggs. Some drugs including ivermectine and methoxychlor are also effective against screwworm.   Key words : Myiasis, Chrysomya bezziana, screwworm, epidemiolog

Detection of immunosuppression caused by Trypanosoma evansi infection and malnutrition in experimental buffaloes with skin sensitisation tests

The main impacts of T. evansi infection in cattle and buffaloes include weight losses, deaths, and reduction of productivity, morover immunosuppressive conditions as a result of this parasite infection are commonly found. Dinitrochlorobenzene skin contact sensitisation (DNCB), phytohaemagglutinin skin (PHA) and homologous passive cutaneous anaphylaxis (HPCA) tests have been used for diagnosis of immunosuppression in man. The purposes of these experiments were to detect immunosuppression caused by T. evansi infection and malnutrition in normal and malnutrition buffaloes. Sixteen male and female buffaloes, 12-18 months of ages were divided into 4 groups, Group1 fed with high grade of ration and infected with T. evansi, Group2 fed with high grade of ration not infected, Group3 fed with low grade of ration and infected with T. evansi, and Group4 fed with low grade of ration and not infected. Buffaloes fed with high grade of ration are assumed as normal animals, while buffaloes fed with low grade of ration are assumed as malnutrion animals. These buffaloes were kept in fly proof fences in the Research Institute for Veterinary Science, Bogor. The experimental results indicated that normal buffaloes produced significantly (P0,05) wider and thicker inflammation areas in DNCB and PHA test respectively than malnutrition and T. Evansi infected buffaloes one week after T. evansi infection. The widest skin reaction of 33 + 4.7 mm2 in DCCB and the thickest skin reaction of 45 + 1,0 in PHA test was obtained in 24 hours after DNCB challenge or PHA injection. Thereafter both DNCB and PHA test showed the reduction of the skin reactions, however they were still positive in 48 hours and becoming negative in 72 hours later. PHA test was able to differenciate the intensity of either the combined effects of malnutrition and T. evansi infection, T. evansi infection, or malnutrition alone. HPCA test showed inconsistent results.   Keys words : Trypanosoma evansi, immunosuppression, DNCB, PHA, HPC

Comparative studies of resistance on Indonesian Thin Tail (ITT) sheep, St. Croix, merino and the crossbreed of ITT and St. Croix, against the infection of Fasciola gigantica

resistance is heritable. In order to re-evaluate this evidence, 20 ITT sheep were infected with 350 metacercariae of F. gigantica and for comparison, 10 St. Croix sheep, 10 Merino sheep and 20 crossbred of ITT x St. Croix sheep were also infected with the same dose of metacercariae. The results showed that ITT sheep was highly resistant than the other breed, whereas St. Croix and Merino sheep were susceptible. 60% of the crossbred were as resistant as ITT sheep and the other 40% were as susceptible as the St. Croix sheep. Thus, it is proposed that there might be a hereditary resistance factor such as a dominant gene which inducing the mechanism of resistance in ITT sheep, and there is some indication that IgG2 might act as a blocking antibody that interferes the mechanism of resistance.   Key words : ITT sheep, Fasciola gigantica, genetic resistance, dominant gen

The development of an “in vivo assay technique” as a tool for measuring protective immune responses of vaccine against myiasis in sheep

An “in vivo assay technique” is urgently needed for measuring protective immune effects of a myiasis vaccine in sheep. Such a technique is being developed simultaneously with the development of a vaccine against myiasis caused by the screwworm fly Chrysomya bezziana under a collaborative project undertaken by Balitvet, ITB and CSIRO (Australia) and funded by ACIAR. Experiments were conducted in naive sheep. C. bezziana larvae were allowed to develop on abraded skin in aluminium rings which had been attached to the sheep by means of a glue (Aibon) on the day prior to infection. Rings were arranged on clipped areas close to the mid line of the sheep’s back, two rings on the right side and two rings on the left. Four trials were performed, involving studies on the effects of including wet sponges in the rings to maintain humidity (Trial 1); the effects of sponge and blended meat as counting and transferring media during infection (Trial 2); the effects of the repellants citronella, eucalyptus oil and neem extract in assisting the recovery of larvae (Trial 3); and the effects of the reducing the infective dose from 50 to 25 1st instar larvae/ring and using a fine brush for counting and transferring larvae instead of using a forceps as in the previous groups (Trial 4) on the larval recovery rates (LRR). The results indicated that the inclusion of wet sponges in the rings, the use of sponge and blended meat as counting and transferring media during infection, and the application of repellants all increased the LRR to some extent; however, variations among individual rings remained high. On the other hand, the reduction of infective dose of larvae from 50 to 25 1st instar larvae/ring and using a fine brush for counting and transferring larvae sharply increased the LRR while substantially decreasing the coefficient variations. Key words : Myiasis, Chrysomya bezziana, larval recovery rat

Extension program on the control of bovine fasciolosis in West Java, Indonesia

An extension program to control fasciolosis in cattle and buffalo was undertaken in collaboration with officers of the District of Livestock Services (DLS) and farmer organizations in the Surade district of West Java. Control strategies were based on results of extensive epidemiological studies on fasciolosis in this area over the past 4 years. Recommendations included: (1) preventing animals grazing harvested rice fields adjacent to a village or cattle pen; (2) feeding stock only the top two-thirds of freshly cut rice stalks; (3) mixing cattle or buffalo faeces with manure of ducks or chicken naturally infected with Echinostoma revolutum, before using them as fertilizer in rice fields; and (4) a single treatment with triclabendazole in July, about 6 weeks after harvest of the last seasonal rice crop. Farmers were surveyed in January 1996 to determine their level of knowledge about fasciolosis. The extension program commenced in February, soon after planting the second seasonal rice crop in four villages. At first, leaflets were distributed to farmers, and posters were displayed in each village to provide basic information. Following discussions with village leaders, groups of farmers met in each village to discuss the advantages they saw in each strategy, ways they could implement them, and to identify socio-economic constraints that needed to be overcome. Taped interviews were prepared for a local radio station and the farmer groups. In August, final survey was conducted to determine the change in knowledge and attitudes that had occurred as a result of the extension program. Bennett’s hierarchy was used at each stage to evaluate the effects of inputs and activities. Farmers adopted the techniques of cutting and feeding rice-stems 2/3 above water-level, and isolating cattle from rice-fields during harvest time, as these appeared to be beneficial in social and economic terms; but they rejected the two other practices where they perceived that socio-economic costs exceededbenefits.   Key words : Fasciolosis control, extension program, cattle, buffal

The susceptibility differences of buffalo and Ongole calves against trickle infection with Fasciola gigantica

A pen trial was carried out in order to determine the susceptibility differences of a trickle infection with Fasciola gigantica in buffalo and Ongole calves. Treated animals were infected orally with 15 metacercariae of F. gigantica twice weekly for 32 weeks and were slaughtered at 36 weeks. The results showed that buffalo calves had significantly lower fluke burdens than Ongole calves (P0 .01) . All of the infected Ongole calves had fasciola eggs in their faeces 18 weeks after the commencement of infection. In contrast, eggs were detected only in 3 out of 7 infected buffalo calves at week 20, in 4 at week 28 and in 6 at week 30. Faeces of the seventh buffalo remained free of eggs until week 36. Rates of growth were reduced by 25%and 10,3% in infected Ongole and buffalo calves respectively . Circulating blood eosinophilia ofboth hosts, ahallmark of helminth infections, increased following infection, but values in buffaloes was greater than Ongole calves mainly in week 4 and 8 after infection (P0.01). These results might be concluded that the susceptibility of buffalo calves to trickle infection with F. gigantica was lower compared to Ongole calves.   Keywords : Fasciola gigantica; susceptibility, buffalo calves, Ongole calve

In vitro studies: The role of immunological cells in Indonesian thin tail sheep in the killing of the liver fluke, Fasciola gigantica

Previous studies have shown that Indonesian Thin Tail (ET) sheep exhibit high resistance to challenge with Fasciola gigantica when compared with Merino sheep, and this resistance is expressed in early infection. In order to study the role of the immune system in this resistance to ET sheep, in vitro studies were undertaken in the laboratory. In vitro study to confirm the ability of immune cells from ET sheep in the killing of F. gigantica larvae has been done by incubating immune cells and F. gigantica larvae together with immune sera or normal sera. The viability of the larvae was observed over a period 3 days incubation by observing their motility. The results showed that the cells isolated from F. gigantica- challenged ET sheep in the presence of immune sera from ET were able to kill 70% of the larvae. In contrast, cells from infected Merino were unable to kill a significant number of F. gigantica using the same sera source. It seems that the cytotoxicity was dependent on the presence of immune sera and ET peritoneal cells, suggesting the potential role of an antibody-dependent cell cytotoxic (ADCC) mechanism in the resistant ET sheep.Key words: In vitro, Fasciola gigantica, peritoneal cell, sheep gigantica