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1.
To determine and compare the prevalence of trypanosome infections in different livestock species (cattle, pigs and goats) in areas where game animals are scarce and livestock constitute the main food source of tsetse, a survey was conducted on the plateau of the Eastern Province of Zambia in Katete and Petauke districts where Glossina morsitans morsitans is the only tsetse species present. Blood was collected from a total of 734 cattle, 333 goats and 324 pigs originating from 59 villages in both districts and was examined using the buffy coat method and the PCR-RFLP as diagnostic tools. The prevalence of trypanosome infections differed substantially between livestock species. Using microscopic diagnostic methods, trypanosome infections were detected in 13.5% of the cattle and 0.9% of the pigs. All goats were parasitologically negative. The PCR-RFLP analyses increased the trypanosomiasis prevalence to 33.5, 6.5 and 3.3% in cattle, pigs and goats respectively. The majority of the infections (91.2%) were due to Trypanosoma congolense. The presence of a trypanosome infection in cattle and pigs resulted in a significant decline in the packed cell volume. The outcome of the study clearly shows that despite the availability of goats and pigs, cattle seem to be the major livestock species affected by the disease in trypanosomiasis endemic areas. The high proportion of infections in cattle could be partly attributed to their higher availability and attractiveness to tsetse.  相似文献   

2.
East Coast fever (ECF), a tick-borne disease of cattle, is a major constraint to livestock development in Africa in general and southern Zambia in particular. Understanding the transmission patterns of this disease complex is very difficult as shown by previous studies in southern and eastern Zambia due to the interplay of risk factors. In this long-term study, we investigated whether global weather changes had any influence on disease transmission in traditionally kept cattle in southern Zambia. The results from this study show a strong association between increased Theileriaparva contacts in cattle and the presence of El Niño, clearly linking a simple climatic index to disease outbreaks. We therefore propose that in southern Zambia, the simple and readily available multiple El Niño Southern oscillation index (MEI) ranks be used in planning ECF control programmes and early warning.  相似文献   

3.
A longitudinal study was done to monitor incidence of livestock diseases in ranch and pastoral herds around Lake Mburo National Park, in South-western Uganda with a high level of wildlife (impala and zebra) and livestock (cattle and goats) interactions. East Coast Fever (ECF), abortions, helminthosis and starvation due to drought were major livestock disease problems encountered. ECF was a major disease affecting mainly calves, causing mortality both in ranch (8.5%) and pastoral (8.2%) herds. Meanwhile, drought was a more serious in pastoral than ranch herds (p < 0.05), killing 28.5 % and 5.8% of adult female cattle in respective production systems. Other endemic diseases found and controlled by vaccination were FMD, CBPP and blackquarter. In both cattle and goats helminthosis was causing mortalities, 3.3% and 0.8% among calves in pastoral and ranches respectively; and 4.8% and 6.9% among kids and sub-adult goats respectively. Many cases of abortions occurred among pastoral herds. In conclusion, the disease incidence among livestock was the same or relatively low as compared to other areas without wildlife.  相似文献   

4.
A study using a structured questionnaire was conducted to assess the perception of cattle farmers of the efficacy of East Coast fever (ECF) immunization in southern Zambia. One hundred and seventy-nine farmers from five districts in southern Zambia were interviewed. The majority of farmers (85%) perceived ECF immunization as being very effective and about half of them (51.4%) preferred immunization to other ECF control strategies. The study showed that the number of calves immunized was strongly associated with the farmer's perception of the benefits of immunization. There was no association between the number of calves immunized and the number of veterinary assistants in a given district or their transport situation. Overall mortality in ECF-immunized calves from various causes stood at 4.2%. Based on farmers' reports, the majority of these deaths seemed to have been caused by anaplasmosis, another tick-borne disease, and might have resulted from relaxation of tick control after ECF immunization. The reasons identified by farmers for not immunizing their animals included failure by immunizing teams to reach certain areas, not having calves of immunization age, and lack of money. These findings provide valuable information on how livestock farmers perceive and adopt new animal disease control strategies and the information could be useful in their planning and implementation.  相似文献   

5.
Livestock keeping is the mainstay for the pastoral community while also providing social and cultural value. This study ranked main production constraints and cattle diseases that impacted livelihood and estimated herd prevalence, incidence rate, and impact of diseases on production parameters in a semiarid pastoral district of Narok in Kenya. Data collection employed participatory techniques including listing, pairwise ranking, disease incidence scoring, proportional piling, and disease impact matrix scoring and this was disaggregated by gender. Production constraints with high scores for impact on livelihood included scarcity of water (19 %), lack of extension services (15 %), presence of diseases (12 %), lack of market for cattle and their products (10 %), and recurrent cycle of drought (9 %). Diseases with high scores for impact on livelihood were East Coast fever (ECF) (22 %) and foot and mouth disease (FMD) (21 %). High estimated incidence rates were reported for FMD (67 %), trypanosomosis (28 %), and ECF (15 %), while contagious bovine pleuropneumonia (CBPP) had an incidence rate <1 %. Milk yield was affected by FMD, ECF, and trypanosomosis, while ECF was the cause of increased mortality. FMD, ECF, CBPP, and brucellosis caused increased abortion, while effect of gender and location of study was not significant. Despite CBPP being regarded as an important disease affecting cattle production in sub-Sahara Africa, its estimated incidence rate in herds was low. This study indicates what issues should be prioritized by livestock policy for pastoral areas.  相似文献   

6.
The immunocompetence of cattle undergoing East Coast Fever (ECF) reactions of varying degrees of intensity was evaluated using the neutralising antibody response of these cattle to the vaccine response was found in animals undergoing severe ECF reactions. The results suggest that the massive lymphoid cell involvement of such severe ECF reactions diminishes the immune responsiveness of cattle to rinderpest vaccine.  相似文献   

7.
Tick-borne diseases are a constraint to livestock production in many developing countries as they cause high morbidity and mortality, which results in decreased production of meat, milk and other livestock by-products. The most important tick-borne diseases of livestock in sub-Saharan Africa are East Coast fever (caused by Theileria parva), babesiosis (caused by Babesia bigemina and B. bovis), anaplasmosis (caused by Anaplasma marginale) and heartwater (caused by Ehrlichia ruminantium). Despite their economic importance, information on the epidemiology of these diseases in many countries, including Zambia, is often inadequate, making rational disease control strategies difficult to implement. In this study 18S and 16S rRNA gene PCR assays were used for a comprehensive epidemiological analysis of tick-borne disease of cattle in three provinces of Zambia (Lusaka, Central and Eastern). All the disease pathogens under study (T. parva, T. mutans, T. taurotragi, B. bovis, B. bigemina, Anaplasma spp and E. ruminantium) were prevalent in each of the provinces surveyed. However, variation was observed in prevalence between regions and seasons. There was no association between live vaccination against East Coast fever and being PCR positive for T. parva. A number of risk factors were shown to be associated with (a) the occurrence of tick-borne pathogens in cattle and (b) cattle tick burdens in the wet season. A negative association was observed between the number of co-infecting pathogens and the erythrocyte packed cell volume (PCV) of carrier cattle.  相似文献   

8.
A longitudinal study was conducted over a 1-year period in six selected villages in Petauke and Katete districts in the Eastern Province of Zambia. Starting in November 1997, 50 animals were sampled at random at each village every 2 months. The parasitological prevalence of trypanosomosis was determined by the haematocrit centrifugation buffy-coat technique, supplemented with thick and thin Giemsa-stained blood films. Serum samples also were collected for anti-trypanosomal antibody determination by indirect enzyme-linked immunosorbent assay.

Parasitological prevalence was highly variable between villages and between visits (range: 0–28.6%; median: 3.1%). Seroprevalence was also variable between villages (range: 0–80.8%; median: 50%), but was less variable between visits. Average annual parasitological prevalence and average annual seroprevalence for each village were highly correlated [R2 (adjusted for d.f.)=0.89, p<0.01]. Seroprevalence measured on any single visit to a study village was better than parasitological prevalence as a predictor of average annual parasitological prevalence.  相似文献   


9.
Immunisation by the infection and treatment method using the Katete strain is currently the most efficient prophylactic technique to control East Coast fever (ECF) in the endemic areas of the Eastern Province of Zambia. The maintenance of the cold chain in liquid nitrogen up to the time of inoculation and the cost of the reference long-acting oxytetracycline (Terramycin LA, Pfizer) are the main drawbacks of the method. The work presented in this paper aims at reducing the cost of immunisation against ECF by using an ice bath for the field delivery and a cheaper long-acting oxytetracycline formulation as chemotherapeutic agent. In experimental conditions, the results from 40 calves immunised after various periods of storage on ice ranging from 4 to 32 h indicate that deferred immunisation performed with a stabilate kept on ice for up to 6h after thawing has an efficiency of 90%. Moreover, sporozoites kept on ice were still surviving 32 h after thawing. In a field trial, 91 calves were inoculated with a stabilate kept for 3.5-5.5 h after thawing and dilution whereas 86 calves were immunised using the standard method. Clinical and parasitological reactions to immunisation were monitored as well as the seroconversion. In the field trial, the deferred immunisation was more efficient than the standard method. The acid formulation of oxytetracycline that was tested was found as suitable as the reference alkaline formulation for the chemotherapeutic control of the Katete strain in ECF immunisation. One indoor trial was carried out on 10 animals and a field trial involved 93 calves.  相似文献   

10.
A survey to investigate resistance to drugs used in the treatment of bovine trypanosomosis was conducted in the eastern province of Zambia between 1996 and 1998. A cross-sectional study was conducted in three districts (Petauke, Katete, Lundazi) at 34 village sampling sites selected at random from villages that had shown greater than 6% prevalence of bovine trypanosomosis during an earlier survey. A longitudinal study was conducted in same three districts over a 1-year period. The study sites were chosen from the cross-sectional study and included eight sites showing high trypanosomosis prevalence and where no control activities were recorded. Use was made of parasitological methods, tests of resistance in cattle and mice and isometamidium-ELISA. Overall mean prevalence of trypanosomosis was 14.4, with 96% of infections caused by Trypanosoma congolense. The remainder was caused by Trypanosoma vivax (2%) and Trypanosoma brucei (2%). Tests in mice showed that of the stabilates collected, 24 (34%) were resistant to only isometamidium chloride, 8 (11.3%) were resistant to only diminazene aceturate, 1 (1.4%) was resistant to both drugs, and 38 (53.5%) were sensitive to both drugs. At least 2 out of 27 stabilates tested in cattle appeared to be resistant to trypanocidal drugs, 1 to isometamidium and 1 to diminazene. Isometamidium could be detected in only 63 (4.1%) of 1526 serum samples from cattle in the study. Only 6 (2.8%) of 212 serum samples from trypanosome-infected cattle had serum levels of the drug above 0.4 ng isometamidium per ml serum which is indicative for drug resistance in the infecting parasite population. Although some drug resistance is apparent, diminazene aceturate and isometamidium chloride can still be expected to be effective as a sanative pair in this area in most cases, since not more than 1 stabilate of 71 investigated showed evidence of resistance to both drugs.  相似文献   

11.
A longitudinal study was carried out in the coastal lowlands coconut-cassava agro-ecological zone of Kaloleni Division, Coast Province, Kenya between June 1990 and December 1991 to estimate disease incidence and cause-specific case-fatality risk in an average of 120 cattle in 26 small-holder dairy herds kept in two grazing-management systems. East Coast fever (ECF) was the predominant disease diagnosed; the mean monthly incidence rate was 2.5 and 6.9% in animals < or = 18 months of age under stall-fed and herded-grazing systems, respectively. In cattle > 18 months of age, the monthly incidence rate was < 1%. The 6-month ECF incidence rate was 20+/-8% (S.E.) in the stall-feeding system compared with 39+/-7% in the herded-grazing systems. There was a gradual increase in antibody prevalence with age to over 90% in cattle over 18 months of age in herded-grazing systems, whilst less than a third of cattle in the stall-feeding systems were sero-positive at any age. Overall accumulated mortality to 18 months of age was estimated to be 56%. Annual mortality in cattle > 18 months averaged 9%. Cattle managed in the herded-grazing system had a 60% higher mortality, although not significantly so, than those fed in stalls. Deaths due to ECF accounted for over two-thirds of the deaths. ECF was then the major disease constraint to small-holder dairy production in the coconut zone of coastal Kenya. Clinical cases occur the whole year round (especially in young stock)--despite apparent tick control, and in both herded-grazing and stall-feeding system.  相似文献   

12.
East Coast fever (ECF) causes considerable mortality and production losses in the Tanzania smallholder dairy sector and limits the introduction of improved dairy breeds in areas where the disease is present. The infection and treatment method (ITM) was adopted by smallholder dairy farms for ECF immunisation in Hanang and Handeni districts of Tanzania. This study recorded incidence rates for ECF and other tick-borne diseases (TBDs) for ECF-immunised and non-immunised cattle between 1997 and 2000. Approximately 80% of smallholder households from both sites (n?=?167) participated in this longitudinal study, with immunisations carried out at the request of the livestock owners. Efficacy of ITM for preventing ECF cases in these crossbred dairy cattle was estimated at 97.6%, while that for preventing ECF deaths was 97.9%. One percent of the cattle developed clinical ECF as a result of immunisation. Since ECF immunisation permits a reduction in acaricide use, an increase in other TBDs is a potential concern. Sixty-three percent of farmers continued to use the same acaricide after immunisation, with 80% of these reducing the frequency of applications. Overall, 78% of farmers increased the acaricide application interval after immunisation beyond that recommended by the manufacturer, resulting in annual savings in the region of USD 4.77 per animal. No statistical difference was observed between the immunised and non-immunised animals in the incidence of non-ECF TBDs. However, immunised animals that succumbed to these diseases showed fewer case fatalities. ITM would therefore appear to be a suitable method for ECF control in Tanzania's smallholder dairy sector.  相似文献   

13.
In Tanzania, control of East Coast fever (ECF) has predominantly relied on tick control using acaricides and chemotherapy, little on ECF vaccination, and very little on dissemination regarding animal immunization. In this paper, the prevalence, control measure, and tolerance of Tanzania Shorthorn Zebu (TSHZ) cattle to ECF are reviewed. In addition, the opportunities available for reducing the use of acaricides for the benefit of the farmers in terms of reduction of costs of purchasing acaricides and environmental pollution are described. The tick distribution and epidemiological factors for ECF such as the agro-ecological zones (AEZ), livestock production systems (LPS), strain, and age of the animals are also described. These factors influence the epidemiology of ECF and the distribution of TSHZ strains in different geographic locations of Tanzania. We have further showed that there is a tendency of farmers to select among the strains of TSHZ for animals which can tolerate ticks and ECF and crossbreed them with their local strains with the aim of benefiting from the inherent characteristics of the most tolerant strains. Generally, many strains of TSHZ cattle are tolerant to tick infestation and ECF infection and can be bred to respond to the needs of the people. In this review paper, we recommend that in future, ECF epidemiological studies should account for factors such as livestock production system, agro-climate, breed of animal, tick control strategy, and the dynamic interactions between them. In conclusion, we have demonstrated that an integrated control method involving use of acaricides, immunization, and ECF-tolerant/-resistant animals is required.  相似文献   

14.
A total of 90 animals was immunized against East Coast fever (ECF) using Theileria parva (Marikebuni) stock on three large-scale farms in Kiminini Division, Trans-Nzoia District, North Rift, Kenya. Another 90 cattle served as non-immunized controls. Following immunization the number of cattle with significant indirect fluorescent antibody (IFA) titres increased from 43.9% to 84.4% and 6.7% of the cattle developed clinical ECF reactions. Two months after immunization, the immunized and non-immunized cattle were divided into two groups one of which was dipped every 3 weeks and the other dipped when total full body tick counts reached 100. All the animals were monitored for 51 weeks for incidences of ECF and other tick-borne diseases. Twenty-four cases of ECF were diagnosed among the non-immunized cattle compared to four cases among the immunized cattle; a difference that was significant (P > 0.05). There was no significant difference in the incidences of babesiosis and anaplasmosis between the immunized and non-immunized cattle.  相似文献   

15.
Faecal samples were collected from January 2010 through September 2010 to determine the prevalence of gastrointestinal (GI) helminths infestation in dogs in urban Lusaka and rural Katete Districts of Zambia. A total of 452 faecal samples (n=160 Katete, n=292 Lusaka) were examined by faecal flotation for the presence of helminth eggs and 82.5% of dogs were positive for GI helminths in Katete compared to 76% for Lusaka. Positive results with the presence of at least one parasite corresponded to 72.9% Ancylostoma caninum, 11% Toxocara canis, 4.8% Toxascaris leonina, 2.4% Dipylidium caninum, 0.7% Taeniidae and 0.3% T. vulpis, species for Lusaka while Katete recorded 70.6% A. caninum, 18.1% T. vulpis, 11.1% T. canis, 13.1% D. caninum, 3.8% T. leonina, and 0.6% Taeniidae. Except for T. vulpis and D. caninum (p<0.05) the results indicated no significant difference in the prevalence of the identified GI helminth between Lusaka and Katete. There was no significant difference in the prevalence between genders of GI helminth infestation demonstrated in this study and only A. caninum showed significant difference in prevalence by age category. The study also showed the presence of zoonotic intestinal helminths A. caninum, T. canis and D. caninum. The study highlights that there was no significant difference in spectrum and prevalence of GI helminths between urban and rural areas in Zambia. It further brings to light the importance of educating owners of dogs on the importance of regular deworming of dogs and control of ectoparasites in order to minimise the risk that these dogs pose to them and the public.  相似文献   

16.
Postmortem records of cattle brought to the Veterinary School in Kabete near Nairobi were examined for a period of 15 years (1984-1998, inclusive) in order to establish the role that parasitic diseases played as causes of death. The cattle were mainly of exotic breeds but a few were crosses or of indigenous breeds. There was a total of 1413 cases of deaths from various diseases of which 177 (13%) were due to parasites. The tick-borne diseases were in high proportions and accounted for 84,7% among the parasitic causes, which represented 10,6% of all the deaths recorded. The main tick-borne disease was East Coast fever (ECF) (65%) followed by heartwater (10,2%), babesiosis (5,1%) and anaplasmosis (4,5%). Hydatidosis was responsible for 7,3% of deaths from parasitic causes. Deaths from ECF were recorded in all the 15 years and in high proportions compared to those due to heartwater (8/15), babesiosis (7/15) and anaplasmosis 5/15). Over the period under consideration, no decline was noted among various disease conditions despite advances made in controlling tick vectors and in the treatment of various parasitic conditions. The area covered by this study has the advantage of having several veterinary-related institutions close by. Hence knowledge and awareness about livestock diseases is relatively high compared to other parts of the country. It is therefore challenging to the Veterinary Department to examine the service delivery systems and other factors that may contribute to the persistent presence of these fatal parasitic conditions of cattle.  相似文献   

17.
This paper presents the results of the follow-up of three sentinel herds between 1994 and 2000 during an East Coast fever (ECF) epidemic in eastern Zambia. The animals of the sentinel herds were closely monitored clinically and serologically together with detailed Rhipicephalus appendiculatus counts. Peaks of disease incidence occurred in the rainy season (December-February) and the dry months of May-July with nymph-to-adult tick transmission dominating the infection dynamics. A second wave of adult R. appendiculatus at the start of the dry season is essential for the occurrence of a full-blown epidemic while the size of the susceptible cattle population acts as a most important limiting factor. The majority of adult cattle of the sentinel herds became infected less than 2 years after the introduction of the disease. The median age at first contact for calves born towards the end of the study (1999) was about 6 months. The case-fatality ratio (including sub-clinical cases) is estimated at 60%. It is argued that part of the so-called 'natural mortality' is actually due to ECF and that ECF occurrence and mortality are systematically underestimated. The direct financial cost of the epidemic, based on loss of animals and cost of treatment only and calculated over 4 years running, is estimated at about 6 US dollars per year per animal at risk. The value of the traditional seroprevalence survey as a tool for monitoring ECF epidemiology is put in question and the prevalence of maternal antibodies in new-born calves, reflecting the immune status of the dam population, is introduced as an alternative. It is demonstrated that an efficient immunisation campaign should concentrate its efforts in the period of low adult R. appendiculatus abundance (July-October).  相似文献   

18.
In 2003 and 2004, a severe epidemic decimated the cattle population on Grand Comore, the largest island of the Union of Comoros. Fatalities started soon after the import of cattle from Tanzania. Theileria parva and its vector, Rhipicephalus appendiculatus, could be identified as the main culprits of the epidemic. Characterisation by multilocus genotyping revealed that the T. parva parasites isolated on the Comoros were identical to the components of the Muguga cocktail vaccine used in Tanzania to immunise cattle. Therefore, it is believed that East Coast Fever reached the Comoros while some of the imported livestock got infected in Tanzania by ticks of which the immature stadia fed on Muguga cocktail vaccinated animals. Since the Comorian government neither has the financial means nor the competent staff to pursue an adequate epidemiosurveillance, the danger exists that without external assistance and in a context of continuing globalisation more transboundary diseases will affect the Comorian livestock sector in the future.  相似文献   

19.
A retrospective cross-sectional study of mortality was conducted on smallholder dairy farms in 2 separate regions (Iringa and Tanga) of Tanzania during the period of January to April 1999. A total of 1789 cattle from 400 randomly sampled smallholder dairy farms (200 each from Iringa and Tanga regions) were included in the study. These animals contributed a total risk period of 690.4 and 653.95 years for Tanga and Iringa, respectively. The overall mortality rates were estimated to be 8.5 and 14.2 per 100 cattle years risk for Tanga and Iringa regions, respectively; 57.7% of the reported deaths were of young stock less than 12 months old; 45% of reported young stock deaths (< or = 12 months old) were due to tickborne diseases, mainly East Coast Fever (ECF) and anaplasmosis. Disease events including ECF were reported to occur in all months of the year. Survival analysis using Cox proportional hazard models indicated that, in both regions, death rate and risk was higher in young stock less than 12 months than in older animals (relative risk RR = 4.92, P < 0.001 for Iringa; RR = 5.03 P = 0.005 for Tanga). In the Tanga region reported mortality rates were significantly higher for male animals (RR = 3.66, P = 0.001) and F2 compared with F1 animals (RR = 3.04, P = 0.003). In the Iringa region, reported mortality rates were lower for cattle on farms where the owner had attended a dairy development project training course (RR = 0.47, P = 0.012). Farms located in Iringa urban district and Pangani were associated with higher risk (mortality risk 21% for Iringa urban and 34% for Pangani). Our findings suggest that timely health and management interventions on these factors are necessary to alleviate losses from disease and emphasise that understanding variation in mortality risk within a population can enhance early response to potential outbreaks, reducing losses.  相似文献   

20.
A serosurvey and a tuberculination campaign have been conducted throughout Niger in 1989-1990 on cattle to measure the prevalence rate of six diseases: brucellosis (1.4%), haemorragic septicemia (3.9%), tuberculosis (2%), coxiellosis (15.4%), pleuropneumonia (3.7%), Rift Valley fever (0.52%). The results were analysed and compared to livestock service reports.  相似文献   

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