Contagious bovine pleuropneumonia (lung sickness) in Africa.

Contagious bovine pleuropneumonia (CBPP) or lung sickness, is an insidious pneumonic disease of cattle caused by Mycoplasma mycoides subspecies mycoides small colony variant (MmmSC) and it is one of the major diseases affecting cattle in Africa. With the imminent eradication of rinderpest from Africa (Somali ecosystem) CBPP has become the disease of prime concern in terms of epizootics that affect cattle on the continent. The control and/or eradication of the disease have suffered from unsustained control actions due to lack of operational funds to support such actions and deterioration in the quality of veterinary services in many countries affected by the disease. Stamping out procedures which were adopted by Botswana to control the disease (1995-1997) cannot be carried out by many countries currently affected by CBPP due to the high financial cost, the widespread nature of disease, animal welfare considerations and the potential loss of a valuable genetic resource base. The current scenario of CBPP disease epidemiology in sub-Saharan Africa requires that proactive measures are taken to safeguard countries in southern Africa which are currently free from CBPP from being contaminated by the disease thus affecting the beef industry and people's livelihoods; and to progressively control the disease in endemic zones of Western and Central Africa. This presentation discusses the epidemiology of CBPP in Africa, diagnosis of the disease, regional strategies that could be deployed to prevent and control the spread of the disease on the continent and research thrusts on CBPP.

Survey of the seroprevalence of brucellosis in ruminants in Tajikistan.

A cross-sectional serological survey of the prevalence of brucellosis in ruminants in the Region of Republican Subordination and Khatlon oblasts (provinces) in Tajikistan was conducted in May 2003. Sera from 13,625 ruminants involving 3513 households in 172 kishlaks (villages) were collected and screened by the rose bengal test. Doubtful and positive results were further tested with competitive and indirect elisas. The overall serological prevalences (95 per cent confidence intervals [cis]) were 5.8 per cent (5.2 to 6.4 per cent) for sheep, 5.5 per cent (5.0 to 6.0 per cent) for goats and 2.1 per cent (1.0 to 3.2 per cent) for cattle. The results show that brucellosis was a common disease of ruminants that was widely but unevenly distributed throughout the two oblasts. Seropositive animals were found in 119 of the 172 kishlaks (69.2 per cent [95 per cent ci 61.9 to 75.6 per cent]) and 14.4 per cent (95 per cent ci 13.3 to 15.6 per cent) of the 3513 households. Evidence of infection was also found in cattle kept for milk production in urban kishlaks in two major cities and in state-owned dairy farms.

Veterinary vaccines and their use in developing countries.

The burden of infectious diseases in livestock and other animals continues to be a major constraint to sustained agricultural development, food security, and participation of developing and in-transition countries in the economic benefits of international trade in livestock commodities. Targeted measures must be instituted in those countries to reduce the occurrence of infectious diseases. Quality veterinary vaccines used strategically can and should be part of government sanctioned-programmes. Vaccination campaigns must be part of comprehensive disease control programmes, which, in the case of transboundary animal diseases, require a regional approach if they are to be successful. This paper focuses on the salient transboundary animal diseases and examines current vaccine use, promising vaccine research, innovative technologies that can be applied in countries in some important developing regions of the world, and the role of public/private partnerships.

Veterinary public health activities at FAO: echinococcosis/hydatid disease.

Cystic hydatidosis is a zoonotic disease that remain as a significant cause of human morbidity and mortality in many parts of the world. The disease has veterinary public health implications. FAO is involved with some activities in the control of echinococcosis/hydatid disease: within the Animal Production and Health Division the Veterinary Public Health (VHP) Programme is constituted by members of the different Services (Animal Health, Animal Production, and Livestock Policy) within the Division. FAO regular programme has also established a global network of professionals directly involved in VPH. Furthermore FAO's Technical Cooperation Projects (TCP) is a tool to assist member countries in responding to urgent and unforeseen demands.

Assessing the burden of Taenia solium cysticercosis and echinococcosis.

This collection of articles provides an account of the papers delivered at the 19th International Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP)(held in New Orleans, LA, USA, from 10 to 14 August 2003) in a symposium session on assessing the burden of Taenia solium cysticercosis and echinococcosis organised and chaired by A. Lee Willingham III from the WHO/FAO Collaborating Center for Research and Training on Emerging and other Parasitic Zoonoses in Denmark and Peter M. Schantz from the Parasitic Diseases Division of the US Centers for Disease Control and Prevention, USA. The focus was on the persistence of the zoonotic parasitic diseases cysticercosis, caused by the pork tapeworm T. solium, and echinococcosis,caused by species of the tapeworm Echinococcus, and why these diseases are given very little attention on the national and international agendas in spite of the availability of tools to detect, treat,control and prevent them when it is quite clear in most instances that they are clearly associated with and help perpetuate poverty. A major reason for this is that in many endemic areas the presence and impact of these diseases are not known due to the lack of investigation and information thus policymakers are not aware of their burden and benefits of their control. Documentation is also needed to help increase awareness of the international community and hopefully result in financial and technical support being made available. Thus, burden assessments of cysticercosis and echinococcosis provide an essential evidence base for securing political will and financial and technical support as well as providing a basis for cost-benefit analysis of prevention and control efforts. In order to make an appropriate and full burden assessment one must consider the health, agricultural, social and other impacts of these parasitic zoonoses comprehensively. During the symposium presentations were given concerning current ongoing initiatives to assess the burden of cysticercosis and echinococcosis and examples of the impact of these diseases in both developing and developed countries were provided. In addition, cost factors related to vaccines for these cestode diseases were discussed and the possibilities for technical and financial support from multilateral agencies for assessments and interventions presented.

The resurgence of trypanosomosis in Botswana.

No sleeping sickness or nagana cases have been reported in Botswana since 1985. In view of several confirmed clinical cases of nagana and reports of heavy bovine mortality, a parasitological survey was conducted to determine the prevalence of trypanosome infection in cattle in Maun and Shakawe areas of Ngamiland district. Wet blood films, buffy coat and Giemsa-stained thick and thin blood smears were used to detect trypanosomes in animals. Overall,trypanosome infection rate was 15.98%, with 5.94% and 27.29% in Maun and Shakawe respectively. The urgent need to combat trypanosomosis in Ngamiland, particularly in the Shakawe area, is highlighted, and a 3-phase integrated tsetse control strategy for this disease problem is discussed.

Bovine borreliosis in Botswana.

Clinical Borrelia theileri infection was reported for the first time in cattle from Botswana concurrent with Babesia bovis and Theileria mutans infections. Two animals, an ox and a cow of the Tswana breed demonstrated clinical signs of fever, haemoglobinuria, inappetance, diarrhoea, pallor of mucous membranes, enlarged superficial lymph nodes and rough hair coats. Examination of the blood smears from the affected animals revealed numerous B. theileri, and very few B. bovis and T. mutans organisms. Oxytetracycline was administered parenterally to all the animals in the herd. The ox, being extremely weak and recumbent for the previous 4-5 days, succumbed to death the day after the examination. The clearance of spirochaetes from the blood circulation and recovery of the cow three days after treatment with oxytetracycline suggest an involvement of B. theileri in producing clinical disease.

Comparison between c-ELISA and CFT in detecting antibodies to Mycoplasma mycoides mycoides biotype SC in cattle affected by CBPP in Botswana.

Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides mycoides biotype small colony (SC) (MmmSC) appears to be making a serious comeback in Africa after successful control programs in many parts of the continent during the 1960s and 1970s. Botswana, a country that has been free from the disease for more than 50 years, was affected in 1995. An eradication policy was adopted by the Government of Botswana in which 320,000 cattle in the affected district of Ngamiland, Northwestern Botswana were slaughtered. This was followed by a restocking exercise in which 70,000 cattle were sent to the outbreak areas as replacement stock. It became necessary to carry out serosurveillance in order to ensure that the disease did not reenter Botswana and to ensure that the replacement stock remained free from the disease. The specificity and sensitivity of the complement fixation test (CFT) in Botswana was assessed in 82 cattle affected by the disease and held in a double fenced quarantine camp. The newly developed competitive ELISA was made available to the National Veterinary Laboratory (NVL) through the FAO/IAEA Joint Division in Vienna, Austria. Using postmortem lesions as the gold standard and a 2 x 2 contingency table, the two tests were compared in terms of their sensitivity and specificity in detecting antibodies to MmmSC. The CFT was found to be slightly more sensitive than the c-ELISA, and this could be related to the stage of the disease. A long-term study comparing the progression of the disease with the two tests is, therefore, essential.

An outbreak of contagious bovine pleuropneumonia in Ngamiland district of north-western Botswana.

An outbreak of contagious bovine pleuropneumonia (CBPP) was detected in Botswana in 1995 after more than half a century of freedom from the disease. Lung tissues, pleural fluids, nasal swabs and serum samples were examined in laboratories in Botswana, South Africa and Namibia and the findings were confirmed in Italy. The disease was confirmed as CBPP from the gross and histopathological changes in the lungs of affected animals and by the culture of the agent of CBPP, Mycoplasma mycoides subspecies mycoides, small colony variant (MmmSC). These findings were supported by the demonstration of specific complement-fixing antibodies and the production of polymerase chain reaction products of MmmSC.

[A note on the first case of dry gangrene of the limbs in cattle, caused by Salmonella typhimurium in Ghana]. / Note sur une première observation de gangrène sèche des extrémités chez des bovins, due à Salmonella typhimurium, au Ghana.

Ischaemia and terminal tissue dry gangrene are among the sequels of Salmonella infection. Up to now, these lesions had been described in Europe and in Chile, on calf exclusively. This time, the syndrome was observed on adult cattle reared in the Accra Plains (Ghana) and infected by S. typhimurium. This case give evidence of the spreading of salmonellosis on the African continent and should foster the search of adequate control measures.

Bovine farcy in the Accra Plains of Ghana.

Bovine farcy is described for the first time in Ghana in herds kept in the Aveyime area of the Accra Plains. Reasons why the disease seems confined to a small geographical area are not yet clear. Different breeds of cattle are equally affected. Mineral deficiencies were not observed in the samples taken for analysis (Ca, Mg, P, Na, K, Cl). Limited examination of tick population on cattle showed a predominance of A. variegatum. Factors enhancing the pathogenicity and persistence of the Mycobacterium are still not clear. A study is soon to start.

Diagnosis of mycoplasmal pneumonia of swine: sequential study by direct immunofluorescence.

An improved direct fluorescent antibody test was evaluated for specificity and efficacy in diagnosing mycoplasmal pneumonia of swine. A sequential study was carried out in which pigs inoculated with a pneumonic lung suspension containing Mycoplasma hyopneumoniae strain 11 were euthanatized at postinoculation (PI) weeks 2 to 12. Fluorescent coating of M hyopneumoniae was detected primarily on bronchial and bronchiolar epithelial surfaces of lungs with gross lesions of pneumonia. Fluorescence was observed to be most intense at PI weeks 4 to 6, with a tendency to decrease in intensity from PI weeks 8 to 12. This indicated that there may be a decrease in number of M hyopneumoniae cells in the more advanced stages of the disease. The use of a counterstain (chelated azo-dye) provided an excellent color contrast and permitted making unambiguous interpretation of results.