Veterinary microbiology
-
Crohn's disease is a chronic, relapsing inflammatory condition affecting any part of the human gastrointestinal tract. It is characterised by transmural inflammation with deep ulceration, thickening of the bowel wall and fistula formation. The hallmark is the non-caseating granuloma. ⋯ The use of antimycobacterial therapy directed against M.a. paratuberculosis shows promising results but needs further evaluation. Up to 80% of patients with Crohn's disease will require surgery at some stage in the course of their illness. The challenge remains to try and prevent resection of inflamed intestine and to improve the quality of life of those affected by this disorder.
-
Veterinary microbiology · Jan 1999
ReviewEpidemiological features and economical importance of bovine virus diarrhoea virus (BVDV) infections.
Infections with bovine virus diarrhoea virus (BVDV) are widespread throughout the world. Although the prevalence of infection varies among surveys, the infection tends to be endemic in many populations, reaching a maximum level of 1-2% of the cattle being persistently infected (PI) and 60-85% of the cattle being antibody positive. Persistently infected cattle are the main source for transmission of the virus. ⋯ At the same incidence of infection, the losses due to a high-virulent BVDV strain were estimated as US$ 57 million per million calvings. Low-virulent BVDV infections caused maximum losses at an incidence of 45%, whereas high-virulent BVDV infections caused maximum losses at an incidence of 65%. Thus, cost-benefit analyses of control programs are highly dependent on the risks of new infections under different circumstances and on the strains of the virus involved.
-
Veterinary microbiology · Nov 1995
Immune responses of the camel (Camelus dromedarius) to contagious ecthyma (Orf) virus infection.
An enzyme-linked immunosorbent assay (ELISA) was developed together with a western blotting technique for the detection of total and specific IgG and IgM antibodies to the contagious ecthyma (orf) virus in camel (Camelus dromedarius) sera and for identifying the seroreactive antigens of the virus. An outbreak of generalised contagious ecthyma in camels was diagnosed for the first time in Libya; the seropositivity rate in a herd with clinically affected camels was 37.9% (and was related to clinical signs) and in apparently normal herds was 0% to 6.8%. ⋯ Very close similarity was seen with the western blot of orf-positive sheep sera. It is considered that the ELISA technique was valid for orf serodiagnosis in the camel and could be usefully applied to other species at risk of orf infection.
-
Veterinary microbiology · May 1995
Towards eradication of measles virus: global progress and strategy evaluation.
Despite an increase in global measles vaccine coverage from under 20% in 1980 to around 80% in 1990, measles remains a major cause of morbidity and mortality world-wide. This paper addresses a number of issues relating to efforts to control measles, namely, (i) at the global level, how might we assess the impact of measles vaccination on the incidence of infection and associated disease, and, (ii), at the strategic level, how can we utilise an understanding of the transmission dynamics of childhood viral infections to aid the design of optimal immunisation programmes? Based on WHO vaccine coverage data, and organising countries according to similarities in demographic and epidemiological parameters, an age-structured model of measles transmission is used to capture the non-linear dynamics of infection and mass vaccination and to generate projections of the impact of measles immunization world-wide. The results provide a crude indication of the percentage reduction in measles cases by year 2000 (compared with no immunization) and suggest an approximately 70% reduction in cases over all ages, and 77% reduction in cases under 5 years (where there is the greatest risk of case fatality); these suggest that WHO targets for 1995 are unlikely to be achieved. ⋯ A realistic age structured model, validated using extensive serological data, is used to compare the merits of single or two dose strategies. Based upon recent estimates of vaccine efficacy (90%) and coverage (92% by end of second year of life) it is suggested that a two-dose policy with a pre-school second dose given irrespective of vaccine history is required to prevent the build up of susceptibles to epidemic proportions in the longer term. In a second example, prompted by the success of the campaign approach to polio and measles elimination in Central and South America, simple models are used to explore and quantify the process by which pulse vaccination programmes (i.e. repeated application across a wide age range) act to control transmission.
-
Veterinary microbiology · Jun 1993
A veterinary antibiotic policy: a personal view on the perspectives in The Netherlands.
To reach a more adequate and responsible use of antibiotics in veterinary medicine a broad approach is required. The growing interest in the optimum use of antibiotics in veterinary medicine is stimulated by awareness of the necessity to prevent the emergence of resistance and the spread of resistant bacteria. This is a matter of primary importance to safeguard the efficacy of antibiotic therapy in animals now and in the future, but will also minimise possible public health risks. ⋯ Until now regular and nationwide systemic monitoring of resistance and registration of veterinary use of antibiotics is not practically feasible in the Netherlands. A new formulary, based on a veterinary antibiotic will be published by the end of 1992. However, to be able to evaluate the impact of this policy on the prevalence of resistance and, if necessary, to adapt the policy the development of facilities for resistance epidemiology is urgently needed.