Appendiceal enterobiasis--its incidence and relationships to appendicitis

An evaluation was made of a bioptic material (21,916 appendices recovered from 1965 to 1974), in order to disclose relationships of the incidence of Enterobius vermicularis and the origin of appendicitis. A separate evaluation was made of a set of appendectomies (10,619 cases--from 1961 to 1970) for the purpose of detecting changes in pin worm-infested appendices by means of histological methods (683 cases). E. vermicularis was found in 6.03% of appendices. Included in our histological examination was a search for granulomas and eosinophile infiltrations. The former occurred in 1.14% of pin worm-infested appendices, the later in 1.74% and in 0.19%, or 2.18% in pin worm non-infested appendices. The results indicated a statistically highly significant difference in the incidence of granulomas. The incidence of granulomas in the appendix was increased in the present of pin worms in the appendix, and seemed also to be responsible for further pathological changes in it.     

A SURVEY OF ANTIBODY TO AINO VIRUS IN CATTLE AND OTHER SPECIES IN AUSTRALIA

SUMMARY A serological survey of healthy cattle in Australia showed that antibodies to Aino virus were present in serums from cattle in northern Australia and down the east coast as far as central New South Wales in 1975, 1976 and 1977, but occurred with a lower frequency than antibodies to Akabane virus. in contrast to the findings with Akabane virus, no neutralising antibodies to Aino virus were detected in serums from camels, dogs or horses. Antibodies to both viruses were detected in buffaloes and sheep, but not in humans or any of the Australian indigenous species so far tested. All positive serums originated from within the known range of Culicoides brevitarsis.     

Evaluation of an antimicrobial resistance monitoring program for Campylobacter in poultry by simulation

An ideal national resistance monitoring program should deliver a precise estimate of the resistance situation for a given combination of bacteria and antimicrobial at a low cost. To achieve this, decisions need to be made on the number of samples to be collected at each of different possible sampling points. Existing methods of sample size calculation can not be used to solve this problem, because sampling decisions do not only depend on the prevalence of resistance and sensitivity and specificity of resistance testing, but also on the prevalence of the bacteria, and test characteristics of isolation of these bacteria. Our aim was to develop a stochastic simulation model that optimized a national resistance monitoring program, taking multi-stage sampling, imperfect sensitivity and specificity of diagnostic tests, and cost-effectiveness considerations into account. The process of resistance testing of Campylobacter spp. isolated from cloacal swab samples from poultry was modeled using a Markov Chain Monte Carlo model. Different sampling scenarios on the number of flocks to be tested, the number of birds from each flock, and the number of campylobacter colonies submitted to susceptibility testing were evaluated regarding the precision of the resulting prevalence estimate. Precision of the prevalence estimate was defined as the absolute difference between apparent and true prevalence of resistance. A partial budget approach was utilized to find the most cost-effective combination of samples to obtain a defined precision of the prevalence estimate. For a sampling scenario testing 100 flocks, five birds per flock, and one campylobacter colony per sample, the median error of the prevalence estimate was 2.5%, and 95% of the simulations resulted in an error of 7% or less. When the total number of samples was kept constant, maximizing the number of flocks tested, and only testing one bird per flock resulted in the most precise prevalence estimate. Submitting more than one campylobacter colony to resistance testing did not improve the prevalence estimate. Partial budget analysis indicated that the most cost-effective strategy was testing of two birds per flock, and submitting one colony per sample to resistance testing.     

Methods for population-based herd sanitation: an overview

There is a considerable number of methods available for the development, maintenance and surveillance of specific-pathogen-free herds. The selection of a method for a specific remediation project is primarily dependent on the goal, the epidemiology of the agent to be eradicated, the feasibility and the available resources. At the beginning of the remediation programme, methods are required for the classification of the herd status. Clinical and analytical diagnostic tests may be used for individual herds or in an entire area. The interpretation of test results applied within a population deserves special attention. A series of techniques are available - alone or in combination - to remediate a herd that was classified as being infected: systematic treatment, vaccination, elimination of infected individual animals ("test and remove"), partial depopulation or total population (stamping out). These strategies are typically accompanied by cleaning and disinfection. After the remediation, the status of the herd needs to be certified and maintained. For the documentation of the status, monitoring and surveillance strategies such as clinical follow-up visits, notification systems and random sampling can be applied. When planning random surveys, statistical and epidemiological considerations are relevant. For the sustainable maintenance of the pathogen-free status, biosecurity measures at the individual farm level, but also broader approaches such as import restrictions, early warning systems and surveillance programmes are needed. General awareness regarding unusual clinical signs needs to be promoted among farmers and veterinarians. The longer a disease or an agent is absent from a herd or region, the lower becomes the risk awareness. In such a situation, mistakes can occur leading to an increased risk of re-infection.     

Epizootiology of bovine cysticercosis in the Jindrichuv Hradec District

The results of the study of the epidemiology and epizootology of Taenia saginata in the Jindrich?v Hradec district indicate that this tapeworm species has adapted successfully to anthropogenic conditions. Mass occurrence of bovine cysticercosis, coming from a limited source, was observed in the Jindrich?v Hradec district. Our of the 907 employees of one farm, T. saginata was found in two workers engaged in animal production and in one person working in crop production. Their recovery resulted in the eradication of cysticercosis in the cattle kept on that farm; before eradication the disease was responsible for losses of several hundreds of thousands of crowns.