In this study the drug resistance pattern of 3559 Mycobacterium tuberculosis strains isolated in Austria between 1995 and 98 was evaluated. Of these strains, 165 (4·6%) were resistant to one or more drugs, 113 (3·2%) to one of the tested drugs and 53 (1·5%) to two or more drugs. Monodrug resistance was observed most often to isoniazid (56 strains), followed by streptomycin (44 strains). Resistance to rifampicin or ethambutol alone was rarely seen (12 strains and 1 strain, respectively). Of the 53 strains resistant to 2 or more drugs, 25 were resistant to isoniazid and streptomycin, while 17 were multidrug resistant. Molecular typing revealed a large diversity among the multidrug-resistant strains.

Mathematical models of transmission dynamics of infectious diseases provide a useful tool for investigating the impact of community based control measures. Previously, we used a dynamic (constant force-of-infection) model for lymphatic filariasis to describe observed patterns of infection and disease in endemic communities. In this paper, we expand the model to examine the effects of control options against filariasis by incorporating the impact of age structure of the human community and by addressing explicitly the dynamics of parasite transmission from and to the vector population. This model is tested using data for Wuchereria bancrofti transmitted by Culex quinquefasciatus in Pondicherry, South India. The results show that chemotherapy has a larger short-term impact than vector control but that the effects of vector control can last beyond the treatment period. In addition we compare rates of recrudescence for drugs with different macrofilaricidal effects.

After a primary infection Coxiella burnetii may persist covertly in animals and recrudesce at parturition to be shed in the products of conception and the milk. Similar latent persistence and recrudescence occurs in man: namely, infection of placenta, heart valve or mural endocardium, bone or liver. The numbers of organisms, their viability and cellular form, and the underlying organ sites of latent infection for the coxiella are obscure. During investigations of 29 patients with a chronic sequel to acute Q fever, the post-Q fever fatigue syndrome (QFS) [1–3], sensitive conventional and TaqMan-based PCR revealed low levels of C. burnetii DNA in blood mononuclear cells (5/29; 17%), thin needle liver biopsies (2/14; 14%) and, notably, in bone marrow aspirates (13/20; 65%). Irrespective of the ultimate significance of coxiella persistence for QFS, the detection of C. burnetii genomic DNA in bone marrow several years after a primary infection unveils a new pathological dimension for Q fever.

Cowpox is an orthopoxvirus infection endemic in European wild rodents, but with a wide host range including human beings. In this longitudinal study we examined cowpox in two wild rodent species, bank voles Clethrionomys glareolus and wood mice Apodemus sylvaticus, to investigate the dynamics of a virus in its wild reservoir host. Trapping was carried out at 4-weekly intervals over 3 years and each animal caught was uniquely identified, blood sampled and tested for antibodies to cowpox. Antibody prevalence was higher in bank voles than in wood mice and seroconversion varied seasonally, with peaks in autumn. Infection was most common in males of both species but no clear association with age was demonstrated. This study provides a model for studying other zoonotic infections that derive from wild mammals since other approaches, such as one-off samples, will fail to detect the variation in infection and thus, risk to human health, demonstrated here.

ELISA techniques developed for the veterinary diagnosis of Rabbit Haemorrhagic Disease (RHD) in domestic rabbits were used for studying the epidemiology of RHD in Australian wild rabbits. The combination of ELISA techniques that distinguished IgA, IgG and IgM antibody responses and a longitudinal data set, mainly based on capture-mark-recapture of rabbits, provided a reliable basis for interpreting serology and set the criteria used to classify rabbits' immunological status. Importantly, young with maternal antibodies, immune rabbits and rabbits apparently re-exposed to RHD were readily separated. Three outbreaks of RHD occurred in 1996–7. The timing of RHD outbreaks was mainly driven by recruitment of young rabbits that generally contracted RHD after they lost their maternally derived immunity. Young that lost maternal antibodies in summer were not immediately infected, apparently because transmission of RHDV slows at that time, but contracted RHD in the autumn when conditions were again suitable for disease spread.

The application of a computer model called Rimpuff for simulating the airborne spread of foot-and-mouth disease (FMD) is described. Rimpuff is more sophisticated and accurate than other FMD simulation models previously described. It can be run on a desktop computer and performs analyses very quickly. It can be linked to a geographical information system and so the information generated can be integrated with geographical and demographical data for display in a format that can be easily assimilated and transmitted electronically. The system was validated using historical data from outbreaks of FMD in France and the UK in 1981, and from Denmark and the former German Democratic Republic (GDR) in 1982. A very good fit was obtained between the direction of the plumes of virus simulated by the model and the spread of disease from France to the UK in 1981. Although cattle in the UK were infected during the episode, the concentrations of airborne virus in the plumes simulated by the model were beneath the infectivity threshold for cattle. It was concluded from the analysis that the number of pigs infected in France, and therefore the source concentration of airborne virus, was probably much higher than was recorded at the time of the outbreaks. Analysis of the Denmark/GDR episode pointed to the possibility that the source of virus for the 1982 epidemic in Denmark could have been one or more unreported outbreaks involving pigs in the former GDR.

VP1 gene sequences of SAT-2 type foot-and-mouth disease (FMD) viruses recovered from impala and African buffalo in the Kruger National Park (KNP) were used to determine intra- and interspecies relationships of viruses circulating in these wildlife populations. On this basis five distinct lineages of SAT-2 virus were identified in routine sampling of oesophageo-pharyngeal epithelium from buffalo between 1988 and 1996. Different lineages were associated with discrete geographic sampling localities. Over the period 1985–95, four unrelated epizootics occurred in impala in defined localities within the KNP. Evidence for natural transmission of FMD between buffalo and impala is presented for the most recent 1995 outbreak, with data linking the 1985 and 1988/9 impala epizootics to viruses associated with specific buffalo herds.

The prevalence of antibody to six serovars of Leptospira interrogans in cattle in Asturias (Northern Spain) was determined by the microscopic agglutination test (MAT). Using 50% agglutination or lysis at a dilution of 1[ratio ]10 or more as the criteria for seropositivity, 371 of 3578 (10·36%) animals were found to react with one serovar. The most commonly detected serovars were pomona (5·59%) and grippotyphosa (2·37%), whilst serovar hardjo (0·75%), icterohaemorrhagiae (0·64%), poi (0·64%) and autumnalis (0·36%) were found at lower frequencies.