Leptospirosis: Public health perspectives

Leptospirosis, caused by a spirochete of genus Leptospira, is considered the most widespread zoonosis in the world. It has a global distribution with a higher incidence in the tropics and subtropics, ranging from 10 to 100 human cases per 100,000 individuals. Leptospirosis is considered an “emerging” zoonosis due to increased contact between animals and humans and the resulting human encroachment into wildlife habitat. Climate change and its associated environmental shifts can affect the degree of transmission of leptospirosis. Surveillance for leptospirosis is important for early detection of cases because early treatment is crucial to decrease morbidity and mortality. In June 2012, the Council of State and Territorial Epidemiologists approved reinstatement of leptospirosis as a Nationally Notifiable Condition. Reinstatement of national surveillance will facilitate the assessment of the incidence, geographic distribution, trends, and risk factors associated with human cases and the identification of outbreaks and potential new animal reservoirs.     

Induction of Invasive Transitional Cell Bladder Carcinoma in Immune Intact Human MUC1 Transgenic Mice: A Model for Immunotherapy Development

A preclinical model of invasive bladder cancer was developed in human mucin 1 (MUC1) transgenic (MUC1.Tg) mice for the purpose of evaluating immunotherapy and/or cytotoxic chemotherapy. To induce bladder cancer, C57BL/6 mice (MUC1.Tg and wild type) were treated orally with the carcinogen N-butyl-N-(4-hydroxybutyl)nitrosamine (OH-BBN) at 3.0 mg/day, 5 days/week for 12 weeks. To assess the effects of OH-BBN on serum cytokine profile during tumor development, whole blood was collected via submandibular bleeds prior to treatment and every four weeks. In addition, a MUC1-targeted peptide vaccine and placebo were administered to groups of mice weekly for eight weeks. Multiplex fluorometric microbead immunoanalyses of serum cytokines during tumor development and following vaccination were performed. At termination, interferon gamma (IFN-γ)/interleukin-4 (IL-4) ELISpot analysis for MUC1 specific T-cell immune response and histopathological evaluations of tumor type and grade were performed. The results showed that: (1) the incidence of bladder cancer in both MUC1.Tg and wild type mice was 67%; (2) transitional cell carcinomas (TCC) developed at a 2:1 ratio compared to squamous cell carcinomas (SCC); (3) inflammatory cytokines increased with time during tumor development; and (4) administration of the peptide vaccine induces a Th1-polarized serum cytokine profile and a MUC1 specific T-cell response. All tumors in MUC1.Tg mice were positive for MUC1 expression, and half of all tumors in MUC1.Tg and wild type mice were invasive. In conclusion, using a team approach through the coordination of the efforts of pharmacologists, immunologists, pathologists and molecular biologists, we have developed an immune intact transgenic mouse model of bladder cancer that expresses hMUC1.     

Feline immunodeficiency virus vaccine: A rational paradigm for clinical decision-making

A veterinarian must take into consideration his/her responsibility to prevent disease when assessing the needs of a client's cat that is risk for FIV infection based on its established lifestyle. Cats infected with FIV have debilitated immune functions and exhibit a high level of chronic morbidity impacting on the animal's welfare and the owner's economic abilities to maintain the pet. Attempts to reduce the prevalence of FIV solely by advising clients to maintain their cats indoors has resulted in poor compliance and not impacted on a change in infection rates with outdoor cats. Therapeutics have not impacted on outcomes in infected animals. There has a need for a vaccine for high-risk cats. Options for vaccines that do not confound the current FIV antibody test have not been efficacious against a broad spectrum of isolates. Fel-O-Vax FIV, a conventional non-marker whole virus, has shown good efficacy against heterologous challenges. The intervention should be discussed with cat owners since the vaccine has a reasonable expectation of preventing FIV infection in cats at risk without undue safety issues. Veterinarians who do not initiate this dialogue with owners who have outdoor cats in an environment where 2.5% of cats in the USA are infected may be remiss in their professional responsibilities.     

Control of the sheep blowfly in Australia and New Zealand – are we there yet?

The last 50 years of research into infections in Australia and New Zealand caused by larvae of the sheep blowfly, Lucilia cuprina, have significantly advanced our understanding of this blowfly and its primary host, the sheep. However, apart from some highly effective drugs it could be argued that no new control methodologies have resulted. This review addresses the major areas of sheep blowfly research over this period describing the significant outcomes and analyses, and what is still required to produce new commercial control technologies. The use of drugs against this fly species has been very successful but resistance has developed to almost all current compounds. Integrated pest management is becoming basic to control, especially in the absence of mulesing, and has clearly benefited from computer-aided technologies. Biological control has more challenges but natural and perhaps transformed biopesticides offer possibilities for the future. Experimental vaccines have been developed but require further analysis of antigens and formulations to boost protection. Genetic technologies may provide potential for long-term control through more rapid indirect selection of sheep less prone to flystrike. Finally in the future, genetic analysis of the fly may allow suppression and perhaps eradication of blowfly populations or identification of new and more viable targets for drug and vaccine intervention. Clearly all these areas of research offer potential new controls but commercial development is perhaps inhibited by the success of current chemical insecticides and certainly requires a significant additional injection of resources.