Prevalence of Coxiella burnetii in Hungary: Screening of Dairy Cows, Sheep, Commercial Milk Samples, and Ticks

Abstract Q fever is an important zoonotic disease caused by Coxiella burnetii. There are few reliable data about C. burnetii infection available. The aim of this study was to assess the importance and potential infectious sources of Q fever in Hungary. A total of 215 milk samples (10 individual samples from each herd and 1 bulk tank milk sample from each cattle herd), and 400 serum samples (20 from each herd) were tested from 15 dairy cattle herds and 5 sheep flocks located in different parts of Hungary. The study found 19.3% (58/300) and 38.0% (57/150) seropositivity in cattle, and 0% (0/100) and 6.0% (3/50) seropositivity in sheep, by complement fixation test (CFT) and enzyme-linked immunosorbent assay (ELISA), respectively. C. burnetii DNA was detected by IS1111 element-based TaqMan real-time polymerase chain reaction (PCR) in 8.7% (13/150) of individual dairy cow milk samples, 4.0% (2/50) of individual sheep milk samples, and 66.7% (10/15) of dairy bulk tank milk samples. Samples taken from nine different commercially-available pasteurized cow milk products from different Hungarian producers were also tested for the presence of C. burnetii DNA, and eight of these samples were found to be positive (88.9%). The real-time PCR examination of 5402 ixodid ticks collected from different parts of the country yielded negative results. Knowledge of the true prevalence of Q fever is crucial for policymakers involved in evidence-based decision making.     

Biodegradable poly(lactic-co-glycolic acid) microparticles for injectable delivery of vaccine antigens

Injectable biodegradable polymeric particles (usually microspheres) represent an exciting approach to control the release of vaccine antigens to reduce the number of doses in the immunization schedule and optimize the desired immune response via selective targeting of antigen to antigen presenting cells. After the first couple of decades of their study, much progress has been made towards the clinical use of antigen-loaded microspheres. Poly(lactide-co-glycolic acids) (PLGAs) have been studied most commonly for this purpose because of their proven safety record and established use in marketed products for controlled delivery of several peptide drugs. PLGA microspheres have many desirable features relative to standard aluminum-based adjuvants, including the microspheres' ability to induce cell-mediated immunity, a necessary requirement for emergent vaccines against HIV and cancer. This review examines several impediments to PLGA microparticle development, such as PLGA-encapsulated antigen instability and deficiency of animal models in predicting human response, and describes new trends in overcoming these important issues. PLGA microparticles have displayed unprecedented versatility and safety to accomplish release of one or multiple antigens of varying physical-chemical characteristics and immunologic requirements, and have now met numerous critical benchmarks in development of long-lasting immunity after a single injected dose.