Infections with A(H1N1)2009 influenza virus in Poland during the last pandemic: experience of the National Influenza Center.

This study presents epidemiological and clinical data on non-sentinel patients considered by physicians as suspected to be infected with pandemic A(H1N1)2009 virus, from whom clinical specimens were sent for testing to the National Influenza Center, NIPH-NIH in Warsaw, Poland. Between April 28, 2009 and August 10, 2010, 988 (15.7%) out of the 6,311 specimens were tested by the National Influenza Center, including 798 from non-sentinel sources and 190 from sentinel influenza surveillance network. The non-sentinel specimens were tested by conventional RT-PCR to detect influenza A and in the case of positive specimens - one-step real-time RT-PCR to detect the pandemic virus A(H1N1)2009. In 145 (18.2%) cases, infections with the pandemic virus were confirmed, with the highest number in patients aged 15-25. In 45% of the confirmed cases, a history of travel to other countries was registered. The most common symptoms were fever ≥38°C (72.7%), cough (50%), sore throat, and myalgia (26.1%). In 40.7% of the swabbed patients, clinical and epidemiological criteria for the novel influenza A(H1N1)2009, set by the European Commission, were met. There were, however, specimens from persons without any reasonable indication for testing for the pandemic virus, specimens collected incorrectly, and documentation without basic information. These weaknesses resulted in unnecessary costs and overload of health care units. An improvement should be achieved in the area of communication between different pandemic players in the future. More attention is also needed to ensure that requirements and recommendations are known and used.

Co-infections with influenza and other respiratory viruses.

Clinicians often do not consider the presence of more than one viral etiologic agent in respiratory infection, and in many cases they order diagnostics for influenza viruses or recently even only for A(H1N1)2009 virus. However, in a substantial number of patients with a respiratory tract disease, co-infection with various viral pathogens has been confirmed. Although the association between the occurrence of co-infection and substantially higher severity of disease is still unclear, a rapid and proper diagnostics of wide spectrum of viral respiratory pathogens reveals an accurate picture of the disease and is essential for appropriate therapeutic management and control of infection. In the present study we reported five cases of multiple respiratory infection in hospitalized immunosuppressed patients: two double infections with influenza virus (IV) type A/respiratory syncytial virus (RSV) type A and IV type A/coronavirus (CoV) OC43, one infection with four viruses - IV type A/RSV type A and B/CoV OC43, and two cases of mixed infections caused by five viral agents - IV type A and B/RSV type A and B/ parainfluenza type 3 or CoV OC43. Each patient had an underlying chronic disease and received immunosuppressive treatment. Despite a low number of tested specimens, our study shows that the inclusions of multiplex PCR methods for diagnostics of respiratory tract infections and the extension of diagnostic strategies by clinicians to detect viruses other than influenza are very important and make a contribution to identifying the true rate of co-infections and their correlation with the clinical symptoms and severity of disease.

Survival of Corynebacterium pseudotuberculosis within macrophages and induction of phagocytes death.

Since C. pseudotuberculosis is a facultative intracellular pathogen the aim of this study was focused on evaluating mechanisms that allowed these bacteria to survive in macrophages and determining their influence on induction of cell death. The influence of Corynebacteria on the programmed cell death of macrophages was determined on the basis of induction the autophagy and apoptosis in the cultures of murine macrophage cell lines J774 infected with bacteria. Corynebacterium pseudotuberculosis strains could survive within macrophages more than 48 hours. During that time bacteria were released as a result of the process that lead to death of phagocytes. This property varied among studied strains. There was no increase of microtubule-associated protein I light chain 3 (MAP I LC3) activity in macrophages infected with examined strains comparing with uninfected cultures and cultures treated with autophagy inducer (rapamycin) that served as negative and positive controls, respectively. The study with confocal microscopy did not show the increasing of caspase-3 activity in the infected macrophages and their nucleus did not reveal the fragmentation.

Epidemiological features of Morel's disease in goats.

Morel's disease caused by Staphylococcus aureus subsp. anaerobius was diagnosed for the first time in Poland in October 2006 in a goat flock. A second infected flock was found two months later. The course of the disease in both flocks was observed for 15-17 months. Clinical manifestation was confined to abscesses located near major superficial lymph nodes, mostly: superficial cervical, subiliac, parotid and mandibular. At necropsy no other lesions were found. The incubation period was estimated at 3 weeks. Clinical signs were seen both in young and adult goats and up to 7 abscesses in one animal were noted. Abscesses tended to persist for 1 to 5 months, then rupture and heal completely. The initial high in-flock point prevalence in both flocks (93.6% and 84.4%) dropped to approximately 10-30% during next 3-4 months. Until the end of the observation period the in-flock point prevalence remained at this level and only single abscesses were observed, mainly in young animals. No influence of the concurrent caprine arthritis encephalitis virus (CAEV) infection on the clinical course of Morel's disease was noticed. It is to be concluded that the clinical course of Morel's disease in a goat flock resembles caseous lymphadenitis (CLA). However, in Morel's disease abscesses occur more frequently in young goats and are located near, not inside, the lymph nodes, as in the case with CLA. Also, the incubation period of Morel's disease seems to be shorter (3 weeks versus 2-6 months in CLA).