Hepatitis A and B seropositivity among medical students.

OBJECTIVE: Health science students are commonly exposed to some infectious agents, including hepatitis A virus (HAV) and hepatitis B virus (HBV), which may cause substantial morbidity and even deaths. The identification of prevalence and risk factors is essential for implementing efficacious preventive measures. A serological survey was performed among medical students of Adnan Menderes University Medical Faculty to determine the prevalence of antibodies against HAV and HBV, and, as a secondary objective, to determine risk factors for acquisition of these infections. METHODS: Nearly all students were included in the study. All participants completed a structured questionnaire that assessed demographic and socio-economic characteristics. Anti-HAV IgG, anti-HBc IgG, HbsAg and anti-HBs were tested using commercially available Elisa kits. RESULTS: A total of 247 students, 146 (59.1%) male and 101 (40.9%) female, were included in the study. The prevalence of anti-HAV IgG was detected as 64%. Number of siblings and place of residence were detected as independent factors affecting the anti-HAV seropositivity. The prevalence of anti-HBc IgG was detected as 7.3%. Among the students positive for anti-HBc IgG, 5 (2%) students were HBsAg positive and the other 13 (5.3%) were anti-HBs positive. HBV infection in household members, risky sexual behaviour and vaccination were independent factors affecting the prevalence of anti-HBc IgG positivity. CONCLUSIONS: The high susceptibility of medical students and their increased risk of clinical HAV and HBV infection identify a need for primary prevention through the administration of vaccination in this group in western Turkey.

Neuraminidase produces dose-dependent decrease of slime production and adherence of slime-forming, coagulase-negative staphylococci.

BACKGROUND: Slime is one of the important structures of certain bacterial strains involved in nonspecific adherence. This study was conducted to determine the role of neuraminidase on slime formation and adherence of slime-forming coagulase-negative staphylococci to inert surface. METHODS: Quantitative biofilm and qualitative bacterial adherence assays were performed with increasing concentrations of neuraminidase extracted from Clostridium perfringens-treated bacteria in polystyrene plates and polypropylene tubes. RESULTS: Slime production of slime-forming, coagulase-negative staphylococci was significantly decreased dose dependently at > or =100 mU/mL (p <0.001). Bacterial adherence to smooth surface was impeded at > or =100 mU/mL of neuraminidase treatment and adherence results were comparable with slime production assay results. CONCLUSIONS: Sialic acid may be a constituent molecule of slime and involved in bacterial adherence to inert surface. These results represent new insight into the mechanism of slime production and adherence of slime-forming, coagulase-negative staphylococci to inert surface.

Effect of preventive applications on prevalence of hepatitis B virus and hepatitis C virus infections in West Turkey.

OBJECTIVE: Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are community health problems in developing countries and the most common causative agents of chronic hepatitis, cirrhosis and hepatocellular carcinoma. This study investigates the prevalence and the effect of preventive applications on prevalence of HBV and HCV infections in blood donors. METHODS: Blood donors enrolled to the University and State Hospital Blood Banks in Aydin region of Turkey through the years 1993 to 2002 were retrospectively analyzed. Blood donors were investigated in 2 groups, Group I (1993-1997) and Group II (1998-2002) to compare the prevalence difference in 10-years period. Serum hepatitis B antigen (HbsAg) and anti-HCV were tested by commercially available enzyme-linked immunosorbent assay kits and anti-HCV positive results were confirmed by recombinant immune blot assays HCV test. RESULTS: The prevalence of HBV and HCV infections was determined as 1.5% and 0.19% over the period 1993-2002. Although, the prevalence of HBV infection declined significantly in Group II (1.17%) in comparison with Group I (2.27%) (p<0.0001), there was no significant difference in both groups regarding HCV infection (p=0.238). CONCLUSION: Preventive applications against blood transfusion related diseases succeed to decrease HBV infection significantly in West Turkey. Vaccination seems to be the most effective method to prevent hepatitis infection.

Tetanus seroepidemiology and factors influencing immunity status among farmers of advanced age.

OBJECTIVES: Tetanus, which is a vaccine preventable disease, remains a significant health concern. The mortality is especially high in elderly and farming is a significant risk factor for the disease. This study evaluates the serological immunity of tetanus and the related factors, in a farmer population. METHODS: This cross-sectional study was carried out in a village located in the western part of Turkey. Volunteer farmers over the age of 50 were included in the study. The study group was determined by the systematic sampling method. IgG class tetanus antibody was measured in sera of each participant. A structured questionnaire evaluating the demographic characteristics was completed by the investigators. RESULTS: A total of 293 participants (55.3% female, 44.7% male) were recruited from March 2010 to June 2010. A serum protective tetanus antitoxin level (> 0.1 IU/ml) was detected in 99 out of 293 (33.9%) of participants. According to univariate analysis; advancing age, female gender, lower education, low monthly income, presence of chronic disease, absent or incomplete vaccination history or being unvaccinated in the last ten years were risk factors for insufficient tetanus immunity. After multiple logistic regression analysis, up-to-date vaccination, gender and age were the only factors that remained independently associated with immune status (p < 0.001). CONCLUSION: Farmers of advancing age are a population at risk for tetanus due to their work environment and their absent or incomplete immunization to the disease. Low rates of immunity detected highlight the importance to explore strategies in order to improve immunization status in this risky population.

Prevalence and risk factors for HEV infection in pregnant women.

BACKGROUND: Hepatitis E is an infectious viral disease with clinical and morphological features of acute hepatitis, clinically similar to other forms of acute viral hepatitis except in pregnant women, in whom the illness is particularly severe and has a high mortality rate. The present study was conducted in western Turkey to investigate the prevalence and risk factors for HEV infection in pregnant women. MATERIAL/METHODS: The data for the study were acquired from health centers in urban and rural areas of Aydin province, Turkey. The study design was cross-sectional. Multistage sampling was used to select the study group. Samples were tested for anti-HEV IgG by commercial ELISA test. RESULTS: A total of 386 pregnant women were included in the study. Antibodies against HEV were detected in 27 of the 386 pregnant women (7.0%). The prevalence of HEV seropositivity was significantly lower (2.5%) in women with a higher education level when compared to women with a lower education level (9.7%) (p=0.023). No significant differences were identified between seropositive and seronegative women in terms of age, source of water supply and place of residence. CONCLUSIONS: According to our results, education seems to be the only factor affecting the prevalence of HEV infection in pregnant women. The prevalence rate we found was similar to the results obtained in previous community-based studies conducted in western Turkey.

Anthrax--an overview.

Anthrax, a disease of mammals (including humans), is caused by a spore-forming Gram-positive bacilli called Bacillus anthracis. Anthrax is one of the oldest threats to humanity, and remains endemic in animals in many parts of the world. The incidence of anthrax has decreased in developed countries, but it remains a considerable health problem in developing countries. The disease is transmitted to humans by contact with sick animals or their products, such as wool, skin, meat etc. Capsular polypeptide and anthrax toxin are the principal virulence factors of B. anthracis. Anthrax toxin consists of three proteins called protective antigen, edema factor, and lethal factor, each of which is nontoxic but acts synergistically. Human anthrax has three major clinical forms: cutaneous, inhalational, and gastrointestinal. The diagnosis is easily established in cutaneous cases, characterized by black eschar. Severe intoxication and collapse during the course of bronchopneumonia or hemorrhagic enteritis should prompt suspicion of anthrax. Treatment with antibiotics is mandatory. If untreated, anthrax in all forms can lead to septicemia and death. Recently, considerable attention has been focused on the potential for B. anthracis to be used in acts of biological terrorism. The ease of laboratory production and its dissemination via aerosol led to its adoption by terrorists, as shown by recent events in the USA. A good knowledge of anthrax, its epidemiology, pathogenesis, clinical forms and potential as a biological weapon is essential for timely prevention and treatment. This review summarizes the current knowledge on anthrax.

Elimination of intraluminal colonization by antibiotic lock in catheters.

Antibiotic lock (AL) technique for catheter related infection encompasses the filling of a catheter lumen with high concentrations of antibiotics for hours. The goal of AL therapy is to decontaminate the intraluminal surface of the catheter. However the duration of antibiotic therapy is not established. An in vitro model was designed to establish the time needed to eliminate intraluminal microbial colonization and to evaluate the efficacy of vancomycin in comparison with teicoplanin by using laboratory AL model. Human plasma was instilled into the catheters to allow deposition of fibrin and other products on the catheter wall. After 48 hours, the catheters were drained and inoculated with bacteria in tryptic soy broth. The catheters were then drained and filled with either (a) vancomycin saline solution (VSS) lock (b) teicoplanin saline solution (TSS) lock or (c) saline solution (SS) as the control and then incubated for 12 hours. After 12 hours incubation all the catheter were drained and filled with human plasma. Instillation of human plasma and AL was alternated every 12 hours to simulate clinical conditions. For each day three catheters, locked with VSS, TSS and SS were cultured for colony count. Microbial counts were expressed as total colony-forming units per longitudinal centimeters of catheter surface. A significant decrease in intraluminal catheter colonization started as early as day 1. At the end of 7th day catheters treated with VSS and TSS lock were completely sterile. The decrease of intraluminal colonization was similar in catheters treated with VSS and TSS lock. Also the decrease of intraluminal colonization were similar in catheter colonized with slime forming S. epidermidis and nonslime-forming S. epidermidis.