Seroprevalence and social determinants of varicella in Turkey.

BACKGROUND: In Turkey, varicella vaccine was introduced into routine childhood immunization in 2013, with a single dose administered to children aged 12 months. However, there is limited information on the morbidity (incidence and seroprevalence), mortality and burden of disease of varicella in the overall Turkish population. AIM: To determine varicella seroprevalence and its social determinants in Manisa Province, Turkey in children aged > 2 years before single-dose varicella vaccination was introduced in 2013. METHODS: The presence of anti varicella-zoster virus IgG antibodies was determined using enzyme-linked immunosorbent assay in serum samples collected from 1250 participants. RESULTS: The overall seroprevalence was 92.8% and the seroprevalence was > 90% among all age groups except 2-9 years (55.7%). Seroprevalence was significantly associated with family size, annual per capita equivalent income, number of people per room and education level. After adjusting by age, only education level remained significantly associated with seroprevalence, reflecting the early age effect. CONCLUSION: High seroprevalance depends on natural exposure to the infectious agent itself and is not associated with social determinants. High vaccine coverage should be maintained for effective varicella control and switching to a 2-dose schedule may also be considered to reduce the number and size of outbreaks in the Turkish population.

[Seroprevalence of pertussis toxin antibody in Manisa province of Turkey, after six years implementation of acellular pertussis vaccine]. / Hücre içermeyen bogmaca asi uygulamasinin altinci yilinda Türkiye'nin Manisa ilindeki pertussis toksin antikoru seroprevalansi.

Vaccination is the most effective way of preventing pertussis disease. Turkey commenced a routine infant immunization program using whole cell (wP) pertussis vaccine in 1968. Immunization accelerated in 1985 after participation of Turkey in the Expanded Programme on Immunization initiated by the World Health Organization. Acellular vaccine (aP) replaced wP in 2008 and a booster was added to age 6 in 2010. The immunization programme was successful in reducing the morbidity rate from 20.58 per 100.000 in 1970 to the lowest level of 0.01 per 100.000 in 2009. However, reduction of vaccine-induced protection and reduced natural boosting of circulating Bordetella pertussis are likely to increase the susceptibility of the population. As a result, morbidity rate increased from 0.09 per 100.000 to 0.41 per 100.000 in 2015 compared to the previous year. The aim of this epidemiological study was to determine the seroprevalence of pertussis toxin (PT) antibodies among healthy people and its association with various social determinants in Manisa province in Turkey, 6 years after aP replaced wP vaccine. The study was conducted as a cross-sectional study with a sample of 1250 people that was randomly selected from the over 2 years of age population in Manisa in 2014. Seroprevalence of PT antibody was determined as the dependent variable of the study. Independent variables of the study were; gender, age, migration in the last 5 years, occupational class, perceived income, house ownership, number of people per room, annually per capita equivalent income. The presence of anti-PT IgG was detected by quantitatively using a commercially available ELISA kit. The antibody levels were categorized into groups according to pertussis infection or vaccination immune response status. The groups consisted of undetectable (< 5 IU/ml), mid-range (5-< 62.5 IU/ml: more than one year previously), high (62.5-< 125: with in 12 months) and very high (≥ 125 IU/ml: with in 6 months) antibody levels. The test results with ≥ 5 IU/ml were defined as seropositive. Level > 100 IU/ml detected among adolescent and adult participants indicated acute or recently recovered pertussis infection. Chi-square test was used to evaluate association between social determinants and pertussis seropositivity. The seroprevalence of the whole study population was 58.1% (95% CI 55.32-60.79) and no association was found with any of the social determinants. The highest seroprevalence was found among 2-9 age group (68.3%) followed by 70-79 age group (63.5%). The lowest seroprevalence was found among 20-29 age group (50.9%) followed by 10-19 age group (51.6%). When seropositivity levels according to ages were compared, it was found that there was a decrease one year after the first vaccination at 2nd, 4th and 6th months and the booster at the 6th year, with a lowest rate (19%) in 11 year-old. The highest seropositivity (77.3%) with a level of >100 IU/ml (13.6%) were detected at age 15 among all adolescent and adult participants. Adding an adolescent booster to immunization schedule and recommendation of vaccine to elderly people should be considered to reduce the incidence of pertussis disease in Turkey.

[Atypical profile problem in serological diagnosis of EBV]. / EBV serolojik tanisinda atipik profil sorunu.

Epstein-Barr virus (EBV) is the causative agent of infectious mononucleosis. Burkitt's lymphoma, nasopharyngeal carcinoma and post-transplant lymphoproliferative diseases are also associated with EBV. Diagnosis is frequently based on detection of specific antibodies. Using three parameters (anti VCA-IgM, anti VCA-IgG and anti EBNA-1 IgG), it is possible to define infection status and diagnose acute or past infection. However, sometimes the detection of atypical serological profiles makes it difficult to interpret these results. This study aims to evaluate the serological profiles of patient sera suspected of EBV infection and to determine atypical profiles. Sera of 2749 patients were analyzed between January 2014 and August 2016, in the Dokuz Eylul University Hospital Central Laboratory and evaluated retrospectively. Serum samples were tested for EBV VCA IgM and EBV VCA IgG antibodies with immunofluorescence test (Euroimmun, Germany), EBNA-1 IgG antibodies with enzyme immunoassay (Euroimmun, Germany). Medical files of the patients with two or more samples and have an atypical profile were reviewed. Patients were grouped as no EBV infection, acute infection, past infection and atypical serologic profile according to three routine laboratory assays (VCA IgG, VCA IgM and EBNA-1 IgG). Out of 2794 subjects 1334 (48.5%) were female and 1415 (51.5%) were male, with mean age 30 (< 1-89 years, median value: 27). The distribution of the results was; 72.5% past infection, 10.9% absence of EBV infection and 5.2% acute infection and 11.4% showed atypical serologic profile. Among the atypical profiles, isolated VCA-IgG positivity was the most frequent pattern detected in 7.9% which is followed by 2.7% of the cases with all three markers positive and 0.8% with isolated EBNA-1 IgG positivity. Off the patients, 72.5% were seropositive for EBV and this result is consistent with the seroprevalence studies previously conducted in Turkey. The rate of atypical profiles was 11.4% which is close to the result (15%) of another study performed in Izmir. Nearly one third of the patients with atypical serological profile had an immune disorder and it was possible to reach a conclusion only among half of the patients during serological follow-up. This study points out that clinical diagnosis and serologic follow-up is important for the interpretation of the atypical profiles.

Ceftazidime-avibactam resistance determination in carbapenem-resistant Klebsiella pneumoniae infections before its use in practice.

INTRODUCTION: To ensure the appropriate usage of ceftazidime-avibactam (CAZ-AVI), recently introduced in our hospital, we aimed to determine susceptibility rates, enzyme analysis, and clonal relationship among strains, together with clinical data. METHODOLOGY: Between June 1 and September 30, 2021, demographic and microbiological data of the patients were recorded. In the obtained samples, meropenem and colistin minimal inhibitory concentration (MIC) levels, carbapenem resistance genes, and the clonal relationship were studied by molecular methods. CAZ-AVI was not used in any of the patients. RESULTS: 140 carbapenem-resistant Klebsiella pneumoniae were isolated from 57 patients. Resistance to CAZ-AVI was found in 76 (54.3%) strains. Out of 57 patients, 31 (54.4%) isolates could be reached. Meropenem MIC level was ≥ 32 µg/mL in 26 (83.9%), and colistin MIC level was ≥ 4 µg/mL in 17 (54.8%) isolates. Enzyme analysis revealed NDM in 20 (64.5%), OXA-48 in 17 (54.8%), and KPC in seven (22.6%). NDM + OXA-48 was determined in 10 (32.2%) strains. NDM was determined in all CAZ-AVI resistant strains, OXA-48 in 16.1% (2/5) strains. Seven genotypes were detected. The largest cluster was genotype 3 clusters (11 isolates). Of 31 patients, 22 (71.0%) died. CAZ-AVI was susceptible in one of the patients who survived and four who died. CONCLUSIONS: Before using a new antibiotic, each center should determine the basal data and phenotypic/genotypic resistance ratios specific to that antibiotic. While a high NDM rate and low CAZ-AVI sensitivity limit the use of the drug in our center, it is clear that CAZ-AVI use in sensitive strains will decrease mortality.

Value of rapid antigen test for pandemic influenza A (H1N1) 2009 in the pediatric emergency department.

OBJECTIVE: Pandemic H1N1 influenza is the predominant influenza virus circulating in Turkey in 2009. Because of the clinical manifestations of influenza overlap with those attributable to other common respiratory illnesses of childhood, establishing a diagnosis of influenza requires confirmatory testing. The aim of our study was to define the predictive value of rapid influenza antigen detection test in children presenting to a pediatric emergency care department with influenza-like illness and to compare with clinical signs and symptoms. METHODS: From October to November 2009, 3646 patients presented with influenza-like illness to the pediatric emergency department. Influenza-like illness is defined as fever with cough or sore throat in the absence of a known cause other than influenza. Enrollment criteria included fever and at least one of the following symptoms: coryza, cough, headache, sore throat, or myalgia. All 322 enrolled patients received a nasal wash for rapid influenza diagnostic tests, and the results were compared with clinical signs. RESULTS: Rapid influenza detection test result was found positive in 167 (51.9%) of 322 patients. Clinical findings included fever as the presenting complaint (100%), fever (≥38 °C) (93.4%), cough (91.3%), rhinorrhea (66.1%), sore throat (35.1%), vomiting-diarrhea (22.4%), myalgia (20.2%), headache (18%) and shortness of breath (12.1%). There were 211 patients (65.5%) at high risk for the development of complications of pandemic H1N1 influenza A such as chronic lung disease (asthma) (n = 103, 48.8%), age younger than 2 years (n = 78, 37%), and neurologic disease (n = 10, 4.7%). The positivity rate and sensitivity of the test increase up to 70% in patients, who had the high body temperature (≥39 °C). The rapid test achieved the highest sensitivity in patients, who have high fever (≥39 °C), myalgia, vomiting, and diarrhea. CONCLUSIONS: We found that if the patients have high fever (≥39 °C), myalgia, and vomiting-diarrhea together, the likelihood of rapid antigen test positivity rate increases in patients, who presented with influenza-like illness.

West Nile Virus Seroprevalence in Manisa Province: A Population-based Study.

Objective: West Nile Virus (WNV), which causes widespread outbreaks in different parts of the world, is a risk to public health in Turkey, too. Community-based study data are needed to identify measures against possible outbreaks. This study aimed to determine the seroprevalence of community-based WNV in Manisa and to investigate the relationship between sociodemographic and socioeconomic variables. Methods: We included individuals older than two years of age (N=1,317,917) registered in the Manisa Province Family Medicine Information System. Selected participants (n=1233) were determined by a simple random sampling method. Specific IgG antibodies against WNV were investigated in serum samples using a commercial ELISA test (Euroimmun, Germany). The relationship between age, gender, location, education and income level, occupation, population density, altitude, the location of the toilet in the house, and the presence of hypertension, diabetes mellitus and cardiovascular disease variables were analyzed by chi-square, Fisher's exact test and t-test. Adjusted odds ratio (OR) with95% confidence interval (CI) for each variable were calculated by the logistic regression method to explain potential risks. Results: WNV IgG antibodies were detected in 47 (3.8%) sera samples by ELISA. Seroprevalence was significantly correlated with independent variables of advanced age, presence of hypertension, diabetes mellitus and cardiovascular disease, low level of education and income, living in low altitude areas and the location of the toilet. In multivariate analysis; age (every one-year increase) (OR:1.05; 95% CI:1.02-1.07; p <0.001), equivalent annual income per capita below 3265 TL (OR:3.21; 95% CI: 1.53-6.73; p=0.002), and living areas below 132 meters altitude (OR=3.21; 95% CI 1.26-8.15; p=0.014) were found to be the risk factors for WNV seropositivity. Conclusion: In Manisa province, WNV IgG seroprevalence was detected as 3.8% with ELISA method. Older age, low income and living in regions with a low altitude were found to be associated with increased seropositivity significantly.

[Inappropriately ordered tests from hepatitis B vaccinated subjects]. / Hepatit B asili kisilerden gereksiz test istekleri.

Laboratory testing for viral hepatitis B constitutes a vast burden regarding the cost and the workload for health care system for many countries including ours. There are several reports stating that the cost in question is not always necessary. As a consequence of larger scale vaccination programmes, an increase in unnecessary hepatitis B testing is expected in vaccinated individuals. The present retrospective study aims to determine the rate of inappropriately ordered tests from vaccinated individuals and to discuss the causes and possible solutions of this problem. Laboratory records of 56.349 subjects admitted to Dokuz Eylul University Hospital, Izmir, during 2007 and 2009, were evaluated retrospectively for hepatitis B serological test results. Unnecessary testing was defined as the requests for HBsAg, anti-HBc, anti-HBc IgM, HBeAg and anti-HBe tests from those who had positive anti-HBs and negative anti-HBc results. The cost burden was calculated by taking account the prices recommended by the Department of Social Security. The appropriateness of anti-HBs test orders were not taken into evaluation since specific clinical conditions (immune response disorders, HIV infection, chronic hemodialysis, newborns of HBsAg positive mothers, contact with HBsAg carriers) were not clarified. It was found that among the 17.869 samples tested for both anti-HBs and anti-HBc, 4402 (24.6%) were ordered from subjects who were vaccinated against hepatitis B virus (anti-HBs positive, anti-HBc negative status). Thus, 11.405 (12.9%) tests out of a total of 88.174 hepatitis B tests (HBsAg, anti-HBc, anti-HBc IgM, HBeAg, anti-HBe) were unnecessarily ordered. Social security services and/or individuals paid approximately 59.000 USD for these unnecessary tests in three years, leading to an economic loss of approximately 20.000 USD yearly. Providing appropriate feedback to clinicians and reflex test application (to order a test according to the results of previous tests in accordance to diagnostic test algorithms) were considered to be useful in prevention of the problem.

Macrolide resistance determinants in erythromycin-resistant Streptococcus pneumoniae in Turkey.

To determine the major molecular mechanisms of macrolide resistance among Streptococcus pneumoniae isolates in Turkey, we examined a total of 151 isolates collected from different regions of Turkey. Overall, 40 (26.4%) isolates were resistant to erythromycin. The most common mechanism (38/40) was target site modification due to erm (B) genes. Only two isolates harbored the mef (A)/(E) efflux gene. A clonal spread of resistant strains could not be demonstrated by BOX-polymerase chain reaction. The results from this study have shown that the erm (B) gene is predominant in Turkish S. pneumoniae isolates, as in isolates from the rest of the world, and a clonal dissemination is not responsible for this resistance profile.

Risk of infection in health care workers following occupational exposure to a noninfectious or unknown source.

BACKGROUND: The major concern after occupational exposures is the possible transmission of blood-borne pathogens, especially hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). This study was undertaken to evaluate the risk of infection after exposure to blood or body fluids of an unknown or an HBV-, HCV-, and HIV-negative source and to determine the epidemiologic characteristics of these incidents in health care workers. METHODS: The survey was conducted over a 6-year period at a university hospital in Turkey, using a questionnaire to elicit demographic and epidemiologic information. Serologic tests for HBV, HCV, and HIV were performed and repeated after 3 months. RESULTS: Of the 449 incidents, complete follow-up was achieved in 320 (71.3%), and no seroconversion was observed for HBV, HCV and HIV. Most of the incidents occurred in medical (34.7%) and surgical (25.4%) work areas. The most frequent type of exposure was percutaneous injury (94%), most commonly caused by handling of garbage bags (58.4%), needle recapping (16.5%), and invasive interventions (13.4%). CONCLUSION: Infection risk seems to be extremely low for HCV and HIV, because of low endemicity, and for HBV in groups immunized against HBV.