Comparison of in-house biotin-avidin tetanus IgG enzyme-linked-immunosorbent assay (ELISA) with gold standard in vivo mouse neutralization test for the detection of low level antibodies.

BACKGROUND: Detection of anti-tetanus antibody levels is necessary for both determination of the immune status of individuals and also for planning preventive measures. ELISA is the preferred test among in vitro tests however it can be affected by the cross reacting antibodies. A previously developed in-house ELISA test was found not reliable for the antibody levels ≤1.0IU/ml. A new method was developed to detect low antibody levels correctly. The aim of the present study was to compare the results of the newly developed in-house biotin-avidin tetanus IgG ELISA test with the in vivo mouse neutralization test, for the antibody levels ≤1.0IU/ml. METHODS: A total of 54 serum samples with the antibody levels of three different levels, =0.01IU/ml, 0.01-0.1IU/ml, 0.1-1IU/ml, which were detected by in vivo mouse neutralization test were studied by the newly developed in-house biotin-avidin tetanus IgG ELISA test. Test was validated by using five different concentrations (0.01IU/ml, 0.06IU/ml, 0.2IU/ml, 0.5IU/ml, 1.0IU/ml). RESULTS: A statistically significant correlation (r2=0.9967 p=0,001) between in vivo mouse neutralization test and in-house biotin-avidin tetanus IgG ELISA test, was observed. For the tested concentrations intra-assay, inter-assay, accuracy, sensitivity, specificity and coefficients of variations were determined as ≤15%. CONCLUSION: In-house biotin-avidin tetanus IgG ELISA test can be an alternative method to in vivo mouse neutralization method for the detection of levels ≤1.0IU/ml. By using in-house biotin-avidin tetanus IgG ELISA test, individuals with non protective levels, will be reliably detected.

Ureaplasma urealyticum: Presence among Sexually Transmitted Diseases.

The aim of this study was to detect the presence of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Mycoplasma hominis, Trichomonas vaginalis, and Ureaplasma urealyticum in genital specimens of symptomatic patients. This study also examined the role of U. urealyticum in infections of the lower genital tract. Cervical and urethral samples from 96 patients (46 males, 50 females) were tested using the Seeplex(®) STD6 ACE kit. Consent forms were received and a questionnaire was applied. All statistical analyses were performed using the SPSS statistical software program (version 17.0). Among the samples tested, at least 1 pathogen was detected in 49% of the samples; specifically, the rate of detection of U. urealyticum, M. hominis, C. trachomatis, N. gonorrhoeae, M. genitalium, and T. vaginalis was 29.1%, 10.4%, 8.3%, 7.3%, 6.3%, and 4.2%, respectively. U. urealyticum was detected as the sole pathogen in samples from 10% of female patients and 28.3% of male patients (p = 0.035). U. urealyticum was present in 54.5% (18/33) of samples in which a single pathogen was detected and 71.4% (10/14) of samples in which multiple pathogens were detected. Among men, significant differences in discharge, dysuria, and pruritus were not noted among those with negative results (84.6%, 69.2%, and 38.5%, respectively), among those positive for only U. urealyticum (100%, 66.7%, and 26.7%, respectively), and those positive for N. gonorrhoeae, C. trachomatis, M. genitalium, and T. vaginalis (100%, 93.3%, and 26.7%, respectively). Detection of U. urealyticum, either alone or together with other pathogens, in a symptomatic group of patients is an important finding, particularly in men.

[Serological evaluation of Bordetella pertussis infection in adults with prolonged cough]. / Uzamis öksürügü olan eriskinlerde Bordetella pertussis enfeksiyonunun serolojik olarak degerlendirilmesi.

Pertussis is a vaccine-preventable disease that is transmitted from infected to susceptible individuals by respiratory route. Bordetella pertussis infection may occur at any age as neither vaccine nor natural infection induced immunity lasts life-long. This study was planned to demonstrate the serological evidence of infection among adults, to raise awareness among clinicians and to provide data for the development of strategies to protect vulnerable infants. A total of 538 patients (345 female, 193 male) ages between 18-87 years who had a complain of prolonged cough for more than two weeks were included in the study. Anti-pertussis toxin (PT) IgG and anti-filamentous hemagglutinin (FH) IgG levels from single serum samples were measured by an in-house ELISA test which was standardized and shown to be efficient previously. Anti-PT IgG antibody levels of ≥ 100 EU/ml were considered as acute/recent infection with B.pertussis. In our study, 9.7% (52/538) of the patients had high levels of anti-PT IgG (≥ 100 EU/ml) and among those patients 43 (43/52; 82.7%) also had high (≥ 100 EU/ml) anti-FHA IgG levels. There were no statistically significant differences in terms of age, gender, education level, DPT (diphtheria-pertussis-tetanus) vaccination history, smoking history or average daily cigarette consumption (p> 0.05) between the cases with high antibody levels (n= 52). When the symptoms and the presence of cases with high antibody levels were evaluated, it was detected that no one parameter was significantly different from others, except that 24.1% of the cases with inspiratory whooping had high anti-PT levels. There was also no statistically significant difference between high anti-PT levels ≥ 100 EU/ml and the patients with risk factors [smoking (21/200; 10.5%), presence of disease that cause chronic cough and/or drug usage (19/171; %11.1), and whole factors which cause chronic cough (32/306; %10.5)] and without risk factors (p= 0.581; p= 0.357; p= 0.249, respectively). The distribution of anti-PT IgG geometric mean titer (GMT) according to the age groups, was as follows; 32.41 in 18-30 years; 36.28 in 31-50 years; 36.82 in 51-70 years and 31.15 in ≥ 71 years. Our results indicated that B.pertussis infections are also present among adult population with a frequency not to be underestimated (9.7%) and the results also emphasized that since typical whooping cough symptoms may not be seen in adults, pertussis infection should be considered as a differential diagnosis in adults with prolonged cough, even if there are some other underlying factors of cough. The data obtained from this study was also considered to be helpful in the development of adult vaccination policies for the protection of infants who have not completed the vaccination schedule yet.

Comparative analysis of phenotypic and genotypic detection of methicillin resistance among Staphylococcus aureus.

AIMS: Staphylococcus aureus is a common pathogen causing a wide range of infections ranging from mild skin and soft tissue infections to severe, life-threatening infections. Accuracy in the detection of methicillin resistance is important to avoid treatment failures. The aim of this study was to compare the results of phenotypic and genotypic test methods to detect methicillin resistance and also to determine the antimicrobial susceptibilities. MATERIALS AND METHODS: Two hundred and forty-two S. aureus strains isolated from skin and soft tissue samples were analyzed for methicillin resistance using oxacillin and cefoxitin disk diffusion (DD), oxacillin screen agar test, cefoxitin E-test, and mecA gene polymerase chain reaction (PCR). RESULTS: 77 of 242 S. aureus isolates were mecA positive. Oxacillin, cefoxitin DD, oxacillin screen agar test and cefoxitin E-test exhibited sensitivities as 98.7%, 98.7%, 100%, 100%, and specificities as 96.9%, 97.5%, 96.9%, 97.5%, respectively. CONCLUSION: Results of oxacillin screen agar and cefoxitin DD test were in concordance with mecA gene PCR. Thus, it is determined that especially cefoxitin test can be an alternative to PCR in routine.

[Evaluation of antibiotic susceptibilities and VISA-VRSA rates among MRSA strains isolated from hospitalized patients in intensive care units of hospitals in seven provinces of Turkey]. / Türkiye'de Yedi Ildeki Hastanelerin Yogun Bakim Ünitelerinden Izole Edilen MRSA Suslarinda VISA-VRSA Arastirilmasi ve Antibiyotik Duyarlilik Durumlarinin Saptanmasi

The aim of this study was to determine whether vancomycin resistant Staphylococcus aureus (VRSA) and vancomycin intermediate susceptible S.aureus (VISA) strains were present among methicillin-resistant S.aureus (MRSA) strains isolated from patients hospitalised at intensive care units (ICU) of hospitals located at different regions of Turkey and to determine the minimum inhibitory concentration (MIC) values of teicoplanin, linezolid, tigecycline, quinupristin-dalfopristin and daptomycin, which are alternative drugs for the treatment of MRSA infections. A total of 260 MRSA clinical strains (isolated from 113 lower respiratory tract, 90 blood, 24 wound, 17 catheter, 13 nasal swabs, two urine and one CSF sample) were collected from nine health-care centers in eight provinces [Ankara (n= 52), Konya (n= 49), Antalya (n= 40), Istanbul (n= 7), Izmir (37), Diyarbakir (n= 15), Van (n= 12), Trabzon (n= 48)] selected as representatives of the seven different geographical regions of Turkey. Methicillin resistance was determined by cefoxitin disk diffusion in the hospitals where the strains were isolated and confirmed by oxacillin salt agar screening at the Refik Saydam National Public Health Agency. Screening for VISA and VRSA was conducted using the agar screening test and E-test. Susceptibility of the MRSA strains to other antibiotics was also determined by E-test method. None of the 260 MRSA strains were determined to be VRSA or VISA. All were susceptible to teicoplanin and linezolid, and susceptibility rates to daptomycin, tigecycline and quinupristin-dalfopristin were 99.6%, 96.9%, and 95%, respectively. Absence of VISA and VRSA among the MRSA strains surveyed currently seemed hopeful, however, continuous surveillance is necessary. In order to prevent the development of VISA and VRSA strains the use of linezolid, tigecycline, quinupristin-dalfopristin and daptomycin should be encouraged as alternative agents of treatment of MRSA infections.

[The presence of extended spectrum beta-lactamase, KPC-type carbapenemase and plasmid-mediated AmpC beta-lactamase in E.coli and K.pneumoniae strains isolated from blood cultures]. / Kan Izolati E.coli ve K.pneumoniae Suslarinda Genislemis Spektrumlu Beta-Laktamaz, KPC-Tip Karbapenemaz ve Plazmid Aracili AmpC Beta-Laktamaz Varliginin Arastirilmasi

The aim of this study was to investigate the presence of extended spectrum beta-lactamase (ESBL), KPC-type carbapenemase and plasmid-mediated AmpC beta-lactamase (pAmpC) which have increased in incidence in recent years in Escherichia coli and Klebsiella pneumoniae strains isolated from the blood samples causing serious infections. Ninety nine E.coli and 114 K.pneumoniae strains which were isolated from the blood samples of patients admitted to Hacettepe University Medical Faculty, Ihsan Dogramaci Children's Hospital between January 2001 and March 2009 were investigated. The screening tests for ESBL, pAmpC beta-lactamase and KPC-type carbapenemase were performed on the same plate. Combined disk test was performed for ESBL and modified Hodge test was done for KPC-type carbapenemase confirmation according to Clinical and Laboratory Standards Institute (CLSI) guidelines. In addition the inhibitory-based test with boronic acid for KPC-type carbapenemase, pAmpC beta-lactamase and the modified Hodge test for pAmpC beta-lactamase were performed. Boronic acid inhibition test was performed to detect the co-presence of the three types of resistance. The frequency of the beta-lactamases in E.coli and K.pneumoniae isolates were as follows respectively: ESBL 26.2% and 61.4%; pAmpC 1% and 0.9% and ESBL + pAmpC 6% and 3.5%. ESBL was masked by pAmpC in an isolate. Ertapenem resistance was shown in three isolates and KPC-type carbapenemases were detected positive by the inhibitory- based test with boronic acid but found to be negative by the modified Hodge test. The results of modified Hodge test was considered valid according to CLSI comments. Since both ESBL and pAmpC were positive but modified Hodge test was negative in these three strains, ertapenem resistance was attributed to another mechanism. For the determination of ESBL and pAmpC beta-lactamases in the routine laboratory, reliable and sensitive susceptibility tests should be performed. The inhibitory-based test with boronic acid is easy for interpretation, and a practical method for the detremination of pAmpC beta lactamases. For KPC-type carbapenemases modified Hodge test which has been standardized by CLSI, is a reliable method. The results of this study showed that ESBL positivity rates are alarming and although the frequency of pAmpC is currently low, it is increasing together with ESBL. These data indicated the need for the establishment of urgent measures to control the increase in plasmid-mediated antibiotic resistance in gram-negative enteric bacteria.

[Seroprevalence of Borrelia burgdorferi and tick-borne encephalitis virus in a rural area of Samsun, Turkey]. / Samsun Kirsalinda Borrelia burgdorferi ve Kene Ensefaliti Virusu Seroprevalansinin Arastirilmasi

Lyme disease or lyme borreliosis is a zoonosis caused by Borrelia burgdorferi transmitted by ticks, especially Ixodes species. Lyme borreliosis is a multi-systemic disease that invades the skin, musculoskeletal, cardiovascular and central nervous systems. Tick-borne encephalitis (TBE) is an important arboviral infection caused by tick-borne encephalitis virus (TBEV). The central nervous system is affected and the disease most often manifests as meningitis, encephalitis or meningoencephalitis. Previous studies have shown that B.burgdorferi and TBEV can be transmitted by the same tick species (Ixodes ricinus). Although the geographic location and climate is similar to some south-eastern European countries where lyme borreliosis and TBE have been reported, the incidence and prevalence of these diseases in Turkey still remain unclear. The aim of this study was to determine the seroprevelance of B.burgdorferi and TBEV in healthy population in Tekkeköy (41° 8-13' North; 36° 24-31' East), a district of Samsun province, Turkey with evidence of tick-borne disease and to explore the possible correlations of life styles of healthy individuals and prevelance. The cross-sectional study population included 419 people selected using a random proportional sampling method. All participants were asked at interview to complete a questionnaire and peripheral blood samples were collected. From the blood samples, B.burgdorferi IgG and IgM antibodies were evaluated using commercial ELISA (Euroimmun, Germany) and confirmed with Western blot (WB, Euroimmun, Germany). ELISA method was also used to asses IgM and IgG antibodies against TBEV, and neutralization test was used for confirmation. Of the 419 samples, 17 (4%) were positive for B.burgdorferi IgG by ELISA, however 14 (14/419; 3.3%) of them were confirmed by WB. B.burgdorferi seropositivity was higher among people living in rural areas, at an altitude of ≥ 400 meters and in locations ecologically suitable for wild boar and rabbits; seropositivity was also seen to be higher among dog owners (p= 0.001, p= 0.001, p= 0.001, p= 0.001, p= 0.018, respectively). For TBEV, two samples yielded IgG positive, and one IgM positive results by ELISA, however none of them were confirmed by neutralization assay. Nevertheless, one of those three TBEV ELISA positive samples, was found positive for West Nile virus specific antibodies with neutralization test. The results of this study emphasized the presence of tick-borne diseases in that specific region, and in this regard the need for public health interventions has been demonstrated.

Panton-Valentine leucocidin gene carriage among Staphylococcus aureus strains recovered from skin and soft tissue infections in Turkey.

OBJECTIVES: Regardless of methicillin resistance, Panton-Valentine leucocidin (PVL)-positive Staphylococcus aureus isolates are associated with various types of infections and outbreaks. Limited data exist about the PVL content of S. aureus strains in Turkey. In this multicentre study, we aimed to assess the PVL positivity and antimicrobial susceptibilities of S. aureus isolates recovered from skin and soft tissue samples of both community and nosocomial origin in the study period, 2007-08. METHODS: Two hundred and forty-two [92 community-acquired (CA) and 150 hospital-acquired (HA)] isolates were included in the study. Analysis of mecA and PVL was carried out using PCR. All isolates underwent susceptibility testing according to the CLSI. RESULTS: Out of 242 isolates, 77 were mecA positive. PVL was not found among methicillin-resistant S. aureus (MRSA) isolates, but 8 (5.3%) HA methicillin-susceptible S. aureus (MSSA) and 14 (15.2%) CA-MSSA, mostly isolated from furuncles (71.4%), were positive for PVL. Among PVL-positive strains, the penicillin resistance rate was 90.9%. Low resistance rates, <10%, were detected for erythromycin, fusidic acid and co-trimoxazole. PVL-positive strains showed higher rates of susceptibility to erythromycin, gentamicin and rifampicin than negative isolates. CONCLUSIONS: Based on the findings of this study, infection related to PVL-carrying CA-MRSA is not at an alarmingly high level, but population-based surveillance studies should be done to determine the real status.

[Development and optimization of an in-house PCR method for molecular diagnosis of pertussis]. / Bogmacanin Moleküler Tanisi Için Laboratuvar Yapimi Bir PCR Yönteminin Gelistirilmesi ve Optimizasyonu.

Pertussis (whooping cough), caused by Bordetella pertussis is a severe, acute contagious disease of the respiratory system and it affects mostly children and also susceptible individuals of all ages. Although the conventional culture method used for diagnosis is highly specific, it has a lower sensitivity. Therefore, there is a need for a sensitive, specific and rapid method for diagnosis of pertussis. Polymerase chain reaction (PCR), introduced recently as a new approach for diagnosis of pertussis, has been shown to be more sensitive than culture method. Pertussis toxin gene (ptxA-Pr), insertion sequence genes (IS481 and IS1001), adenylate cyclase genes and structural porin and flagellin genes were chosen as targets for PCR, in different studies. This study aimed to develop and optimize a diagnostic inhouse PCR method by using primers specific for ptxA-Pr and IS481 gene regions. An in-house PCR method was developed by using primer pairs of PTp1/PTp2 specific for ptxA-Pr gene and PIp1/PIp2 specific for IS481 gene and DNAs of various bacterial reference strains. Throat samples obtained from 45 healthy individuals and B.pertussis reference strain with decreasing concentrations were mixed to constitute a group of "representative clinical samples" and used to test and optimize sensitivity and specificity of the method. The in-house PCR with PTp1/PTp2 primers showed a very high specificity but a low sensitivity with a value of 34.4 cfu/Rm (colony forming unit/reaction mixture). Whereas, the inhouse PCR with PIp1/PIp2 primers exhibited a low specificity due to cross-reactivity with B. Pertussis and B.bronchiseptica but much higher sensitivity with a value of 1.12 cfu/Rm. The experiments performed with the representative clinical samples yielded similar results. Simultaneously applied cultivation studies indicated the detection limit of the PCR method as 2 x 103 cfu/ml. Based on our results, the PCR targeting IS481 gene had high sensitivity while the PCR targeting ptxA-Pr gene had high specificity. It was concluded that, PCR method targeting the IS481 gene might be used for pre-diagnosis and then PCR for ptxA-Pr gene might be applied for the confirmation of B.pertussis in the molecular diagnosis of pertussis.

[Comparison of conventional methods and real-time multiplex polymerase chain reaction for identification and typing of Brucella isolates of human origin]. / Insan Kaynakli Brucella izolatlarinin tanimlama ve tiplendirmesinde konvansiyonel yöntemler ile gerçek zamanli multipleks polimeraz zincir reaksiyonunun karsilastirilmasi.

Brucellosis which is a worldwide zoonotic disease, still constitutes a major public health problem in rural areas of Turkey. The aim of the present study was to evaluate the species and biovar distribution of 187 presumptive Brucella strains isolated from patients inhabiting at the provinces in Eastern, South Eastern and Mediterranean regions over a 7-years period (from 2001 to 2007) and to compare multiplex real-time-polymerase chain reaction (M-RT-PCR) and conventional biotyping for the differentiation of three Brucella species. The isolates were identified at genus level by conventional microbiological methods and classified using the classical Brucella species biotyping scheme based on CO2 requirement for growth, urease activity, H2S production, sensitivity to basic fuchsin and thionin (20 and 40 µg/ml), lysis by Tbilisi and Berkeley phages, and agglutination with monospecific antisera for A and M antigens. All Brucella isolates were identified as Brucella melitensis biovar 3. M-RT-PCR assay targeted bcsp31 gene and the specific integration of IS711 elements within the genome of the respective Brucella species. For the identification of Brucella spp. The primers and probes which targeted the bcsp31 gene were used. The Brucella abortus primers and probe set targeted the specific insertion of an IS711 element downstream of the alkB gene, whereas the B.melitensis primers and probe set targeted the insertion of an IS711 element downstream of BMEI1162. M-RT-PCR results were found to be 100% compatible with the reference conventional typing methods. Due to its high sensitivity, the M-RT-PCR assay could be a valuable tool for the rapid detection and differentiation of Brucella species in clinical samples which usually have very low bacterial load. These findings indicated that B.melitensis biovar 3 was by far the most frequent species for human brucellosis in these specific regions of Turkey and multiplex-RT-PCR seemed to be promising in the detection and differentiation of Brucella species.

[Establishment of an algorithm for serological testing of syphilis identification]. / Sifiliz tanisinda kullanilan serolojik testler için akis semasinin olusturulmasi.

Serological methods are widely used for the laboratory diagnosis of syphilis or for screening purposes. The aim of this study was to determine an algorithm for the application of laboratory tests that will provide accurate diagnosis of syphilis in a cheap, fast and practical way. A total of 162 serum samples were evaluated by the following tests: VDRL (Venereal Disease Research Laboratory; Omega Diagnostic, UK), TPHA (Treponema pallidum Hemagglutination Test; Omega Diagnostic, UK), ELISA IgG + IgM (Enzyme Linked Immunosorbent Assay; DiaPro Diagnostic Bioprobes, Italy), FTA-ABS (Fluorescent Treponemal Antibody-Absorption; IgG, Euroimmun, Germany) and WB (Western Blot; IgG Euroimmun, Germany). When the gold standard was considered as FTA-ABS test, the sensitivity, specificity, positive and negative predictive values for VDRL were 77.1%, 100% 100% an 80.6%; for TPHA were 92.8%, 98.7%, 98.7% and 92.9%, for ELISA 98.8%, 98.7%, 98.8% and 98.7%, and for WB 98.8%, 100%, 100% and 98.7%, respectively. When the results of screening with VDRL together with TPHA were compared with FTA-ABS, it was observed that if both VDRL and TPHA results were positive, then there was 100% concordance between the tests. However, when both of the test results were negative, 1.3% of them yielded positive result with FTA-ABS. If either one of VDRL or TPHA results were positive (n = 24), 95.8% (n = 23) was positive with FTA-ABS. Therefore, inconsistent results obtained by VDRL and TPHA requires verification by another method. When ELISA or WB tests were used, the borderline results need verification, however, positive or negative results would be reported. The determination of an algorithm for laboratory tests also depend on the number of patients, cost, cost per positive patient and workload of the laboratory. Thus, ELISA could be selected when the number of cases is high and the results should be reported unless they are suspicious. When the number of cases is low, VDRL/TPHA should be selected, and the results should be verified if they are inconsistent. However, the demographic characteristics of patient groups are also important in test selection and work flow. False positive results are troublesome in case of marriage pre-screening and false negative results in sex workers. When all these factors are taken into consideration it may be suggested that either ELISA or VDRL together with TPHA should be performed and the results should be confirmed by a reference test in case of borderline results in ELISA or inconsistency between VDRL and TPHA results. Although screening for syphilis in the setting of blood banking is a matter of debate, if it is to be performed, then ELISA would be better since the work load is high. In case of pregnancy inconsistent VDRL and TPHA results should be verified since no risk could be afforded.

[Pertussis seroprevalence and vaccination status in three selected provinces of Turkey]. / Seçilmis üç ilde bogmaca seroprevalansi ve asilanma durumu.

The aim of this community-based seroepidemiological survey was to assess the immune status against pertussis among the healthy population in three selected provinces with different geographical and socioeconomical status (Antalya, Diyarbakir and Samsun, located at Mediterrenean, Southeast Anatolia and Black Sea regions of Turkey, respectively) in relation with DwPT (whole cell pertussis vaccine combined with diphtheria and tetanus toxoids) vaccination status. A total of randomly selected 2085 subjects ages between 6 months to > 50 years were included to the study. Serum samples have been screened for the presence of pertussis antibodies by an in house ELISA method with the use of pertussis toxin (PT) and filamentous hemagglutinin (FHA) antigens. The levels of > or = 10 EU/mL was accepted as positive for anti-PT and anti-FHA. Vaccination rate with 3-4 doses among children under 15 years old was significantly lower in Diyarbakir compared to the other two provinces (p< 0.05). The antibody positivity was increased with age up to the 10-14 year group and was maintained among older groups. There was no statistically significant relationship between the vaccination rate and antibody prevalence (p> 0.05). Adult females showed a significantly higher antibody-positivity rate for anti-PT than the males (p< 0.05). Our study pointed out a high prevalence of pertussis infection in those selected provinces, suggesting that the adults play a role as potential reservoirs for B. pertussis. It can be concluded that adult immunization, especially of those who are likely to have close contact with infants, should be considered.

The presence of tick-borne encephalitis in an endemic area for tick-borne diseases, Turkey.

The aim of this study was to indicate the presence of tick-borne encephalitis (TBE) in an endemic area for Crimean-Congo haemorrhagic fever (CCHF) in Turkey. Of 39 CCHF suspected cases, one was found to be TBE virus immunoglobulin M positive and seven were TBE virus immunoglobulin G positive. It is important to report this first appearance of the TBE virus in Turkey since 1967.

[Typing of Shigella sonnei strains isolated in some provinces of Turkey using antimicrobial resistance and pulsed field gel electrophoresis methods]. / Türkiye'nin bazi illerinde izole edilen Shigella sonnei suslarinin antimikrobiyal direnç ve "pulsed field" jel elektroforezi yöntemleri ile tiplendirilmesi.

Shigella species may lead to large epidemics owing to their low infective doses and frequent transmission from person to person with high secondary attack rates. Shigella sonnei is one of the most prevalent causative agent of infectious gastroenteritis in developing and developed countries and it is the most frequently reported Shigella serotype from Turkey in recent years. The aim of this study was to determine the types of S. sonnei strains isolated in different provinces of Turkey [in Marmara earthquake regions (Izmit, n=5; Adapazari, n=6; Yalova, n=2) in 1999 and in Ankara (n=17) in 1997, 2000 and 2001] according to their antimicrobial resistance and pulsed field gel electrophoresis (PFGE) patterns. All isolates were found sensitive to gentamicin, ceftriaxone, imipenem, nalidixic acid and ciprofloxacin. Twenty three (76.6%) of isolates were found resistant to streptomycin, 21 (70%) to trimethoprim-sulfamethoxazole, 20 (66.6%) to tetracycline, 6 (20%) to ampicillin, 3 (10%) to ampicillin/sulbactam and 1 (3.3%) to chloramphenicol. Three (%10) isolates were detected as intermediate susceptible to tetracycline and cefoperazone, while four isolates (13.3%) were susceptible to all antimicrobial agents tested. A total of nine different patterns were obtained according to antimicrobial resistance patterns. PFGE was performed by Xbal restriction enzyme. Isolates were grouped into A (n=24) and B (n=6) main PFGE types and into 13 closely or possibly related types. A total of 15 different PFGE patterns were identified among the isolates. It was determined that isolates from the same clone disseminated in Ankara during the years 2000-2001. Overall, different clones of S. sonnei strains were in dissemination in the provinces included. This study indicated that different S. sonnei clones were in circulation in Turkey and these results constitute the basic molecular preliminary data for the National Enteric Pathogens Laboratory Network in Turkey.

[A field survey carried out on the confirmation of a pertussis case in a village of Kirikkale Province, Turkey]. / Kirikkale'nin bir köyünde dogrulanmis bir bogmaca olgusu nedeniyle yapilan saha arastirmasi.

The aim of this study was to evaluate the existence and the rate of pertussis infection in December 2002 among the symptomatic contacts in Konurhaciobasi village of Kirikkale province (placed in middle Anatolia, Turkey, with a population of 500 people), where a laboratory-confirmed pertussis case was defined by culture positivity. Sixty contacts with cough history of more than two weeks have been interviewed and their nasopharyngeal swabs have been collected together with the serum samples from 47 of them. "Probable case" definition included cough lasting longer than two weeks together with at least one of the following symptoms: paroxysms of cough, inspiratory "whooping" and post-tussive vomiting without other apparent cause. The samples were inoculated onto cephalexin Bordet-Gengou agar (C-BGA), and following the growth of suspected colonies identification tests including slide agglutination by using Bordetella pertussis phase 1 and B.parapertussis specific antisera, were performed. IgG antibodies against B.pertussis were searched with an in-house ELISA method by using purified pertussis toxin, and titers of > or = 100 ELISA units (EU)/ml were considered as acute/recent infection. Among the subjects 80% were children and 75% were female. Thirty-six subjects (76.6%) had a history of immunization with 3-4 doses of diphtheria-pertussis-tetanus (DPT) vaccine. According to questionnaires the mean household number was calculated as 5.0 +/- 0.26. Fifteen contacts (age range: 4-12 years, 11 were female) were defined as "probable cases", however all of them were found to be culture negative. All these cases had been vaccinated with DPT vaccine. Among the probable cases 12 serum samples were available, and six of them were evaluated as acute/recent pertussis infection, since their antibody titers were found as > or = 100 EU/ml. In addition, the evaluation of ELISA results of 47 individuals indicated that 27 of them had antibody titers of > or = 100 EU/ml, who could be considered as acute or recent pertussis infection. The data of this field survey indicated a possible pertussis outbreak in this village.

Prevalence of high antibody titers of pertussis in Turkey: reflection of circulating microorganism and a threat to infants.

Acute pertussis infection among adults can cause its transmission to the larger population, especially to infants and young children, who can develop severe disease. In order to determine an age-dependent pertussis immune response, anti-pertussis toxin (PT) antibody was detected by the indirect enzyme-linked immunosorbent assay (ELISA) method in serum samples from 2,085 healthy subjects ranging in age from 6 months to > or = 60 years. Also included in the evaluation were responses to a questionnaire including sociodemographic characteristics, vaccination, and infection history. Titers of 50-99 ELISA units (EU)/mL and of > or = 100 EU/mL were accepted as indicative for recent exposure or infection. In addition, 30 EU/mL was estimated to be a sufficient titer in women of childbearing age to protect their newborns until administration of their first dose of pertussis vaccine. After the age of 4-5 years, presence of high-titered antibodies that increase with age might be a reflection of circulating infection and indicate the magnitude of the threat to infants. According to the questionnaires, in the groups younger than 15 years old, three to four doses of diphtheria toxoid-whole cell pertussis-tetanus toxoid (DwPT) were administered in 47.2 to 77.4%, 91.2 to 100.0%, and 83.5 to 100.0% of participants in Diyarbakir, Samsun, and Antalya, respectively. In addition, up to half of the expectant mothers we studied lacked a sufficient level of estimated antibody titers. To protect infants from life-threatening pertussis infection, improving vaccination coverage to ensure herd immunity and uniformly establishing coverage throughout the country are essential. Furthermore, revaccination with acellular vaccine for schoolchildren as well as for the households of pregnant women is recommended.

Tetanus immunization status among women of childbearing age in Turkey.

In order to assess the effect of the neonatal tetanus elimination program in Turkey, tetanus antibody prevalence among women of childbearing age from three selected provinces was evaluated in relation to vaccination doses of the single-type tetanus vaccine. A combined method of in-house enzyme-linked immunosorbent assay and particle agglutination test was used to determine tetanus antibody titers. Among 205 women aged 20-39 years, the tetanus antibody level was higher in women with 1-3 children than those without children. The geometric mean of the log antibody titer was increased proportionally with a slope of 0.405 +/- 0.174 per dose between 0 and 3 doses (P > 0.05). However, the proportion of 20-39-year-old women with the protective antibody in the provinces ranged from 54.8 to 86.6%. Diyarbakir had the lowest immunity with a larger number of children in the household, and a lower educational level. The results of our serological study demonstrated that the neonatal tetanus elimination program in Turkey is effectively promoting immunity against tetanus in pregnant women. However, the study also revealed that the tetanus immunity among women of childbearing age was still insufficient. Intensive implementation of the supplemental immunization activities and encouraging vaccinations through neonatal care services will improve the situation.

High incidence of Pertussis among schoolchildren with prolonged cough in Turkey.

Older children, adolescents and adults with prolonged cough should be screened for pertussis, because they can be a major source of transmission for infants who are not yet fully immunized. This study aimed to estimate the incidence of pertussis among schoolchildren of 6-14 years old with prolonged cough attending two government primary schools in central Ankara. A questionnaire and an informed consent form were sent to the parents of 1,859 schoolchildren. The former comprised questions regarding sociodemographics, and the presence and duration of cough. Parents of 1,698 (91.3%) schoolchildren returned the questionnaire. Three hundred and eighty three (22.6%) of the schoolchildren had cough for more than two weeks, and 307 (80.2%) of them, whose parents gave consent, were included in the study. Their blood samples were collected twice, with a two-week interval. Anti-pertussis toxin IgG levels were measured by enzyme-linked immunosorbent assay (ELISA). Fifty-one children (16.6%) had evidence of recent pertussis infection documented by either a titer > or = 100 ELISA Unit (EU)/ml in one of two serum samples or seroconversion in paired sera. None of the schoolchildren who had attended health care facilities for cough had been diagnosed as pertussis by a physician. In conclusion, pertussis is evident among older children and adolescents in Turkey, and in order to control the disease, priority should be given to strengthen primary immunization services along with the implementation of booster vaccinations beyond childhood.

Crimean-Congo haemorrhagic fever cases in Turkey.

Crimean-Congo haemorrhagic fever (CCHF) is an arbovirus infection, which is transmitted through ticks or via blood and secretions. Until recently, human cases of CCHF were unknown in Turkey; however, several acute disease cases were reported in 2002. We report on the investigation of a cluster of suspected CCHF cases in the middle part of the Black Sea from May 2002 to October 2003. The medical charts that we reviewed were obtained from all local physicians and our field investigations. 'Suspected case' was defined with regard to time, place, and both clinical and laboratory characteristics. A total of 108 patients were defined as suspected case. Among them 36 patients were reached and blood samples taken for examination for CCHF by using ELISA and RT-PCR. According to the laboratory analysis, 80.6% (29/36) were acute cases and 8.3% (3/36) were past CCHF infections. The overall mortality rate was 5.6%. There was no nosocomial infection; however, there were 2 family clusters. Tick exposure was the most prevalent risk factor (74.2%). A multidisciplinary collaboration should be developed in order to understand the magnitude of the disease and also to keep it under control.

Immunity against tetanus and effect of vaccination in Turkey.

The immune status against tetanus in relation to vaccination was investigated among healthy populations in 3 selected provinces in Turkey (n=2094). In-house ELISA supplemented with the particle agglutination test was performed for this purpose. An exact correlation was found between vaccination status and immunity against tetanus. The immunity was high among children and sharply decreased with age among adults. The primary vaccination for children increased the immunity, reaching a geometric mean titer (GMT) of 6.2 IU/ml at the fourth dose. There was a reduction of immunity during the next y, followed by an increase with a booster injection at primary school age. Among adolescents and adults, the GMTs after the last vaccination fell off exponentially with a slope of -0.068 log10 IU/ml per y. Extrapolation of the regression line predicted that the minimum protective level (> or =0.01 IU/ml) would be maintained for approximately 30 y on average after the last vaccination. Diyarbakir, 1 of the selected provinces, had lower immunity than the other 2 provinces with poor immunization. Adult females tended to show slightly higher GMTs than males, probably due to the neonatal tetanus elimination program. Reinforcement of immunization against tetanus for adults is recommended.