Cost-effectiveness of Helicobacter pylori test and eradication versus upper gastrointestinal series versus endoscopy for gastric cancer mortality and outcomes in high prevalence countries.

Background: The latest version of Japanese guidelines for effective secondary prevention of gastric cancer recommend upper gastrointestinal series (UGI) and endoscopy in adults 50 years of age and older. A Helicobacter pylori antibody test and eradication (H. pylori screening) reduces gastric cancer risk. Objective: This study aimed to evaluate the cost-effectiveness of H. pylori screening, compared to UGI and endoscopy in high prevalence countries. Methods: We developed decision trees with Markov models using a healthcare payer perspective and a lifetime horizon. Targeted populations were hypothetical cohorts of asymptomatic individuals at the age of 50, 60, 70 and 80 years. We calculated per-person costs and effectiveness with discounting at a fixed annual rate of 3% and compared incremental cost-effectiveness ratios. Results: H. pylori screening was cost-saving and more cost-effective for individuals at the age of 50, 60, 70, and 80 than UGI and endoscopy. One-way and multiway sensitivity analyses showed the robustness of the cost-effectiveness results. Probabilistic sensitivity analyses using Monte-Carlo simulation for 10,000 trials demonstrated that H. pylori screening was cost-effective 100% of the time at a willingness-to-pay level of US$50,000/QALY gained. Conclusions: H. pylori screening for the adults 50 years of age and older could be cost-effective compared to UGI and endoscopy in high prevalence countries. The main reasons for the superiority of H. pylori screening are that an H. pylori antibody test has a higher sensitivity and specificity than UGI and endoscopy and the benefits to reduce gastric cancer incidence and mortality.

Variability in Risk Assessment and Management Plan (RAMP) scores completed as part of the Ontario Johne's Education and Management Assistance Program(2010-2013).

As a proactive measure toward controlling the nontreatable and contagious Johne's disease in cattle, the Ontario dairy industry launched the voluntary Ontario Johne's Education and Management Assistance Program in 2010. The objective of this study was to describe the results of the first 4 yr of the program and to investigate the variability in Risk Assessment and Management Plan (RAMP) scores associated with the county, veterinary clinic, and veterinarian. Of 4,158 Ontario dairy farms, 2,153 (51.8%) participated in the program between January 2010 and August 2013. For this study, RAMP scores and whole-herd milk or serum ELISA results were available from 2,103 farms. Herd-level ELISA-positive prevalence (herds with one or more test-positive cows were considered positive) was 27.2%. Linear mixed model analysis revealed that the greatest RAMP score variability was at the veterinarian level (24.2%), with relatively little variability at the county and veterinary clinic levels. Consequently, the annual RAMP should be done by the same veterinarian to avoid misleading or discouraging results.

Enzyme-free signal amplification for electrochemical detection of Mycobacterium lipoarabinomannan antibody on a disposable chip.

A simple, rapid, and disposable immunosensor at screen printed carbon electrode (SPCE) was developed by using gold nanoparticles (AuNPs) labeled Staphylococcal protein A (Au-SPA) as the electrochemical tag for detection of lipoarabinomannan antibody (anti-LAM). The immunosensor as the disposable chip was prepared by immobilizing capture antigen on screen printed carbon working electrode by passive adsorption, and characterized with scanning electron microscopy. After binding with the anti-LAM for further capture of Au-SPA, AuNPs were introduced as an electrochemical tag by the eletrooxidation of AuNPs in 0.1M HCl to produce strong electroactive substance for signal amplification. Compared with the enzyme-based immunosensor, AuNPs as enzyme-free tag for signal amplification exhibited many advantages such as no requirement of deoxygenation, and high stability. Under optimal detection conditions and at a preoxidation potential of +1.3 V for 30s, this method achieved the linear concentration of anti-LAM from 15.6 to 1000 ng mL(-1) with a detection limit of 5.3 ng mL(-1). The immunosensor showed a good performance with high selectivity, acceptable stability, and simple operation, providing a promising application as an adjunctive tool in early tuberculosis diagnosis.

Changes in management practices and apparent prevalence on Canadian dairy farms participating in a voluntary risk assessment-based Johne's disease control program.

The objectives of this study were (1) to describe the change in Mycobacterium avium ssp. paratuberculosis (MAP) antibody milk ELISA-positive prevalence in Canadian dairy herds that participated in a risk assessment (RA)-based Johne's disease (JD) control program; (2) to describe the distribution of so-called high-risk management practices on Canadian dairy farms; and (3) to assess if compliance with selected recommendations translated into changes in the scores of associated RA questions. In Ontario and western Canada, 226 herds voluntarily participated in a RA-based JD control program for several years. In 2005-2007, a previsit survey, RA, and MAP-antibody milk ELISA of the entire milking herd were conducted. Therefore, the interpretation of the results of this study is strictly for the MAP-antibody milk ELISA status of cows or herds, because no culture of MAP (of fecal or environmental samples) was conducted due to economic restrictions. In early 2008, a telephone interview was used to determine compliance with recommended management changes after the first RA. In 2008-2009, a second RA and another whole-herd MAP antibody milk ELISA were performed. At both herd tests, about 35% of the farms had at least one MAP-antibody milk ELISA-positive cow, classifying them as a MAP-antibody milk ELISA-positive herd. However, 28.8% of herds had changed their MAP-antibody milk ELISA status between the 2 tests, demonstrating that a single herd test was insufficient to determine the long-term MAP-antibody ELISA status of a herd. The average within-herd MAP-antibody milk ELISA-positive prevalence changed from 5.4 to 4.2% over the study period, but management practices did not change much throughout the 2- to 3-yr period and were similar to those reported in other parts of North America. The overall RA scores decreased at the second RA, in particular for management practices in the calving and preweaned calf area, and when herds were test-positive at the first test. This was not surprising, because many of the recommendations at the first RA focused on these management areas and compliance with some recommended farm-specific management practices in this area might be linked to reduced scores for associated RA questions. In conclusion, the participating farms did, on average, decrease their within-herd MAP-antibody milk ELISA positive-prevalence and RA total scores. Changes in RA scores could be linked to improved management practices, indicating that the RA questions appropriately reflected management practices. Some herds changed their MAP-antibody milk ELISA status between tests, which underlines that a current test of the entire milking herd is necessary to determine the present MAP-antibody milk ELISA status of a dairy herd.

Assessment of the IgA immunoassay diagnostic potential of the Mycobacterium tuberculosis MT10.3-MPT64 fusion protein in tuberculous pleural fluid.

Pleural tuberculosis (PL-TB) remains difficult to diagnose. An enzyme-linked immunosorbent assay (ELISA) was developed based on a construction containing the fusion of the Rv3019c (MT10.3) and Rv1980c (MPT64) gene sequences, and its performance was evaluated in an area where TB is endemic. A total of 92 pleural fluid (PF) samples at serial dilutions of 1:50 to 1:800 were included in the ELISA IgA MT10.3-MPT64 evaluation: 70 from TB patients and 22 from patients with other pleurisies. Confirmation of the expression and subsequent purification of the protein was made by SDS-PAGE and Western blot assays, resulting in a 36-kDa protein. ELISA IgA MT10.3-MPT64 showed sensitivities of 61.4%, 58.6%, 62.9%, 67.1%, and 70% at each PF dilution, respectively. The cumulative results of all dilutions increased sensitivity to 81.4% without jeopardizing specificity. Similar results were also obtained at the combined dilutions of 1:50, 1:200, and 1:800 or 1:50 plus 1:800 dilutions (80%). The overall sensitivity of the reference test, i.e., histopathological examination, was 74%. But, via the ELISA IgA MT10.3-MPT64 test, sensitivity was high for specimens with a negative culture (23/27; 85.2%) or nonspecific histopathology (17/18; 94.4%). Our findings demonstrated the promising use of this test as an adjunct in PL-TB diagnoses, particularly in cases with lower bacterial loads and false-negative results in the reference tests, since the new test includes such important features as quick and easy application, high sensitivity and, perhaps most importantly, affordability, which is so crucial for its widespread use in developing countries.

[Immunological parameters in the assessment of the activity of a specific process in Mycobacterium tuberculosis-infected children and patients with intrathoracic lymphatic tuberculosis].

The data of a comprehensive study of 86 children aged 6 to 14 years, who were examined and treated at the Research Institute of Phthisiology for various manifestations of tuberculous infection: 25.6% with infected Mycobacterium tuberculosis with varying specific sensitization; 34.9% with minor forms of intrathoracic lymphatic tuberculosis (ITLT), 39.5% with disseminated processes into the intrathoracic lymph nodes, are analysed. Of the greatest informative value in the determination of the activity of tuberculous infection are RM V, VI, VII, and VIII dilutions in combination with immunological parameters of specific immunity: blast transpormation reaction (BTR) to PPD, a complex of serological reactions, IL-8, and lysosomal cationic test (LCT). Most children with ITLT showed a significant cellular response to PPD in the BTR test. It should be noted that on admission to the clinic, neutrophilic granulocytes were functionally inadequate in all the children as shown by LCT. The currently available immunological tests used in combination with the existing methods in the diagnosis of ITLT adequately evaluate the activity of tuberculous infection in children.

Simultaneous detection of multifood-borne pathogenic bacteria based on functionalized quantum dots coupled with immunomagnetic separation in food samples.

This paper reports a method that simultaneously detects three food-borne pathogenic bacteria, Salmonella typhimurium, Shigella flexneri, and Escherichia coli O157:H7, via an approach that combines magnetic microparticles for the enrichment and antibody-conjugated semiconductor quantum dots (QDs) as fluorescence markers. Using the water-in-oil reverse microemulsions method, the gamma-Fe(2)O(3) magnetic nanoparticles were coated with silica to empower the particles with high dispersibility and broad compatibility to biomacromolecules. The magnetic beads were then modified with amino silane, which could immobilize antibodies by glutaraldehyde treatment. The immunized magnetic beads and pathogenic bacteria formed "bead-cell" complexes in the enrichment procedure. QDs with different emission wavelengths (620, 560, and 520 nm) were immobilized with anti-S. typhimurium antibody, anti-S. flexneri antibody, and anti-E. coli O157:H7 antibody, respectively. Fluorescence microscope images and the fluorescence intensity of QDs labeled "sandwich" complexes (conjungated with antibodies against S. typhimurium, S. flexneri, and E. coli O157:H7, respectively) demonstrated that antibody-conjugated QDs could attach to the surface of bacterial cells selectively and specifically. In our method, we could detect food-borne pathogen bacteria in a food matrix at 10(-3) cfu/mL. We determined that a high concentration of proteins in food matrix would decrease the sensitivity of this method. This method, of which the detection procedures are completed within 2 h, can be applied to the rapid and cost-effective monitoring of bacterial contamination in food samples.

Diagnosis of Helicobacter pylori.

The different invasive and noninvasive diagnostic tests for Helicobacter pylori have been applied mainly in emerging countries. Molecular methods have been developed, especially a test for detection of H. pylori and its clarithromycin resistance directly from stools. The long-term effects of eradication on histologic lesions have been studied in a meta-analysis and the prognostic value of post-treatment in gastric mucosa-associated lymphoid tissue lymphoma has been assessed. An operating link for gastritis assessment (the OLGA staging) has also been published. Attempts to simplify the urea breath test protocol have been made, and new stool antigen tests have been proposed and compared to those previously available.

Interlaboratory comparison of results of an anthrax lethal toxin neutralization assay for assessment of functional antibodies in multiple species.

The anthrax lethal toxin neutralization assay (TNA) will likely be used to correlate the protection offered by new anthrax vaccines in animal models to the immunogenicity that will be provided in humans. TNA data are being generated in several different laboratories to measure the immune responses in rabbits, nonhuman primates, and humans. In order to compare data among species and laboratories, a collaborative study was conducted in which 108 samples from the three species were analyzed in seven independent laboratories. Six of the seven laboratories had participated in an interlaboratory technology transfer of the TNA. Analysis of the titration curves generated by samples from each species indicated that the behaviors of the samples from all species were similar; the upper and lower asymptotes and the slopes of the curves were less than 30% divergent from those for human reference material. Dilutional linearity was consistent among samples from each species, with spike to effective dilution at 50% inhibition (ED(50)) slopes of less than 1.2 for all species. Agreement among the laboratories with consensus values was within 10% of the ED(50)s for all samples and within 7.5% of the quotients of the test sample ED(50) and the reference standard ED(50) (NF(50)s) for all samples. The relative standard deviations obtained when data from all laboratories and for all species were combined were 45% for the ED(50)s and 35% for the NF(50)s. These precision data suggest that the NF(50) readout may normalize the values generated by different laboratories. This study demonstrates that the TNA is a panspecies assay that can be performed in several different laboratories with a high degree of quantitative agreement and precision.

Simulation model for evaluation of testing strategies for detection of paratuberculosis in midwestern US dairy herds.

We developed a stochastic simulation model to compare the herd sensitivity (HSe) of five testing strategies for detection of Mycobacterium avium subsp. paratuberculosis (Map) in Midwestern US dairies. Testing strategies were ELISA serologic testing by two commercial assays (EA and EB), ELISA testing with follow-up of positive samples with individual fecal culture (EAIFC and EBIFC), individual fecal culture (IFC), pooled fecal culture (PFC), and culture of fecal slurry samples from the environment (ENV). We assumed that these dairies had no prior paratuberculosis-related testing and culling. We used cost-effectiveness (CE) analysis to compare the cost to HSe of testing strategies for different within-herd prevalences. HSe was strongly associated with within-herd prevalence, number of Map organisms shed in feces by infected cows, and number of samples tested. Among evaluated testing methods with 100% herd specificity (HSp), ENV was the most cost-effective method for herds with a low (5%), moderate (16%) or high (35%) Map prevalence. The PFC, IFC, EAIFC and EBIFC were increasingly more costly detection methods. Culture of six environmental samples per herd yielded >or=99% HSe in herds with >or=16% within-herd prevalence, but was not sufficient to achieve 95% HSe in low-prevalence herds (5%). Testing all cows using EAIFC or EBIFC, as is commonly done in paratuberculosis-screening programs, was less likely to achieve a HSe of 95% in low than in high prevalence herds. ELISA alone was a sensitive and low-cost testing method; however, without confirmatory fecal culture, testing 30 cows in non-infected herds yielded HSp of 21% and 91% for EA and EB, respectively.

Assessment of the protective effect of pneumococcal vaccination in preventing meningitis after cochlear implantation.

OBJECTIVES: To examine if a 23-valent pneumococcal capsular polysaccharide vaccine (PPV23) reduces the risk of meningitis in healthy rats after cochlear implantation. DESIGN: Interventional animal study. INTERVENTIONS: Thirty-six rats (18 immunized and 18 unimmunized) received cochlear implantations and were then infected with Streptococcus pneumoniae via 3 different routes (hematogenous, middle ear, and inner ear) in numbers sufficient to induce meningitis. RESULTS: The rats with implants that received PPV23 were protected from meningitis when the bacteria were delivered via the hematogenous and middle-ear routes (Fisher exact test P<.05). However, the protective effect of the vaccine in the rats with implants was only moderate when the bacteria were inoculated directly into the inner ear. CONCLUSIONS: Our animal model clearly demonstrates that immunization can protect healthy rats with a cochlear implant from meningitis caused by a vaccine-covered serotype. This finding supports the notion that all current and future implant recipients should be vaccinated against S pneumoniae.

Immunogenicity, safety and tolerability of meningococcal C CRM197 conjugate vaccine administered 3, 5 and 11 months post-natally to pre- and full-term infants.

A total of 79 pre-term infants with a gestational age > or =32 weeks and 74 full-term infants were studied in order to evaluate the immunogenicity, safety and tolerability of meningococcal C (MenC)-CRM(197) conjugate vaccine administered 3, 5 and 11 months post-natally. The evoked immune response seemed to be substantially similar in the pre- and full-term infants, and there were only clinically marginal differences in safety and tolerability between the groups. The results support the use of two doses of MenC-CRM(197) vaccine at 3 and 5 months of age for primary immunisation, with a booster dose being given at about 1 year. In addition to reducing costs, this scheme seems to assure global immunogenicity and potential efficacy that is better than that offered by the accelerated scheme of administration with only three doses of vaccine in the first months of life, and similar to that observed with a fourth dose used as booster after the first year.

Simulated economic effects of improving the sensitivity of a diagnostic test in paratuberculosis control.

Low sensitivity (Se) of diagnostic tools is often mentioned as a major problem in the control of paratuberculosis (PTB) and much effort is put into the improvement of these tests. The hypothetical perspectives of improving the Se of a milk-antibody ELISA (hereafter: milk-ELISA) used in test-&-cull strategies against PTB in dairy cattle were investigated by simulations. The current Se varies between 10 and 80%, increasing with increasing lactation stage, parity and infection stage. We simulated the effects on a dairy herd's production of improving this Se to 80% (independent of these factors) and assumed no concomitant decrease in specificity. By using a PTB model called PTB-Simherd, 12 scenarios were simulated to study three test-&-cull strategies in each of four herds with 200 dairy cows. To show the maximal effect of using test-&-cull with such an improved test we simulated three strategies: (1) no testing, (2) testing with milk-ELISA test with the current Se and culling of positive cows immediately and (3) testing with milk-ELISA test with a Se improved to 80% and culling positive cows immediately. The four herds were defined by a moderate (25%) or high (80%) initial true within-herd prevalence (including young stock), and a poor or good heat-detection success of 40 or 60%. We assumed that these factors influenced the effects of improving the Se of the milk-ELISA. Management both concerning calf management and in general was specified to represent a typical Danish herd. Using an improved milk-ELISA was predicted to reduce the prevalence of PTB more effectively than the current ELISA, and over 10 years bring the production of a herd with moderate initial prevalence up to a production level comparable to a non-infected herd (unlike if the current ELISA had been used). In a herd with high initial prevalence (80%) milk production was increased more by using the improved milk-ELISA, but after 10 years the replacement rate was still very high causing problems with having enough recruitment animals-especially in high-prevalence herds with poor reproductive performance. Economically important measurements in all four herds benefited from the improvement of the test over a 10-year period. However, in the first 3-5 years the improved test would be more expensive to use than the current test, due to increased replacement (reduced net annual revenue per cow euro15 on average) but after that, net annual revenue increased continuously; after 10 years it was euro70-90 higher, than if the current milk-ELISA was used. Also, the milk-ELISA test with its current Se seemed to be profitable already after 2 years in high-prevalence herds using a test-&-cull strategy based on the milk-ELISA alone.

Characterization of rabbit antibodies for immunochemical detection of Yersinia enterocolitica.

Rabbit IgG raised against whole cells of Yersinia enterocolitica O:3, O:9 and against a group of pathogenic Y. enterocolitica strains (serotypes O:3, O:5,27, O:8. and O:9) were prepared. The antibody limiting titers were within the range of 1:9.5 x 10(4)-1:7.5 x 10(5). The immunoblotting analysis of Yersinia lipopolysacchides separated by SDS-PAGE showed that IgG against the single serotype O:3 interacted with high-molar-mass LPS of O:3 whereas other antibodies were bound to low-molar-mass LPS of serotypes O:3, O:5,27, O:9 and strain Y. enterocolitica (CNCTC Y 2/68). IgG against the group of pathogenic serotypes also weakly interacted with low-molar-mass LPS of serotypes O:5, O:6,30, and O:10. The cross-reactivity of the antibodies with Y. pseudotuberculosis Ia and/or Y. rohdei b, d, e, f, i, which was observed by means of dot-blotting procedure using the whole bacterial cells as an antigen, was shown not to be caused by LPS of these bacteria. The prepared antibodies were used in the development of indirect competitive ELISA. At the optimum concentration of the immunoreactants the detection limits were within the range of 3-7 x 10(6) colony-forming units per mL.

[Assessment of occupational risk of Legionella spp. infection among dental health-care personnel]. / Valutazione del rischio professionale per infezioni da Legionella spp nel personale di assistenza odontoiatrica.

Various authors have reported the presence of Legionella spp. in dental unit waterlines with prevalence rates reaching, in some cases, 69.7% In order to evaluate the association between occupational exposure to Legionella and risk of infection, anti-Legionella spp. antibodies were measured in 88 dental assistants, 44 of which exposed and 44 not exposed to dental environments. Antibody levels > 1:128 were considered positive for infection. Relative risk was found to be 3.5 (p<0.01). These results confirm the hypothesis that workers in dental health-care settings are at occupational risk for Legionella infection. It is essential, therefore, that surveillance of microbiological quality of dental waterlines be implemented and appropriate disinfection procedures performed where necessary.

Doxycycline versus ceftriaxone for the treatment of patients with chronic Lyme borreliosis.

BACKGROUND: Therapeutic guidelines for treatment of late manifestations of Lyme borreliosis have not yet become well established. Patients with symptoms suggesting central nervous system involvement are often treated with courses of intravenous ceftriaxone. This is an expensive treatment approach with potentially severe side effects. We compared the efficacy, side effects and costs of doxycycline and ceftriaxone in the treatment of such patients. PATIENTS AND METHODS: Adult patients qualified for the study if they had nonspecific symptoms suggesting central nervous system involvement for more than six months (but without overt clinical signs of the involvement), had positive serum borrelial antibody titers and/or erythema migrans prior to the onset of symptoms, had not been previously treated with antibiotics and did not have pleocytosis in the cerebrospinal fluid. Patients were given either 100 mg of oral doxycycline twice daily for 4 weeks (23 patients) or 2 g of intravenous ceftriaxone daily for 2 weeks followed by 100 mg of doxycycline twice daily for another 2 weeks (23 patients). Clinical outcome was assessed during a 12-month follow-up period. RESULTS: Improvement in the frequency and/or the intensity of symptoms was reported by more than two-thirds of the 46 patients enrolled in the study. The two treatment regimens were found to be correspondingly effective. Photosensitivity reactions and gastrointestinal symptoms were noted more often among patients receiving doxycycline than in those receiving ceftriaxone. Treatment with doxycycline proved to be much cheaper than with ceftriaxone. CONCLUSIONS: In patients with previously untreated chronic Lyme borreliosis with symptoms suggesting central nervous system involvement but without overt clinical signs of it, and without pleocytosis in the cerebrospinal fluid, treatment with doxycycline is as effective as with ceftriaxone. Treatment with doxycycline is cheap and relatively safe, but gastrointestinal symptoms and photosensitivity reactions can be expected more often than with ceftriaxone.

Assessment of the compatibility of co-administered 7-valent pneumococcal conjugate, DTaP.IPV/PRP-T Hib and hepatitis B vaccines in infants 2-7 months of age.

This study assessed compatibility of concurrently administered 7-valent pneumococcal conjugate (PCV7), hepatitis B (HB) and DTaP.IPV/Hib vaccines. Infants were given DTaP.IPV/Hib and HB at 2, 4, 6 months and randomly assigned (2:1) to receive PCV7 concurrently or sequentially (at 3, 5, 7 months). Antibody levels were compared in 246 concurrent and 122 sequential vaccinees. Responses to PCV7, DTaP.IPV/Hib and HB were generally unaltered with concurrent administration except that Hib responses were increased (p=0.008) and HB responses were reduced (p=0.006) with concurrent dosing, the latter possibly from same thigh injection with DTaP.IPV/Hib. We conclude that PCV7, DTaP.IPV/Hib and HB are compatible with concurrent, separate injections.

Effect of socio-economic status, age and sex on antibody titre profile to Salmonella typhi/paratyphi in Ile-Ife, Nigeria.

BACKGROUND: Typhoid fever remains a great socio-medical problem in many poor and underdeveloped countries, with an estimated 16 million cases and 600,000 deaths occurring each year. Although it has a world wide distribution, typhoid fever is endemic where sanitary controls are inadequate. The distribution of the infection in relation to age and sex has shown that typhoid fever is more prevalent in males than in females with out satisfactory explanation. Also, those in their second and third decades are more susceptible. The aim of the study is to evaluate the effect of socio-economic status, age and sex on antibody titre profile to Salmonella typhi and praratyphi in Ile-Ife, using both healthy individuals with immunological scar to Salmonella typhi/paratyphi and enteric fever patients. METHOD: Healthy volunteers (310) were recruited into the study and clinically diagnosed/culture proven cases (48) were used as control. Widal text was performed on each serum. Slide agglutination was first done, then positive samples were further subjected to tube agglutination for quantitative titration. RESULTS: The relationship between age and antibody titres in both healthy subjects and enteric fever patients is not statistically significant, (P values > 0.05). From the study also, sex and social status do not influence antibody titres to salmonella typhi/paratyphi (P value > 0.05). CONCLUSION: The study has shown that age, sex and social class do not statistically influence antibody titre profile to S. typhi/paratyphi in Ile-Ife, south western Nigeria.

Pre-treatment and post-treatment assessment of the C(6) test in patients with persistent symptoms and a history of Lyme borreliosis.

It was recently reported that antibody to C(6), a peptide that reproduces an invariable region of the VlsE lipoprotein of Borrelia burgdorferi, declined in titer by a factor of four or more in a significant proportion of patients after successful antibiotic treatment of acute localized or disseminated Lyme borreliosis. The present study evaluated the C(6) test as a predictor of therapy outcome in a population of patients with post-treatment Lyme disease syndrome. The serum specimens tested were from patients with well-documented, previously treated Lyme borreliosis who had persistent musculoskeletal or neurocognitive symptoms. All of the patients had participated in a recent double-blind, placebo-controlled antibiotic trial in which serum samples were collected at baseline and 6 months thereafter, i.show $132#e. 3 months following treatment termination. In this patient population no correlation was found between a decline of C(6) antibody titer of any magnitude and treatment or clinical outcome. Antibodies to C(6) persisted in these patients with post-treatment Lyme disease syndrome following treatment, albeit at a markedly lower prevalence and titer than in untreated patients with acute disseminated Lyme disease. The results indicate that C(6) antibody cannot be used to assess treatment outcome or the presence of active infection in this population.