Positivity cut-off for Pgp3 was greater than or equal to 1083, and CT694 cutoff was greater than or equal to 496 as determined by receiver operator characteristic (ROC) curve analysis from a pediatric U.S.-based unfavorable panel (N = 117) and Tanzania based positive panel from children with ocular Ct infection (N = 40) . Statistical analysis Data were entered into a customized database (Microsoft Access v2007) developed at the Dana Center, Johns Hopkins University. antibody data, TF prevalence was 7.8% (95% CI 6.1 to 9.5) and TI prevalence was 1.6% (95% CI 0.9 to 2.6). The overall prevalence of antibody positivity to Pgp3 was 27.2% (95% CI 24.5 to 30), and to CT694 was 23.7% (95% CI 21 to 26.2). Ocular chlamydia infection prevalence was 5.2% (95% CI 2.8 to 7.6). Seropositivity to Pgp3 and/or CT694 was significantly associated with TF at the individual and community OSI-930 level and with ocular chlamydia infection and TI at the community level. Older children were more likely to be seropositive than younger children. Conclusion Seropositivity to Pgp3 and CT694 correlates with clinical signs and ocular chlamydia infection in a mesoendemic region of Niger. Trial registration ClinicalTrials.gov “type”:”clinical-trial”,”attrs”:”text”:”NCT00792922″,”term_id”:”NCT00792922″NCT00792922. Author summary Trachoma programs currently use the clinical sign of trachomatous inflammation-follicular (TF) to guide community treatment decisions and evaluate response to mass drug administration with azithromycin. These programs rely on clinical grading that poorly correlates with infection with the causative agent of trachoma, may provide additional information about exposure and transmission patterns. Here, we evaluated the relationship between serologic markers of (infection in low-prevalence settings . Following MDA, the clinical sign trachomatous inflammationintense (TI) has been shown to correlate better with infection than TF does . However the measurement of clinical signs is subject to inter-grader variability and lack of real-time auditing since grading is performed in the field and thus can only later be validated or audited if images are OSI-930 taken. As trachoma elimination programs stand to benefit from an accurate, reproducible assessment of trachoma prevalence, other testing methods may be useful to help guide program decisions. These include tests of infection (polymerase chain reaction [PCR] testing of ocular swabs) and antibody-based testing [4C7]. Antibodies to antigens may act as markers of cumulative exposure to antigens, Pgp3 and CT694, have been shown to be reactive against sera in young children living in trachoma-endemic communities [4,7,8]. At the individual level, antibodies to these proteins demonstrate high sensitivity to ocular infection and high specificity against non-endemic control specimens [8C10]. However, individual associations may not always hold at the community level, and trachoma elimination programs treat ocular infection on a population level. Additionally, as antibody markers are not yet widely used to assess Rabbit polyclonal to Caspase 3.This gene encodes a protein which is a member of the cysteine-aspartic acid protease (caspase) family.Sequential activation of caspases plays a central role in the execution-phase of cell apoptosis.Caspases exist as inactive proenzymes which undergo pro for prevalence, better characterization of how seropositivity compares to other methods of assessing trachoma prevalence is necessary. Here, we evaluate the association between seropositivity, PCR positivity, and clinical signs of active trachoma (TF and TI) at the individual and community level in a region of Niger OSI-930 where some trachoma transmission is occurring (TF prevalence approximately 25% at baseline). Data were collected during the final follow-up visit of the Partnership for the Rapid Elimination of Trachoma (PRET)-Niger trial, in which communities were randomized to OSI-930 receive annual or biannual oral azithromycin for 3 years in order to assess the impact of treatment frequency on ocular chlamydia infection . Methods Study design The study methods have been previously reported in detail elsewhere [11C13]. Briefly, a cluster randomized trial of annual versus biannual mass azithromycin distribution for trachoma control was conducted in the Matameye district of the Zinder region of Niger from May 2010 until August 2013 [4C6]. Data on active trachoma and ocular infection were collected biannually on children aged 0C5 years; dried blood spots for serological analysis were collected only at the 36-month time point and only from children aged 1C5 years. Dried blood spots were shipped to CDC at ambient temperature and tested for antibodies from July to August 2014. Site selection Communities were chosen from among six different catchment areas for primary health care facilities and were eligible for inclusion if they met the following criteria: (1) contained a population between 250 to 600 persons, (2) were located more than 4 kilometers from the center of any semi-urban area, and (3) had a prevalence of active trachoma more than 10% in children aged 0C5 years . 235 communities in the 6 health centers were deemed eligible, of which 48 were randomly selected for inclusion in the trial. Children aged 1C5 years were included in this analysis, due to the inability of antibody tests to differentiate between maternal-child antibodies in 1Cyear-olds. Community randomization 48 communities were randomly divided into 4 treatment arms in a 2×2 factorial design (12 communities per arm), comparing two azithromycin coverage targets (standard versus enhanced coverage) and annual versus biannual treatment. Randomization of communities to.