Attitudes about vaccines to prevent Ebola virus disease in Guinea at the end of a large Ebola epidemic: Results of a national household survey.

INTRODUCTION: In 2014-2016, an Ebola epidemic devastated Guinea; more than 3800 cases and 2500 deaths were reported to the World Health Organization. In August 2015, as the epidemic waned and clinical trials of an experimental, Ebola vaccine continued in Guinea and neighboring Sierra Leone, we conducted a national household survey about Ebola-related knowledge, attitudes, and practices (KAP) and opinions about "hypothetical" Ebola vaccines. METHODS: Using cluster-randomized sampling, we selected participants aged 15+ years old in Guinea's 8 administrative regions, which had varied cumulative case counts. The questionnaire assessed socio-demographic characteristics, experiences during the epidemic, Ebola-related KAP, and Ebola vaccine attitudes. To assess the potential for Ebola vaccine introduction in Guinea, we examined the association between vaccine attitudes and participants' characteristics using categorical and multivariable analyses. RESULTS: Of 6699 persons invited to participate, 94% responded to at least 1 Ebola vaccine question. Most agreed that vaccines were needed to fight the epidemic (85.8%) and that their family would accept safe, effective Ebola vaccines if they became available in Guinea (84.2%). These measures of interest and acceptability were significantly more common among participants who were male, wealthier, more educated, and lived with young children who had received routine vaccines. Interest and acceptability were also significantly higher among participants who understood Ebola transmission modes, had witnessed Ebola response teams, knew Ebola-affected persons, believed Ebola was not always fatal, and would access Ebola treatment centers. In multivariable analyses of the majority of participants living with young children, interest and acceptability were significantly higher among those living with vaccinated children than among those living with unvaccinated children. DISCUSSION: The high acceptability of hypothetical vaccines indicates strong potential for introducing Ebola vaccines across Guinea. Strategies to build public confidence in use of Ebola vaccines should highlight any similarities with safe, effective vaccines routinely used in Guinea.

Eurogin 2010 roadmap on cervical cancer prevention.

The EUROGIN 2010 roadmap represents a continuing effort to provide and interpret updated information on cervical cancer screening and vaccination against the cause of the disease, high-risk human papillomavirus (HPV). Contrary to the two previous reports in 2008 and 2009, the present roadmap gives equal room to HPV-based screening and HPV vaccination, as a result of the recent strengthening of the evidence on the efficacy and feasibility of both approaches. The superiority of HPV testing in primary screening compared to cytology (in more developed countries) and to cytology or visual inspection methods (in less developed countries) has been demonstrated in several randomised trials. High vaccine efficacy has been confirmed up to 7 years after vaccination; school-based programmes in some countries have been able to reach over 70% coverage among adolescent girls. Demonstration projects have indicated that the delivery of HPV vaccines in less developed countries is feasible and favourably received by populations where cervical cancer is very common. HPV-based screening can diminish cervical cancer incidence more quickly than HPV vaccination, but vaccination can eventually facilitate screening efforts, especially if new vaccines against a greater number of HPV types are introduced. The availability of two highly complementary prevention tools such as HPV testing and HPV vaccination makes it possible to conceive integrated strategies for the elimination of cervical cancer that have no precedent in the cancer field. HPV tests and HPV vaccines remain, however, too expensive, and large-scale financing of screening and vaccination in less developed countries is sorely lacking.

Receipt of HIV and STD testing services during routine general medical or gynecological examinations: variations by patient sexual risk behaviors.

OBJECTIVE: Clinical practice guidelines in the United States recommend screening patients who report high-risk sexual behaviors (HRSB) for human immunodeficiency virus (HIV) and selected sexually transmitted diseases (STDs). The objective of this study was to estimate HIV and STD diagnostic and testing practices during routine general medical examinations (RGME) or gynecological examinations (GYNE) of patients by their reported HRSB status. METHODS: We analyzed medical claims data from commercially-insured patients in the United States who sought care during 2000-2003. International Classification of Disease-9 (ICD-9) diagnostic and Current Procedural Terminology procedural codes were used to identify claims for HRSB, RGME or GYNE, HIV and STD diagnoses, and HIV and STD tests. RESULTS: Of 4296 patients aged 15 to 54 years during RGME or GYNE, almost none had ICD-9 codes for HIV, syphilis, Chlamydia trachomatis (CT) or Neisseria gonorrhoeae (NG) infection. Patients with claims for HRSB were significantly more likely than patients without a claim for HRSB to be tested for HIV, syphilis, CT, and NG. Among patients with HRSB-RGME, men were significantly more likely to be tested for HIV (79.3% vs. 38.8%) and syphilis (39.1% vs. 27.6%) and less likely to be tested for CT (20.7% vs. 56.9%) and NG (20.7% vs. 50.9%) than were women. CONCLUSIONS: A large proportion of patients with HRSB at RGME or GYNE did not receive HIV and STD tests. Interventions to increase HIV and STD testing of patients at visits with claims for HRSB are needed to enhance guideline adherence.

Cervical cancer screening and management practices among providers in the National Breast and Cervical Cancer Early Detection Program (NBCCEDP).

BACKGROUND: This study was conducted to describe clinicians serving women in the National Breast and Cervical Cancer Early Detection Program (NBCCEDP) with regard to demographic and practice characteristics and their usual practices in cervical cancer screening and abnormal cytology management, as well as human papillomavirus (HPV) test use. METHODS: The authors analyzed data from a nationally representative survey conducted in 2004 of providers practicing 7 specialties that commonly offer cervical cancer screening. The program providers were compared with nonprogram providers. RESULTS: Program providers were found to be significantly more likely than nonprogram providers to be midlevel providers and to serve low-income, racial/ethnic minorities who are insured by Medicaid. In addition, they had significantly more patients with abnormal Papanicolaou tests and were more likely to offer onsite colposcopy (57% vs 40%). Program providers were less likely to use liquid-based cytology (LBC) as their sole method for cytology. Approximately 20% of program and nonprogram providers used HPV DNA testing as an adjunct to screening cytology and two-thirds used HPV tests to manage patients with abnormal cytology results. However, many also used HPV testing for reasons not approved by the U.S. Food and Drug Administration (FDA), such as for screening women age <30 years. CONCLUSIONS: As of mid-2004, program providers served racially and ethnically diverse, low-income patients who are at high risk for cervical cancer compared with nonprogram providers, as intended by this program. Because many providers offered on-site colposcopy, used LBC, and used HPV tests for patients with abnormal cytology results, they are well equipped to reduce the risk of cervical cancer. Many program providers used the HPV test for reasons that were not approved of by the FDA or reimbursed by the NBCCEDP. The results of this survey have informed training materials for program providers, reimbursement policies for LBC and HPV tests, and interventions to discourage inappropriate HPV testing.

Anogenital warts knowledge and counseling practices of US clinicians: results from a national survey.

OBJECTIVES: To examine messages US clinicians use when counseling patients diagnosed with anogenital warts. STUDY DESIGN: In mid-2004, we conducted a confidential mail survey of nationally representative samples of physicians practicing internal and adolescent medicine, family/general practice, obstetrics/gynecology, urology, or dermatology; nurse midwives; physician assistants; and nurse practitioners. The survey assessed knowledge and counseling practices of clinicians who had diagnosed anogenital warts. RESULTS: After adjusting for survey eligibility, 81% responded. Most (89%) were aware that human papillomavirus (HPV) causes anogenital warts, but only 48% were aware that oncogenic and wart-related HPV genotypes usually differ. Most (>95%) clinicians reported telling patients with warts that warts are an STD, are caused by a virus, or that their sex partners may have or may acquire warts. Many clinicians (>/=85%) also reported discussing STD prevention or assessing STD risk with such patients. Most reported addressing ways to prevent HPV (89%), including using condoms; limiting sex partners or practicing monogamy; or abstinence. Many also reported recommending prompt (82%) or more frequent (52%) Pap testing to female patients with anogenital warts. Potential barriers to counseling included providing definitive answers on how HPV infection was acquired, dealing with patients' psychosocial issues, and inadequate reimbursement. CONCLUSIONS: Most surveyed clinicians appropriately counseled patients about the cause and prevention of anogenital warts. However, many clinicians were unaware that oncogenic and wart-related HPV types usually differ, and this may explain why many reported recommending more aggressive cervical cancer screening for female patients with warts.

A cost-effectiveness evaluation of a jail-based chlamydia screening program for men and its impact on their partners in the community.

BACKGROUND: Few cost-effectiveness evaluations of screening men in jails for chlamydia have been published, and none have evaluated the cost-effectiveness of providing partner notification services to the partners of chlamydia-infected inmates. GOAL: The goal of this study was to evaluate the cost-effectiveness of the chlamydia screening and partner notification programs for men conducted by a Massachusetts jail compared with 3 hypothetical alternatives. STUDY DESIGN: Using jail cost and testing data, we used decision analyses to compare the cost and effectiveness of universal screening, age-based screening with 2 age cutoffs, and testing of symptomatic inmates at intake using treated cases of chlamydia and gonorrhea as the primary outcome. We also evaluated the cost-effectiveness of adding partner notification to these alternatives. RESULTS: Universal screening was the most effective and expensive alternative. Age-based screening would have identified slightly fewer cases at half the cost of universal screening. The net cost of partner notification was low. Assuming high sequelae costs in female partners made partner notification a cost-saving intervention. CONCLUSIONS: Age-based screening could lower costs without substantially sacrificing effectiveness. Notifying partners of infected inmates was a cost-effective adjunct to screening inmates.

Family physicians' knowledge of genital human papillomavirus (HPV) infection and HPV-related conditions, United States, 2004.

BACKGROUND AND OBJECTIVES: Information about human papillomavirus (HPV) has evolved rapidly and HPV DNA tests are now available. Little is known about family physicians' knowledge about HPV and how it relates to HPV test use and counseling practices. METHODS: In mid-2004, confidential surveys were mailed to a nationally representative sample of 760 family physicians. We assessed and analyzed relationships between knowledge about HPV, HPV test use, and counseling messages provided when collecting cervical cytology and managing anogenital warts. RESULTS: The adjusted response rate was 68% (n=368). Ninety-one percent provided cervical cancer screening, and 90% had managed genital warts. Responses indicated that more than 90% had up-to-date knowledge about several issues: HPV infection is common, persistent infection increases risk of cervical neoplasia, and treatment does not eliminate the causative infection. However, fewer than 50% were aware that HPV infections may clear spontaneously and that the HPV types associated with warts and cervical neoplasia differ. Only 57% had ever used HPV tests. Some HPV knowledge varied by clinician characteristics, and knowledge was associated with HPV test use but not counseling messages. CONCLUSIONS: Most physicians were aware of new information about HPV infection, but some were unaware of important information relevant for patient counseling. These topics have been highlighted in new clinical training and patient education materials.

Gonorrhea prevention and clinical care in the private sector: lessons learned and priorities for quality improvement.

We reviewed literature on gonorrhea prevention and clinical care in the private sector, the setting where most gonorrhea cases in the United States are now diagnosed. Although most private-sector health settings had a low prevalence of gonorrhea (0.1-2.5%), some private emergency departments and specialty clinics that serve a large number of high-risk or infected patients had prevalences ranged from 1.7% to 11.0%. Studies of diverse settings and populations suggest that, in general, diagnostic testing of symptomatic patients (69-83%), appropriate treatment (61-100%), and case reporting (64-94%) are delivered more commonly than risk assessment for asymptomatic patients (15-28%), routine screening of pregnant women (31-77%), risk-reduction counseling (35-78%), and sex partner management (0-82%). To sustain the recent declines in gonorrhea incidence in the United States, private-sector providers and health systems must continue to offer gonorrhea prevention and clinical services and consider implementing interventions to improve delivery of risk assessment, risk-reduction counseling, and partner management services.

Chlamydia screening in a Health Plan before and after a national performance measure introduction.

OBJECTIVE: To evaluate chlamydia-screening policies, testing practices, and the proportion testing positive in response to the new Health Plan Employer Data and Information Set (HEDIS) chlamydia-screening performance measure in a large commercial health plan. METHODS: We interviewed health plan specialty departmental chiefs to describe interventions used to increase chlamydia screening and examined electronic medical records of 15- to 26-year-old female patients--37,438 from 1998 to 1999 and 37,237 from 2000 to 2001--who were classified as sexually active by HEDIS specifications to estimate chlamydia testing and positive tests 2 years before and after the HEDIS measure introduction. RESULTS: In January 2000, the obstetrics and gynecology department instituted a policy to collect chlamydia tests at the time of routine Pap tests on all females 26 years old or younger by placing chlamydia swabs next to Pap test collection materials. Other primary care departments provided screening recommendations and provider training. During 1998-1999, 57% of eligible female patients seen by obstetrics and gynecology exclusively and 63% who were also seen by primary care were tested for chlamydia; in 2000-2001 the proportions tested increased to 81% (P < .001) and 84% (P < .001). Proportions tested by other primary care specialists did not increase substantially: 30% in 1998-1999 to 32% in 2000-2001. The proportion of females testing positive remained high after testing rates increased: 8% during 1998-1999 and 7% during 2000-2001, and the number of newly diagnosed females increased 10%. CONCLUSION: After the obstetrics and gynecology department introduced a simple systems-level change in response to the HEDIS measure, the proportion of females chlamydia-tested and number of newly diagnosed females increased.

Estimating prenatal syphilis and HIV screening rates for commercially insured women.

OBJECTIVE: Although routine serologic testing for syphilis and human immunodeficiency virus (HIV) for all pregnant women is recommended by the Centers for Disease Control and Prevention and many health professional organizations, little is known about the extent of prenatal syphilis and HIV screening rates among commercially insured pregnant women. METHODS: A claims database for a large commercially insured population was analyzed to estimate syphilis and HIV screening rates for pregnant women who were continuously enrolled in the same health insurance plan during 1998 and 1999 in 13 U.S. states. Diagnostic and procedural services were used to determine pregnancy status, receipt of prenatal care, and syphilis and HIV testing during pregnancy. RESULTS: Of 13,250 identified pregnancies, 12,156 (92%) were among women who had prenatal visits; 8368 (63%) included claims for syphilis testing; and 4411 (33%) included claims for HIV testing. Of the 8368 pregnancies with syphilis testing, 6326 (76%) included syphilis tests that were performed during the initial prenatal visit. Of the 4411 pregnancies with HIV testing, 3168 (72%) included HIV testing on the initial prenatal visit. Of 4249 pregnancies with syphilis and HIV testing, 3146 (74%) included HIV testing and syphilis testing on the initial prenatal visit. CONCLUSIONS: Most HIV and syphilis tests had been provided during initial prenatal visits among women who had HIV and syphilis testing. Prenatal screening rates for syphilis and HIV identified through claims were lower than expected. This may be due to deficiencies in documentation of syphilis and HIV screening in administrative databases or actual screening rates. Further investigation is needed to determine how accurately claims data can measure actual screening practices.

Mental health disorders and sexually transmitted diseases in a privately insured population.

OBJECTIVES: To consider whether patients who use mental health services in privately insured settings are also more likely to have received sexually transmitted disease (STD) or human immunodeficiency virus (HIV) diagnoses and whether this relationship extends to patients with milder mental health disorders. METHODS: Using frequency tables stratified by age and sex, a logistic regression model, and difference of means tests, we examined the relationship between mental health claims and STDs in a sample of 289 604 privately insured people across the United States. RESULTS: Patients with mental health claims were more than twice as likely as other patients to have an STD claim in the same year after controlling for confounding factors (odds ratio, 2.33; 95% confidence interval, 2.11-2.58). This relationship held for severe and milder mental health diagnoses, for male and female patients, and in each age category from 15 to 44 years. Among women, patients aged 20 to 24 years with a mental health claim had the highest predicted probability of STD diagnoses (3.0%); among men, patients aged 25 to 29 years with a mental health claim had the highest predicted probability of STD diagnoses (1.2%). CONCLUSIONS: In this population, patients with mental health claims were more likely to also have claims with diagnoses for STDs than patients without mental health claims, and this relationship applied to severe and milder mental health disorders. This suggests that people with mental health disorders in privately insured populations may benefit from routine STD risk assessments to identify high-risk patients for referral to cost-effective preventive services.

Cost-effectiveness of universal screening for chlamydia and gonorrhea in US jails.

Universal screening for the sexually transmitted diseases (STDs) of chlamydia and gonorrhea on intake in jails has been proposed as the most effective strategy to decrease morbidity in inmates and to reduce transmission risk in communities after release. Most inmates come from a population that is at elevated risk for STDs and has limited access to health care. However, limited resources and competing priorities force decision makers to consider the cost of screening programs in comparison to other needs. The costs and cost-effectiveness of universal screening in correctional settings have not been documented. We estimated the incremental cost-effectiveness of universal urine-based screening for chlamydia and gonorrhea among inmates on intake in US jails compared to the commonly used practice of presumptive treatment of symptomatic inmates without laboratory testing. Decision analysis models were developed to estimate the cost-effectiveness of screening alternatives and were applied to hypothetical cohorts of male and female inmates. For women, universal screening for chlamydia only was cost-saving to the health care system, averting more health care costs than were incurred in screening and treatment. However, for men universal chlamydia screening cost $4,856 more per case treated than presumptive treatment. Universal screening for both chlamydia and gonorrhea infection cost the health care system $3,690 more per case of pelvic inflammatory disease averted for women and $650 more per case of infection treated for men compared to universal screening for chlamydia only. Jails with a high prevalence of chlamydia and gonorrhea represent an operationally feasible and cost-effective setting to universally test and treat women at high risk for STDs and with limited access to care elsewhere.

Applying a mixed-integer program to model re-screening women who test positive for C. trachomatis infection.

We proposed a mixed-integer program to model the management of C. trachomatis infections in women visiting publicly funded family planning clinics. We intended to maximize the number of infected women cured of C. trachomatis infections. The model incorporated screening, re-screening, and treatment options for three age groups with respective age-specific C. trachomatis infection and re-infection rates, two possible test assays, and two possible treatments. Our results showed the total budget had a great impact on the optimal strategy incorporating screening coverage, test selection, and treatment. At any budget level, the strategy that used a relatively small per-patient budget increase to re-screen all women who tested positive 6 months earlier always resulted in curing more infected women and more cost-saving than the strategy that was optimal under the condition of not including a re-screening option.

Evaluating the quality of sexual health care provided to adolescents in medicaid managed care: a comparison of two data sources.

This study compares 2 data sources to evaluate the quality of sexual health care provided to adolescents in Medicaid managed care: (a) Medicaid encounter data and (b) medical record data. Data from 1998 for 1112 adolescent enrollees came from 3 Seattle-area managed care organizations (MCOs): a group model health maintenance organization, an independent practice association, and a clinic network. Quality of care was tracked by estimating within-MCO chlamydia testing rates for sexually active female enrollees. Rates varied dramatically depending on which data source was used. Logistic regression models indicated substantially less difference between MCOs when analysis was based on data from the 2 sources combined than when based on either data source alone. Study results did not support the use of Medicaid encounter data as a sole data source for evaluating quality of adolescent sexual health care, despite the cost savings this would represent. However, encounter data, used as an adjunct to medical record review, may increase the reliability of quality evaluations.

The estimated direct medical cost of sexually transmitted diseases among American youth, 2000.

CONTEXT: Each year, millions of U.S. youth acquire sexually transmitted diseases (STDs). Estimates of the economic burden of STDs can help to quantify the impact of STDs on the nation's youth and on the payers of the cost of their medical care. METHODS: We synthesized the existing literature on STD costs to estimate the lifetime medical cost per case of eight major STDs-HIV, human papillomavirus (HPV), genital herpes simplex virus type 2, hepatitis B, chlamydia, gonorrhea, trichomoniasis and syphilis. We then estimated the total burden of disease by multiplying these cost-per-case estimates by the approximate number of new cases of STDs acquired by youth aged 15-24. RESULTS: The total estimated burden of the nine million new cases of these STDs that occurred among 15-24-year-olds in 2000 was $6.5 billion (in year 2000 dollars). Viral STDs accounted for 94% of the total burden ($6.2 billion), and nonviral STDs accounted for 6% of the total burden ($0.4 billion). HIV and HPV were by far the most costly STDs in terms of total estimated direct medical costs, accounting for 90% of the total burden ($5.9 billion). CONCLUSIONS: The large number of infections acquired by persons aged 15-24 and the high cost per case of viral STDs, particularly HIV, create a substantial economic burden.

Risk behavior for transmission of human immunodeficiency virus (HIV) among HIV-seropositive individuals in an urban setting.

We conducted interviews with 256 human immunodeficiency virus (HIV)-infected patients who attended an HIV clinic in New York City to assess ongoing risk behaviors for HIV transmission. After learning that the result of an HIV test was positive, 106 subjects (41%) had unprotected sex, 63 (25%) had a new sexually transmitted disease diagnosis, and 38 (15%) used injection drugs. Unprotected sex was reported by 50% of women, 29% of heterosexual men (P=.006, compared with women), and 42% of men who have sex with men, and it was reported more often by persons with a history of trading sex for money or drugs (P<.001). In multivariate analysis, unprotected sex was associated with a history of trading sex for money or drugs (adjusted odds ratio [AOR], 4.0; 95% confidence interval [CI], 2.2-7.0) and use of highly active antiretroviral therapy (AOR, 1.8; 95% CI, 1.1-3.1). Ongoing risk-reduction counseling and substance abuse treatment for HIV-infected persons are needed to reduce behaviors associated with HIV transmission.

Do physicians provide counseling with HIV and STD testing at physician offices or hospital outpatient departments?

OBJECTIVES: To estimate the frequency of HIV/sexually transmitted disease (STD) counseling among patients tested for HIV or STD infection at physician offices and hospital outpatient departments and to describe the factors associated with HIV/STD counseling in private settings in the USA. DESIGN: Cross-sectional study of patients served by physicians in private settings in the USA. METHODS: We analyzed 1997-1998 data from two representative national surveys of ambulatory care visits in private settings by persons aged 18-64 years. RESULTS: During 1997-1998, 12.7 million ambulatory care visits included HIV or STD testing. HIV/STD counseling was documented in 35% of all visits and in 28% of visits by pregnant women at the time HIV or STD tests were done. Counseling was less common when only HIV tests (21%) or STD tests (37%) alone were carried out than when both HIV and STD tests (50%) were performed. Counseling was more common (65%) if the patient's reason for visit was related to HIV, STD, or genitourinary complaints than if the visit was for other reasons. CONCLUSIONS: Private physicians often counseled about HIV/STD when testing patients with symptoms. The proportion of other visits in which counseling accompanied HIV or STD tests was variable. This suggests the need for a better understanding of the reasons why clinicians in private settings decide whether to counsel patients about HIV and STD when they order testing, barriers to offering counseling, and interventions to increase counseling when appropriate.

New sexually transmitted diseases in HIV-infected patients: markers for ongoing HIV transmission behavior.

OBJECTIVE: The objective of this study was to describe the rate of new sexually transmitted diseases (STDs) among HIV-infected patients and to define the behavioral and clinical characteristics of HIV-infected patients who return with a new STD in follow-up. DESIGN: The study design was a record-based clinical cohort study focusing on patients testing HIV-seropositive in the STD clinics of Baltimore, Maryland from 1993 to 1998. METHODS: The authors identified those HIV-infected patients later diagnosed with an STD in follow-up and compared their demographic, behavioral, and clinical characteristics with those who were not diagnosed with an STD in follow-up. RESULTS: Of 796 men and 354 women with HIV infection, 13.9% of men and 11.9% of women were diagnosed with an STD after their initial HIV diagnosis. HIV-infected men returned with a new STD at a rate of 7 cases per 100 person-years; HIV-infected women returned at a rate of 5.6 cases per 100 person-years. In men, multiple sex partners and sex worker contact were associated with a subsequent STD diagnosis (OR = 1.67, p =.037; OR = 1.82, p =.015, respectively). In women, age younger than 30 years was associated with the diagnosis of an STD after the diagnosis of HIV infection (OR = 2.94, p =.0009). CONCLUSIONS: Patients diagnosed with HIV in an STD clinic setting commonly return with new STDs in follow-up, suggesting continued exposure of HIV to others. More intensive screening and counseling interventions focused on STD prevention in those with HIV infection is a necessary HIV prevention strategy.

Screening tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections--2002.

Since publication of CDC's 1993 guidelines (CDC, Recommendations for the prevention and management of Chlamydia trachomatis infections, 1993. MMWR 1993;42[No. RR-12]:1-39), nucleic acid amplification tests (NAATs) have been introduced as critical new tools to diagnose and treat C. trachomatis and Neisseria gonorrhoeae infections. NAATs for C. trachomatis are substantially more sensitive than previous tests. When using a NAAT, any sacrifice in performance when urine is substituted for a traditional swab specimen is limited, thus reducing dependence on invasive procedures and expanding the venues where specimens can be obtained. NAATs can also detect both C. trachomatis and N. gonorrhoeae organisms in the same specimen. However, NAATs are usually more expensive than previous tests, making test performance from an economic perspective a key consideration. This report updates the 1993 guidelines for selecting laboratory tests for C. trachomatis with an emphasis on screening men and women in the United States. (In this report, screening refers to testing persons in the absence of symptoms or signs indicating C. trachomatis or N. gonorrhoeae infection.) In addition, these guidelines consider tests from an economic perspective and expand the previous guidelines to address detection of N. gonorrhoeae as well as C. trachomatis infections. Because of the increased cost of NAATs, certain laboratories are modifying manufacturers' procedures to improve test sensitivity without incurring the full cost associated with screening with a NAAT. Such approaches addressed in these guidelines are pooling of specimens before testing with a NAAT and additional testing of specimens whose non-NAAT test result is within a gray zone. This report also addresses the need for additional testing after a positive screening test to improve the specificity of a final diagnosis. To prepare these guidelines, CDC staff identified pertinent concerns, compiled the related literature published during 1990 or later, prepared tables of evidence, and drafted recommendations. Consultants, selected for their expertise or disciplinary and organizational affiliations, reviewed the draft recommendations. These final guidelines are the recommendations of CDC staff who considered contributions from scientific consultants. These guidelines are intended for laboratorians, clinicians, and managers who must choose among the multiple available tests, establish standard operating procedures for collecting and processing specimens, interpret test results for laboratory reporting, and counsel and treat patients.