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Screening for Infectious Diseases in Adult Primary Care; Who, What, When?. Ronald Dworkin MD Medical Grand Rounds Providence St. Vincent Med Center 12/6/11. Where, Why and How will also be covered when appropriate. Outline. Definition of screening Principles of screening
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Screening for Infectious Diseases in Adult Primary Care; Who, What, When? Ronald Dworkin MD Medical Grand Rounds Providence St. Vincent Med Center 12/6/11
Outline • Definition of screening • Principles of screening • Historical background • Screening recommendations in ID • Sex tips etc • USPSTF, CDC, local health dept recs • General adult recommendations • Pregnancy
This morning 3 patients walk into your office; a 58 yo married malpractice attorney, a 32 yo Catholic nun, and a 23 yo Colombian born woman who is 16 weeks pregnant (whose boyfriend is glaring at you in an unfriendly manner). Which screening test should be done on all 3? • A. Chlamydia urine NAAT • B. Syphilis antibody • C. HIV antibody • D. PPD or IGRA for TB • E. Urine culture
What is screening ? “Detecting the presence of a disease while it is still in its preclinical stage.” Rose G, Barker D. BMJ, 1978
History of Medical Screening(Morabia, Zhang. Postgrad Med J 2004;80:463-469) • US Army screening for mental illness in recruits • Started in 1917 • Developed concepts of sensitivity/specificity • US Army screening for syphilis • Prevalence 5.6% in Army • Evolution of nontreponemal/treponemal testing • Extension to civilian uses (premarital, hosp admission)
Wilson and Jungner. WHO Public Health Paper #34, 1968“Principles and Practice of Screening for Disease” Screening is “The presumptive identification of unrecognized disease by the application of (tests) which can be applied rapidly . . . sort out apparently well persons who probably have a disease from those who probably do not . . . is not intended to be diagnostic but . . . must be referred to their physicians for diagnosis.” Concepts of “mass” vs “selective” screening
Wilson and Jungner. WHO Public Health Paper #34, 1968(cont’d) Appraising the validity of a screening program • Important health problem – Prevalence, cost • Natural history understood • Detectable early stage • Early treatment better than late • Suitable test for early stage - sensitivity • Acceptable to patients • Testing interval determined • Extra clinical workload provisions • Risks < benefits • Costs balanced against benefits
Screening Authorities • US Preventive Services task Force (USPSTF) • CDC
Screening recommendations USPSTF (Guide to Clinical Preventive Services 2010-2011) • 60 screening recommendations • Largest # in Cancer – 17 • ID is second largest with 11 http://www.ahrq.gov/clinic/pocketgd1011/pocketgd1011.pdf http://epss.ahrq.gov/PDA/index.jsp
USPSTF Screening Recommendations for General Adult Infectious Diseases • Genital herpes • Chlamydial genital infection • Gonorrhea • Hepatitis B • Hepatitis C • HIV • Syphilis • (TB) SEX
STDs • 19 million new infections per year in US • Cost $14.7 billion • Half occur in individuals ages 15-24 • Underserved, minority populations most at risk • Chlamydial infection most common reported ID • Women most at risk for serious complications of chlamydia and GC, and pregnancy puts fetus at risk • There is a large reservoir of asymptomatic/minimally symptomatic infections with many STDs (HIV, chlamydia, GC, HSV, syphilis) • Primary care clinicians in critical position to know about individual patient risk, establish rapport on sensitive issues, and screening/treating
Sex and Infectious Diseases • Majority of US med school graduates feel inadequately trained on taking sexual history. • Patients report they would want to discuss with their physicians but often are not asked. • Physicians often make assumptions that are not correct
Patients lie to their doctors 2004 online survey by WebMD • 45% admitted lying • 17% sex • 12% drug use • 22% smoking • 16% drinking
Human Sexuality is Complicated • Kinsey (1948, 1953) reported 37% of males had at least one homosexual experience and 10% of males “more or less exclusively” homosexual for at least 3 years between ages 16-55; 2-6% of females ages 20-35 “more or less exclusively” homosexual
“The danger of assumptions”Arch Intern Med 1999:159;2730 • 6935 self-identified lesbian women • 77% had 1 or more lifetime male partners • 70% vaginal and 17% anal intercourse • 6% had male partner within past year
“The danger of assumptions” (2)J Sexual Med 2007:4;1247 • Among 50 patients over 70 (81 +/- 6 yrs) • 56% woman, 18% “sexually active” • 41% of men “sexually active” • Only 4% of women initiated discussion with their physician, but 32% would want physician to do so.
“The danger of assumptions” (3)NEJM 2007:357;762 • 3005 adults (1550 women, 1455 men) 57-85 yrs • Age 65-74 prevalence of “sexual activity” 53% • Age 75-85 prevalence of “sexual activity” 26%
STD’s and the elderly • Very little specific data exists but there is suggestion that STD’s are on the rise • Prevalence of HIV rising • Olowokure et al. Sexually transmitted infections 2008;84:312 • British study showed doubling of STD rates in >45 yo • Contributing factors • Divorce • Online dating • ED drugs • Lack of STD education • PCPs could be a great source
Sexually Transmitted Diseases On Rise Among Elderly Seniors Gone Wild STDs Running Rampant In Retirement Community Doctor Blames Viagra, Lack Of Sex Education http://www.thedailyshow.com/watch/thu-april-9-2009/dirty-bird-special
A Good Sexual History: Tips • Orienting sentence helps break the ice • Be “matter of fact” – and avoid making assumptions • Use specific language, e.g. “sexually active” or “sexual intercourse” are vague • Ask about always using barrier protection • Ask about any “concerns”
USPSTFGrading of Recommendations/Level of Evidence Level I : at least one properly designed RCT II-1: well-designed, non-randomized trials II-2: well-designed cohort or case-control studies from more than 1 center or group II-3: multiple series III : opinions of respected authorities
Categories of Recommendations for a Clinical Service A : Good evidence that benefits outweigh risks* B : At least fair evidence that benefit outweighs risk* C : At least fair evidence of benefit but fair risk** D : At least fair evidence that risk outweighs benefit*** I : Evidence lacking, unable to assess risk/benefit * Clinicians should discuss the service with eligible pts ** No need to offer unless there are mitigating individual circumstances ***Do not offer
Asymptomatic bacteriuria in pregnancy • Bacteriuria develops in 2-7% in early pregnancy • 40% of asxbacteriuria pts develop pyelo • Bacteriuria is assoc with low birthweight, preterm delivery and perinatal mortality • Multiple studies have shown treatment of identified women reduces these complications • Dipstick UA has low sensitivity in asx women, thus urine culture required, >5 logs CFU
Screening for Asymptomatic Bacteriuria in pregnancy • Summary of Recommendations The U.S. Preventive Services Task Force (USPSTF) recommends screening for asymptomatic bacteriuria with urine culture for pregnant women at 12 to 16 weeks gestation or at the first prenatal visit, if later. Grade: A Recommendation. • The USPSTF recommends against screening for asymptomatic bacteriuria in men and nonpregnant women. Grade: D Recommendation.
Bacterial vaginosis (BV) in pregnancy • The association between BV and preterm delivery is well established, prevalence of BV is 9-23% in pregnancy, higher in those with additional risk factors for STDs • Risk factors for preterm delivery include AA race, low BMI, previous preterm delivery, some anatomical factors • Diagnosis of BV by Amsel criteria requires 3 out of 4 – pH>4.7, clue cells, thin homogenous discharge, fishy odor with KOH (vs gram stain) variably sensitive/specific • Many cases spontaneously remit (up to 50%) • Evidence of benefit of screening and treatment is lacking
Screening for Bacterial vaginosis in pregnancy • The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for bacterial vaginosis in asymptomatic pregnant women at high risk for preterm delivery. (This is an "I" statement.) • The USPSTF recommends against screening for bacterial vaginosis in asymptomatic pregnant women at low risk for preterm delivery. (This is a grade "D" recommendation.)
Background on Chlamydia Screening • Most women with chlamydia infection are asymptomatic • Complications include infertility, PID, ectopic pregnancy, low birth weight, premature labor, infant morbidity/mortality • NAAT’s (PCR, other DNA based tests) are the most sensitive and can be done with urine or vaginal swabs if no pelvic is performed • Expedited partner therapy is recommended (providing prescriptions for sexual partners without personally examining them) and is “permissible” in Oregon • See updated treatment guidelines at www.cdc.gov/std/treatment/2010/toc.htm -doxycycline for 7 days or azithro 1 gm x 1 • F/U testing not recommended except in pregnancy • Men serve as a reservoir but data is lacking to recommend routine screening
Screening for Chlamydial Infection • The U.S. Preventive Services Task Force (USPSTF) recommends screening for chlamydial infection for all sexually active non-pregnant young women aged 24 and younger and for older nonpregnant women who are at increased risk. CDC cutoff is 25.Grade: A Recommendation. • The USPSTF recommends screening for chlamydial infection for all pregnant women aged 24 and younger and for older pregnant women who are at increased risk. Grade: B Recommendation. • The USPSTF recommends against routinely providing screening for chlamydial infection for women aged 25 and older, whether or not they are pregnant, if they are not at increased risk. Grade: C Recommendation. • The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for chlamydial infection for men. CDC recommends “when resources permit”Grade: I Statement.
Chlamydia Recommendation in Plain English • Screen all women under 25 • Don’t screen women over 25 (pregnant or not) who are not in a risk group • Don’t screen men
What constitutes increased risk for Chlamydia (aside from age)? • History of STI’s • New or multiple sexual partners • Inconsistent condom use • Exchanging sex for money or drugs
Screening for Genital Herpes • The U.S. Preventive Services Task Force (USPSTF) recommends against routine serological screening for herpes simplex virus (HSV) in asymptomatic pregnant women at any time during pregnancy to prevent neonatal HSV infection.Grade: D Recommendation. • The USPSTF recommends against routine serological screening for HSV in asymptomatic adolescents and adults.Grade: D Recommendation.
Additional comments on HSV screening • Most infections are asymptomatic • Infections are lifelong with episodic shedding • Testing methods include serology (glycoprotein G type specific) and viral detection (culture or PCR) • While antiviral therapy reduces viral shedding and recurrent episodes, there is little data in asymptomatic seropositive individuals that treatment (or counseling) reduces transmission • Highest risk in pregnancy is with primary infection, but there is no data on use of screening of asymptomatics in pregnancy to detect primary infection • There is no evidence that antiviral use in women with a hx of HSV leads to reduced neonatal infection
Screening for Gonorrhea • The U.S. Preventive Services Task Force (USPSTF) recommends that clinicians screen all sexually active women, including those who are pregnant, for gonorrhea infection if they are at increased risk for infection (that is, if they are young or have other individual or population risk factors; see Clinical Considerations for further discussion of risk factors).Grade: B Recommendation. • The USPSTF found insufficient evidence to recommend for or against routine screening for gonorrhea infection in men at increased risk for infection (see Clinical Considerations for discussion of risk factors).Grade: I Statement. • The USPSTF recommends against routine screening for gonorrhea infection in men and women who are at low risk for infection (see Clinical Considerations for discussion of risk factors).Grade: D Recommendation. • The USPSTF found insufficient evidence to recommend for or against routine screening for gonorrhea infection in pregnant women who are not at increased risk for infection (see Clinical Considerations for discussion of risk factors).Grade: I Statement.
Screening for GC In Plain English • Only screen women for GC who are at high risk, even if pregnant • That includes age <25 • Do not screen men for GC
Comments on GC Screening • Most men are symptomatic • <25 yo, hx previous GC, other STIs, new/multiple partners, inconsistent condoms, sex work and drug use are risk factors • Prevalence varies by locale (highest risk in Oregon Multnomah followed by college locales) and epidemiologic group (African Americans and MSM highest) • 1100 cases in 2009 in Oregon, 5 fold higher rate in AAs though 60 occurred in caucasians • NAAT and other nucleic acid based tests on urine or vaginal swabs are more accurate than culture, though culture still important due to ability to do susceptibility testing • Recent CDC recommendation in treatment is to treat all pts with GC with Ceftriaxone 250 mg IM plus azithromycin 1 gm po (to reduce risk of cephalosporin failure and drug resistance emergence)
Screening for Hepatitis B Virus Infection • The USPSTF recommends against routinely screening the general asymptomatic population for chronic hepatitis B virus infection. Grade: D Recommendation. • The U.S. Preventive Services Task Force (USPSTF) recommends screening for hepatitis B virus (HBV) infection in pregnant women at their first prenatal visit.Grade: A Recommendation.
Additional comments on Hep B • Strategies around Hep B prevention focus on preventing perinatal transmission and vaccination of infants and previously unvaccinated children • Highest risk groups (IDU, MSM, STI risk groups) should be targeted for vaccination • 90% of individuals with acute hep B recover and do not have chronic infection • Chronically infected individuals should have referral to a specialist – treatment is cost effective • Co-infection in HIV is important with regard to choice of ART because of increased progression risk and overlap of antiviral treatment
CDC recommendations on Hep B screening • 2008 recommendations modified; “individuals born in Asia, Africa or other geographic regions with 2% or higher prevalence of chronic HBV… should be screened” • Screening populations with prevalence as low as >0.3% may be cost effective (US prevalence estimated at 0.3-0.5%) in terms of QALY<$50K • Eckman et al. CID 2011;52:1294
Screening for Hepatitis C in Adults • The U.S. Preventive Services Task Force (USPSTF) recommends against routine screening for hepatitis C virus (HCV) infection in asymptomatic adults who are not at increased risk (general population) for infection.Grade: D Recommendation. • The USPSTF found insufficient evidence to recommend for or against routine screening for HCV infection in adults at high risk for infection.Grade: I Statement.
Comments on Hep C screening • Much more prevalent in US than Hep B (3.2 million chronically infected vs 700 k) • Risk factors include blood/factor transfusion prior to 1992, hemodialysis, IDU, nasal cocaine, occupational, and to a lesser extent but increasingly recognized sexual (MSM, multiple partners) • Hep C is a leading cause of morbidity and mortality in HIV • Guidelines for HIV care recommend screening for Hep C, and recent studies suggest periodic retesting in individuals with ongoing risks (CID 2011)
Screening for HIV • The U.S. Preventive Services Task Force (USPSTF) strongly recommends that clinicians screen for human immunodeficiency virus (HIV) all adolescents and adults at increased risk for HIV infection.Grade: A Recommendation. • The USPSTF makes no recommendation for or against routinely screening for HIV adolescents and adults who are not at increased risk for HIV infection.Grade: C Recommendation. • The USPSTF recommends that clinicians screen all pregnant women for HIV.Grade: A Recommendation.
CDC Recommends UniversalScreening for HIV Disease • CDC recommendation 2006 • HIV screening of all pts 13-64 yrs should be offered in all healthcare settings • General consent for medical care should be adequate, no need for special consent forms, etc (in Oregon, oral consent is adequate) • Option to decline or defer (opt-out testing) • Frequency of re-testing depends on ongoing risk • Once if no ongoing risk • As much as every 6 months if ongoing risk • Cost effectiveness is dependent on availability of ART
Rationale for Expanded HIV Screening • 1.1 million people with HIV in U.S. • 21% are unaware of their status (250,000) • 36% of newly diagnosed pts have or develop AIDS within 1 yr of diagnosis • Only 40% of adults have ever been tested • <25% of at-risk adults have been tested within the prior 12 months • Knowledge of HIV status can substantially reduce high risk behaviors (68% in metanalysis JAIDS 1995;39:446) • Rate of new infections has plateaued at approx 56,000 cases annually • Only 28% of infected individuals in the US have fully suppressed HIV RNA (CDC, 12/1/11)
Expanding HIV screening cost-effective measure to reduce spread Long et al. Ann Int Med 2010;153:778 • One time screening of low risk persons could prevent 200-300k new infections over 20 yrs, reducing annual incidence by 17-24% • Assumed only 20% reduction in risky behavior and without more aggressive screening than currently occurs in high risk groups, assumed 75% treated • $22,000/QALY
Screening for Syphilis Infection • The U.S. Preventive Services Task Force (USPSTF) strongly recommends that clinicians screen persons at increased risk for syphilis infection. • The USPSTF recommends against routine screening of asymptomatic persons who are not at increased risk for syphilis infection. Grade: D Recommendation. • The USPSTF strongly recommends that clinicians screen all pregnant women for syphilis infection.
2010 2009 2011 2007 2008 Source: Multnomah county analysis of DIS surveillance data; reported numbersmay not match official OHA numbers.
Characteristics of Cases in 2010 • 100% MSM • 64% non-Hispanic white • Avg age is 38 years (range 19 - 66 years) • 67% between 30-49 years old • 53% known HIV(+) • 71% diagnosed w/primary or secondary