Secondary prevention—screenings, guidelines, and recommendations. Clinical screening of at-risk populations for infectious and communicable diseases is considered secondary prevention, because you are looking for disease in an asymptomatic person. According to Katz and colleagues, the minimum requirements for an effective screening program include the following1:
- The disease must be serious, there must be effective treatment if detected, and the natural history of the disease must be understood and not too rare or common to be cost effective.
- The screening test must be reasonably quick, inexpensive, and safe, with a known and acceptable sensitivity, specificity, and positive predictive value.
- Follow-up must be available for positive results with acceptable treatment.
In primary care, the most frequent screening tests done for communicable diseases and infectious disease are for prevalent and treatable sexually transmitted infections (STI) and during pregnancy to protect the pregnant woman and fetus according to the U.S. Preventive Services Task Force (USPSTF) guidelines. Chlamydia screening is done per these recommendations, as Chlamydia trachomatis is the most prevalent reported genital, bacterial STI in women and men ages 14 to 24 in the U.S. Chlamydia is often asymptomatic, with the potential for serious consequences if left untreated (for example, pelvic inflammatory disease, ectopic pregnancy, infertility, and newborn infection). There is a safe, reliable diagnostic test (self-collected vaginal swab or urine nucleic acid amplification [NAAT] testing). Patients with positive results can be treated with effective antibiotic(s) (a single one-gram oral dose of azithromycin). Screening and follow-up treatment are offered in most local health departments free of charge.27
USPSTF screening recommendations. The USPSTF is an independent panel of preventive and evidence-based experts who make recommendations on clinical preventive services to primary care clinicians for screening tests, counseling, and preventive medications that are applicable to at-risk populations of adults and children with no signs or symptoms of disease.28
The panel makes recommendations based on “rigorous review” of peer-reviewed research to evaluate the benefits and harms of each clinical preventive service. It then assigns an A, B, C, or D grade or I (insufficient evidence statement) based on the strength of the evidence regarding the harms and benefits of a specific preventive service.29 In general, there is little difference in clinical practice between A and B recommended practices, and these recommendations correlate well with the Affordable Care Act. Table 1 lists the USPSTF A and B recommendations for infection-related diseases as of October 2014.30
TABLE 1. USPSTF A and B recommendations for infection-related diseases
|Bacteriuria screening: pregnant women||The USPSTF recommends screening for asymptomatic bacteriuria with urine culture in pregnant women at 12 to 16 weeks’ gestation or at the first prenatal visit, if later.|
|Cervical cancer screening||The USPSTF recommends screening for cervical cancer in women ages 21 to 65 years with cytology (Pap smear) every three years or, for women ages 30 to 65 years who want to lengthen the screening interval, screening with a combination of cytology and human papillomavirus (HPV) testing every five years.|
|Chlamydia screening: women||The USPSTF recommends screening for chlamydia in sexually active women age 24 years or younger and in older women who have an increased risk for infection.|
|Gonorrhea prophylactic medication: newborns||The USPSTF recommends prophylactic ocular topical medication for all newborns for the prevention of gonococcal ophthalmia neonatorum.|
|Gonorrhea screening: women||The USPSTF recommends screening for gonorrhea in sexually active women age 24 years or younger and in older women who have an increased risk for infection.|
|Hepatitis B screening: nonpregnant adolescents and adults||The USPSTF recommends screening for hepatitis B virus infection in persons with a high risk for infection.|
|Hepatitis B screening: pregnant women||The USPSTF strongly recommends screening for hepatitis B virus infection in pregnant women at their first prenatal visit.|
|Hepatitis C virus infection screening: adults||The USPSTF recommends screening for hepatitis C virus (HCV) infection in persons with a high risk for infection. The USPSTF also recommends offering one-time screening for HCV infection to adults born between 1945 and 1965.|
|HIV screening: nonpregnant adolescents and adults||The USPSTF recommends that clinicians screen for HIV infection in adolescents and adults ages 15 to 65 years. Younger adolescents and older adults who are at increased risk should also be screened.|
|HIV screening: pregnant women||The USPSTF recommends that clinicians screen all pregnant women for HIV, including those who present in labor and are untested and whose HIV status is unknown.|
|Sexually transmitted infections counseling||The USPSTF recommends intensive behavioral counseling for all sexually active adolescents and for adults who have an increased risk for sexually transmitted infections.|
|Syphilis screening: nonpregnant persons||The USPSTF strongly recommends that clinicians screen persons with an increased risk for syphilis infection.|
|Syphilis screening: pregnant women||The USPSTF recommends that clinicians screen all pregnant women for syphilis infection.|