Screening Tests for Adults (Ages 30-49)

Colon cancer is the uncontrolled growth of abnormal cells within the layers of tissue that line the colon. It is the third most common, non-skin cancer in adults and the third leading cause of cancer deaths in men and women in the United States. The lifetime risk of developing colon cancer is about 1 in 21 (or 4.7%) for men and 1 in 23 (4.4%) for women, according to the American Cancer Society (ACS).

The incidence of colon cancer has decreased over the last several years in people age 55 and older due in part to screening tests that have resulted in the removal of cancerous and precancerous polyps. However, there has been a 51% increase in colon cancer among people younger than age 50 since 1994. In 2018, the ACS lowered their recommended starting age for colon cancer screening to age 45 for people with an average risk of colon cancer. ACS says they decided to make the change in their latest guidelines because of increasing rates of colon cancer among younger people in recent years.

Furthermore, if you have one or more risk factors for colon cancer you should talk to your healthcare practitioner who can help you assess your individual risk factors and determine if you should begin screening at a younger age and more frequently. As the Centers for Disease Control and Prevention (CDC) notes, any of the recommended tests is better than no test.

Screening Recommendations 

Several health organizations have colon cancer screening recommendations. In 2017, screening guidelines for the early detection of pre-cancerous polyps and colon cancer were released by the US Multi-Society Task Force (MSTF) on Colorectal Cancer. The US Preventive Services Task Force released updated similar recommendations in 2016 and the American Cancer Society (ACS) updated their guidelines in 2018. While these groups may differ on which tests to use and how often, they each support screening for colon cancer. Recommendations are based on your age and level of risk.

Increased and High Risk: 
Risk of colon cancer increases with age, being overweight or obese, and with the occurrence of cancers in other parts of the body. Examples of other risk factors include:

• Family history—having one or more family members with colon cancer or multiple polyps, especially if they were younger than age 60 at diagnosis
• Diet—high fat and meat diets are risk factors, especially combined with not eating enough fruits, vegetables, and/or high-fiber foods
• Lifestyle—these risk factors include cigarette smoking, drinking excessive amounts of alcohol, and lack of regular exercise
• Having ulcerative colitis, a form of inflammatory bowel disease
• Having type 2 diabetes
• Racial or ethnic background—African Americans and Ashkenazi Jews have higher risk and rates of colon cancer compared to others.
• Having a personal history of colon cancer and/or high risk precancerous polyps
• Having a rare inherited disease called familial adenomatous polyposis (FAP)—this causes benign polyps to develop early in life and causes cancer in almost all affected persons unless the colon is removed. (See the Genetics Home Reference article on FAP)
• Having a genetic syndrome called Lynch syndrome (hereditary non-polyposis colon cancer or HNPCC) (See the Genetics Home Reference article on Lynch syndrome.)
   

People with increased or high risk of colon cancer may be advised to start screening at a younger age (e.g. age 40). A colonoscopy is usually recommended because it is the most accurate and thorough. Also, the recommended screening interval for high-risk individuals is shorter than for people with average risk (such as every 1-2 years compared to every 10 years).

Additionally, people who have been screened and found to have colon cancer or high risk pre-cancerous polyps also need more frequent re-testing, usually at least every 3 years. (This is called surveillance.) For example, the MSTF guidelines advise enhanced surveillance for people with 3-10 small tubular adenomas as well as those with 1 or more high-risk polyps (i.e., villous features, larger than 10 mm diameter tubular adenoma or serrated sessile polyp, or any polyp that has very atypical features, called high grade dysplasia). On the other hand, those with 1-2 small (less than 10 mm) tubular adenomas in the colon can be re-screened at normal intervals (i.e., every 10 years). Another common polyp, termed a hyperplastic polyp, is not felt to increase risk of colon cancer.

For more information on these types of polyps, read the American Cancer Society’s webpage Understanding Your Pathology Report: Colon Polyps

Average Risk

This includes people with no known risk factors other than age. The ACS recommends that all average-risk people begin screening at age 45. Both the MSTF and the USPSTF recommend that people with average risk for colon cancer begin screening at age 50. MSTF recommends that African-Americans begin at age 45.

Screening Tests 
The following table summarizes the screening tests that are options for people with average risk. Tier 1 tests are the tests of choice, according to the MSTF, while tier 2 tests have some disadvantages compared to tier 1 tests. The ACS guidelines do not prioritize a particular screening test and instead says patients and their healthcare practitioners should choose from among several tests based on the patient's preference.

 

TEST	DESCRIPTION	SCREENING INTERVAL FOR PEOPLE AT AVERAGE RISK	PROS	CONS
Tier 1 tests
Colonoscopy	Examination of the rectum and entire colon with a lighted instrument	Every 10 years	Can examine the entire colon Detects pre-cancerous polyps and cancer Can remove polyps and take biopsies for pathological testing	Extensive full bowel preparation ahead of time Sedation needed to perform Takes at least one day for prep and recovery Risk of bleeding, infection or bowel tears
Fecal Immuno-chemical test (FIT) stool test	Test to detect hidden blood in stool samples	Annually	No dietary or drug restrictions No bowel preparation No direct risk to bowel Samples can be collected at home	Cannot detect precancerous changes May miss some cancers May need to have colonoscopy if positive result
Tier 2 tests
Flexible sigmoidoscopy	Examination of the rectum and lower colon with a rigid or flexible lighted instrument	Every 5-10 years	Minimal preparation ahead of time Detects pre-cancerous polyps and cancer Does not usually need sedation Fairly quick and safe	Only examines about 30% of colon Small risk of bleeding, infection or bowel tear May need to have colonoscopy if abnormal result found
Virtual colonoscopy (CTC, or computed tomographic colonography)	Examination of the rectum and entire colon to the small intestine using x-rays and computers; tube inserted in rectum and bowel is inflated with air	Every 5 years	No sedation required Can view entire colon Detects pre-cancerous polyps and cancer Relatively safe; minimal risk of tear to colon	Full bowel preparation required May need standard colonoscopy if abnormal results Effectiveness as a screening tool is not fully accepted
Fecal Immunochemical test (FIT)-DNA	Detects blood and mutations in specific genes associated with colon cancer in DNAisolated from a stool sample	Every three years, according to the American Cancer Society and MSTF	No bowel preparation or dietary restrictions Sample can be collected at home No risk of bowel tear	Cannot detect precancerous changes Not as effective as annual FIT Adequate stool sample must be obtained Special handling needed May need colonoscopy if abnormal result found
Capsule colonoscopy	Examination of the colon performed by swallowing an indigestible pill with embedded video cameras	Every 5 years per MSTF	Detects pre-cancerous polyps and cancer No sedation required Relatively safe	May need standard colonoscopy if abnormal results Not approved by the FDA for screening people at average risk
No Tier recommendation
Guaiac-based fecal occult blood test (gFOBT) stool test	Test to detect hidden blood in stool sample	Annually	No bowel preparation No direct risk to bowel Sample can be collected at home	Dietary restrictions before testing Cannot detect precancerous changes Detects any blood, not just from cancers but from food or dental procedures May need colonoscopy if positive result

In addition to screening tests, a healthcare practitioner may perform a digital rectal examination (DRE) to feel for a rectal mass with a gloved finger. Most colon cancers, however, are beyond the detection range of a DRE.

If a test other than colonoscopy gives a result suggestive of polyps or cancer, a colonoscopy is often done to examine the full colon and remove polyps or potentially cancerous areas.

Decision Aids

Because any invasive procedure carries some level of risk, you should talk to your healthcare provider about the screening tests recommended for you. Some employers, health plans, and health practitioners offer decision aids.

Also, don't neglect the protection of getting re-tested at the interval recommended by your healthcare provider.

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Links
Tests: Fecal Occult Blood Test and Fecal Immunochemical Test
Condition: Colon Cancer

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Sources Used in Current Review (September 17, 2018)

(2016 June). Colorectal Cancer: Screening. US Preventive Services Task Force. Available online at https://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryFinal/colorectal-cancer-screening2?ds=1&s=colon . Accessed on September 2018.

Rex DK, Boland CR, Dominitz JA, et al. Colorectal Cancer Screening: Recommendations for Physicians and Patients from the U.S. Multi-Society Task Force on Colorectal Cancer. Am J Gastroenterol. 2017; 112(7):1016–1030. Available online at http://www.nature.com/articles/ajg2017174. Accessed on 9/12/2018.

Canadian Task Force on Preventive Health Care, Recommendations on screening for colorectal cancer in primary care Canadian Med Assoc J. 2016 Mar 15; 188(5): 340–348. Available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4786388/ Accessed 9/12/2018

Wolf AMD, Fontham ETH, Church TR, et al. Colorectal cancer screening for average‐risk adults: 2018 guideline update from the American Cancer Society. CA Cancer J Clin. 2018; 68(4):250-281. First published: 30 May 2018 https://doi.org/10.3322/caac.21457 https://onlinelibrary.wiley.com/doi/full/10.3322/caac.21457 Last accessed 9/12/2018

Prostate cancer is the second most frequently diagnosed cancer in men, after skin cancer. It is also the second leading cause of cancer death, after lung cancer. As many as 1 in 7 American men will develop it during their lifetime, with most cases diagnosed in men 65 years of age or older. Some prostate cancers progress quickly and cause death within months or a few years, but most grow slowly and never pose a major health threat.

Screening for prostate cancer is important for men to discuss with their healthcare providers. Many complicated issues are involved:

• Current technology cannot tell a slow-growing cancer from a fast one, and the cancer may never significantly affect a man's health or life expectancy.
• Screening tests for prostate-specific antigen (PSA) do not detect all cases, and some elevated PSA results do not prove to be cancer.
• Diagnosis through biopsy (with a small risk of infection and bleeding) and side effects of treatment (which could cause erectile dysfunction and incontinence) can potentially be harmful itself. Most prostate cancers are slow-growing and may not cause any trouble.
• Results from long-term trials on whether PSA testing improves prostate cancer survival rates have been inconclusive.
   

Informed decisions
In spite of the questions surrounding prostate cancer screening, most health organizations agree that men should receive balanced information about prostate cancer screening and recommend that men discuss it with their healthcare provider. You need to know the risks, uncertainties, benefits, and limits of prostate cancer testing and treatment and should work with your healthcare provider to understand your options and decide what is best for you. Before choosing prostate screening, you should weigh the pros and cons based on your age, life expectancy, family history, race, overall health, previous test results, and individual risk tolerance.

Risk
One important factor to consider is your personal risk of developing prostate cancer:

• Average risk: Healthy men with no known risk factors
• Increased risk: African American men or men who have a father or brother who was diagnosed before they were 65
• High risk: Men with more than one relative who was affected at a young age
   

Tests
If you choose to undergo screening, the following tests may be recommended:

• Prostate specific antigen (PSA)—blood test that measures the level of PSA in the blood
• Digital rectal exam (DRE)—part of a physical exam that the health practitioner performs to examine the prostate gland
   

Recommendations
Most organizations do not recommend prostate cancer screening for men 49 and younger, unless they have increased or high risk. The exception is the National Comprehensive Cancer Network.

• The National Comprehensive Cancer Network (NCCN) recommends a baseline test at age 45 for men who want screening, which will determine when and how often to have future tests. It advises using the DRE and the PSA test, in combination, for the broadest detection of cancer in its early stages. If the PSA test result is greater than 1.0 ng/mL, or if the man is at a higher risk, it recommends a DRE and PSA test at one- to two-year intervals.
• The U.S. Preventive Services Task Force (USPSTF) says that for men younger than age 50 at increased risk, including African American men and men with a family history of prostate cancer, a reasonable approach is to discuss the benefits and harms of PSA screening to make an informed decision. The decision is based on the harm that can come from false-positive PSA test results which then may lead to surgical or radiation treatment that may ultimately provide little benefit.
• The American Cancer Society (ACS) recommends that healthy men with average risk who wish to be screened consider waiting to get tested until age 50. ACS recommends considering earlier testing for higher-risk groups.
  • If you are African American or have a father or brother who was diagnosed before they were 65, ACS recommends considering testing at 45 years of age.
  • If more than one relative was affected at a young age, you could begin testing at 40 years old; then, depending on the results, get tested again at age 45 or earlier as results warrant.
  • ACS recommends re-screening every two years if your PSA level is less than 2.5 ng/mL and annual screening if it is 2.5 ng/mL or higher.
• The American Urological Association (AUA) recommends waiting to have a baseline PSA and DRE until age 55 for men at average risk who wish to be screened. For those at increased or high risk, AUA advises that decisions regarding prostate cancer screening be individualized based on patient preferences and an informed discussion about benefits and harms.
• The American College of Physicians advises against screening men younger than age 50.

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Link

Articles: Making Informed Decisions for Better Health
 

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Sources Used in Current Review (last reviewed 6/25/2018)

(March 11, 2016) American Cancer Society. About Prostate Cancer. Available online at https://www.cancer.org/content/dam/CRC/PDF/Public/8793.00.pdf. Accessed on June 22, 2018.

(March 11, 2016) American Cancer Society. Prostate Cancer Risk Factors. Available online at https://www.cancer.org/cancer/prostate-cancer/causes-risks-prevention/risk-factors.html. Accessed on June 22, 2018.

(April 14, 2016) American Cancer Society. If Prostate Cancer Screening Test Results Aren’t Normal. Available online at https://www.cancer.org/cancer/prostate-cancer/early-detection/if-test-results-not-normal.html. Accessed on June 22, 2018.

(April 14, 2016). American Cancer Society. Recommendations for Prostate Cancer Early Detection. Available online at https://www.cancer.org/cancer/prostate-cancer/early-detection/acs-recommendations.html. Accessed on June 22, 2018.

(April 5, 2018) National Comprehensive Cancer Network. Clinical Practice Guidelines in Oncology: Prostate Cancer Early Detection. Available online at https://www.nccn.org/professionals/physician_gls/pdf/prostate_detection.pdf. Accessed on June 22, 2018.

(May 8, 2018) U.S. Preventive Services Task Force Bulletin. USPSTF Issues Final Recommendation on Screening for Prostate Cancer. Available online at https://www.uspreventiveservicestaskforce.org/Home/GetFile/6/250/prostate-cancer-final-rec-statement-bulletin/PDF. Accessed on June 22, 2018.

(May 2018) U.S. Preventive Services Task Force. Final Recommendation Statement: Prostate Cancer: Screening. Available online at https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/prostate-cancer-screening1. Accessed on June 22, 2018. 

(May 5, 2018) American Urological Association. Press release: AUA Responds to USPSTF Final Recommendations on Screening for Prostate Cancer. Available online at http://auanet.mediaroom.com/2018-05-08-AUA-Responds-to-USPSTF-Final-Recommendations-on-Screening-for-Prostate-Cancer. Accessed on June 22, 2018.

(2015) American Urological Association. Clinical Guidelines: Early Detection of Prostate Cancer. Available online at http://www.auanet.org/guidelines/early-detection-of-prostate-cancer-(2013-reviewed-and-validity-confirmed-2015). Accessed on June 22, 2018.

(19 May 2015) American College of Physicians. Screening for Cancer, Summary for Patients. Available online at http://annals.org/aim/fullarticle/2293232/screening-cancer. Accessed June 2018.

HIV is the virus that causes AIDS (acquired immunodeficiency syndrome), a life-threatening disease. Initially, an HIV infection may cause no symptoms or cause non-specific, flu-like symptoms that resolve after a short time period. The only way to determine whether a person has been infected is through HIV testing.

If the infection is not detected and treated, eventually symptoms of AIDS emerge and begin to progressively worsen. Without treatment, HIV destroys the immune system over time and leaves a person's body vulnerable to debilitating infections.

HIV is spread in the following ways:

• By having sex with an infected partner
• By sharing needles or syringes (such as with intravenous injection drug abuse)
• During pregnancy or birth; if a pregnant woman is infected with HIV, the virus can be passed to and infect her developing baby.
• Through contact with infected blood
• In the U.S. today, because of screening blood for transfusion and heat-treating techniques and other treatments of blood derivatives, the risk of getting HIV from transfusions is extremely small. However, before donated blood was screened beginning in 1985 in the U.S. and before treatments were introduced to destroy HIV in some blood products, such as factor 8 and albumin, HIV was transmitted through transfusion of contaminated blood or blood components.

Why Get Screening?
Screening for HIV is now part of routine healthcare in the United States and is an important part of wellness and prevention. This is because diagnosis early in the course of infection leads to timely, effective treatment that decreases the risk of progression to AIDS. A major National Institutes of Health (NIH) clinical trial published in 2015 found that individuals with HIV have a lower risk of developing AIDS and other serious illnesses if they start antiretroviral therapy sooner rather than later.

Early diagnosis also has important benefits for others and society at large. Thousands of people are diagnosed with HIV each year, and about 1 in 8 people in the United States with HIV are unaware that they have it. An individual can prevent further disease spread by learning their status, modifying behavior and not exposing others to infected blood or body fluids. Pregnant women who have HIV can start treatment to prevent spreading the disease to their children.

If an HIV screening test shows a person is not infected, he or she can take steps to avoid infection. For individuals who are HIV-negative but at high risk for HIV, the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) recommend that they consider taking pre-exposure prophylaxis (PrEP), a daily pill to help prevent infection. For people taking PrEP consistently, the risk of HIV infection is significantly lower compared to those who did not take it.

Know Your Risk
Several situations put you at high risk of contracting HIV:

• You've had unprotected sex with more than one partner.
• You have or have had a sexually transmitted disease (STD), which appears to make people more susceptible to and at higher risk for acquiring HIV infection during sex with infected partners.
• You're a man who has had sexual contact with another man.
• You have exchanged sex for money or drugs or had anonymous sex.
• You use or used injection drugs and are likely to have shared unsterilized needles.
• You have an HIV-positive sexual partner.
• You have had sex with anyone who falls into one of the categories listed above or are uncertain about your sexual partner's risk behaviors.
• You've been diagnosed with or treated for hepatitis or tuberculosis (TB).

How often you are tested should depend on your risk, activities, and sexual contacts. For example, during a long-term, truly monogamous sexual relationship, you may want just one test. However, if you or your partner have had sexual contact with more than one person in recent months, your risk of infection is greater. If you or a person with whom you've had sexual contact (even unwanted sexual contact) engaged in some risky behavior, you have even more reason to be tested.

Screening Tests
Different types of tests are available for HIV screening:

• Combination HIV antibody and HIV antigen test—this is the recommended screening test for HIV. It is available only as a blood test. It detects the HIV antigen called p24 plus antibodies to HIV-1 and HIV-2. (HIV-1 is the most common type found in the United States, while HIV-2 has a higher prevalence in parts of Africa.) By detecting both antibody and antigen, the combination test increases the likelihood that an infection is detected soon after exposure. These tests can detect HIV infections in most people by 2-6 weeks after exposure.
• HIV antibody testing—all HIV antibody tests used in the U.S. detect HIV-1, and some tests have been developed that can also detect HIV-2. These tests are available as blood tests or tests of oral fluid. HIV antibody tests can detect infections in most people 3-12 weeks after exposure.

Various options are available for getting tested:

• A blood or oral sample can be collected in a healthcare provider's office or a local clinic and sent to a laboratory for testing. In these same settings, a rapid test may available in which results are generated in about 20 minutes.
• A home collection kit approved by the U.S. Food and Drug Administration (FDA) is available for HIV antibody testing. This allows a person to take a sample at home and then mail it to a testing center. Results are available over the phone, along with appropriate counseling.
• The FDA has approved an HIV test for home use. The testing kit is the same as that used in many healthcare providers' offices and clinics in which an oral sample is collected for testing and results are available in about 20 minutes. Though the home test is convenient, it has limitations. It is less sensitive than a blood test so the home test may miss some cases of HIV that a blood test would detect and it is not as accurate when it is performed at home by a lay person compared to when it is performed by a trained healthcare professional. Care must be taken to avoid errors when performing the test. (For more, see the article on Home Testing, Avoiding Errors.)

Screening tests have limitations, so it is important to remember that:

• A negative screening test means only that there is no evidence of disease at the time of the test. If you have increased risk of HIV infection but negative screening results, it is very important to get screening tests on a regular basis.
• HIV tests will not detect the virus immediately after infection. Still, talk to your healthcare provider immediately if you think you’ve been infected. If exposure to the virus is recent, then antibody levels may be too low to detect. If an initial test is negative, it may be necessary to repeat testing at a later time with another antibody test or combination HIV antibody/antigen test. In the case of a negative result, the CDC recommends retesting three months after likely exposure.
• A positive screening test is not a diagnosis. A positive result must be followed by a second antibody test that differentiates between HIV-1 and HIV-2 to establish a diagnosis.

For more details on HIV screening, see the article on HIV Antibody and p24 Antigen.

Screening Recommendations

• The Centers for Disease Control and Prevention (CDC) recommends that everyone 13 to 64 years old have an HIV screening test at least once. The CDC recommends getting tested each year if you've engaged in an activity that can put you at increased risk of infection and spreading the disease. Additionally, men who have sexual contact with other men should be tested be tested every three to six months.
• The United States Preventive Services Task Force (USPSTF) recommends that all teens and adults ages 15 to 65 be screened for HIV infection. It also recommends that younger adolescents and older adults at increased risk undergo screening for HIV. As for how often, the Task Force says a reasonable approach is one-time testing for all people ages 15 to 65 and at least annual screenings for those at very high risk of HIV, such as men who have sex with men, injection drug users, and those who live or receive medical care in areas where the rate of HIV infection is high. Individuals at increased but not very high risk may be screened less frequently than every year. The USPSTF recommends every three to five years as a guideline. The Task Force points out that risk is "on a continuum" and health professionals should use their own discretion in deciding how frequently to test people for HIV.
• The American College of Physicians agrees with the CDC that everyone aged 13 to 64 be offered an HIV screening test in healthcare settings. It also recommends that healthcare practitioners should determine the frequency of repeat screening on an individual basis.
• The American Academy of Pediatrics (AAP) recommends targeted HIV screening for all sexually active youth. In addition, the academy advises routine testing starting at age 16 for all teens who live in areas where prevalence is high; that is, where more than 1 in 1,000 individuals are infected.
• For recommendations specific for pregnant women, see the article on Pregnancy.

Aside from these recommendations, certain individuals should get tested and learn their status. These include:

• People diagnosed with hepatitis, TB, or an STD
• People who received a blood transfusion prior to 1985 or had a sexual partner who received a transfusion and later tested positive for HIV
• A healthcare worker with direct exposure to blood on the job
• Any individual who thinks he or she may have been exposed

Talk to your healthcare provider
Don't be surprised if a healthcare practitioner, in any care setting, offers you an HIV screening test, in keeping with CDC recommendations. If your healthcare provider does not bring up sexual health topics, you can simply ask for a test or a risk assessment. You can also use confidential services to obtain testing or counseling.

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Resources & Links

For confidential information, you can call the STDs and HIV/AIDS hotline of the CDC: 800-CDC-INFO (232-4636).
To find a testing site near you, visit National HIV and STD Testing Resources
KidsHealth.org: HIV and AIDS
MedlinePlus: Screening and diagnosis for HIV
Mayo Clinic: HIV/AIDS - Preparing for your appointment
AIDSinfo: HIV Testing

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Sources Used in Current Review

Qaseem, A. et al. (2009 January 20). Screening for HIV in health care settings: A guidance statement from the American College of Physicians and HIV Medicine Association. Annals of Internal Medicine. Available online at http://annals.org/aim/article/744218/screening-hiv-health-care-settings-guidance-statement-from-american-college. Accessed 11/6/2016.

(2011 October 31). The pediatrician's role in preventing HIV infection. American Academy of Pediatrics. Available online at https://healthychildren.org/English/news/Pages/The-Pediatricians-Role-in-Preventing-HIV-Infection.aspx. Accessed 11/6/2016.

(2013 April). Human Immunodeficiency Virus (HIV) infection: Screening. U.S. Preventive Services Task Force. Available online at https://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryFinal/human-immunodeficiency-virus-hiv-infection-screening. Accessed 11/6/2016.

(2015 May 27). Press release: Starting antiretroviral treatment early improves outcomes for HIV-infected individuals. National Institutes of Health. Available online at https://www.nih.gov/news-events/news-releases/starting-antiretroviral-treatment-early-improves-outcomes-hiv-infected-individuals. Accessed 11/6/2016.

(Updated 2016 January 22). Working in healthcare and HIV. AVERT. Available online at http://www.avert.org/hiv-transmission-prevention/working-healthcare. Accessed 11/6/2016.

(2016 May 23). Recommendations for HIV prevention with adults and adolescents with HIV. Centers for Disease Control and Prevention. Available online at http://www.cdc.gov/hiv/guidelines/personswithhiv.html. Accessed 11/6/2016.

(2016 October 27). HIV and AIDS: Testing. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/hiv/basics/testing.html. Accessed 11/6/2016.

(2016 June 20). HIV testing. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/hiv/testing. Accessed 11/6/2016.

Chlamydia and gonorrhea are the most common bacterial sexually transmitted diseases (STDs) in the United States today, but many infected people have no symptoms. These infections usually affect the genitals but may also cause infections of other areas, such as the throat and rectum. Pregnant women may transmit the infections to their newborns. Left untreated, these diseases can cause infertility and other health complications. However, both diseases can be cured with antibiotics.

While rates of chlamydia and gonorrhea are highest in younger people, any sexually active person can get a chlamydia or gonorrhea infection. Many people have both chlamydia and gonorrhea infections at the same time.

Recommendations for Women

The U.S. Centers for Disease Control and Prevention (CDC), the U.S. Preventive Services Task Force (USPSTF), the American Academy of Family of Physicians (AAFP), and the American College of Obstetricians and Gynecologists (ACOG) recommend chlamydia and gonorrhea screening for all sexually active adult women who have risk factors, such as having a new or multiple sex partners. The CDC specifically recommends annual screening for those at risk.

For screening recommendations during pregnancy, see Pregnancy & Prenatal Testing.

Recommendations for Men

These organizations do not recommend routine screening for healthy, sexually active, heterosexual men. Health care providers may, however, use their judgment and consider risks, such as prevalence in the community. It is important to remember that an infected male can spread these diseases and even re-infect a partner if he does not complete treatment. For sexually active men who have sex with men, the CDC recommends chlamydia and gonorrhea screening at least annually.

Risk

Examples of risk factors include:

• Previous chlamydia or gonorrhea infections, even if you were treated
• Having other STDs, especially HIV
• Having new or multiple sex partners
• Using condoms inconsistently
• Exchanging sex for money or drugs
• Using illegal drugs
• Living in a detention facility
   

Because reinfection rates are high, the CDC recommends that both women and men who are treated for chlamydia or gonorrhea infection be retested approximately 3 months after treatment or at their next health care visit, regardless of whether they believe that their sex partners were treated. It is important to continue annual screening for these diseases because reinfection is always possible.

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Link

CDC: Get Tested, Find Free, Fast, and Confidential Testing Near You

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Sources Used in Current Review (last reviewed 12/5/2017)

(2016 October 17, Updated). Chlamydia - CDC Fact Sheet (Detailed). Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/std/chlamydia/stdfact-chlamydia-detailed.htm. Accessed on October 2017.

(2016 October 28, Updated). Gonorrhea – CDC Fact Sheet (Detailed Version). Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/std/gonorrhea/stdfact-gonorrhea-detailed.htm. Accessed on October 2017.

(2016 December). Chlamydia, Gonorrhea, and Syphilis FAQ. American Congress of Obstetricians and Gynecologists. Available online at https://www.acog.org/Patients/FAQs/Chlamydia-Gonorrhea-and-Syphilis. Accessed on October 2017.

Fisher, M. and Schlaberg, R. (2017 July, Updated). Sexually Transmitted Infections. ARUP Consult. Available online at https://arupconsult.com/content/sexually-transmitted-infections/?tab=tab_item-1. Accessed on October 2017.

(December 1, 2016) Centers for Disease Control and Prevention, STD Risk and Oral Sex - CDC Fact Sheet. Available online at https://www.cdc.gov/std/healthcomm/stdfact-stdriskandoralsex.htm. Accessed on October 2017.

(September 2014) US Preventive Services Task Force, Final Recommendation Statement Chlamydia and Gonorrhea: Screening. Available online at https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/chlamydia-and-gonorrhea-screening. Accessed on October 2017.

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis bacteria. TB primarily targets the lungs but may affect any area of the body. It can be spread through the air from person to person through droplets of respiratory secretions such as sputum or aerosols released by coughing, sneezing, laughing, or breathing.

Most people who become infected with M. tuberculosis manage to confine the mycobacteria to a few cells in their lungs, where they stay alive but in an inactive form. This latent TB infection does not make the person sick or infectious and, in most cases, it does not progress to active tuberculosis. However, some people - especially those with compromised immune systems - may progress directly from initial TB infection to active tuberculosis. People who have HIV are much more likely to become sick if they contract TB. A person who has latent TB and their immune system becomes weakened may then develop active TB. Another increasing concern is drug-resistant forms of TB that are resistant to the antibiotics typically prescribed to treat the disease.

TB is one of the world's deadliest diseases, although it is relatively uncommon in the U.S. Still, it is a large health issue among at-risk groups. Current guidelines call for targeted screening among such groups.

At Risk

• People who have close contact with a person who has known or suspected TB disease
• People with weakened immune systems such as resulting from HIV infection, malnutrition, advanced age, or substance abuse including alcohol and drugs
• Immigrants from countries with a high rate of TB disease (many countries in Latin America, Africa, Asia, Eastern Europe, and Russia)
• Medically underserved people, such as those from a low-income environment
• Residents of long-term care facilities (such as nursing homes, mental health facilities, prisons, AIDS care facilities, and homeless shelters)
• People who live in unclean or crowded environments and/or without a healthy diet
• Healthcare workers who work in any of the above situations or with patients who are at increased risk
• Laboratorians who work with specimens that may contain TB or with TB cultures

Recommendations

The U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Preventive Services Task Force (USPSTF) recommend use of TB tests to identify people who will likely benefit from treatment, including those at increased risk for M. tuberculosis infection or for progression to active TB if they are infected. There are two types of tests that might be performed:

• IGRA TB blood test (preferred): also known as interferon gamma release assay, requires a blood sample to be drawn.
• Tuberculin skin test (TST) also called the Mantoux tuberculin skin test, the TST (or PPD for Purified Protein Derivative) is performed by injecting a small amount of fluid (called tuberculin) into the skin in the lower part of the arm. Following this test, you must return within 48 to 72 hours for a trained healthcare worker to measure the reaction and determine if it indicates exposure to M. tuberculosis.

 

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Link
CDC: Tuberculosis (TB)

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Sources Used in Current Review

Screening for Latent Tuberculosis Infection in Adults. US Preventive Services Task Force Recommendation Statement. JAMA. 2016;316(9):962-969. doi:10.1001/jama.2016.11046. Available online at http://jama.jamanetwork.com/article.aspx?articleid=2547762. Accessed October 2016.

U.S. Centers for Disease Control and Prevention. TB Testing & Diagnosis. Available online at http://www.cdc.gov/tb/topic/testing/. Accessed October 2016.

According to the Centers for Disease Control and Prevention (CDC), approximately 850,000 to 2.2 million people in this country have chronic infection with hepatitis B virus (HBV). Many of these people are unaware that they are infected.

HBV is one of five "hepatitis viruses" identified so far that are known to mainly infect the liver. It is spread through contact with blood or other body fluids from an infected person, such as during sex or by sharing needles, razors or toothbrushes, and can also be passed from an infected mother to her baby during or after birth.

HBV infection can be acute or chronic, with the course of infection varying from a mild form that lasts only a few weeks to a more serious form lasting years that can lead to complications such as cirrhosis or liver cancer. According to the CDC, approximately 1,800 people die every year in the U.S. from HBV-related liver disease.

The vast majority of those with chronic infections will have no symptoms. A test for hepatitis B surface antigen (HBsAg) may be used for screening asymptomatic people who fall into one of the high-risk categories for chronic HBV. Effective vaccines against HBV are available; however, those who have not been vaccinated or who are at high risk and were vaccinated before being screened for HBV infection may want to consider getting tested.

Recommendations
Since the prevalence of HBV infection is low in the general U.S. population and most of those infected do not develop complications, HBV screening is not recommended for those who are not at increased risk.

For people with increased risk of infection, several health organizations including the CDC, the American Association for the Study of Liver Diseases (AASLD) and the United States Preventive Services Task Force recommend screening for HBV. Examples of people at risk include:

• Healthcare and public safety workers with possible exposure to infected blood or other body fluids
• People born in areas of the world that have a greater than 2% prevalence of HBV (for example, much of Asia and Africa), regardless of whether they have been vaccinated
• People born in the U.S. but who were not vaccinated early in life and whose parents are from an area with greater than 8% prevalence of HBV
• Men who have sex with men
• Injection drug users
• People who have elevated liver enzymes (ALT and AST) with no known cause
• People with certain medical conditions that require that their immune system be suppressed, such as organ transplant recipients
• Dialysis patients
• People who are in close contact with someone infected with HBV or who have a sexual partner with HBV (i.e. have tested positive for HBsAg)
• Those infected with HIV
• People who were vaccinated for HBV after they had already begun high-risk behavior (e.g., men who have sex with men and injection drug users)
   

In addition, the AASLD recommends HBV screening for:

• People with multiple sex partners
• Those who have a history of sexually transmitted diseases (STDs)
• Prison inmates
• People with hepatitis C infection
   

Recommendations for HBV screening during pregnancy are addressed separately. For more information, read the Pregnancy article.

Why get tested?
People with chronic HBV can unknowingly spread the infection to others and remain at risk for serious complications of the infection.

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Related Content
Tests: Hepatitis B Testing
Conditions: Hepatitis

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Sources Used in Current Review (last reviewed 10/11/17)

LeFevre, M. (2014 July 1). Screening for Hepatitis B Virus Infection in Nonpregnant Adolescents and Adults: U.S. Preventive Services Task Force Recommendation Statement. Annals of Internal Medicine V 161 (1). Available online at https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/hepatitis-b-virus-infection-screening-2014. Accessed on 8/06/17.

(2016 May 23, Updated). Hepatitis B FAQs for the Public. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/hepatitis/hbv/bfaq.htm. Accessed on 8/06/17.

(2015 March). Guidelines for the Prevention, Care and Treatment of Persons with Chronic Hepatitis B Infection. World Health Organization. Available online at http://apps.who.int/iris/bitstream/10665/154590/1/9789241549059_eng.pdf Accessed on 8/06/17.

(2017 May 11 Updated). Viral Hepatitis. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/hepatitis/statistics/index.htm Accessed on 8/06/17.

(2016 August 4, Updated). Hepatitis B FAQs for Health Professionals. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/hepatitis/hbv/hbvfaq.htm. Accessed on 8/06/17.

Hillyard, D. and Slev, P. (2017 July Updated). Hepatitis B Virus – HBV. ARUP Consult. Available online at https://arupconsult.com/content/hepatitis-b-virus/?tab=tab_item-2. Accessed on 8/06/17.

Workowski, K. and Bolan, G. (2015). Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR June 5, 2015 / 64(RR3);1-137. Available online at https://www.cdc.gov/mmwr/preview/mmwrhtml/rr6403a1.htm. Accessed on 8/06/17.