Screening Tests for Adults (Ages 30-49)

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.

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

Diabetes is the seventh leading cause of death in the United States. The Centers for Disease Control and Prevention (CDC) estimates that 30.2 million people age 18 and older, or 12.2% of all people in this age group, have diagnosed or undiagnosed diabetes. Of these, 4.6 million are 18-44 and 14.3 million are 45-64 years old. Type 2 diabetes accounts for 90-95% of all diagnosed cases of diabetes among adults. Unhealthy weight and physical inactivity, also significant national health problems, are both contributing factors to the rising incidence of type 2 diabetes.

Another 84.1 million American adults age 18 years or older have prediabetes, meaning that their blood glucose levels are higher than normal but not yet high enough to be diagnosed with diabetes. Detecting prediabetes allows individuals to take steps to stop or slow the development of type 2 diabetes and its complications. These complications include heart attack, stroke, hypertension, blindness and eye problems, kidney disease, and nervous system maladies. More than 60% of lower limb amputations occur in people with diabetes.

Risk Factors
Being overweight – having a body mass index (BMI) equal to or greater than 25 kg/m² – is a major risk factor for type 2 diabetes.

Other risk factors related to your own health include:

• Physical inactivity
• Having high blood pressure (hypertension), meaning blood pressure 140/90 mmHg or higher or receiving therapy for hypertension
• History of cardiovascular disease
• Having a HDL-cholesterol level less than 40 mg/dL (1.00 mmol/L) and/or a triglyceride level greater than 150 mg/dL (1.70 mmol/L)
• Having a previous hemoglobin A1c test result equal to or greater than 5.7%, impaired glucose tolerance (glucose tolerance test result 140 to 199 mg/dL (7.8 to 11.1 mmol/L)), or impaired fasting glucose (fasting glucose level 100 to 125 mg/dL (5.6 to 6.9 mmol/L))
• Having conditions associated with insulin resistance, such as severe obesity and acanthosis nigracans

Family-related risk factors are:

• Having a parent or sibling with diabetes
• Being of African American, Latino, Native American, Asian American, or Pacific Islander descent

Women's risk factors include:

• Delivering a baby weighing more than 9 pounds or having had gestational diabetes
• Having polycystic ovary syndrome

Screening tests for men and non-pregnant women

• Fasting glucose (fasting blood glucose, FBG) – this test measures the level of glucose in the blood after an 8-12 hour fast.
• Hemoglobin A1c (also called A1c or glycated hemoglobin) – this test evaluates the average amount of glucose in the blood over the last 2 to 3 months and has been recommended as another test to screen for diabetes.
• 2-hour glucose tolerance test (OGTT) – this test involves drawing a fasting blood sample for glucose measurement, followed by having the person drink a solution containing 75 grams of glucose and then drawing another sample two hours after the person begins to consume the glucose solution.

If any of these results is abnormal, the test is repeated on another day. If the repeat result is also abnormal, a diagnosis of diabetes is made.

Recommendations
The American Diabetes Association (ADA) and the U.S. Preventive Services Task Force (USPSTF) recommend the following:

• If you are age 45 or older, you should be screened.
• If you are younger than 45 but overweight or have any of the other risk factors, consider diabetes screening.
• Even if initial screening results are normal, get repeat testing at least every 3 years, say the ADA and USPSTF. If you are identified as having prediabetes, get tested yearly.

The American Association of Clinical Endocrinologists (AACE) also recommends diabetes screening for asymptomatic people with these risk factors, as well as those on antipsychotic therapy for schizophrenia or who have severe bipolar disease.

As public health experts work to educate Americans on what to do to avoid diabetes and its serious complications, be aware that healthy eating habits and activity choices can lower your risk of developing type 2 diabetes and of suffering complications from the disease.

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Links
NIDDK: Preventing Type 2 Diabetes
American Diabetes Association
National Diabetes Education Program 
Centers for Disease Control and Prevention: Type 1 or Type 2 Diabetes and Pregnancy 

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Sources Used in Current Review (last reviewed 9/18/17)

(2017). National diabetes Statistics Report, 2017. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/diabetes/pdfs/data/statistics/national-diabetes-statistics-report.pdf. Accessed on 8/06/17.

(2015 October). Abnormal Blood Glucose and Type 2 Diabetes Mellitis: Screening. U.S. Preventive Services Task Force. Available online at https://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryFinal/screening-for-abnormal-blood-glucose-and-type-2-diabetes?ds=1&s=diabetes. Accessed on 8/06/17.

(2017 July 27, Updated). What’s New in Diabetes. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/diabetes/new/index.html. Accessed on 8/06/17.

(2017 July 25, Updated). Who’s at Risk? Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/diabetes/basics/risk-factors.html. Accessed on 8/06/17.

Genzen, J. et. al. (2017 July, Updated). Diabetes Mellitus. ARUP Consult. Available online at https://arupconsult.com/content/diabetes-mellitus. Accessed on 8/06/17.

(2016 November). Diabetes Tests & Diagnosis. National Institute of Diabetes and Digestive and Kidney Diseases. Available online at https://www.niddk.nih.gov/health-information/diabetes/overview/tests-diagnosis. Accessed on 8/06/17.

(2015). Screening and Monitoring of Prediabetes. American Association of Clinical Endocrinologists. Available online at http://outpatient.aace.com/prediabetes/screening-and-monitoring-prediabetes. Accessed on 8/06/17.

Diabetes Management Guidelines, American Diabetes Association (ADA) 2016 Guidelines. National Diabetes Education Initiative. Available online at http://www.ndei.org/ADA-2013-Guidelines-Criteria-Diabetes-Diagnosis.aspx.html#children. Accessed on 8/06/17.

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.

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 United States Preventive Services Task Force (USPSTF), approximately 700,000 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 Centers for Disease Control and Prevention (CDC), approximately 2,000-4,000 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.

Risk
According to the USPSTF, in the U.S., people considered at high risk for HBV infection include those from countries with a high prevalence of HBV infection, those who are HIV-positive, injection drug users, household contacts of those with HBV infection, and men who have sex with men. 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.

Recommendations
In 2008, the CDC revised its guidelines to recommend that the following groups be screened for HBV:

• Healthcare and public safety workers
• People born in areas of the world that have a greater than 2% prevalence of HBV (for example, much of Asia and Africa)
• People born in the U.S. but who were not vaccinated and whose parents are from an area with greater than 8% prevalence of HBV
• Men who have sex with men
• 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
• Pregnant women
• People who are in close contact with someone infected with HBV
• Those infected with HIV

In 2014, the USPSTF updated its statement to recommend screening for HBV among asymptomatic, non-pregnant adolescents and adults in certain high-risk groups, bringing their recommendations into line with those of the CDC. The USPSTF had previously published the recommendation for HBV screening during pregnancy.

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

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Link
CDC: Hepatitis B Information for the Public 

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Sources Used in Current Review

USPSTF Urges HBV Screening for High-Risk People. By Michael Smith. MedPage Today. Published May 27, 2014. Available online through http://www.medpagetoday.com. Accessed June 2014.

USPSTF Recommends Hepatitis B Screening for High-Risk Groups. By Amy Orciari Herman. May 27, 2014. Journal Watch. Available online at http://www.jwatch.org/fw108870/2014/05/27/uspstf-recommends-hepatitis-b-screening-high-risk-groups?query=pfw through http://www.jwatch.org. Accessed June 2014.

Screening for Hepatitis B Virus Infection in Nonpregnant Adolescents and Adults: U.S. Preventive Services Task Force Recommendation Statement. Michael L. LeFevre, MD, MSPH, on behalf of the U.S. Preventive Services Task Force. Annals of Internal Medicine. Article published online 27 May 2014. Available online at http://annals.org/article.aspx?articleid=1874740 through http://annals.org. Accessed June 2014.

Centers for Disease Control and Prevention. Hepatitis B FAQs for the Public. Available online at http://www.cdc.gov/hepatitis/b/bFAQ.htm#statistics through http://www.cdc.gov. Accessed June 2014.

Centers for Disease Control and Prevention. Hepatitis B Information for the Public. Available online at http://www.cdc.gov/hepatitis/B/index.htm through http://www.cdc.gov. Accessed June 2014.

Recommendations for Identification and Public Health Management of Persons with Chronic Hepatitis B Virus Infection. Recommendations and Reports. September 19, 2008 / 57(RR08);1-20. Morbidity and Mortality Weekly Report. Available online at http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5708a1.htm through http://www.cdc.gov. Accessed June 2014.