# Presentation: 175690

## Spotlight Case May 2008

**Diagnosing HIV: It Doesn’t Take a Brain Surgeon**

## Source and Credits

- This presentation is based on the May 2008 AHRQ WebM&M Spotlight Case
- See the full article at _[http://webmm.ahrq.gov](http://webmm.ahrq.gov/)_
- CME credit is available
- Commentary by: **Roger Chou, MD, **Oregon Health & Science University
- Editor, AHRQ WebM&M: Robert Wachter, MD
- Spotlight Editor: Niraj Sehgal, MD, MPH
- Managing Editor: Erin Hartman, MS

## Objectives

*	**At the conclusion of this educational activity, participants should be able to:*
- Describe the current epidemiology of HIV infection
- Identify the risk factors for HIV infection
- Indicate the challenges associated with HIV screening practices
- Review current guidelines for HIV screening

## Case: Diagnosing HIV

*	**A 41-year-old healthy man was admitted after one week of new onset headaches, and a witnessed generalized seizure. On examination, he was neurologically intact with stable vital signs, and the exam was otherwise unremarkable. Laboratory studies were notable for a mild leukopenia and anemia. Imaging revealed a 3 cm left-sided brain mass with surrounding edema.** *

## Case: Diagnosing HIV (2)

*	**The radiologist reported the findings to be concerning for a malignant rather than infectious process. The patient was single, with no children, and had emigrated from Mexico 8 years earlier. He was started on steroids and transferred to a referral facility for neurosurgical biopsy and possible excision. *

## Case: Diagnosing HIV (3)

*	**Upon arrival to the referral facility, the patient remained neurologically stable and underwent left-sided craniotomy and brain biopsy. Unexpectedly, pathology revealed toxoplasma cysts, confirming a diagnosis of cerebral toxoplasmosis, for which therapy was initiated. This diagnosis prompted an HIV test that returned positive.*

## HIV Infection

- Estimated to affect more than 1 millionin the United States
- About 1⁄4 of infected persons may be unaware of their infection status

*See Notes for references.*

## Acquired Immunodeficiency Syndrome

- Without treatment, median time from HIV seroconversion to developing AIDS is 8-11 years
- Many persons with HIV infection not diagnosed until after an opportunistic infection, such as toxoplasmosis or pneumocystis
- About 1⁄4 of patients are simultaneously diagnosed with HIV and AIDS
- About 40% of newly diagnosed meet criteria for AIDS within 1 year

*See Notes for references.*

## Most Common Risk Factors for HIV

*In men*
- Male-to-male sexual contact (60%)
- Injection drug use (16%)
- Heterosexual contact with person known to have or be at high risk for HIV (17%)
*In women*
- High-risk heterosexual contact (76%)
- Injection drug use (21%)
- Providers must take complete and targeted history to fully understand patient’s risk factors for HIV infection

*See Notes for references.*

**Notes:**
HIV/AIDS Surveillance Report, 2006. Vol 18. Atlanta, GA: US Department of Health and Human Services, Centers for Disease Control and Prevention; 2008:1-55.

## Risk Factor Assessment

- Failure to take a thorough history, particularlyfor sensitive questions, may result in the failureto order an HIV test
- Risk factor assessment is crucial because clinical diagnosis of acute HIV infection is challenging
- Symptoms are short-lived, non-specific, and often atypical
- Following resolution of acute HIV infection, patients often experience prolonged, relatively asymptomatic phase until they become severely immunocompromised

*See Notes for references.*

## Risk Factor Assessment (cont.)

- Clinicians should view every health care encounter as potential opportunity to inquire about HIV risk factors
- About 40% of persons reporting an HIV risk factor have never been tested
- Even in settings with good access to health care, high-risk behaviors often remain undetected or fail to lead to testing
- Important to test those who report risk factors, given high yield of testing in such persons
- Another high-yield strategy is to routinely test persons evaluated in higher-prevalence settings

*See Notes for references.*

## Case (cont.): Diagnosing HIV

*	**The patient's clinical status deteriorated steadily following surgery. He developed worsening neurological status, required mechanical ventilation for airway protection, and developed a number of infectious complications that ultimately led to his death after a 5-week hospitalization. *

## Issues in Present Case

- Difficult to know whether identifying HIV infection at time of admission would have led to a change in overall outcome
- However, with described imaging findings, earlier knowledge of HIV infection could have led to immediate toxoplasmosis antibody testing, which may have prevented an unnecessary brain biopsy

## Issues in Present Case (cont.)

- Toxoplasmosis typically occurs only after the CD4 count has dropped below 100 cells/mm3
- Thus, there is a good chance patient had been infected with HIV for a decade or more
- Although patient is described as previously healthy, he probably had previous encounters with the health care system following seroconversion

*See Notes for references.*

## Benefits of Screening for HIV

- May identify infected persons at earlier stages of disease
- May reduce morbidity and mortality by starting patients on appropriate therapies before they develop a serious infection or advanced immunodeficiency
- May reduce secondary transmission, as persons aware of their HIV-positive serostatus may engage in fewer risky behaviors than those unaware of their status

*See Notes for references.*

## Challenges in Screening

- No direct evidence showing benefits of routine screening or early identification of HIV infection on morbidity/mortality and transmission rates
- Evidence of decreases in HIV-related morbidity and mortality are primarily from studies of patients with more advanced disease
- Although screening asymptomatic patients with no identifiable risk factors would detect additional persons with HIV, the overall number of new infections identified would be limited

*See Notes for references.*

## Cost-effectiveness of Routine HIV Screening

- When potential benefits from reduced secondary transmission are factored in:
- Routine screening is cost-effective (<$50,000 per quality-adjusted life-year [QALY] gained)
- Remains cost-effective even when prevalence of undiagnosed HIV was at or substantially below that in general population (~ 0.2%)
- Without secondary transmission benefits:
- Routine screening is not cost-effective (>$50,000 per QALY) in low-prevalence settings
- Remains cost-effective in higher-prevalence (>1%) settings

*See Notes for references.*

## Centers for Disease Control and Prevention (CDC) Guidelines

- New CDC guidelines in 2006
- Recommends routine HIV screening for all persons 13 to 64 years
- Unless prevalence of HIV in that setting documented to be <0.1%
- Streamlined counseling using “opt-out” approach
- Patients should be informed that HIV testing will be performed unless they decline (opt-out of) testing, without requiring specific signed consent for HIV testing
- This opt-out approach is similar to recommendations for routine screening in the prenatal setting
- By streamlining consent process and eliminating need for risk assessment, this recommendation is theoretically less burdensome on clinicians and easier to put into practice

*See Notes for references.*

## Opt-Out Testing

- Studies that assess routine opt-out testing in low-risk and low-prevalence settings are not yet available
- Even in higher-prevalence settings, substantial proportion of patients decline testing
- Challenges
- Need to insure that testing remains truly voluntary and informed, as well as confidential
- Higher proportions of false-positives in low-prevalence settings
- Continued stigmatization of persons with HIV infection
- Current laws or policies in some states mandate specific informed consent or extensive pretest counseling

*See Notes for references.*

## US Preventive Services Task Force (USPSTF) Recommendations

- In low-risk, low-prevalence settings, USPSTF found that potential benefits of routine screening appear small relative to potential burdens/harms (labeling, anxiety, false-positives)
- Strongly recommends for screening in persons reporting high-risk behaviors and in high-prevalence settings
- Task Force does not recommend for or against routine screening

*See Notes for references.*

## Screening Pitfalls

- HIV screening can take place during any health care encounter, including primary care, urgent or emergency care, and inpatient visits
- 40%-60% of HIV-infected persons do not regularly see a provider outside of the emergency department
- Studies of routine testing in urgent care centers found that up to 1⁄4 of positive patients didn’t receive results
- To realize maximum potential benefits of any HIV screening program, patients must be informed of test results and linked to appropriate follow-up care

*See Notes for references.*

## Take-Home Points

- About 1⁄4 of HIV-infected persons are unaware of status
- A substantial proportion of HIV-infected persons are diagnosed late in the course of disease or when they present with an opportunistic infection
- Patients with clinical presentations consistent with an HIV-related infection or cancer should be tested for HIV
- Routine screening of patients could reduce the proportion of HIV-infected persons unaware of their status and potentially reduce secondary transmission, morbidity, and mortality

## Take-Home Points (cont.)

- Screening will have higher yield in persons reporting risk factors and in higher prevalence settings, but may be cost-effective even in very low prevalence settings if presumed secondary transmission benefits are factored in
- Effective screening strategies require protocols for notifying patients of initial and confirmatory results and linking infected patients to HIV follow-up care