eMedicine Specialties > Emergency Medicine > Infectious Diseases

HIV, Early Recognition and Rapid Testing

Author: Jeff Dubin, MD, Medical Director, Emergency Department, Washington Hospital Center, Assistant Professor, Department of Emergency Medicine, Georgetown University School of Medicine
Contributor Information and Disclosures

Updated: Apr 7, 2009

Introduction

Background

Clinically apparent human immunodeficiency virus (HIV) infection first was recognized in 1981 in homosexual men and parenteral drug users in San Francisco and New York City who presented with evidence of a profound acquired immune deficiency syndrome (AIDS). With the continued growing numbers of HIV-infected individuals, physicians need to recognize acute HIV infection as well as screen for asymptomatic infections. Early diagnosis of acute HIV infection can help identify patients who may be candidates for antiretroviral treatment, which has been shown to delay the progression to AIDS and death. Rapid HIV testing may also be useful to quickly confirm HIV status in a patient not known to be HIV positive who presents with an AIDS-defining illness. 

The Centers for Disease Control and Prevention (CDC) recommends HIV screening of all US residents aged 13-64 years.¹ This can be completed at any convenient physician encounter, including emergency department visits and even outreach programs utilizing mobile clinic vans to see patients. Studies have shown that nearly one third of patients screened for HIV by traditional programs with pretest counseling and blood tests that are sent to a central laboratory fail to return for follow-up visits to learn the results.² Rapid HIV testing provides the results during the single counseling session. Identification of asymptomatic HIV-positive patients benefits the individual and the public health. Seropositive patients can be referred for treatment and taught about practices that will help reduce the risk of infecting others. 

This article reviews presenting signs and symptoms of acute HIV infection and discusses rapid HIV testing.

For more information, see guidelines for HIV Infection: detection, counseling, and referral and revised recommendations for HIV testing of adults, adolescents, and pregnant women in health-care settings.^3,4

Pathophysiology

HIV, or human immunodeficiency virus, is a Lentivirus, a subgroup of the retroviruses. This family of viruses is known for latency, persistent viremia, infection of the nervous system, and weak host immune responses. HIV has high affinity for CD4 T lymphocytes and monocytes. HIV binds to CD4 cells and becomes internalized. The virus replicates itself by generating a DNA copy by reverse transcriptase. Viral DNA becomes incorporated into the host DNA, enabling further replication.

HIV is transmitted primarily through sexual contact (>70%). Worldwide, it is more common in heterosexual men and women than in homosexual men. Although the majority of initial HIV-related AIDS cases in the United States were in homosexual men, increasingly, new cases of HIV infection are in the heterosexual population. Parenteral transmission occurs largely among intravenous drug users; transmission by contaminated blood products is exceedingly unlikely in the United States, although this remains a serious problem in developing countries. Since the introduction of universal precaution practices, infection of health care workers through parenteral exposure remains rare. Children are infected primarily by perinatal transmission.

In acute HIV infection, the symptoms of the disease are thought to be mediated by the immune response to the high viral load as the virus rapidly replicates once it infects a new host.

For supplementary information, see eMedicine articles HIV Disease and Early Symptomatic HIV Infection.

Frequency

United States

• The US CDC estimates that approximately 1.1 million people are currently living with HIV infection in the United States.²
• The CDC estimates that more than 250,000 people are not aware that they are HIV positive.²
• An estimated 56,300 new HIV infections occur each year in the United States.⁵

International

Since the AIDS epidemic began, more than 20 million deaths have been attributed to AIDS. The current estimate of worldwide disease prevalence is more than 33 million HIV infections; nearly two thirds of these cases are in developing countries, generally in sub-Saharan Africa and Southeast Asia.^6,7,8

Mortality/Morbidity

The course of HIV infection is characterized primarily by latency. Unfortunately, profound immune suppression eventually develops and the illness appears to be almost uniformly lethal. More than 500,000 persons have died of AIDS in the United States.

Progression from HIV infection to AIDS occurs at a median of 11 years after infection. In the recent past, most patients would not survive more than 1-2 years following diagnosis of AIDS. However, since the introduction of highly active antiretroviral therapy (HAART) and prophylaxis against opportunistic pathogens, death rates from AIDS have declined significantly. An HIV-positive patient older than 50 years with a nearly undetectable viral load and a CD4 count more than 350 now has less than a 5% chance of dying or progressing to full blown AIDS within 3 years.

Race

In the United States, the breakdown of HIV infections by race/ethnicity is as follows:

• Caucasians - 35% of all cases
• African Americans - 46%
• Hispanics - 18%
• Asian/Pacific Islander - 1%
• American Indian/Alaska Native - <1%

Sex

In the United States, most HIV infections still occur in men via homosexual contact; however, the frequency of infection in women is increasing. In the United States, fewer than 25% of all HIV cases are in women, whereas worldwide an estimated 50% of all HIV patients are women.⁵

Age

Most AIDS cases occur in adults aged 25-49 years (70% of cases). Adolescents and young adults (aged 13-24 y) represent 25% of new cases. Young children represent fewer than 1% of AIDS cases in the United States. Internationally, children younger than 15 years are estimated to account for close to 10% of all HIV cases.⁵

Clinical

History

Symptoms of HIV infection

• Constitutional
  • Fever 
  • Fatigue
  • Night sweats
• Ear, nose, and throat
  • Oral ulcers
  • Pharyngitis
• Gastrointestinal - Diarrhea   
• Skin
  • Generalized rash
  • Genital ulcers 
• Musculoskeletal - Myalgia/arthralgia
• Neurological -Headache 

Physical

Physical findings of HIV infection

• Constitutional - Fever
• Head, eyes, ears, nose, and throat - Oral candidiasis (thrush)
• Neck - Lymphadenopathy
• Skin -Maculopapular rash (often on the trunk)

Causes

• Infection is caused by the human immunodeficiency virus (HIV). The following factors are associated with an increased risk of acquiring HIV infection. Questions regarding exposure to these risk factors should be part of the history taken in the emergency department.
  • Unprotected sex
  • Receptive anal intercourse carries a particularly high risk.
  • Parenteral drug use (sharing needles or drug paraphernalia)
  • Occupational needle stick or body fluid splash (estimated transmission rate <0.3%)
  • Contaminated blood products (before 1985 in the United States)

• Search for CME/CE on This Topic »

• HIV-1 Encephalopathy and AIDS Dementia Complex (Neurology)
• Early Symptomatic HIV Infection (Infectious Diseases)
• HIV Nephropathy (Nephrology)
• HIV Infection, Antiretroviral Therapy (Infectious Diseases)

• HIV/AIDS Overview
• HIV/AIDS Treatment
• Immune System Center
• Sexually Transmitted Diseases Center
• HIV/AIDS Causes
• HIV/AIDS Symptoms
• Yeast and Fungal Infections Center
• Yeast Infection Overview
• Rapid Oral HIV Test Introduction

• Asymptomatic Chlamydia More Prevalent in HIV-Negative Than HIV-Positive Men
• HIV Speeds Brain Aging
• Low Bone Mineral Density, Fragility Fracture Risk Increased in HIV Patients

• British HIV Association, BASHH and FSRH Guidelines for the Management of the Sexual and Reproductive Health of People Living With HIV Infection 2008
• British HIV Association Guidelines for Immunization of HIV-Infected Adults 2008
• HIV Transmission Risk Among HIV Seroconcordant and Serodiscordant Couples: Dyadic Processes of Partner Selection

• HIV Transmission & Prevention Resource Center
• HIV Pathogenesis Resource Center
• Pregnancy and Vertical HIV Transmission