HIV (Human Immunodeficiency Virus)

Human Immunodeficiency Virus (HIV) is a virus that attacks the body's immune system. Specifically, HIV targets CD4 cells (also called T cells or helper cells), which are crucial for fighting infections. Over time, HIV can destroy so many of these cells that the body can't fight off infections and diseases, leading to opportunistic infections or cancers that take advantage of the weakened immune system.

HIV is different from most other viruses because the human body cannot completely eliminate it, even with treatment. Once someone has HIV, they have it for life. However, with proper medical care and adherence to antiretroviral therapy (ART), HIV can be controlled. Treatment can reduce the viral load (amount of HIV in the blood) to undetectable levels, which keeps the immune system working and prevents illness.

Without treatment, HIV advances in stages. The final stage is AIDS (Acquired Immunodeficiency Syndrome), which occurs when the immune system is severely damaged. However, with today's treatments, most people with HIV never develop AIDS. It's important to understand that HIV and AIDS are not the same thing - HIV is the virus that can lead to AIDS if left untreated.

Stage 1: Acute HIV Infection

• Timeline: 2-4 weeks after infection
• Viral load: Very high, person is very contagious
• Symptoms: Flu-like illness in 50-80% of people
• Testing: May not show positive on antibody tests yet
• Also called: Acute retroviral syndrome or primary HIV infection

Stage 2: Clinical Latency (Chronic HIV)

• Timeline: Can last 10 years or longer without treatment
• Viral load: HIV reproduces at low levels
• Symptoms: May have no symptoms or mild ones
• With treatment: Can last several decades
• Transmission: Can still transmit HIV to others

Stage 3: AIDS

• CD4 count: Falls below 200 cells/mm³ (normal is 500-1,500)
• Opportunistic infections: Body can't fight off infections
• Without treatment: Survival typically 3 years
• Symptoms: Severe illness, weight loss, chronic diarrhea
• Note: With treatment, most people never reach this stage

Important Note: Many people with HIV have no symptoms for years. The only way to know if you have HIV is to get tested. Symptoms alone cannot diagnose HIV.

HIV Can Be Transmitted Through:

• Sexual contact: Vaginal, anal, or oral sex with someone who has HIV
• Blood: Sharing needles, syringes, or drug injection equipment
• Mother to child: During pregnancy, birth, or breastfeeding
• Blood transfusions: Very rare in countries that screen blood
• Occupational exposure: Needlestick injuries in healthcare settings

HIV Is NOT Transmitted Through:

• Air or water
• Mosquitoes, ticks, or other insects
• Saliva, tears, or sweat
• Hugging, shaking hands, or social kissing
• Sharing toilets, dishes, or drinking glasses
• Closed-mouth kissing
• Touching objects touched by a person with HIV

Factors That Increase Risk:

• Having another sexually transmitted infection (STI)
• Having multiple sexual partners
• Sharing injection drug equipment
• Engaging in risky sexual behaviors
• Having a high viral load (for transmission)

Types of HIV Tests

Antibody Tests

• Most common type of test
• Detects antibodies to HIV in blood or oral fluid
• Can take 23-90 days after infection to detect
• Rapid tests available with results in 20 minutes

Antigen/Antibody Tests

• Detects both HIV antibodies and antigens
• Can detect HIV 18-45 days after infection
• Recommended for routine screening
• Laboratory versions more accurate than rapid tests

Nucleic Acid Tests (NAT)

• Detects HIV in blood directly
• Can detect HIV 10-33 days after infection
• Most expensive test
• Used when recent infection is suspected

Who Should Get Tested

• Everyone aged 13-64 should be tested at least once
• Pregnant women should be tested
• People with risk factors should test annually or more often
• Anyone who has been exposed to HIV
• People with symptoms of HIV
• Sexual partners of people with HIV

Window Period

The window period is the time between when a person gets HIV and when a test can detect it. During this time, a person can transmit HIV even though tests may be negative. Different tests have different window periods:

• NAT: 10-33 days
• Antigen/antibody test: 18-45 days
• Antibody test: 23-90 days

Antiretroviral Therapy (ART)

HIV is treated with antiretroviral therapy (ART), which involves taking a combination of HIV medicines every day. ART is recommended for everyone with HIV, regardless of viral load or CD4 count. When taken consistently, ART can:

• Reduce viral load to undetectable levels
• Keep the immune system strong
• Prevent transmission to sexual partners (U=U)
• Prevent progression to AIDS
• Allow people to live near-normal lifespans

Common ART Regimens

Most people start with a combination of three HIV medicines from at least two drug classes:

• NRTIs: Nucleoside reverse transcriptase inhibitors
• NNRTIs: Non-nucleoside reverse transcriptase inhibitors
• PIs: Protease inhibitors
• INSTIs: Integrase strand transfer inhibitors
• Entry inhibitors: Block HIV from entering cells

Starting Treatment

• Treatment should begin as soon as possible after diagnosis
• Same-day treatment start is increasingly common
• Treatment is lifelong
• Regular monitoring is essential
• Adherence is crucial for success

Monitoring Treatment

• Viral load tests: Every 3-4 months initially, then every 6 months
• CD4 count: Monitors immune system health
• Resistance testing: If treatment isn't working
• Side effect monitoring: Regular check-ups
• Other health screenings: For related conditions

Pre-Exposure Prophylaxis (PrEP)

PrEP is a daily pill that can prevent HIV infection in people who don't have HIV but are at high risk. When taken consistently, PrEP reduces the risk of getting HIV from sex by about 99% and from injection drug use by at least 74%.

• For people at high risk of HIV
• Must be HIV-negative to start
• Requires regular HIV testing
• Very effective when taken daily
• Injectable PrEP now available

Post-Exposure Prophylaxis (PEP)

PEP is emergency medication taken after potential HIV exposure. It must be started within 72 hours of exposure and taken for 28 days.

• For emergency situations only
• Must start within 72 hours (best within 24 hours)
• Taken for 28 days
• About 80% effective when taken correctly
• Available in emergency rooms

Other Prevention Methods

• Condom use: Highly effective when used correctly
• Testing and treatment: Know your status and your partner's
• Limiting partners: Reduce number of sexual partners
• Never share needles: Use clean needles and equipment
• Treatment as prevention: U=U principle
• Male circumcision: Reduces risk for heterosexual men

Mother-to-Child Prevention

• Test all pregnant women for HIV
• Provide ART during pregnancy and delivery
• Give baby HIV medicine for 4-6 weeks
• Consider alternatives to breastfeeding where safe
• Can reduce transmission to less than 1%

Health Management

• Take medications as prescribed: Adherence is crucial
• Regular medical care: See HIV specialist regularly
• Healthy lifestyle: Good nutrition, exercise, adequate sleep
• Avoid smoking: Higher health risks with HIV
• Limit alcohol: Can interfere with medications
• Mental health care: Address depression, anxiety
• Preventive care: Vaccinations, cancer screenings

Disclosure and Relationships

• Know your local disclosure laws
• Consider who needs to know
• Prepare for different reactions
• Seek support for disclosure process
• Remember U=U for sexual partners
• Dating with HIV is normal and safe

Support Resources

• HIV support groups
• Case management services
• Mental health counseling
• Peer support programs
• Online communities
• Legal assistance programs
• Financial assistance for medications

Aging with HIV

Thanks to effective treatment, people with HIV are living longer. Special considerations include:

• Managing multiple health conditions
• Drug interactions with age-related medications
• Bone health monitoring
• Cardiovascular health
• Cognitive health screening
• Cancer prevention and screening

When HIV weakens the immune system, opportunistic infections (OIs) can occur. With effective ART, these are now rare in people with HIV who are in care.

Common Opportunistic Infections

• Pneumocystis pneumonia (PCP): Lung infection
• Toxoplasmosis: Brain infection
• Cryptococcosis: Fungal infection
• Candidiasis: Thrush in mouth, throat, or vagina
• Tuberculosis: Leading cause of death in people with HIV globally
• MAC: Mycobacterium avium complex
• CMV: Cytomegalovirus
• Kaposi's sarcoma: Type of cancer

Prevention of OIs

• Take ART consistently to keep CD4 count high
• Prophylactic medications when CD4 is low
• Avoid undercooked meat and eggs
• Safe water practices
• Avoid cat litter if possible
• Regular screening for TB

People with HIV may be at increased risk for severe COVID-19, especially if their HIV is not well-controlled or they have a low CD4 count.

• COVID-19 vaccination is recommended for all people with HIV
• Continue taking HIV medications during COVID-19
• Maintain regular HIV care via telemedicine if needed
• Follow general COVID-19 prevention measures
• Seek care promptly if COVID-19 symptoms develop