HIV Types (HIV-1 & HIV-2): Understanding HIV-2

Last Updated on 02/26/2023 by Helal Medical

Human immunodeficiency virus (HIV), both types, is a virus that attacks the immune system and causes acquired immunodeficiency syndrome (AIDS). It was first identified in 1981 and has since become a global pandemic.

HIV can be classified into two types: HIV-1 and HIV-2. Both types are similar in many ways, but there are also important differences between them.

HIV Types (HIV-1 & HIV-2)

This article aims to provide an in-depth understanding of the key differences between HIV-1 and HIV-2, including their origins, characteristics, and modes of transmission.

What is HIV Type-1?

HIV-1 is the most common and virulent strain of the virus. It is responsible for the majority of HIV infections and AIDS cases worldwide. The origin of HIV-1 is believed to be in West Africa, where it likely crossed over from non-human primates to humans, then became human to human. It then spread globally through travel and sexual contact. HIV-1 is highly infectious and can rapidly progress to AIDS if left untreated. It can be transmitted through blood, semen, vaginal fluid, and breast milk.

What is HIV Type-2?

HIV-2: HIV-2 is a less common and less virulent strain of the virus that primarily affects people in West Africa. Like HIV-1, the origin of HIV-2 is believed to be in West Africa, where it crossed over from non-human primates to humans. However, it has not spread globally as extensively as HIV-1. HIV-2 is less infectious and progresses more slowly to AIDS compared to HIV-1. It can be transmitted through the same bodily fluids as HIV-1, but it is less easily transmitted through sexual contact.

Differences between the two HIV Types

A. Mode of Transmission: While both types of HIV can be transmitted through blood, semen, vaginal fluid, and breast milk, HIV-1 is more easily transmitted through sexual contact compared to HIV-2.

B. Disease Progression: HIV-1 progresses more rapidly to AIDS compared to HIV-2, which has a slower progression.

C. Antibody Detection: Antibodies produced in response to HIV-1 and HIV-2 can be detected by tests, but some tests may not accurately detect HIV-2.

D. Treatment and Medication: HIV-1 and HIV-2 are both treatable, but the medications used for treatment may differ between the two types.

Differences	HIV-1	HIV-2
Origin Start Dicovered	West Africa First	West Africa Later
Transmission Sex Trans Mother to Baby	Sexual, blood-to-blood, mother-to-child Faster 15% – 45%	Sexual (less), blood-to-blood Slower (3 times) Less than 5%
Infectivity/Virulence Incubation	High 2 to 4 weeks	Low 2 to 4 weeks
Progression to AIDS	Faster 7-10 years	Slower 10-25 years
Tests Ab tests	ELISA, Western Blot Accurate	ELISA, Western Blot, Line Immunoassay Less accurate
Treatment	Antiretroviral therapy	Antiretroviral therapy
Prevalence	Global	Mainly in West Africa

Diagnosis and Testing of HIV

Tests for HIV-1 and HIV-2 include antibody tests, antigen/antibody tests, and nucleic acid tests (NATs). While tests for HIV-1 are generally accurate, tests for HIV-2 may not be as accurate and may require follow-up testing. Early diagnosis is critical for effective treatment and management of both HIV types.

Prevention and Management

Safe sex practices, such as condom use and pre-exposure prophylaxis (PrEP), can help prevent the transmission of HIV-1 and HIV-2.

SUMMARY

Understanding the differences between HIV Types, (HIV-1 and HIV-2), is crucial for proper diagnosis and treatment. Early diagnosis and effective treatment, as well as prevention measures, are important in controlling the spread of HIV-2. This article provides a comprehensive overview of the key differences between the two types of HIV and highlights the importance of addressing the issue of HIV-2.

SOURCES

• HEALTH!! HUMAN IMMUNE VIRUS, SUBTYPES, GROUPS CONTINUE » NAIJAHITZ
• HIV (who.int)
• http://www.ncbi.nlm.nih.gov/pubmed/23444290
• http://www.aidsmap.com
• http://www.avert.org/professionals
• http://cid.oxfordjournals.org/content/38/10/1447.full