What's in this article?
What is HIV1?
HIV-1 is the most common and pathogenic strain of the virus. Scientists divide HIV-1 into a major group (Group M) and two or more minor groups, namely Group N, O and possibly a group P. Each group is believed to represent an independent transmission of SIV into humans (but subtypes within a group are not). A total of 39 ORFs are found in all six possible reading frames (RFs) of HIV-1 complete genome sequence, but only a few of them are functional.
Symptoms of HIV-1
HIV may not cause symptoms early on. People who do have symptoms may mistake them for the flu or mono. Common early symptoms include:
- Sore throat.
- Muscle aches and joint pain.
- Swollen glands (swollen lymph nodes).
- Skin rash.
Symptoms may appear from a few days to several weeks after a person is first infected. The early symptoms usually go away within 2 to 3 weeks.
After the early symptoms go away, an infected person may not have symptoms again for many years. After a certain point, symptoms reappear and then remain. These symptoms usually include:
- Swollen lymph nodes.
- Extreme tiredness.
- Weight loss.
- Night sweats.
Who is at Risk for HIV1?
HIV infection is usually acquired through sexual intercourse or exposure to infected blood or body fluids. This may occur:
- During sexual contact with an infected person, especially if you have unprotected vaginal or anal sex
- By sharing needles or syringes used by an infected person.
Transmission from a pregnant woman to her baby may occur during pregnancy, birth, or breastfeeding, although this is uncommon with the use of HIV medications during and after pregnancy.
HIV infection is NOT spread by casual contact.
Certain individuals may have an increased risk of HIV infection, including the following:
- Men who have sex with men
- Injection drug users who share needles or “works”
- Sexual partners of people who are infected with HIV
- People with a history of a sexually transmitted disease
- Victims of sexual assault (see “Patient education: Care after sexual assault (Beyond the Basics)”)
- Men and women who have unprotected sex with multiple partners
- Men and women who exchange sex for money or drugs or have sex partners who do
- Anyone who is accidentally stuck with a needle or sharp in a healthcare facility
- People who received a blood transfusion or other blood products before 1984
What is HIV2?
HIV-1 and HIV-2 are distinct retroviruses originating from two different primate species.1 Transmission modes for both strains are the same, and infection with either strain can lead to the development of AIDS.
The origin of HIV-2 is attributed to the sooty mangabey monkey. There are at least eight identified subtypes of HIV-2, but only subtypes A and B are commonly found. Although the majority of HIV-2 infections have been found in West Africa, the number of diagnosed cases in India is increasing. HIV-2 cases are also found in European countries with former colonial ties (particularly Portugal and France) to West Africa. Incidence of HIV-2 infection remains low in the UK (144 HIV-2 mono-infections and 22 HIV-1 and 2 dual infections).
Symptoms of HIV-2
The list of signs and symptoms mentioned in various sources for HIV-2 includes the 69 symptoms listed below:
- Some people may be asymptomatic for many years.
- Extreme fatigue
- Rash – early symptom
- Flu-like symptoms – early symptom
- Early symptom
- Weakened immune system
- Low CD4+ count
- Persistently swollen lymph nodes
- Persistently tender lymph nodes
- Rapid weight loss
- Persistent diarrhea
- Shortness of breath
- Dry cough
- Intermittent fevers
- Night sweats
- Increased incidence of infections and other illnesses
- Purple spots on skin
- Purple spots on mucous membranes
- Mouth sores
- Stiff muscles
- Sore muscles
- Reduced mental functioning
- Susceptibility to opportunistic infection
- Susceptibility to opportunistic bacterial infections
- Susceptibility to opportunistic Mycobacterial infections
- Susceptibility to opportunistic fungal infections
- Susceptibility to AIDS-related cancers
- Susceptibility to opportunistic protozoal infections
- Susceptibility to opportunistic viral infections
- Positive HIV test result
- Increased susceptibility to Mycobacteriu avium complex (MAC)
- Increased susceptibility to Salmonellosis
- Increased susceptibility to Syphilis
- Increased susceptibility to Neurosyphilis
- Increased susceptibility to Tuberculosis
- Increased susceptibility to Bacillary angiomatosis
- Increased susceptibility to Aspergillosis
- Increased susceptibility to Candidiasis
- Increased susceptibility to Coccidioidomycosis
- Increased susceptibility to Cryptococcal meningitis
- Increased susceptibility to Histoplasmosis
- Increased susceptibility to Kaposi’s sarcoma
- Increased susceptibility to Non-Hodgkin’s lymphoma
- Increased susceptibility to Primary central nervous system lymphoma
- Increased susceptibility to Invasive cervical cancer
- Increased susceptibility to Cryptosporidiosis
- Increased susceptibility to Isosporiasis
- Increased susceptibility to Microsporidiosis
- Increased susceptibility to Toxoplasmosis
- Increased susceptibility to Pneumocystis carinii pneumonia
- Increased susceptibility to Cytomegalovirus
- Increased susceptibility to Hepatitis
- Increased susceptibility to Herpes simplex
- Increased susceptibility to Herpes zoster
- Increased susceptibility to Human papillomavirus
- Increased susceptibility to Molluscum contagiosum
- Increased susceptibility to Oral hairy leukoplaia
- Increased susceptibility to aphthous ulcers
- Increased susceptibility to idiopathic thrombocytopenia purpura
- Increased susceptibility to listerosis
- Increased susceptibility to pelvic inflammatory disease
- Increased susceptibility to Burkitt’s lymphoma
- Increased susceptibility to immunoblastic lymphoma
Difference Between HIV1 and HIV2
|This strain is found worldwide and is more common.||This strain is found predominantly in West Africa.|
|This strain is more likely to progress and worsen.||This strain is less likely to progress and many of those infected remain lifelong non-progressors. Progression is slower.|
|Average level of immune system activation are higher.||Average level of immune system activation are lower.|
|During progression, HIV-1 has lower CD4 counts than HIV-2.||During progression, CD4 counts are higher in this strain.|
|Plasma viral loads are higher.||Plasma viral loads are lower.|