- December 2, 2021
- Posted by: admin1
- Category: DPN Topics
Subject – Science and Tech
Context – People with past exposure to antiretroviral drugs thrice as likely to resist them: WHO
- It is a combination of daily medications that stop the virus from reproducing.
- The therapy helps in protecting CD4 cells thus keeping the immune system strong enough to fight off the disease.
- It, besides reducing the risk of transmission of HIV, also helps in stopping its progression to AIDS (a spectrum of conditions caused by infection due to HIV).
- Nevirapine (NVP) or efavirenz (EFV)-based regimens were the most frequent ART regimens initiated in 16 of 20 countries reporting survey findings to WHO (2014-2020).
To know about Human Immunodeficiency Virus (HIV), please refer August 2021 DPN.
HIV Strains and Types
HIV-1 and HIV-2
- HIV-1 and HIV-2 are two distinct viruses.
- Worldwide, the predominant virus is HIV-1. HIV-1 accounts for around 95% of all infections worldwide.
- HIV-2 is estimated to be more than 55% genetically distinct from HIV-1.
- The relatively uncommon HIV-2 virus is concentrated in West Africa but has been seen in other countries with links to West Africa. It is less infectious and progresses more slowly than HIV-1, resulting in fewer deaths.
- However, without treatment, most people living with HIV-2 will eventually progress to AIDS and die from the disease.
- While many commonly used antiretroviral drugs are active against HIV-2, non-nucleoside reverse transcriptase inhibitors (NNRTIs) like nevirapine and efavirenz do not work against it.
- The best way to treat HIV-2 has been less clearly defined than HIV-1.
Groups within HIV-1
- The strains of HIV-1 can be classified into four groups.
- Of these, M is the ‘major’ group and is responsible for the majority of the global HIV epidemic.
- Within group M there are known to be at least nine genetically distinct subtypes of HIV-1. These are subtypes A, B, C, D, F, G, H, J and K.