How many types of HIV are there?

There are two types of HIV, HIV-1 and HIV-2, as well as several related viruses that infect certain monkeys or great apes. HIV-1 can be found throughout the world, but HIV-2 is almost exclusively limited to West Africa. HIV-1 is transmitted more easily than HIV-2, and HIV-1 infection progresses more rapidly to AIDS.

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Are there multiple subtypes of HIV?

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. The dominant HIV subtype in the Americas, Western Europe and Australasia is subtype B.

What is HIV-1 subtype B?

Abstract. Human migration is a major process that shaped the origin and dissemination of HIV. Within HIV-1, subtype B (HIV-1B) is the most disseminated variant and it is assumed to be the causative agent in approximately 11% of all cases of HIV worldwide.

Which subtype is most virulent?

HIV-1 subtype C was less virulent than either A or D in humans; the latter being the most virulent. Longer periods of asymptomatic HIV-1 subtype C could explain the continued expansion and dominance of subtype C in the global epidemic.

Does non reactive mean positive?

What is the difference between non reactive and negative?

Nonreactive vs. A nonreactive result means that the fluid sample did not contain HIV antigens or antibodies that the test aims to react to at the time of testing. It can mean a person has tested negative for HIV. However, if an individual has a nonreactive result, it does not necessarily mean they do not have HIV.

What does nonreactive mean in a test result?

Negative Test Result. A nonreactive test result indicates that signs of the condition being tested for are not present.