Features of the Human Immunodeficiency Virus (HIV) in Military Personnel with Recent Infection

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The summary below is from the full report titled "Drug Resistance Patterns, Genetic Subtypes, Clinical Features, and Risk Factors in Military Personnel with HIV-1 Seroconversion." It is in the 5 October 1999 issue of Annals of Internal Medicine (volume 131, pages 502-506). The authors are S.K. Brodine, R.A. Shaffer, M.J. Starkey, S.A. Tasker, J.L. Gilcrest, M.K. Louder, A. Barile, T.C. VanCott, M.T. Vahey, F.E. McCutchan, D.L. Birx, D.D. Richman, and J.R. Mascola.

What is the problem and what is known about it so far?

The human immunodeficiency virus (HIV, the virus that causes AIDS) can undergo genetic changes resulting in different forms of the virus (subtypes). The existence of subtypes is a problem because the drugs that we use to treat HIV do not work on some subtypes. Subtypes vary by geographic region, with certain types being uncommon in the United States, but quite common in parts of Asia or Africa. HIV experts believe that drugs used to treat the virus may have something to do with the development of some subtypes. When the virus is exposed to a drug, it may change itself genetically so that the drug does not work anymore.

Why did the researchers do this particular study?

The researchers wanted to see how often subtypes of HIV, particularly subtypes that anti-HIV drugs do not work on, occur in persons with new infection who had no yet been given anti-HIV drugs. They also wanted to identify factors, such as where or the ways in which people got HIV infection, associated with uncommon or drug-resistant subtypes of the virus.

Who was studied?

Ninety-five military personnel with recent HIV infection participated in this study. The researchers knew these people had recent infection because they had positive HIV tests following a negative one several months before.

How was the study done?

The researchers studied the subtypes of HIV found in military personnel with recent HIV infection. They then examined relationships between the various subtypes and the characteristics of the infected persons.

What did the researchers find?

Almost 8% of the study patients had subtype E virus, a subtype that is uncommon in the United States, while the rest had the more common subtype B. Patients with subtype E were more likely to be heterosexual and to have been exposed to HIV when they were outside the United States or through contact with prostitutes than were those with subtype B. Thirty-one patients had drug-resistant subtypes even though they themselves had never received any HIV drugs. The researchers could not find any clear relationships between the ways the people were likely to have gotten the HIV infection and drug resistance.

What were the limitations of the study?

The study included only 95 people and findings in military personnel may not be the same as what would be found in civilians. The study was too small to provide information on factors associated with drug-resistant subtypes.

What are the implications of the study?

Uncommon or drug-resistant subtypes in persons with new HIV infection may be more frequent than we previously thought. Usually, the drugs work for a while before the virus changes itself and the drugs stop working. Some patients may be resistant to HIV drugs even before they receive treatment with the drugs. This means that the drugs to treat HIV infection would not work on them from the beginning.