Acute HIV infection

Acute HIV infection or primary HIV infection (also known as "Acute seroconversion syndrome"[1]:416) is the second stage of HIV infection. It occurs after the incubation stage, before the latency stage and the potential AIDS succeeding the latency stage.

Contents

Symptoms

During this period (usually 2–4 weeks post-exposure) an individual may develop influenza or mononucleosis-like symptoms, most commonly fever, lymphadenopathy, pharyngitis, generalized rash of maculopapular[2] type, myalgia, malaise, mouth and esophageal sores, and may also include, but less commonly, headache, nausea and vomiting, enlarged liver/spleen, weight loss, thrush, and neurological symptoms. Infected individuals may experience all, some, or none of these symptoms. The acute illness can last between a few days and 10 weeks, though usually less than 14 days.[3] In some very rare cases, about 10 patients from 1989 to date[4], a bilateral facial palsy has been associated with acute HIV-1 infection.

Because of the nonspecific nature of these symptoms, they are often not recognized as signs of HIV infection. Even if patients go to their doctors or a hospital, they will often be misdiagnosed as having one of the more common infectious diseases with the same symptoms. Consequently, these primary symptoms are not used to diagnose HIV infection as they do not develop in all cases and because many are caused by other more common diseases. However, recognizing the syndrome can be important because the patient is much more infectious during this period. [5]

These nonspecific symptoms can also be symptoms of other infections; consequently, having these symptoms does not reliably indicate the presence of HIV.

History and physical findings for primary HIV infection[5]
sensitivity specificity
Fever 88% 50%
Malaise 73% 58%
Myalgia 60% 74%
Rash 58% 79%
Headache 55% 56%
Night sweats 50% 68%
Sore throat 43% 51%
Lymphadenopathy 38% 71%
Arthralgia 28% 87%
Nasal congestion 18% 62%

Cause

Acute HIV infection is a period of rapid viral replication that immediately follows the individual's exposure to HIV leading to an abundance of virus in the peripheral blood with levels of HIV commonly approaching several million viruses per mL.[6] This response is accompanied by a marked drop in the numbers of circulating CD4+ T cells. This acute viremia is associated in virtually all patients with the activation of CD8+ T cells, which kill HIV-infected cells, and subsequently with antibody production, or seroconversion. The CD8+ T cell response is thought to be important in controlling virus levels, which peak and then decline, as the CD4+ T cell counts rebound to around 800 cells per mL (the normal value is 1200 cells per mL ). A good CD8+ T cell response has been linked to slower disease progression and a better prognosis, though it does not eliminate the virus.[7] A strong immune defense reduces the number of viral particles in the blood stream, marking the end of the acute HIV infection and the start of the infection's clinical latency stage, which, in turn, may be succeeded by true AIDS.

References

  1. ^ James, William D.; Berger, Timothy G. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. ISBN 0-7216-2921-0. 
  2. ^ wrongdiagnosis.com skin rash causes
  3. ^ Kahn, J. O. and Walker, B. D. (1998). "Acute Human Immunodeficiency Virus type 1 infection". N. Engl. J. Med. 331 (1): 33–39. doi:10.1056/NEJM199807023390107. PMID 9647878. 
  4. ^ http://www.journals.uchicago.edu/doi/abs/10.1086/511876
  5. ^ a b Daar ES, Little S, Pitt J et al. (2001). "Diagnosis of primary HIV-1 infection. Los Angeles County Primary HIV Infection Recruitment Network". Ann. Intern. Med. 134 (1): 25–9. PMID 11187417. 
  6. ^ Piatak, M., Jr, Saag, M. S., Yang, L. C., Clark, S. J., Kappes, J. C., Luk, K. C., Hahn, B. H., Shaw, G. M. and Lifson, J.D. (1993). "High levels of HIV-1 in plasma during all stages of infection determined by competitive PCR". Science 259 (5102): 1749–1754. doi:10.1126/science.8096089. PMID 8096089. 
  7. ^ Pantaleo G, Demarest JF, Schacker T, Vaccarezza M, Cohen OJ, Daucher M, Graziosi C, Schnittman SS, Quinn TC, Shaw GM, Perrin L, Tambussi G, Lazzarin A, Sekaly RP, Soudeyns H, Corey L, Fauci AS. (1997). "The qualitative nature of the primary immune response to HIV infection is a prognosticator of disease progression independent of the initial level of plasma viremia". Proc Natl Acad Sci U S A. 94 (1): 254–258. doi:10.1073/pnas.94.1.254. PMC 19306. PMID 8990195. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=19306.