Relationships between sexually transmitted diseases and human immunodeficiency virus infection

Although human immunodeficiency virus infection is, in itself, often a sexually transmitted disorder, the bidirectional synergy between this viral disease and the more “classical” sexually transmitted diseases has only recently been recognized. Three specific potential interrelationships are of paramount importance: (1) the potential for sexually transmitted diseases to increase the rate of both human immunodeficiency virus acquisition and transmission; (2) the potential for sexually transmitted diseases to accelerate the natural progression of human immunodeficiency virus infection; and (3) the potential for human immunodeficiency virus coinfection to alter critical clinical and/or serologic parameters used to diagnose and treat sexually transmitted diseases. Human experimentation to demonstrate any or all of these synergistic interactions would be ethically unthinkable. Therefore inferences must be drawn from prospective and retrospective studies, case-controlled studies, and even isolated case reports. Conclusions must be tempered by the inherent difficulty in analyzing data derived from populations where true “control” for such variables as number of sexual partners, sexual practices, social strata, accessibility and quality of medical care, nutritional status, and geographic ecological factors is very difficult. Nevertheless, it does appear that genital ulcer disease, and in particular syphilis and chancroid, increase the risk of human immunodeficiency acquisition and transmission. Nonulcerative sexually transmitted diseases (such as gonorrhea and chlamydia) may also increase these risks, but data are much less convincing in this regard. The role of human papillomavirus infection is unclear. The role of sexually transmitted diseases in human immunodeficiency virus progression is unsettled at present. In vitro evidence suggests that herpesvirus infection (e.g., herpes progenitalis) may be capable of accelerating human immunodeficiency virus disease through retroviral transactivation. Other sexually transmitted diseases may generally depress the patient's immune state and, in this nonspecific fashion, hasten the progression of human immunodeficiency virus. However, conclusive in vivo human data are lacking to verify this “commonsense” hypothesis. From a clinical standpoint, human immunodeficiency virus coinfection affects sexually transmitted diseases in a variable and unpredictable manner. For example, although most human immunodeficiency virus-positive patients with syphilis exhibit typical serologic and clinical features, some do have atypical lesions and may be prone to either the prozone phenomenon (early in human immunodeficiency virus infection) or false-negative serologic tests (late in human immunodeficiency virus infection). There appears to be a small but distinct risk that human immunodeficiency virus-positive patients treated with standard antitreponemal antibiotic regimens may still have neurosyphilis develop. The effect of early antiretroviral therapy on these alterations has not been adequately investigated. Patients with chancroid and human immunodeficiency virus coinfection tend to have larger lesions and may not respond to recommended single-dose antibiotic treatment schedules. Herpetic lesions may be larger and more persistent. Moreover, acyclovir resistance caused by thymidine kinase deficiency seems almost unique to human immunodeficiency virus-positive individuals. Human papillomavirus infection in those who are also human immunodeficiency virus-positive may result in larger and more multicentric venereal warts, and the risk of human papillomavirus-induced anogenital dysplasia and neoplasia appears high. Tretment for human papillomavirus is even more difficult than usual among the human immunodeficiency virus-positive patients, and repeated applications of multiple different modalities may be required to achieve even a modicum of control. Crusted scabies carries a real risk of bacterial septicemia in the human immunodeficiency virus-positive host. Chlamydial infections tend to run a typical clinical course in the human immunodeficiency virus-positive population, but gonorrhea and gonococcemia are more often due to penicillin-resistant organisms. Sexually transmitted disease prevention in the human immunodeficiency virus era has become an even more urgent matter. The condom, when used properly and consistently, appears to be a reliable method of preventing both sexually transmitted diseases and human immunodeficiency virus acquisition. Early therapeutic intervention in sexually transmitted diseases also appears to be globally beneficial in reducing the risk of human immunodeficiency virus acquisition. Easy access to such treatment should be a goal for all communities.