People with HIV infection can be expected to acquire new sexually transmitted diseases (STDs) at a rate equal to or greater than the general population,1–5 and syphilis may be a particular problem. In a 2002 study, Chesson and coworkers5 reported that the prevalence of primary and secondary syphilis in the general population was 186 per 100,000 people living with HIV compared with 2.4 per 100,000 in the general population; one fourth of all cases of primary and secondary syphilis detected in the United States in 2002 were in patients with HIV infection.
Clearly, acquisition of syphilis and/or other STDs in patients with HIV demonstrates unsafe sexual behavior and a failure in counseling messages. However, syphilis also portends problems for the patients themselves and the health of the public.
In this issue of the Journal, Koefed et al6 describe syphilis infections in 41 subjects with HIV who represented an outbreak of the disease in Copenhagen, Denmark. They demonstrated three findings of great concern: 1) four treatment failures, including one patient with probable neurosyphilis; 2) increased blood viral burden and decreased CD4 count linked to syphilis infection; and 3) apparent recurrent infections in seven subjects, further emphasizing ongoing high-risk behavior that could lead to the further spread of HIV.
Increases in blood viral load associated with syphilis infection have been previously noted by Buchaz and coworkers.7 In a retrospective study of 52 men in San Francisco, they observed a 0.22 log increase in HIV RNA before syphilis therapy with a fall of CD4 count by 62 cells. These results are of similar magnitude similar to those provided in the current report. In another study conducted in Malawi, Dyer et al8 demonstrated that subjects with genital ulcer disease (primarily chancroid and herpes simplex virus infection) had higher viral load in blood and semen compared with subjects with urethritis as well as lower CD4 cells. In this latter study, semen (but not blood plasma) viral load was reduced by appropriate antibiotic therapy.
The results of these studies have two important implications. First, syphilis coinfections might adversely affect the health of HIV-infected subjects. CD4 concentration correlates closely with susceptibility to opportunistic infections. Although the changes noted by both Kofoed and Buchaz were transitory, they are disturbing nevertheless. Such alteration in host defenses might also make treatment of syphilis more difficult or lead to changes in the natural history of infection.9
Second, the acquisition of syphilis by the subjects in this study is bad news for public health. The probability of the sexual transmission of HIV correlates closely with blood10 and genital tract viral burden.11 The presence of a genital ulcer caused by syphilis would also increase the risk of HIV transmission.12
These results emphasize HIV “prevention for positives.” Until quite recently, nearly all prevention methods have been focused on HIV-negative people. However, it seems clear that attention to HIV-infected subjects deserves equal if not greater emphasis. A variety of biologic and behavioral approaches have been suggested,13 and these include newer forms of counseling and routine screening for STDs. Recognition and implementation of these practices is absolutely critical for HIV caregivers.
References
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2. Belongia EA, Danila RN, Angamuthu V, et al. A population-based study of sexually transmitted disease incidence and risk factors in human immunodeficiency virus-infected people. Sex Transm Dis 1997; 24:251–256.
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6. Kofoed K, Gerstoft J, Mathiesen LR, Benfield T. Syphilis and HIV-1 co-infection: Influence on CD4 T cell count, HIV-1 viral load and treatment response. Sex Transm Dis. In press.
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8. Dyer JR, Eron JJ, Hoffman IF, et al. Association of CD4 cell depletion and elevated blood and seminal plasma human immunodeficiency virus type 1 (HIV-1) RNA concentrations with genital ulcer disease in HIV-1-infected men in Malawi. J Infect Dis 1998; 177:224–227.
9. Rolf RT, Joesoef MR, Hendershot EF, et al., for the Syphilis and HIV Study Group. A randomized trial of enhanced therapy for early syphilis in patients with and without human immunodeficiency virus infection. N Engl J Med 1997; 337:307–314.
10. Quinn TC, Wawer MJ, Sewankambo N, et al. Viral load and heterosexual transmission of human immunodeficiency virus type 1. N Engl J Med 2000; 342:921–929.
11. Chakraborty H, Sen PK, Helms RW, et al. Viral burden in genital secretions determines male-to-female sexual transmission of HIV-1: A probabilistic empiric model. AIDS 2001; 15:621–627.
12. Cohen MS, Pilcher C. Amplified HIV transmission and new approaches to HIV prevention. J Infect Dis 2005; 191:1391–1393.
13. Centers for Disease Control and Prevention. Incorporating HIV prevention into the medical care of persons living with HIV: Recommendations of CDC, the Health Resources and Services Administration, the National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America. MMWR Morb Mortal Wkly Rep 2003; 52:1–17.
