Molecular diagnosis using real-time polymerase chain reaction (PCR) may allow earlier diagnosis of rickettsiosis. We developed a duplex real-time PCR that amplifies (1) DNA of any rickettsial species and (2) DNA of both typhus group rickettsia, that is, Rickettsia prowazekii and Rickettsia typhi. Primers and probes were selected to amplify a segment of the 16S rRNA gene of Rickettsia spp. for the pan-rickettsial PCR and the citrate synthase gene (gltA) for the typhus group rickettsia PCR. Analytical sensitivity was 10 copies of control plasmid DNA per reaction. No cross-amplification was observed when testing human DNA and 22 pathogens or skin commensals. Real-time PCR was applied to 16 clinical samples. Rickettsial DNA was detected in the skin biopsies of three patients. In one patient with severe murine typhus, the typhus group PCR was positive in a skin biopsy from a petechial lesion and seroconversion was later documented. The two other patients with negative typhus group PCR suffered from Mediterranean and African spotted fever, respectively; in both cases, skin biopsy was performed on the eschar. Our duplex real-time PCR showed a good analytical sensitivity and specificity, allowing early diagnosis of rickettsiosis among three patients, and recognition of typhus in one of them.

Background Syphilis is re-emerging globally in general and HIV-infected populations, and repeated syphilis episodes may play a central role in syphilis transmission among core groups. Besides sexual behavioral factors, little is known about determinants of repeated syphilis episodes in HIV-infected individuals—including the potential impact of preceding syphilis episodes on subsequent syphilis risk. Methods In the prospective Swiss HIV cohort study, with routine syphilis testing since 2004, we analyzed HIV-infected men who have sex with men (MSM). Our primary outcome was first and repeated syphilis episodes. We used univariable and multivariable Andersen-Gill models to evaluate risk factors for first and repeated incident syphilis episodes. Results Within the 14-year observation period, we included 2513 HIV-infected MSM with an initially negative syphilis test. In the univariable and multivariable analysis, the number of prior syphilis episodes (adjusted hazard ratio [aHR] per 1-episode increase, 1.15; 95% confidence interval [CI], 1.01–1.31), having occasional sexual partners with or without condomless anal sex (aHR, 4.99; 95% CI, 4.08–6.11; and aHR, 2.54; 95% CI, 2.10–3.07), and being currently on antiretroviral therapy (aHR, 1.62; 95% CI, 1.21–2.16) were associated with incident syphilis. Conclusions In HIV-infected MSM, we observed no indication of decreased syphilis risk with repeated syphilis episodes. The extent of sexual risk behavior over time was the strongest risk factor for repeated syphilis episodes. The observed association of antiretroviral therapy with repeated syphilis episodes warrants further immunological and epidemiological investigation.

The role of Malassezia spp in seborrheic dermatitis (SD) is controversial. To compare the cutaneous density and the cultural characteristics of Malassezia in persons with or without SD, quantitative cultures were obtained by stripping the forehead with a tape placed on Leeming and Notman medium. Plates were incubated at 37 degrees C in a plastic bag, and colonies were counted after 14 days. High yeast density was defined as > 100 colony forming units (CFU)/tape. Volunteers were divided into four groups depending on their HIV serology [HIV (+) versus HIV (-) or unknown] and their clinical status (with or without SD). 126/129 cultures were positive (97.7%). Malassezia spp density was low on clinically normal skin in all HIV (-) persons (40/40) but was high in 8/34 (24%) HIV (+) persons without SD (p < 0.001). In SD patients, high densities were found in 10/22 (45%) HIV (+) and in 17/33 (52%) HIV (-) persons. The strains could be divided into three basic groups on the basis of their cultural characteristics. Colony morphology type A predominated on normal skin (72%), and morphology type C predominated on persons with SD (78%). High yeast density can be present without skin symptoms. The pathogenicity of Malassezia seems more likely to be determined by the subtype present on the skin rather than by its density.

The use of highly active antiretroviral therapy (HAART) has been associated with a marked decrease in the prevalence of opportunistic infections in HIV-infected patients. However, chronic mucocutaneous herpes simplex virus (HSV) infection remains a difficult clinical challenge. ObjectiveThe aim of the study was to optimize the diagnosis and follow-up of chronic HSV-2 infection in HIV-infected patients and to correlate clinical data with CD4 cell count, in vitro HSV virological resistance and histology. MethodsA retrospective case series was collected from a specialist out-patient clinic providing consultations to patients with infectious skin diseases. Clinical, biological, virological and histological data were analysed. ResultsSeven HIV-infected patients with genital and perianal herpes simplex infection were followed over 10 years. Ulcerative and pseudo-tumoral forms were observed. Lesions occurred at various stages of immune suppression (CD4 counts from 1 to 449 cells/mL). Clinical resistance to conventional anti-herpetic drugs was correlated with the in vitro resistance of HSV in 70% of cases. ConclusionsChronic mucocutaneous HSV infection in AIDS patients remains a rare but regularly observed infection in very immunosuppressed patients or those with unstable immunity during HAART. Virological results obtained from mucocutaneous samples were in most cases found to be correlated with clinical evolution and should therefore be used in making decisions on treatment. Despite efficient antiviral therapy, mucocutaneous healing is slow in the majority of cases.