The role of travel agents in travel medicine – a study with agencies from Sao Paulo, Brazil

A survey in São Paulo, Brazil, assessed travel agents’ knowledge on travellers’ health. Data were collected using an online questionnaire. Of 200 agencies contacted, 32 answered (34 agents). Most consultants reported discussing personal safety, healt insurance and vaccination. Few provided information on water and food diseases or sexually transmitted infections.

CD4/CD8 Ratio and KT Ratio Predict Yellow Fever Vaccine Immunogenicity in HIV-Infected Patients.

BACKGROUND: HIV-infected individuals have deficient responses to Yellow Fever vaccine (YFV) and may be at higher risk for adverse events (AE). Chronic immune activation-characterized by low CD4/CD8 ratio or high indoleamine 2,3-dioxygenase-1 (IDO) activity-may influence vaccine response in this population. METHODS: We prospectively assessed AE, viremia by the YFV virus and YF-specific neutralizing antibodies (NAb) in HIV-infected (CD4>350) and -uninfected adults through 1 year after vaccination. The effect of HIV status on initial antibody response to YFV was measured during the first 3 months following vaccination, while the effect on persistence of antibody response was measured one year following vaccination. We explored CD4/CD8 ratio, IDO activity (plasma kynurenine/tryptophan [KT] ratio) and viremia by Human Pegivirus as potential predictors of NAb response to YFV among HIV-infected participants with linear mixed models. RESULTS: 12 HIV-infected and 45-uninfected participants were included in the final analysis. HIV was not significantly associated with AE, YFV viremia or NAb titers through the first 3 months following vaccination. However, HIV-infected participants had 0.32 times the NAb titers observed for HIV-uninfected participants at 1 year following YFV (95% CI 0.13 to 0.83, p = 0.021), independent of sex, age and prior vaccination. In HIV-infected participants, each 10% increase in CD4/CD8 ratio predicted a mean 21% higher post-baseline YFV Nab titer (p = 0.024). Similarly, each 10% increase in KT ratio predicted a mean 21% lower post-baseline YFV Nab titer (p = 0.009). Viremia by Human Pegivirus was not significantly associated with NAb titers. CONCLUSIONS: HIV infection appears to decrease the durability of NAb responses to YFV, an effect that may be predicted by lower CD4/CD8 ratio or higher KT ratio.

CD4/CD8 Ratio Predicts Yellow Fever Vaccine-Induced Antibody Titers in Virologically Suppressed HIV-Infected Patients.

BACKGROUND: Yellow fever vaccine (YFV) induces weaker immune responses in HIV-infected individuals. However, little is known about YFV responses among antiretroviral-treated patients and potential immunological predictors of YFV response in this population. METHODS: We enrolled 34 antiretroviral therapy (ART)-treated HIV-infected and 58 HIV-uninfected adults who received a single YFV dose to evaluate antibody levels and predictors of immunity, focusing on CD4(+) T-cell count, CD4(+)/CD8(+) ratio, and Human Pegivirus (GBV-C) viremia. Participants with other immunosuppressive conditions were excluded. RESULTS: Median time since YFV was nonsignificantly shorter in HIV-infected participants than in HIV-uninfected participants (42 and 69 months, respectively, P = 0.16). Mean neutralizing antibody (NAb) titers was lower in HIV-infected participants than HIV-uninfected participants (3.3 vs. 3.6 log10mIU/mL, P = 0.044), a difference that remained significant after adjustment for age, sex, and time since vaccination (P = 0.024). In HIV-infected participants, lower NAb titers were associated with longer time since YFV (rho: -0.38, P = 0.027) and lower CD4(+)/CD8(+) ratio (rho: 0.42, P = 0.014), but not CD4(+) T-cell count (P = 0.52). None of these factors were associated with NAb titers in HIV-uninfected participant. GBV-C viremia was not associated with difference in NAb titers overall or among HIV-infected participants. CONCLUSIONS: ART-treated HIV-infected individuals seem to have impaired and/or less durable responses to YFV than HIV-uninfected individuals, which were associated with lower CD4(+)/CD8(+) ratio, but not with CD4(+) T-cell count. These results supports the notion that low CD4(+)/CD8(+) ratio, a marker linked to persistent immune activation, is a better indicator of functional immune disturbance than CD4(+) T-cell count in patients with successful ART.

Hyperlipidemia related to the use of HIV-protease inhibitors: natural history and results of treatment with fenofibrate

Hyperlipidemia has been frequently recorded as a side effect of treating HIV patients with protease inhibitors (PI). This study was initiated to analyze the modifications on blood lipids in HIV-patients receiving PI and the safety and efficacy of the treatment with fenofibrate. Total (TC) and HDL-cholesterol, triglycerides (TG), and CD(4)(+) T-cell counts were measured in 30 HAART-naive patients (Group I) before and after PI introduction. In a second phase of the study, the effects of fenofibrate on lipids, CPK, CD(4)(+), and viral load were determined in 13 patients (Group II) with elevated TC or TG. In Group I, 60 of the patients showed TC or TG elevations. Average increments of 31 and 146 in TC and TG respectively (p<0.0006 and p<0.0001) were observed. In Group II, fenofibrate treatment was associated with decrements of 6.6 (TC) and 45.7 (TG) (p=0.07 and 0.0002) and no modifications on CPK, CD(4)(+), and viral load. In conclusion, hyperlipidemia is common during the treatment of HIV with protease inhibitors, and fenofibrate appears to be an effective and safe choice for its treatment.

The lipoprotein profile in HIV infected patients

Infection can change plasma lipoproteins by increasing the triglycerides and decreasing the cholesterol plasma levels. This process is thought to be result of alterations in lipoprotein metabolism produced by cytokines that mediate the immune response, including tumor necrosis factor, interleukin-1 and the interferons. The acquired immunodeficiency syndrome (AIDS) has been shown to accompanied by increased plasma triglyceride levels and a trend toward decreased plasma cholesterol levels. Plasma low density lipoprotein (LDL) patterns are also changed by infection and patients with AIDS have increased levels of small dense particles. Decreases in high density lipoprotein cholesterol (HDL-C) and apoliprotein A-I, and an increase in lipoprotein (a) [Lp(a)] are the usual lipidic disorders during HIV infection, even in those patients with CD4 lynphocyte counts above 400 cells/mmü. Plasma lipoproteins possess well-recognized transport functions. Certain classes of these lipoproteins can also regulate selected metabolic functions of a variety of cell types. Among these bioregulatory properties is the regulation of lymphocyte function and regulation of immune response. Thus, a number of immune functions may be significantly influenced by the lipoprotein alterations present in AIDS. Furthermore, the decreased HDL-C and increased triglycerides and Lp(a) are associated with an increased risk of myocardial infarction and some cardiovascular events have been reported in HIV positive individuals. This paper describes lipoprotein alterations during HIV infection, and evaluates their relationship to immune function and atherogenic profile