Origin and Spread of HIV-1 Subtype B Among Heterosexual Individuals in Bulgaria.

Human immunodeficiency virus (HIV) was originally introduced in Bulgaria through heterosexual transmission (HET) and later transferred to other vulnerable groups along with numerous more recent introductions from outside Bulgaria. To define the diversity, origins, and dynamics of the HIV-1 subtypes prevalent in HET population in Bulgaria, we applied phylogenetic and phylodynamic analyses using polymerase (pol) sequences from HET individuals to infer the spatiotemporal evolutionary history of the HIV-1 epidemic in this population in Bulgaria. High genetic diversity was found, including 13 different HIV-1 subtypes: 45.7% subtype B, 19.9% CRF01_AE, 7.5% CRF02_AG, 7.5% sub-subtypes A1 and A6, 7.1% subtype C, 5.3% subtype F1, 4.0% URFs, 1.2% CRF05_DF, 0.6% subtype G, 0.3% CRF04_cpx, 0.3% CRF29_BF, 0.3% CRF14_BG, and 0.3% subtype H. The estimated root of the subtype B in the phylogenetic tree dated back to the year 1980 largely due to multiple introductions of subtype B from outside the country. Several significant clades have been identified highlighting six different main epidemic entrances of subtype B dating from 1989 to 2007. The Bayesian skyline plot showed two different exponential growth periods starting in the 1980s to 1990 followed by a constant phase up to about 2008, with another exponential growth period from 2008 to the year 2012. The migration analysis identified dynamic pattern of gene flow and demonstrated that many HET probably acquired the infection abroad (14.6%), while only (6.6%) of non-HET were infected outside country. The phylogenetic analysis showed an intermixing between sequences from Bulgarians with sequences from other countries, suggesting different HIV introduction in this country followed by the internal spread through local transmission networks.

Non-pharmacological methods in the treatment of resistant hypertension.

INTRODUCTION: Arterial hypertension is the most common chronic cardiovascular disease affecting about 25% of the adult population. Meta-analyses have demonstrated a linear relationship between blood pressure and the risk of cardiovascular events. Resistant hypertension defined as failure to reach blood pressure targets despite treatment with three antihypertensive drugs including a diuretic represents a serious clinical problem. It has been estimated that it affects between 8.9% and 12.8% of all treated hypertensive subjects. In resistant hypertension the optimal blood pressure is illusive despite very well tailored therapy. OBJECTIVE: Management of resistant hypertension is exactly the field where blood pressure-controlling non-pharmacological methods fit best. The present article aims at throwing light on these methods' principles of action, on who the target patient groups are and the respective results. Two methods are especially reviewed here: the carotid baroreflex stimulation and the transcatheter renal sympathetic denervation. Current results from the use of renal denervation suggest stable efficiency of the method, the results becoming significant 6 months after the procedure is applied and sustained for two years in the follow-up. As much as 90% of the treated patients respond to the procedure. The transcatheter renal denervation is associated with only 2.61% of procedural complications. The baroreflex carotid stimulation, too, is known to produce a stable effect on blood pressure: the effect become obvious at 12 months in 88% of the treated subjects. The neurologic complications associated with the procedure are reported to occur in 4.4% of cases. CONCLUSION: The present review article clearly demonstrates that non-pharmacological methods for treatment of resistant hypertension show great promise despite some open questions concerning their long term effects and procedural safety.