Efficacy of a spatial repellent for control of Aedes-borne virus transmission: A cluster-randomized trial in Iquitos,Peru

Over half the world’s population is at risk for viruses transmitted by Aedes mosquitoes, such as dengue and Zika. The primary vector, Aedes aegypti, thrives in urban environments. Despite decades of effort, cases and geographic range of Aedes-borne viruses (ABVs) continue to expand. Rigorously proven vector control interventions that measure protective efficacy against ABV diseases are limited to Wolbachia in a single trial in Indonesia and do not include any chemical intervention. Spatial repellents, a new option for efficient deployment, are designed to decrease human exposure to ABVs by releasing active ingredients into the air that disrupt mosquito–human contact. A parallel, cluster-randomized controlled trial was conducted in Iquitos, Peru, to quantify the impact of a transfluthrin-based spatial repellent on human ABV infection. From 2,907 households across 26 clusters (13 per arm), 1,578 participants were assessed for seroconversion (primary endpoint) by survival analysis. Incidence of acute disease was calculated among 16,683 participants (secondary endpoint). Adult mosquito collections were conducted to compare Ae. aegypti abundance, blood-fed rate, and parity status through mixed-effect difference-in-difference analyses. The spatial repellent significantly reduced ABV infection by 34.1% (one-sided 95% CI lower limit, 6.9%; one-sided P value = 0.0236, z = 1.98). Aedes aegypti abundance and blood-fed rates were significantly reduced by 28.6 (95% CI 24.1%, ∞); z = −9.11) and 12.4% (95% CI 4.2%, ∞); z = −2.43), respectively. Our trial provides conclusive statistical evidence from an appropriately powered, preplanned cluster-randomized controlled clinical trial of the impact of a chemical intervention, in this case a spatial repellent, to reduce the risk of ABV transmission compared to a placebo.

Aedes-borne viral diseases (ABVDs) [e.g., dengue (DENV), chikungunya, Zika (ZIKV), and yellow fever] are devastating, expanding global public health threats that disproportionally affect low- and middle-income countries. DENV, one of the most rapidly increasing vector-borne infectious diseases, results in ∼400 million infections each year (1, 2), with 4 billion people at risk for infection annually (3). Currently, the primary means for ABVD prevention is controlling the primary mosquito vector, Aedes aegypti. Existing vector control interventions, however, have failed to prevent ABV transmission and epidemics (4–6).There is an urgent need to develop evidence-based guidance for the use of new and existing ABV vector control tools. The evidence base for vector control against ABVs is weak, despite considerable government investments in World Health Organization (WHO)-recommended control of larval habitats (larviciding, container removal) and ultra-low-volume insecticide spraying (4, 5, 7–9). These strategies continue to be implemented despite the lack of rigorously generated data from controlled clinical trials demonstrating they reduce ABV infection or disease (6). The only ABV intervention with a proven epidemiological impact in a cluster-randomized control trial (cRCT) assessed community mobilization to reduce mosquito larval habitats (10). A recent test-negative trial with Wolbachia-infected mosquitoes reported a significant reduction of DENV illness in Indonesia (11).Spatial repellents (SRs) are devices that contain volatile active ingredients that disperse in air. The active ingredients can repel mosquitoes from entering a treated space, inhibit attraction to human host cues, or disrupt mosquito biting and blood-feeding behavior and, thus, interfere with mosquito–human contact (12–14). Any of these outcomes reduce the probability of pathogen transmission. Pyrethroid-based SRs have shown efficacy in reducing malaria infections in China (15) and Indonesia (16). There have, however, been no clinical trials evaluating the protective efficacy (PE) of SRs against ABV infection or disease.To generate evidence for public health consideration, we conducted a double-blinded, parallel cRCT to demonstrate and quantify the PE of a transfluthrin-based SR to reduce ABV infection incidence over 2 y in a human cohort in Iquitos, Peru.     

Pork intake and human papillomavirus‐related disease

Clinical and ecological evidence supporting an association between human papillomavirus (HPV)‐related tumors and dietary factors are presented. Abstinence from high intake of fried pork (600–1,000 g/day) was associated with regression of an urethral condyloma in a healthy 19‐year‐old man treated with interferon gamma. International correlations suggest that pork intake is positively associated with incidence of cervical cancer, a disease also related to HPV. Pork meat or dietary factors associated with pork meat consumption may be involved in the development of HPV‐related diseases.     

Aortic valve disease with severe ventricular dysfunction: stentless valve for better recovery

BACKGROUND: Stentless bioprostheses and homografts show better hemodynamic profiles compared with conventional stented bioprostheses and mechanical valves. Few data are available on stentless aortic valve implantation for patients with severe left ventricular dysfunction. The aim of this retrospective study was to assess the potential benefits of stentless aortic valve implantation for patients undergoing isolated aortic valve replacement with left ventricular ejection fraction < or = 35%. METHODS: From November 1988 through March 2000, 53 patients (45 men and 8 women, aged 64.2 +/- 15.2 years) with a LVEF < or = 35% (mean EF, 28.7 +/- 5.4%) underwent isolated, primary aortic valve replacement for chronic aortic valve disease. Twenty patients received stentless aortic valves and 33 patients received conventional stented bioprostheses and mechanical valves. Predictive factors for LVEF recovery at echocardiographic follow-up (36.2 +/- 32.1 months) were analyzed by simple and multiple regression analysis. RESULTS: There were no significant differences between groups in early and late mortality. Stentless aortic valve implantation required a longer aortic cross-clamp time (p = 0.037). The stentless aortic valve group showed a better LVEF recovery (p = 0.016). Stentless aortic valves had a larger indexed effective orifice area compared with conventional stented bioprostheses and mechanical valves (p < 0.0001). A smaller indexed effective orifice area (p = 0.0008), chronic obstructive pulmonary disease (p = 0.015), and implantation of a conventional stented bioprosthesis or mechanical valve (p = 0.016) were related to reduced LVEF recovery by univariate analysis. A larger indexed effective orifice area (p = 0.024) was an independent predictive factor for a better LVEF recovery by multivariate analysis. CONCLUSIONS: Stentless aortic valve implantation for patients with severe left ventricular dysfunction, even if technically more demanding, is a safe procedure that warrants a larger indexed effective orifice area leading to an enhanced LVEF recovery.     

Changes in bone mineral density, lean body mass and fat content as measured by dual energy x-ray absorptiometry in patients with prostate cancer without apparent bone metastases given androgen deprivation therapy

PURPOSE: We characterize the consequences of androgen deprivation therapy on body composition in elderly men. MATERIALS AND METHODS: Using a dual energy x-ray absorptiometry instrument, we determined the changes in bone mineral density, bone mineral content, fat body mass and lean body mass in 35 patients with prostate cancer without bone metastases who received luteinizing hormone releasing hormone analogue for 12 months. RESULTS: At baseline conditions 46% of cases were classified as osteopenic and 14% as osteoporotic at the lumbar spine and 40% were osteopenic and 4% osteoporotic at the hip. Androgen deprivation significantly decreased bone mineral density either at the lumbar spine (mean gm./cm.2 [SD] 1.00 [0.194], 0.986 [0.172] and 0.977 [0.182] at baseline, and 6 and 12 months, respectively, p <0.002) or the hip (0.929 [0.136], 0.926 [0.144] and 0.923 [0.138], p <0.03). A more than 2% decrease in bone mineral density was found at the lumbar spine in 19 men (54.3%) and at the hip in 15 (42.9%). Bone mineral content paralleled the bone mineral density pattern. Lean body mass decreased (mean gm. [SD] 50,287 [6,656], 49,296 [6,554] and 49,327 [6,345], p <0.003), whereas fat body mass consistently increased (18,115 [6,209], 20,724 [6,029] and 21,604 [5,923] p <0.001). CONCLUSIONS: Serial bone densitometry evaluation during androgen deprivation therapy may allow the detection of patients with prostate cancer at risk for osteoporotic fractures, that is those with osteopenia or osteoporosis at baseline and fast bone loss. The change in body composition may predispose patients to accidental falls, thus increasing the risk of bone fracture.