40 research outputs found
Field Testing of Different Chemical Combinations as Odour Baits for Trapping Wild Mosquitoes in The Gambia
Odour baited traps have potential use in population surveillance of insect vectors of disease, and in some cases for vector population reduction. Established attractants for human host-seeking mosquitoes include a combination of CO2 with L-lactic acid and ammonia, on top of which additional candidate compounds are being tested. In this field study in rural Gambia, using Latin square experiments with thorough randomization and replication, we tested nine different leading candidate combinations of chemical odorants for attractiveness to wild mosquitoes including anthropophilic malaria vectors, using modified Mosquito Magnet-X (MM-X) counterflow traps outside experimental huts containing male human sleepers. Highest catches of female mosquitoes, particularly of An. gambiae s.l. and Mansonia species, were obtained by incorporation of tetradecanoic acid. As additional carboxylic acids did not increase the trap catches further, this ‘reference blend’ (tetradecanoic acid with L-lactic acid, ammonia and CO2) was used in subsequent experiments. MM-X traps with this blend caught similar numbers of An. gambiae s.l. and slightly more Mansonia and Culex mosquitoes than a standard CDC light trap, and these numbers were not significantly affected by the presence or absence of human sleepers in the huts. Experiments with CO2 produced from overnight yeast cultures showed that this organic source was effective in enabling trap attractiveness for all mosquito species, although at a slightly lower efficiency than obtained with use of CO2 gas cylinders. Although further studies are needed to discover additional chemicals that increase attractiveness, as well as to optimise trap design and CO2 source for broader practical use, the odour-baited traps described here are safe and effective for sampling host-seeking mosquitoes outdoors and can be incorporated into studies of malaria vector ecology
HIV Testing Experience and Risk Behavior Among Sexually Active Black Young Adults: A CBPR-Based Study Using Respondent-Driven Sampling in Durham, North Carolina
African Americans are disproportionately affected by the HIV epidemic inclusive of men who have sex with men, heterosexual men, and women. As part of a community-based participatory research study we assessed HIV testing experience among sexually active 18 to 30 year old Black men and women in Durham, North Carolina. Of 508 participants, 173 (74%) men and 236 (86%; p=.0008) women reported ever being tested. Barriers to testing (e.g., perceived risk and stigma) were the same for men and women, but men fell behind mainly because a primary facilitator of testing---routine screening in clinical settings---was more effective at reaching women. Structural and behavioral risk factors associated with HIV infection were prevalent but did not predict HIV testing experience. Reduced access to health care services for low income Black young adults may exacerbate HIV testing barriers that already exist for men and undermine previous success rates in reaching women
Which intervention is better for malaria vector control: insecticide mixture long-lasting insecticidal nets or standard pyrethroid nets combined with indoor residual spraying?
malERA: An updated research agenda for malaria elimination and eradication
Achieving a malaria-free world presents exciting scientific challenges as well as overwhelming health, equity, and economic benefits. WHO and countries are setting ambitious goals for reducing the burden and eliminating malaria through the “Global Technical Strategy” and 21 countries are aiming to eliminate malaria by 2020. The commitment to achieve these targets should be celebrated. However, the need for innovation to achieve these goals, sustain elimination, and free the world of malaria is greater than ever. Over 180 experts across multiple disciplines are engaged in the Malaria Eradication Research Agenda (malERA) Refresh process to address problems that need to be solved. The result is a research and development agenda to accelerate malaria elimination and, in the longer term, transform the malaria community’s ability to eradicate it globally
Hitting Hotspots: Spatial Targeting of Malaria for Control and Elimination
Teun Bousema and colleagues argue that targeting malaria “hotspots” is a highly efficient way to reduce malaria transmission at all levels of transmission intensity
Level of agreement between frequently used cardiovascular risk calculators in people living with HIV
Objectives
The aim of the study was to describe agreement between the QRISK2, Framingham and Data Collection on Adverse Events of Anti‐HIV Drugs (D:A:D) cardiovascular disease (CVD) risk calculators in a large UK study of people living with HIV (PLWH).
Methods
PLWH enrolled in the Pharmacokinetic and Clinical Observations in People over Fifty (POPPY) study without a prior CVD event were included in this study. QRISK2, Framingham CVD and the full and reduced D:A:D CVD scores were calculated; participants were stratified into ‘low’ ( 20%) categories for each. Agreement between scores was assessed using weighted kappas and Bland–Altman plots.
Results
The 730 included participants were predominantly male (636; 87.1%) and of white ethnicity (645; 88.5%), with a median age of 53 [interquartile range (IQR) 49–59] years. The median calculated 10‐year CVD risk was 11.9% (IQR 6.8–18.4%), 8.9% (IQR 4.6–15.0%), 8.5% (IQR 4.8–14.6%) and 6.9% (IQR 4.1–11.1%) when using the Framingham, QRISK2, and full and reduced D:A:D scores, respectively. Agreement between the different scores was generally moderate, with the highest level of agreement being between the Framingham and QRISK2 scores (weighted kappa = 0.65) but with most other kappa coefficients in the 0.50–0.60 range.
Conclusions
Estimates of predicted 10‐year CVD risk obtained with commonly used CVD risk prediction tools demonstrate, in general, only moderate agreement among PLWH in the UK. While further validation with clinical endpoints is required, our findings suggest that care should be taken when interpreting any score alone
Validation of a Novel Multivariate Method of Defining HIV-Associated Cognitive Impairment
Background. The optimum method of defining cognitive impairment in virally suppressed people living with HIV is unknown. We evaluated the relationships between cognitive impairment, including using a novel multivariate method (NMM), patientreported outcome measures (PROMs), and neuroimaging markers of brain structure across 3 cohorts.Methods. Differences in the prevalence of cognitive impairment, PROMs, and neuroimaging data from the COBRA, CHARTER, and POPPY cohorts (total n = 908) were determined between HIV-positive participants with and without cognitive impairment defined using the HIV-associated neurocognitive disorders (HAND), global deficit score (GDS), and NMM criteria.Results. The prevalence of cognitive impairment varied by up to 27% between methods used to define impairment (eg, 48% for HAND vs 21% for NMM in the CHARTER study). Associations between objective cognitive impairment and subjective cognitive complaints generally were weak. Physical and mental health summary scores (SF-36) were lowest for NMM-defined impairment (P<.05). There were no differences in brain volumes or cortical thickness between participants with and without cognitive impairment defined using the HAND and GDS measures. In contrast, those identified with cognitive impairment by the NMM had reduced mean cortical thickness in both hemispheres (P<.05), as well as smaller brain volumes (P<.01). The associations with measures of white matter microstructure and brain-predicted age generally were weaker.Conclusion. Different methods of defining cognitive impairment identify different people with varying symptomatology and measures of brain injury. Overall, NMM-defined impairment was associated with most neuroimaging abnormalities and poorer selfreported health status. This may be due to the statistical advantage of using a multivariate approach
Spatio-temporal heterogeneity of malaria vectors in northern Zambia: implications for vector control
Mosquito Attraction: Crucial Role of Carbon Dioxide in Formulation of a Five-Component Blend of Human-Derived Volatiles
Validation of a novel multivariate method of defining HIV-associated cognitive impairment
Background. The optimum method of defining cognitive impairment in virally suppressed people living with HIV is unknown.
We evaluated the relationships between cognitive impairment, including using a novel multivariate method (NMM), patient–
reported outcome measures (PROMs), and neuroimaging markers of brain structure across 3 cohorts.
Methods. Differences in the prevalence of cognitive impairment, PROMs, and neuroimaging data from the COBRA, CHARTER,
and POPPY cohorts (total n = 908) were determined between HIV-positive participants with and without cognitive impairment defined using the HIV-associated neurocognitive disorders (HAND), global deficit score (GDS), and NMM criteria.
Results. The prevalence of cognitive impairment varied by up to 27% between methods used to define impairment (eg, 48% for HAND
vs 21% for NMM in the CHARTER study). Associations between objective cognitive impairment and subjective cognitive complaints generally were weak. Physical and mental health summary scores (SF-36) were lowest for NMM-defined impairment (P < .05).
There were no differences in brain volumes or cortical thickness between participants with and without cognitive impairment defined using the HAND and GDS measures. In contrast, those identified with cognitive impairment by the NMM had reduced mean
cortical thickness in both hemispheres (P < .05), as well as smaller brain volumes (P < .01). The associations with measures of white
matter microstructure and brain-predicted age generally were weaker.
Conclusion. Different methods of defining cognitive impairment identify different people with varying symptomatology and
measures of brain injury. Overall, NMM-defined impairment was associated with most neuroimaging abnormalities and poorer selfreported health status. This may be due to the statistical advantage of using a multivariate approac