TUBERCULOSIS IN HIGH-PREVALENCE COUNTRIES: CURRENT CONTROL STRATEGIES AND THEIR TECHNICAL AND OPERATIONAL LIMITATIONS

Tuberculosis ◽  
1999 ◽  
pp. 123-165
Author(s):  
Klaus Jochem ◽  
John Walley
Keyword(s):  
Control Strategies ◽  
Current Control ◽  
High Prevalence

scholarly journals Phylogenetic Complexity of Morphologically Identified Anopheles squamosus in Southern Zambia

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 146
Author(s):  
Jordan Hoffman ◽  
Ilinca Ciubotariu ◽  
Limonty Simubali ◽  
Twig Mudenda ◽  
William Moss ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Catchment Area ◽  
Control Strategies ◽  
Light Trap ◽  
Current Control ◽  
Control Measures ◽  
Morphological Identification ◽  
The Past ◽  
Blood Meal Source ◽  
Residual Malaria Transmission

Despite dramatic reductions in malaria cases in the catchment area of Macha Hospital, Choma District, Southern Province in Zambia, prevalence has remained near 1–2% by RDT for the past several years. To investigate residual malaria transmission in the area, this study focuses on the relative abundance, foraging behavior, and phylogenetic relationships of Anopheles squamosus specimens. In 2011, higher than expected rates of anthropophily were observed among “zoophilic” An. squamosus, a species that had sporadically been found to contain Plasmodium falciparum sporozoites. The importance of An. squamosus in the region was reaffirmed in 2016 when P. falciparum sporozoites were detected in numerous An. squamosus specimens. This study analyzed Centers for Disease Control (CDC) light trap collections of adult mosquitoes from two collection schemes: one performed as part of a reactive-test-and-treat program and the second performed along a geographical transect. Morphological identification, molecular verification of anopheline species, and blood meal source were determined on individual samples. Data from these collections supported earlier studies demonstrating An. squamosus to be primarily exophagic and zoophilic, allowing them to evade current control measures. The phylogenetic relationships generated from the specimens in this study illustrate the existence of well supported clade structure among An. squamosus specimens, which further emphasizes the importance of molecular identification of vectors. The primarily exophagic behavior of An. squamosus in these collections also highlights that indoor vector control strategies will not be sufficient for elimination of malaria in southern Zambia.

scholarly journals Mosquito Control Priorities in Florida—Survey Results from Florida Mosquito Control Districts

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 947
Author(s):  
Rishi Kondapaneni ◽  
Ashley N. Malcolm ◽  
Brian M. Vazquez ◽  
Eric Zeng ◽  
Tse-Yu Chen ◽  
...  
Keyword(s):  
State Government ◽  
Mosquito Control ◽  
Control Strategies ◽  
Mosquito Species ◽  
Research Priorities ◽  
Current Control ◽  
Control Programs ◽  
Common Control ◽  
Surveillance Programs ◽  
Research Questions

Florida lies within a subtropical region where the climate allows diverse mosquito species including invasive species to thrive year-round. As of 2021, there are currently 66 state-approved Florida Mosquito Control Districts, which are major stakeholders for Florida public universities engaged in mosquito research. Florida is one of the few states with extensive organized mosquito control programs. The Florida State Government and Florida Mosquito Control Districts have long histories of collaboration with research institutions. During fall 2020, we carried out a survey to collect baseline data on the current control priorities from Florida Mosquito Control Districts relating to (1) priority control species, (2) common adult and larval control methods, and (3) major research questions to address that will improve their control and surveillance programs. The survey data showed that a total of 17 distinct mosquito species were considered to be priority control targets, with many of these species being understudied. The most common control approaches included truck-mounted ultra-low-volume adulticiding and biopesticide-based larviciding. The districts held interest in diverse research questions, with many prioritizing studies on basic science questions to help develop evidence-based control strategies. Our data highlight the fact that mosquito control approaches and priorities differ greatly between districts and provide an important point of comparison for other regions investing in mosquito control, particularly those with similar ecological settings, and great diversity of potential mosquito vectors, such as in Florida. Our findings highlight a need for greater alignment of research priorities between mosquito control and mosquito research. In particular, we note a need to prioritize filling knowledge gaps relating to understudied mosquito species that have been implicated in arbovirus transmission.

scholarly journals Multiple horizontal acquisitions of plant genes in the whitefly Bemisia tabaci

2022 ◽  
Author(s):  
Clément Gilbert ◽  
Florian Maumus
Keyword(s):  
Bemisia Tabaci ◽  
Control Strategies ◽  
Purifying Selection ◽  
Amino Acid Identity ◽  
Current Control ◽  
Eukaryote Evolution ◽  
Plant Genes ◽  
Insect Interactions ◽  
High Level ◽  
Open Question

The extent to which horizontal gene transfer (HGT) has shaped eukaryote evolution remains an open question. Two recent studies reported four plant-like genes acquired through two HGT events by the whitefly Bemisia tabaci, a major agricultural pest (Lapadula et al. 2020; Xia et al. 2021). Here, we performed a systematic search for plant-to-insect HGT in B. tabaci and uncovered a total of 50 plant-like genes deriving from at least 24 independent HGT events. Most of these genes are present in three cryptic B. tabaci species, show high level of amino-acid identity to plant genes (mean = 64%), are phylogenetically nested within plant sequences, and are expressed and evolve under purifying selection. The predicted functions of these genes suggest that most of them are involved in plant-insect interactions. Thus, substantial plant-to-insect HGT may have facilitated the evolution of B. tabaci towards adaptation to a large host spectrum. Our study shows that eukaryote-to-eukaryote HGT may be relatively common in some lineages and it provides new candidate genes that may be targeted to improve current control strategies against whiteflies.

scholarly journals Effectiveness of Screening Hospital Admissions to Detect Asymptomatic Carriers of Clostridium difficile: A Modeling Evaluation

2014 ◽  
Vol 35 (8) ◽  
pp. 1043-1050 ◽  
Author(s):  
Cristina Lanzas ◽  
Erik R. Dubberke
Keyword(s):  
Clostridium Difficile ◽  
Hospital Admissions ◽  
Control Strategies ◽  
Turnaround Time ◽  
Current Control ◽  
Hospital Ward ◽  
Transmission Model ◽  
Baseline Scenario ◽  
Asymptomatic Carriers ◽  
Contact Precautions

ObjectiveBoth asymptomatic and symptomatic Clostridium difficile carriers contribute to new colonizations and infections within a hospital, but current control strategies focus only on preventing transmission from symptomatic carriers. Our objective was to evaluate the potential effectiveness of methods targeting asymptomatic carriers to control C. difficile colonization and infection (CDI) rates in a hospital ward: screening patients at admission to detect asymptomatic C. difficile carriers and placing positive patients into contact precautions.MethodsWe developed an agent-based transmission model for C. difficile that incorporates screening and contact precautions for asymptomatic carriers in a hospital ward. We simulated scenarios that vary according to screening test characteristics, colonization prevalence, and type of strain present at admission.ResultsIn our baseline scenario, on average, 42% of CDI cases were community-onset cases. Within the hospital-onset (HO) cases, approximately half were patients admitted as asymptomatic carriers who became symptomatic in the ward. On average, testing for asymptomatic carriers reduced the number of new colonizations and HO-CDI cases by 40%–50% and 10%–25%, respectively, compared with the baseline scenario. Test sensitivity, turnaround time, colonization prevalence at admission, and strain type had significant effects on testing efficacy.ConclusionsTesting for asymptomatic carriers at admission may reduce both the number of new colonizations and HO-CDI cases. Additional reductions could be achieved by preventing disease in patients who are admitted as asymptomatic carriers and developed CDI during the hospital stay.

scholarly journals Forecast Possible Risk for COVID-19 Epidemic Dissemination under Current Control Strategies in Japan

2020 ◽  
Vol 17 (11) ◽  
pp. 3872 ◽  
Author(s):  
Zhongxiang Chen ◽  
Jun Yang ◽  
Binxiang Dai
Keyword(s):  
Confidence Interval ◽  
Prevention And Control ◽  
Control Strategies ◽  
Current Control ◽  
Self Healing ◽  
Current State ◽  
Imported Cases ◽  
The Times ◽  
Robust Measures ◽  
And Control

COVID-19 has globally spread to over 4 million people and the epidemic situation in Japan is very serious. The purpose of this research was to assess the risk of COVID-19 epidemic dissemination in Japan by estimating the current state of epidemic dissemination and providing some epidemic prevention and control recommendations. Firstly, the period from 6 January to 31 March 2020 was divided into four stages and the relevant parameters were estimated according to the imported cases in Japan. The basic reproduction number of the current stage is 1.954 (95% confidence interval (CI) 1.851–2.025), which means COVID-19 will spread quickly, and the self-healing rate of Japanese is about 0.495 (95% CI 0.437–0.506), with small variations in the four stages. Secondly, the results were applied to the actual reported cases from 1 to 5 April 2020, verifying the reliability of the estimated data using the accumulated reported cases located within the 95% confidence interval and the relative error of forecast data of five days being less than 2.5 % . Thirdly, considering the medical resources in Japan, the times the epidemic beds and ventilators become fully occupied are predicted as 5 and 15 May 2020, respectively. Keeping with the current situation, the final death toll in Japan may reach into the millions. Finally, based on experience with COVID-19 prevention and control in China, robust measures such as nationwide shutdown, store closures, citizens isolating themselves at home, and increasing PCR testing would quickly and effectively prevent COVID-19 spread.

scholarly journals Current Source Based on H-Bridge Inverter with Output LCL Filter

2015 ◽  
Vol 66 (5) ◽  
pp. 287-291 ◽  
Author(s):  
Vojtech Blahnik ◽  
Jakub Talla ◽  
Zdenek Peroutka
Keyword(s):  
Single Phase ◽  
Control Strategies ◽  
Current Source ◽  
Current Control ◽  
Control Technique ◽  
Laboratory Model ◽  
Output Current ◽  
Lcl Filter ◽  
Precise Control ◽  
Single Phase Inverter

Abstract The paper deals with a control of current source with an LCL output filter. The controlled current source is realized as a single-phase inverter and output LCL filter provides low ripple of output current. However, systems incorporating LCL filters require more complex control strategies and there are several interesting approaches to the control of this type of converter. This paper presents the inverter control algorithm, which combines model based control with a direct current control based on resonant controllers and single-phase vector control. The primary goal is to reduce the current ripple and distortion under required limits and provides fast and precise control of output current. The proposed control technique is verified by measurements on the laboratory model.

Sign in / Sign up

Export Citation Format

Share Document