RESUMO
Background: Tuberculosis was the deadliest infectious agent before covid-19; 1.5 million deaths in 2020. Despite, a variety, of easy and cheap diagnostic tools, detection rates still fall below 90%; diagnosis delays are long exceeding 30 days in many continents. This study aimed to determine risk factors for pulmonary TB diagnosis delays in Mali. Methods: A cross-sectional study was conducted in Bamako to include pulmonary TB patients at treatment initiation centers. Verbal consent was obtained before the interview. Demographics, clinical, treatment cost, and patient, medical, and diagnostic delays were computed using SPSS 25.0 considering a significance level p < 0.05. Results: In total 266 patients were included, 80.8% were male, mean age was ± 12 years, primary education level was 50.4%, treatment cost before diagnosis was 100 - 200 thousand CFA in 65.4%, smokers were 42.1%, median patient, medical and total diagnostic delays were 58, 57 and 114 days respectively. Education level below university, social reasons, and non-request of health workers were identified as independent risk factors for diagnostic delay > 100 days in Mali. Conclusion: Diagnostic delay is relatively very long in Mali, there is an urgent need for identification and action to shorten the delays to limit the transmission chain and avoid disabling pulmonary sequels.
RESUMO
Current mark-release-recapture methodologies are limited in their ability to address complex problems in vector biology, such as studying multiple groups overlapping in space and time. Additionally, limited mark retention, reduced post-marking survival and the large effort in marking, collection and recapture all complicate effective insect tracking.We have developed and evaluated a marking method using a fluorescent dye (SmartWater®) combined with synthetic DNA tags to informatively and efficiently mark adult mosquitoes using an airbrush pump and nebulizer. Using a handheld UV flashlight, the fluorescent marking enabled quick and simple initial detection of recaptures in a field-ready and non-destructive approach that when combined with an extraction-free PCR on individual mosquito legs provides potentially unlimited marking information.This marking, first tested in the laboratory with Anopheles gambiae s.l. mosquitoes, did not affect survival (median ages 24-28 days, p-adj > 0.25), oviposition (median eggs/female of 28.8, 32.5, 33.3 for water, green, red dyes, respectively, p-adj > 0.44) or Plasmodium competence (mean oocysts 5.56-10.6, p-adj > 0.95). DNA and fluorescence had 100% retention up to 3 weeks (longest time point tested) with high intensity, indicating marks would persist longer.We describe a novel, simple, no/low-impact and long-lasting marking method that allows separation of multiple insect subpopulations by combining unlimited length and sequence variation in the synthetic DNA tags. This method can be readily deployed in the field for marking multiple groups of mosquitoes or other insects.
