Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 126
Filter
2.
Sci Total Environ ; 925: 171675, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38485022

ABSTRACT

Globally rising antibiotic-resistant (AR) and multi-drug resistant (MDR) bacterial infections are of public health concern due to treatment failure with current antibiotics. Enterobacteria, particularly Escherichia coli, cause infections of surgical wound, bloodstream, and urinary tract, including pneumonia and sepsis. Herein, we tested in vitro antibacterial efficacy, mode of action (MoA), and safety of novel amino-functionalized silver nanoparticles (NH2-AgNP) against the AR bacteria. Two AR E. coli strains (i.e., ampicillin- and kanamycin-resistant E. coli), including a susceptible strain of E. coli DH5α, were tested for susceptibility to NH2-AgNP using Kirby-Bauer disk diffusion and standard growth assays. Dynamic light scattering (DLS) was used to determine cell debris and relative conductance was used as a measure of cell leakage, and results were confirmed with transmission electron microscopy (TEM). Multiple oxidative stress assays were used for in vitro safety evaluation of NH2-AgNP in human lung epithelial cells. Results showed that ampicillin and kanamycin did not inhibit growth in either AR bacterial strain with doses up to 160 µg/mL tested. NH2-AgNP exhibited broad-spectrum bactericidal activity, inhibiting the growth of all three bacterial strains at doses ≥1 µg/mL. DLS and TEM revealed cell debris formation and cell leakage upon NH2-AgNP treatment, suggesting two possible MoAs: electrostatic interactions followed by cell wall damage. Safety evaluation revealed NH2-AgNP as noncytotoxic and antioxidative to human lung epithelial cells. Taken together, these results suggest that NH2-AgNP may serve as an effective and safer bactericidal therapy against AR bacterial infections compared to common antibiotics.


Subject(s)
Bacterial Infections , Metal Nanoparticles , Humans , Anti-Bacterial Agents/toxicity , Escherichia coli , Silver/toxicity , Metal Nanoparticles/toxicity , Bacteria , Ampicillin/pharmacology , Kanamycin/pharmacology , Microbial Sensitivity Tests
3.
J Agromedicine ; 29(3): 372-383, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38445302

ABSTRACT

OBJECTIVES: The objectives of this study on the forestry and logging workforce are to: 1) Analyze causes of injuries/fatalities to inform future intervention studies focused on risk mitigation, 2) determine whether there are any trends or associations between work-related risk factors and workplace injuries/fatalities over a 16-year period (2003-2019), and 3) identify knowledge gaps related to injuries and fatalities for future studies to address. METHODS: Data on fatalities, injuries, and illnesses of the forestry and logging workforce from the United States Bureau of Labor Statistics were analyzed. Correlation analysis (p < .05) was conducted to assess the relationship between causes of forestry and logging workforce fatalities by cause of fatality in the United States. Injury and fatality rates were calculated for each year (fatalities: 2003-2018; injuries: 2005-2019) and time span-specific incidence rates were calculated by cause. RESULTS: Contact with objects and equipment was the primary cause of injuries and fatalities in the forestry and logging workforce during the study period. Transportation-related incidents ranked second as the cause of fatalities, while the category of falls, slips, and trips was the second leading cause of injuries. CONCLUSION: Gaps in occupational health and safety identified by this study should be collaboratively addressed by researchers and the forestry industry.


Subject(s)
Accidents, Occupational , Forestry , Occupational Injuries , Forestry/statistics & numerical data , Humans , United States/epidemiology , Occupational Injuries/epidemiology , Occupational Injuries/mortality , Risk Assessment , Retrospective Studies , Accidents, Occupational/statistics & numerical data , Accidents, Occupational/mortality , Risk Factors , Farmers/statistics & numerical data
4.
Pest Manag Sci ; 80(7): 3140-3148, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38345320

ABSTRACT

BACKGROUND: Ultra-low volume (ULV) space sprays aerosolize insecticide formulated products (FP) to contact flying mosquitoes, while barrier sprays expose mosquitoes to FP residue on vegetation and other surfaces. Centers for Disease Control and Prevention bottle bioassays used to assess insecticide resistance are based on residual active ingredient (AI) exposure and do not directly relate to FP efficacy. The current pilot study developed a novel compact wind tunnel for mosquito exposure to FP. Caged Aedes albopictus and Culex pipiens/quinquefasciatus were exposed to undiluted Biomist®3 + 15 FP (permethrin AI) or air (control) within the wind tunnel, transferred to new cages, and held in a 28 °C incubator. Separate mosquitoes were exposed to residual permethrin AI (8 µg mL-1) in bottle bioassays. Mortality was monitored 15, 30, 60, and 120 min post-exposure. RESULTS: Chi-square tests (P < 0.05) showed significantly higher mortality in Aedes compared to Culex populations for most time points in both bioassay and wind tunnel exposure groups. As expected, mosquitoes exposed to Biomist®3 + 15 showed higher mortality rates than bottle bioassay exposure to permethrin. Two Culex colonies resistant to permethrin in bottle bioassays were susceptible to Biomist®3 + 15 in the wind tunnel. CONCLUSION: The novel compact wind tunnel developed here may be an alternative to field trials for testing FP efficacy, avoiding factors such as weather, logistical planning, and extended personnel hours. The wind tunnel could allow programs to conveniently test efficacy of multiple FP. Comparisons of different insecticide exposure methods provide practical information to inform operational decisions. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Subject(s)
Aedes , Culex , Insecticides , Mosquito Control , Permethrin , Animals , Insecticides/pharmacology , Permethrin/pharmacology , Culex/drug effects , Aedes/drug effects , Mosquito Control/methods , Pilot Projects , Female , Wind , Insecticide Resistance
5.
Int J Environ Health Res ; 34(2): 991-1001, 2024 Feb.
Article in English | MEDLINE | ID: mdl-36960881

ABSTRACT

Pyrethroids are commonly used in barrier treatments but less is known about how mosquitoes are affected by the simultaneous application of an insect growth regulator (i.e., pyriproxyfen) used in barrier treatments. This field study, conducted from May 14 - October 16, 2018, evaluated the effect of lambda-cyhalothrin (pyrethroid adulticide) and pyriproxyfen on the reproduction (measured by fecundity and adult emergence) and abundance of Aedes albopictus. Nine properties were treated with Demand®CS 0.06% + Archer® 0.010% (every 60 days) and three control properties received no treatment (N=12 total properties). No significant (P>0.05) differences were observed between abundance of Ae. albopictus in treatment compared to control groups. However, significant differences were observed in abundance of Ae. albopictus adults between weeks at both control (P = 0.003) and treatment (P < 0.0001) properties. Results from our research show that continued studies are needed to determine the efficacy of barrier treatments for this species. .


Subject(s)
Aedes , Insecticides , Nitriles , Pyrethrins , Pyridines , Animals , North Carolina , Mosquito Control/methods , Pyrethrins/pharmacology
6.
J Occup Environ Hyg ; 21(1): 77-85, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37756362

ABSTRACT

Outdoor workers perform tasks throughout the year that expose them to solar ultraviolet radiation (UVR) and increase their risk of UVR-related adverse health effects. Multiple studies on occupational solar UVR exposures during summer have been published but similar investigations during other seasons are limited. The purpose of this study was to assess solar UVR exposure in an eastern North Carolina university setting during all four seasons (fall, winter, spring, and summer) to assess risk for outdoor workers, particularly groundskeepers, throughout the year. UVR effective irradiance (UVReff) was measured by area monitoring using a digital data-logging radiometer and a weatherproof UVR detector for 164 days from October 2020 to October 2021. Results showed that hourly and daily mean UVReff exceeded the 1-hr and 8-hr ACGIH Threshold Limit Values (TLVs), respectively, in all months and seasons at varying degrees. Winter had the lowest mean UVReff (3.4 × 10-3 ± 1.7 × 10-3 mW/cm2), but 91.1% and 100% of the hourly and daily UVReff measurements, respectively, still exceeded the TLVs. This study demonstrates the risk of overexposure to solar UVR among outdoor workers during cold months and seasons and the importance of implementing UVR protection throughout the year.


Subject(s)
Occupational Exposure , Ultraviolet Rays , Humans , Ultraviolet Rays/adverse effects , Seasons , North Carolina , Universities , Occupational Exposure/analysis
7.
Sci Total Environ ; 906: 167492, 2024 Jan 01.
Article in English | MEDLINE | ID: mdl-37778563

ABSTRACT

Arguably the most ecologically and economically valuable pollinators worldwide, honey bees play a significant role in food production and enrich biodiversity through pollination. Varroa destructor is an invasive ectoparasitic mite that attacks and feeds on European honey bee, Apis mellifera. Because literature on the effectiveness and sustainability of various treatment modalities available for Varroa mite control in honey bee colonies are scattered, this scoping review was conducted to serve as a guiding document with a focus on: (1) identifying the detrimental impact Varroa mites have on the European honey bee; (2) determining current methods for Varroa mite control and their limitations; (3) examining current market landscape and key players in the pesticide market; and (4) identifying opportunities for more sustainable Varroa mite control methods. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, 397 articles published between 1998 and 2022 were screened; of which 65 articles were retained using inclusion/exclusion criteria, which were systematically analyzed in-depth, information extracted, and included in this scoping review. The results suggest that Varroa mites are one of the predominant causes of global honey bee decline as they lack natural resistance to Varroa mites, thereby negatively affecting honey bee reproduction and immunity, killing broods, and transmitting pathogenic viruses to colonies. Further, our findings suggest that: apiarists have many options for Varroa control, but no method has proven to be effective, safe and nonpersistent in the environment; adoption of nano-pesticides and development of sustainable alternatives to traditional pesticides are key drivers for growing pesticide market; and nano-pesticides may have potential to serve as an effective, safe and non-ecopersistent pesticide for Varroa mite and associated virus control. In conclusion, this review highlights an unmet need for effective and sustainable control strategies and tools for Varroa mite and virus control.


Subject(s)
Pesticides , Varroidae , Bees , Animals , Immunity, Innate , Host-Parasite Interactions
8.
Disaster Med Public Health Prep ; 17: e511, 2023 10 18.
Article in English | MEDLINE | ID: mdl-37849374

ABSTRACT

OBJECTIVES: Ideally, mosquito control programs (MCPs) use surveillance to target control measures to potentially dangerous mosquito populations. In North Carolina (NC), where there is limited financial support for mosquito control, communities may suffer from mosquito-related issues post-hurricane due to lack of existing MCPs. Here, study objectives were to (1) investigate the emergency response of a subset of NC counties post-Hurricane Florence and (2) develop guidelines and policy recommendations to assist MCPs in post-hurricane mosquito control response. METHODS: A survey was administered to a subset of eastern NC counties (an area previously impacted by hurricanes) with various levels of MCPs (from none to well-developed). RESULTS: All respondents indicated that having Federal Emergency Management Agency (FEMA) training would be helpful in developing a post-hurricane emergency response plan for mosquito control. There was concern related to a lack of knowledge of emergency control methods (eg, aerial/ground, adulticiding/larviciding) post-hurricane. MCP structure (eg, infrastructure, resources, operational plans/policies) could facilitate response activities and help ensure necessary emergency financial support from agencies such as FEMA. CONCLUSIONS: Mosquito control post-hurricane protects public health. Public health and other agencies can be networking resources for MCPs. Policy recommendations include implementation of routine FEMA assistance training workshops to improve an understanding of processes involved in assistance and reimbursement.


Subject(s)
Cyclonic Storms , Humans , North Carolina , Mosquito Control/methods , Retrospective Studies , Public Health
9.
Pan Afr Med J ; 44: 175, 2023.
Article in English | MEDLINE | ID: mdl-37455889

ABSTRACT

Introduction: whilst many studies have focused on acute and chronic complications of COVID-19, few studies have been performed on the immediate post-acute COVID-19 phase complications. The objective of the study was to describe computed tomography (CT) imaging findings in patients from a South African (SA) cohort during the post-acute COVID-19 phase. To describe the findings using existing CT description systems and, if present, pulmonary imaging findings unique to our cohort. Methods: a review of CT chest examinations performed over the second wave of COVID-19 in SA for post-acute COVID-19 cardiorespiratory complaints at Worcester Hospital. The CT findings were described using a modified semi-quantitative tabulation method. Results: eight males and 12 females met the inclusion criteria with a mean age of 56 years. Half had hypertension, 11 had diabetes, two had human immunodeficiency virus (HIV), half had raised D-dimers and six had pre-existing lung disease. The predominant parenchymal pattern was mixed ground glass and reticular changes in a diffuse/peripheral multilobar distribution with relative sparing of the left upper lobe. Four cases demonstrated pulmonary emboli, 50% pulmonary hypertension, three pleural effusions and nine lymphadenopathy. None of the cases had evidence of active pulmonary tuberculosis. Conclusion: CT lung findings appear to mirror global findings with expected evolutionary differences. An interesting observation was the relative sparing of the left upper lobe. Reporting using the modified table proved efficient. Real-world extrapolation of our findings is limited by low-case numbers.


Subject(s)
COVID-19 , Female , Humans , Male , Middle Aged , COVID-19/diagnostic imaging , Lung/diagnostic imaging , Retrospective Studies , SARS-CoV-2 , South Africa , Tomography, X-Ray Computed/methods
10.
PLoS One ; 18(3): e0278253, 2023.
Article in English | MEDLINE | ID: mdl-36961789

ABSTRACT

Geographic information systems (GIS) can be used to map mosquito larval and adult habitats and human populations at risk for mosquito exposure and possible arbovirus transmission. Along with traditional methods of surveillance-based targeted mosquito control, GIS can help simplify and target efforts during routine surveillance and post-disaster (e.g., hurricane-related flooding) to protect emergency workers and public health. A practical method for prioritizing areas for emergency mosquito control has been developed and is described here. North Carolina (NC) One Map was used to identify state-level data layers of interest based on human population distribution and mosquito habitat in Brunswick, Columbus, Onslow, and Robeson Counties in eastern NC. Relevant data layers were included to create mosquito control treatment areas for targeted control and an 18-step protocol for map development is discussed. This protocol is expected to help state, territorial, tribal, and/or local public health officials and associated mosquito control programs efficiently create treatment area maps to improve strategic planning in advance of a disaster. This protocol may be applied to any NC county and beyond, thereby increasing local disaster preparedness.


Subject(s)
Disasters , Geographic Information Systems , Animals , Adult , Humans , Mosquito Control/methods , North Carolina , Ecosystem
11.
Travel Med Infect Dis ; 51: 102505, 2023.
Article in English | MEDLINE | ID: mdl-36427707

ABSTRACT

BACKGROUND: There are 1,000-2,000 cases of malaria diagnosed in the United States annually and most are imported. METHODS: Malaria cases reported between 2000 and 2020 in North Carolina (NC) were analyzed (NC Department of Health and Human Services, Division of Public Health). Differences in numbers of NC malaria cases were further analyzed by year, month, county, gender, age, and country of origin. RESULTS: Most cases originated from travelers visiting Africa and returning to NC (i.e., Mecklenburg [N = 162 cases], Wake [N = 153], Guilford [N = 103], Durham [N = 74], and Cumberland [N = 41] Counties). Per capita analysis (i.e., per 100,000 population) was used to correct for differences in NC county population sizes and Durham (N = 22.8), Guilford (N = 19.0), Onslow (N = 14.7), Mecklenburg (N = 14.5), Wake (N = 13.5), Orange (N = 12.8) and Cumberland (N = 12.2) Counties showed the highest cases. Malaria was more prevalent among males (N = 532) relative to females (N = 245), and this difference was statistically significant. CONCLUSIONS: Travelers visiting malaria-endemic regions should be educated on malaria prevention measures (e.g., chemoprophylaxis, mosquito repellent). These measures should be readily available to travelers. The malaria registry in NC should be improved by requiring additional data related to imported malaria cases.


Subject(s)
Antimalarials , Malaria , Plasmodium , Male , Female , Humans , United States , Antimalarials/therapeutic use , Retrospective Studies , Travel , Population Surveillance , Seasons , Malaria/drug therapy , Spatio-Temporal Analysis
12.
Front Plant Sci ; 14: 1284529, 2023.
Article in English | MEDLINE | ID: mdl-38162303

ABSTRACT

Outside the protection of Earth's magnetic field, organisms are constantly exposed to space radiation consisting of energetic protons and other heavier charged particles. With the goal of crewed Mars exploration, the production of fresh food during long duration space missions is critical for meeting astronauts' nutritional and psychological needs. However, the biological effects of space radiation on plants have not been sufficiently investigated and characterized. To that end, 10-day-old Arabidopsis seedlings were exposed to simulated Galactic Cosmic Rays (GCR) and assessed for transcriptomic changes. The simulated GCR irradiation was carried out in the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Lab (BNL). The exposures were conducted acutely for two dose points at 40 cGy or 80 cGy, with sequential delivery of proton, helium, oxygen, silicon, and iron ions. Control and irradiated seedlings were then harvested and preserved in RNAlater at 3 hrs post irradiation. Total RNA was isolated for transcriptomic analyses using RNAseq. The data revealed that the transcriptomic responses were dose-dependent, with significant upregulation of DNA repair pathways and downregulation of glucosinolate biosynthetic pathways. Glucosinolates are important for plant pathogen defense and for the taste of a plant, which are both relevant to growing plants for spaceflight. These findings fill in knowledge gaps of how plants respond to radiation in beyond-Earth environments.

13.
Article in English | MEDLINE | ID: mdl-38596539

ABSTRACT

Adult intussusception is a rare diagnosis that can be caused by non-Hodgkin's diffuse large B-cell lymphoma (DLBCL). In this case report, we discuss a middle-aged man who presented with non-specific symptoms of intussusception and absence of classic B symptoms. He was found to have intussusception secondary to stage IIIE, CD20 positive DLBCL. The patient underwent small bowel resection with anastomosis, followed by 6 cycles of R-CHOP, which resulted in complete remission of his neoplasm. In reporting this case, we hope to further highlight the role of malignancy in intussusception and guidance on appropriate therapy.

14.
Environ Health Insights ; 16: 11786302221112917, 2022.
Article in English | MEDLINE | ID: mdl-35899223

ABSTRACT

Diversity in the environmental health sciences (EHS) workforce is crucial in providing culturally sensitive services to diverse communities. This may be influenced by academic faculty training a diverse student body in the field of environmental health. This study aimed to characterize the diversity of students and faculty in EHS programs accredited by the National Environmental Health Science and Protection Accreditation Council (EHAC). A retrospective analysis was conducted on secondary data obtained from annual surveys administered to program directors in EHAC-accredited academic programs that included both undergraduate and graduate EHS degrees. The database covered surveys on gender and race that were conducted by EHAC for 12 academic years spanning 2009-2010 to 2020-2021. Results show most students (undergraduate and graduate) were female (54.4% and 52.1%, respectively) and white (61.0% and 50.7%, respectively). Increasing trends were observed over the last 12 years (2009-2021) in female undergraduate (from 53.7% to 59.8%) and graduate (from 47.1% to 60.3%) students and in non-white undergraduate students (from 40.0% to 48.2%). Most faculty (teaching in undergraduate and graduate programs) were male (64.4% and 64.3%, respectively) and white (77.9% and 92.1%, respectively). Increasing trends were observed from 2009 to 2021 in female faculty teaching undergraduate (from 27.7% to 42.2%) and graduate (from 31.3% to 42.1%) students. Native American, Alaska Native, Native Hawaiian, and Pacific Islander are consistently the most underrepresented racial groups in both undergraduate and graduate students and faculty. This study provides baseline data on the diversity of students and faculty in EHAC-accredited programs, which is important in informing future research and efforts to increase such diversity. Gender and racial disparity in EHS students and faculty needs to be addressed to provide necessary support to women and non-White constituents by institutional change in culture through active recruitment and by stronger collaboration between professional organizations and minority groups.

15.
J Med Entomol ; 59(5): 1827-1830, 2022 09 14.
Article in English | MEDLINE | ID: mdl-35751624

ABSTRACT

Mosquito control programs have increasingly used Centers for Disease Control and Prevention bottle bioassays (BB) to evaluate insecticide resistance (IR). The reported utility, benefits, and limitations of BB and other methods were assessed via electronic survey of U.S. mosquito control professionals to identify potential areas for improvement, future study, and professional training. Opportunities were identified to improve BB operational value and IR detection.


Subject(s)
Insecticides , Pyrethrins , Animals , Biological Assay/methods , Centers for Disease Control and Prevention, U.S. , Insecticide Resistance , Insecticides/pharmacology , Mosquito Control/methods , Mosquito Vectors , United States
16.
J Clin Immunol ; 42(4): 760-770, 2022 05.
Article in English | MEDLINE | ID: mdl-35230563

ABSTRACT

Measurement of pre- and post-pneumococcal antibody levels after immunization with the 23-valent capsular polysaccharide pneumococcal vaccine (23vPPV) is indicative of a T-independent antibody response. The World Health Organisation ELISA is considered gold standard yet is labor-intensive and technically difficult to perform. Interpretation criteria defining an adequate response to 23vPPV remain controversial. The diagnostic Immunology Laboratory at The Royal Children's Hospital, Melbourne (RCH), performs an in-house multi-serotype automated ELISA. The primary objective of this study was to verify RCH interpretation criteria for the laboratory's automated ELISA. Forty pneumococcal conjugate vaccine (PCV)-naïve healthy adults aged 18 to 25 years and 22 PCV-primed healthy children aged 2 to 5 years were immunized with 23vPPV. A serum sample was collected immediately prior and 28 to 42 (± 7) days post immunization. Samples were analyzed on the Tecan Freedom Evo 200 ELISA with adequate response defined as post-immunization antibody level of 1.3 µg/mL or fourfold rise from baseline in ≥ 10/15 serotypes in adult participants and ≥ 4/8 serotypes in pediatric participants. Thirty-nine (97.5%) adults and 22 (100%) children achieved an adequate response to 23vPPV. In PCV-naïve adults, serotypes contained within the conjugate vaccines were less immunogenic, with 12 (30%) adults not achieving an adequate antibody response when only PCV serotypes were used for interpretation. Our diagnostic laboratory has verified the interpretation criteria used for an automated multi-serotype pneumococcal ELISA method. Clinical Trial Registration: ANZCTR registration number ACTRN12618000822280.


Subject(s)
Pneumococcal Infections , Adult , Antibodies, Bacterial , Antibody Formation , Child , Enzyme-Linked Immunosorbent Assay , Humans , Immunoglobulin G , Pneumococcal Infections/diagnosis , Pneumococcal Infections/prevention & control , Pneumococcal Vaccines , Streptococcus pneumoniae , Vaccines, Conjugate
17.
Life (Basel) ; 12(2)2022 Jan 19.
Article in English | MEDLINE | ID: mdl-35207432

ABSTRACT

One of the major concerns for long-term exploration missions beyond the Earth's magnetosphere is consequences from exposures to solar particle event (SPE) protons and galactic cosmic rays (GCR). For long-term crewed Lunar and Mars explorations, the production of fresh food in space will provide both nutritional supplements and psychological benefits to the astronauts. However, the effects of space radiation on plants and plant propagules have not been sufficiently investigated and characterized. In this study, we evaluated the effect of two different compositions of charged particles-simulated GCR, and simulated SPE protons on dry and hydrated seeds of the model plant Arabidopsis thaliana and the crop plant Mizuna mustard [Brassica rapa var. japonica]. Exposures to charged particles, simulated GCRs (up to 80 cGy) or SPEs (up to 200 cGy), were performed either acutely or at a low dose rate using the NASA Space Radiation Laboratory (NSRL) facility at Brookhaven National Lab (BNL). Control and irradiated seeds were planted in a solid phytogel and grown in a controlled environment. Five to seven days after planting, morphological parameters were measured to evaluate radiation-induced damage in the seedlings. After exposure to single types of charged particles, as well as to simulated GCR, the hydrated Arabidopsis seeds showed dose- and quality-dependent responses, with heavier ions causing more severe defects. Seeds exposed to simulated GCR (dry seeds) and SPE (hydrated seeds) had significant, although much less damage than seeds exposed to heavier and higher linear energy transfer (LET) particles. In general, the extent of damage depends on the seed type.

19.
Pathog Glob Health ; 116(6): 365-375, 2022 09.
Article in English | MEDLINE | ID: mdl-35038971

ABSTRACT

Permethrin is a synthetic pyrethroid insecticide used to treat uniforms (e.g. military, foresters) and other clothing to protect people against pests (e.g., mosquitoes, ticks). Pests contacting the surface of permethrin-treated clothing (PTC) are repelled and/or killed, depending on the dose and duration of exposure. Hence, it is important to assess the amount of permethrin on the surface of clothing. Fabric swatches prepared using two commercially available permethrin treatments (Insect Shield® & Sawyer Repellant) and one laboratory created treatment (4g permethrin/L) were tested. A Martindale Abrasion and Pilling Tester (MAPT) and gas chromatography were used to assess surface permethrin content (SPC) and total permethrin content (TPC). Sawyer PTC had the highest SPC (mean ± standard error) (32.68±14.55µg/g), followed by Insect Shield® (23.35±2.71µg/g) and lab-created 4g/L permethrin (8.7±0.78µg/g). SPC (after 1000 rubs on MAPT) for Insect Shield®, Sawyer, and 4g/L permethrin groups was significantly lower than TPC (P=0.011, P<0.001, and P=0.001, respectively). The SPC/TPC relationship varied widely between permethrin treatment methods and practical implications for this are discussed. Mosquito repellency tests indicate that Insect Shield®, Sawyer, and lab-created (4g/L) permethrin-treated fabrics showed a significantly higher repellency rate than control (untreated) fabrics (P=0.001, P<0.0001, P<0.0001, respectively). While Insect Shield® had the highest repellency rate against susceptible (53%) and exposed (48%) mosquitoes, differences between groups were not significant. Repellency rates indicate SPC plus other factors (e.g. treatment method) may contribute to mosquito repellency and should be considered in risk assessments for protection against pests.


Subject(s)
Culicidae , Insect Repellents , Insecticides , Animals , Clothing , Humans , Insect Repellents/pharmacology , Insecticides/pharmacology , Permethrin/pharmacology
20.
J Med Entomol ; 59(2): 615-622, 2022 03 16.
Article in English | MEDLINE | ID: mdl-34958094

ABSTRACT

Long lasting permethrin-impregnated (LLPI) clothing can retain permethrin and repel ticks for up to three months and without exceeding EPA-approved safe levels; however, little is known about longer term effects of wearing LLPI clothing. Here, permethrin content was measured in new forester pants soon after initial impregnation (Insect Shield) and again one year later after being repeatedly worn by foresters in the field. Urine samples were collected from foresters for biomonitoring of permethrin metabolites at multiple time intervals (pre-use, one-month, three-to-four-months, and one-year post-use). Lethality against nymphal Ixodes scapularis Say was measured in clothing after one year of wear by foresters. Furthermore, to test potential variability in permethrin impregnation of different batches of clothing, separate sets of clothing were anonymously sent to Insect Shield for permethrin treatment over a period of three months and permethrin was quantified. Results demonstrated 33% of participants' pants had no measurable permethrin after one year of wear and permethrin content and tick mortality varied significantly between clothing. Only two of the participants' clothing resulted in ≥ 30% tick mortality after one year of wear. Significant differences were observed in 3-PBA and trans-DCCA, but not cis-DCCA metabolites in participants over the four measured time points and were higher than general United States population levels. This study provides practical information on the safety (measured by urinary metabolites) over time of LLPI clothing. It also provides snapshots (pre-washing and after one year of wear) of effectiveness of LLPI clothing as personal protective equipment against ticks for outdoor workers.


Subject(s)
Insecticides , Ixodes , Tick Bites , Animals , Clothing , Humans , Insecticides/pharmacology , Permethrin/pharmacology , Protective Clothing , Tick Bites/prevention & control
SELECTION OF CITATIONS
SEARCH DETAIL
...