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1.
J Int Med Res ; 52(6): 3000605241259428, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38844785

RESUMEN

A few cases have shown that bee stings can be linked to coronary stent thrombosis. However, instances of recurrent myocardial infarction resulting from bee stings among patients who have successfully undergone revascularization treatment are rare. This case report describes a man in his early 60s who experienced an acute myocardial infarction. The left anterior descending coronary artery was revascularized by a drug-eluting stent. Just 1 week later, the patient experienced a second acute myocardial infarction and it occurred immediately after a bee sting. Angiography revealed stent thrombosis so thrombus aspiration was performed. Subsequently, the blood flow in the stent was unobstructed. Follow-up coronary angiography 1 year later revealed no signs of restenosis within the stent. Hymenoptera venoms contains thrombogenic substances that might lead to acute stent thrombosis.


Asunto(s)
Angiografía Coronaria , Mordeduras y Picaduras de Insectos , Infarto del Miocardio , Humanos , Masculino , Infarto del Miocardio/etiología , Infarto del Miocardio/diagnóstico , Mordeduras y Picaduras de Insectos/complicaciones , Abejas , Animales , Persona de Mediana Edad , Stents Liberadores de Fármacos/efectos adversos
3.
Proc Natl Acad Sci U S A ; 121(24): e2320898121, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38833464

RESUMEN

The World Health Organization identifies a strong surveillance system for malaria and its mosquito vector as an essential pillar of the malaria elimination agenda. Anopheles salivary antibodies are emerging biomarkers of exposure to mosquito bites that potentially overcome sensitivity and logistical constraints of traditional entomological surveys. Using samples collected by a village health volunteer network in 104 villages in Southeast Myanmar during routine surveillance, the present study employs a Bayesian geostatistical modeling framework, incorporating climatic and environmental variables together with Anopheles salivary antigen serology, to generate spatially continuous predictive maps of Anopheles biting exposure. Our maps quantify fine-scale spatial and temporal heterogeneity in Anopheles salivary antibody seroprevalence (ranging from 9 to 99%) that serves as a proxy of exposure to Anopheles bites and advances current static maps of only Anopheles occurrence. We also developed an innovative framework to perform surveillance of malaria transmission. By incorporating antibodies against the vector and the transmissible form of malaria (sporozoite) in a joint Bayesian geostatistical model, we predict several foci of ongoing transmission. In our study, we demonstrate that antibodies specific for Anopheles salivary and sporozoite antigens are a logistically feasible metric with which to quantify and characterize heterogeneity in exposure to vector bites and malaria transmission. These approaches could readily be scaled up into existing village health volunteer surveillance networks to identify foci of residual malaria transmission, which could be targeted with supplementary interventions to accelerate progress toward elimination.


Asunto(s)
Anopheles , Teorema de Bayes , Malaria , Mosquitos Vectores , Animales , Anopheles/parasitología , Mosquitos Vectores/parasitología , Humanos , Malaria/transmisión , Malaria/epidemiología , Malaria/inmunología , Malaria/parasitología , Estudios Seroepidemiológicos , Mordeduras y Picaduras de Insectos/epidemiología , Mordeduras y Picaduras de Insectos/inmunología , Mordeduras y Picaduras de Insectos/parasitología , Esporozoítos/inmunología
4.
Parasit Vectors ; 17(1): 250, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38849919

RESUMEN

BACKGROUND: Flea bites could trigger a series of complex molecular responses in the host. However, our understanding of the responses at the molecular level is still relatively limited. This study quantifies the changes in gene expression in mice after flea bites by RNA sequencing (RNA-seq) from their spleens, revealing the potential biological effects of host response to flea bites. METHODS: RNA-seq was used for transcriptome analysis to screen for differentially expressed genes (DEGs) between the control mice group and the flea bite mice group. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed on DEGs. Protein-protein interaction (PPI) network analysis on DEGs related to immune processes was performed. Finally, we randomly selected several genes from the screened DEGs to validate the results from the transcriptome data by real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR). RESULTS: A total of 521 DEGs were identified, including 277 upregulated and 244 downregulated. There were 258 GO terms significantly enriched by upregulated DEGs and 419 GO terms significantly enriched by downregulated DEGs. Among the upregulated DEGs, 22 GO terms were associated with immune cells (e.g., B cells and T cells) and immune regulatory processes, while among the downregulated DEGs, 58 GO terms were associated with immune cells and immune regulatory processes. Through PPI analysis, we found that CD40 molecules with significantly downregulated expression levels after flea bites may play an important role in host immune regulation. Through KEGG pathway enrichment analysis, a total of 26 significantly enriched KEGG pathways were identified. The RT-qPCR analysis results indicated that the transcriptome sequencing results were reliable. CONCLUSIONS: Through in-depth analysis of transcriptome changes in mice caused by flea bites, we revealed that flea bites could stimulate a series of biological and immunological responses in mice. These findings not only provided a deeper understanding of the impact of flea bites on the host but also provided a basis for further research on the interaction between ectoparasites and the host. We believe that digging deeper into the significance of these transcriptome changes will help reveal more about the adaptive response of the host to ectoparasites.


Asunto(s)
Perfilación de la Expresión Génica , Transcriptoma , Xenopsylla , Animales , Ratones , Xenopsylla/genética , Mordeduras y Picaduras de Insectos/inmunología , Ontología de Genes , Mapas de Interacción de Proteínas , Bazo/inmunología , Bazo/metabolismo , Femenino , Análisis de Secuencia de ARN
5.
Malar J ; 23(1): 166, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38807105

RESUMEN

BACKGROUND: Deforestation is an important driver of malaria dynamics, with a relevant impact on mosquito ecology, including larval habitat availability, blood-feeding behaviour, and peak biting time. The latter is one of several entomological metrics to evaluate vectorial capacity and effectiveness of disease control. This study aimed to test the effect of forest cover percentage on the peak biting time of Plasmodium-uninfected and infected Nyssorhynchus darlingi females. METHODS: Mosquitoes were captured utilizing human landing catch (HLC) in the peridomestic habitat in field collections carried out in the wet, wet-dry transition, and dry seasons from 2014 to 2017 in areas with active malaria transmission in Amazonian Brazil. The study locations were in rural settlements in areas with the mean annual malaria parasite incidence (Annual Parasite Incidence, API ≥ 30). All Ny. darlingi females were tested for Plasmodium spp. infection using real time PCR technique. Forest cover percentage was calculated for each collection site using QGIS v. 2.8 and was categorized in three distinct deforestation scenarios: (1) degraded, < 30% forest cover, (2) intermediate, 30-70% forest cover, and (3) preserved, > 70% forest cover. RESULTS: The highest number of uninfected female Ny. darlingi was found in degraded landscape-sites with forest cover < 30% in any peak biting time between 18:00 and 0:00. Partially degraded landscape-sites, with (30-70%) forest cover, showed the highest number of vivax-infected females, with a peak biting time of 21:00-23:00. The number of P. falciparum-infected mosquitoes was highest in preserved sites with > 70% forest cover, a peak biting at 19:00-20:00, and in sites with 30-70% forest cover at 22:00-23:00. CONCLUSIONS: Results of this study show empirically that degraded landscapes favour uninfected Ny. darlingi with a peak biting time at dusk (18:00-19:00), whereas partially degraded landscapes affect the behaviour of Plasmodium-infected Ny. darlingi by shifting its peak biting time towards hours after dark (21:00-23:00). In preserved sites, Plasmodium-infected Ny. darlingi bite around dusk (18:00-19:00) and shortly after (19:00-20:00).


Asunto(s)
Conducta Alimentaria , Bosques , Mosquitos Vectores , Animales , Brasil , Femenino , Mosquitos Vectores/fisiología , Mosquitos Vectores/parasitología , Conservación de los Recursos Naturales , Mordeduras y Picaduras de Insectos/epidemiología , Estaciones del Año , Malaria/transmisión
7.
Allergy Asthma Proc ; 45(3): 195-200, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38755779

RESUMEN

Introduction: Hymenoptera venom immunotherapy (VIT) is the only therapy that protects patients with Hymenoptera venom allergy by preventing systemic reactions after a new sting. Various extracts for VIT are available and used. VIT administration consists of an induction phase and a maintenance phase. Depot preparations of Hymenoptera VIT extracts are typically used for cluster and conventional protocols, and the maintenance phase. Many patients with Hymenoptera allergy need to achieve tolerance quickly because of the high risk of re-sting and possible anaphylaxis. Objective: Our study aimed to show the safety and efficacy of an accelerated regimen with depot preparations on aluminum hydroxide by using relatively high starting doses in a heterogeneous group of patients. Methods: The research focused on a group of patients with a history of severe systemic reactions to Hymenoptera stings, with the necessity of swift immunization due to high occupational risks. Aluminum hydroxide depot extracts either of Vepula species or Apis mellifera extracts were used. Results: The induction protocol was started with the highest concentration of depot venom extract of 100,000 standard quality unit and was well tolerated by 19 of 20 patients. Onne patient presented with a mild systemic reaction during the accelerated induction schedule, which was promptly treated with intravenous steroids and intramuscular H1 antihistamine; when switched to a conventional induction protocol, he had a similar reaction but finally reached maintenance with an H1-antagonist premedication. Conclusion: If validated, the accelerated induction protocol by using depot aluminum adsorbed extracts with the highest concentration of venom from the beginning could offer a streamlined and accessible treatment modality for patients diagnosed with anaphylaxis from bee and wasp venoms in need of rapid desensitization.


Asunto(s)
Desensibilización Inmunológica , Himenópteros , Humanos , Desensibilización Inmunológica/métodos , Desensibilización Inmunológica/efectos adversos , Animales , Adulto , Masculino , Femenino , Persona de Mediana Edad , Himenópteros/inmunología , Hidróxido de Aluminio , Mordeduras y Picaduras de Insectos/inmunología , Mordeduras y Picaduras de Insectos/terapia , Resultado del Tratamiento , Adulto Joven , Alérgenos/inmunología , Alérgenos/administración & dosificación , Adolescente , Hipersensibilidad/terapia , Hipersensibilidad/inmunología , Venenos de Artrópodos/inmunología , Anciano , Venenos de Abeja/inmunología , Venenos de Abeja/administración & dosificación , Venenos de Abeja/efectos adversos
8.
Front Immunol ; 15: 1368066, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38751433

RESUMEN

Introduction: Aedes spp. are the most prolific mosquito vectors in the world. Found on every continent, they can effectively transmit various arboviruses, including the dengue virus which continues to cause outbreaks worldwide and is spreading into previously non-endemic areas. The lack of widely available dengue vaccines accentuates the importance of targeted vector control strategies to reduce the dengue burden. High-throughput tools to estimate human-mosquito contact and evaluate vector control interventions are lacking. We propose a novel serological tool that allows rapid screening of human cohorts for exposure to potentially infectious mosquitoes. Methods: We tested 563 serum samples from a longitudinal pediatric cohort study previously conducted in Cambodia. Children enrolled in the study were dengue-naive at baseline and were followed biannually for dengue incidence for two years. We used Western blotting and enzyme-linked immunosorbent assays to identify immunogenic Aedes aegypti salivary proteins and measure total anti-Ae. aegypti IgG. Results: We found a correlation (rs=0.86) between IgG responses against AeD7L1 and AeD7L2 recombinant proteins and those to whole salivary gland homogenate. We observed seasonal fluctuations of AeD7L1+2 IgG responses and no cross-reactivity with Culex quinquefasciatus and Anopheles dirus mosquitoes. The baseline median AeD7L1+2 IgG responses for young children were higher in those who developed asymptomatic versus symptomatic dengue. Discussion: The IgG response against AeD7L1+2 recombinant proteins is a highly sensitive and Aedes specific marker of human exposure to Aedes bites that can facilitate standardization of future serosurveys and epidemiological studies by its ability to provide a robust estimation of human-mosquito contact in a high-throughput fashion.


Asunto(s)
Aedes , Dengue , Proteínas de Insectos , Mosquitos Vectores , Proteínas y Péptidos Salivales , Humanos , Aedes/inmunología , Aedes/virología , Animales , Proteínas y Péptidos Salivales/inmunología , Niño , Mosquitos Vectores/inmunología , Mosquitos Vectores/virología , Dengue/inmunología , Dengue/transmisión , Proteínas de Insectos/inmunología , Femenino , Preescolar , Inmunoglobulina G/inmunología , Inmunoglobulina G/sangre , Masculino , Cambodia , Estudios Longitudinales , Virus del Dengue/inmunología , Adolescente , Mordeduras y Picaduras de Insectos/inmunología
9.
Med Clin North Am ; 108(4): 757-776, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38816116

RESUMEN

Stinging insects are a frequent cause of local and systemic hypersensitivity reactions, including anaphylaxis. For those with a history of life-threatening anaphylaxis, venom immunotherapy is effective, safe, and can be life-saving. Arachnids are a much less common source of envenomation through bites or stings and are less likely to cause a hypersensitivity reaction. However, recognizing the clinical manifestations when they do present is important for accurate diagnosis and treatment, and, when indicated, consideration of other diagnoses.


Asunto(s)
Anafilaxia , Mordeduras y Picaduras de Insectos , Humanos , Mordeduras y Picaduras de Insectos/complicaciones , Anafilaxia/terapia , Anafilaxia/diagnóstico , Anafilaxia/etiología , Animales , Hipersensibilidad/terapia , Hipersensibilidad/diagnóstico , Venenos de Artrópodos/inmunología , Venenos de Artrópodos/efectos adversos , Desensibilización Inmunológica/métodos , Hipersensibilidad al Veneno
10.
PLoS One ; 19(5): e0298919, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38805442

RESUMEN

BACKGROUND: A simple treated fabric device for passively emanating the volatile pyrethroid transfluthrin was recently developed in Tanzania that protected against nocturnal Anopheles and Culex mosquitoes for several months. Here these transfluthrin emanators were assessed in Port-au-Prince, Haiti against outdoor-biting Aedes. METHODS: Transfluthrin emanators were distributed to participating households in poor-to-middle class urban neighbourhoods and evaluated once every two months in terms of their effects on human landing rates of wild Aedes populations. A series of three such entomological assessment experiments were conducted, to examine the influence of changing weather conditions, various transfluthrin formulations and emanator placement on protective efficacy measurements. Laboratory experiments assessed resistance of local Aedes aegypti to transfluthrin and deltamethrin, and the irritancy and repellency of the transfluthrin-treated fabric used in the field. RESULTS: Across all three entomological field assessments, little evidence of protection against wild Ae. aegypti was observed, regardless of weather conditions, transfluthrin formulation or emanator placement: A generalized linear mixed model fitted to the pooled data from all three assessment rounds (921 females caught over 5129 hours) estimated a relative landing rate [95% Confidence interval] of 0.87 [0.73, 1.04] for users of treated versus untreated emanators (P = 0.1241). Wild Ae. aegypti in this setting were clearly resistant to transfluthrin when compared to a fully susceptible colony. CONCLUSIONS: Transfluthrin emanators had little if any apparent effect upon Aedes landing rates by wild Ae. aegypti in urban Haiti, and similar results have been obtained by comparable studies in Tanzania, Brazil and Peru. In stark contrast, however, parallel sociological assessments of perspectives among these same end-users in urban Haitian communities indicate strong satisfaction in terms of perceived protection against mosquitoes. It remains unclear why the results obtained from these complementary entomological and sociological assessments in Haiti differ so much, as do those from a similar set of studies in Brazil. It is encouraging, however, that similar contrasts between the entomological and epidemiological results of a recent large-scale assessment of another transfluthrin emanator product in Peru, which indicate they provide useful protection against Aedes-borne arboviral infections, despite apparently providing only modest protection against Aedes mosquito bites.


Asunto(s)
Aedes , Ciclopropanos , Fluorobencenos , Insecticidas , Control de Mosquitos , Animales , Aedes/efectos de los fármacos , Ciclopropanos/farmacología , Haití , Control de Mosquitos/métodos , Humanos , Insecticidas/farmacología , Femenino , Piretrinas/farmacología , Mosquitos Vectores/efectos de los fármacos , Resistencia a los Insecticidas , Mordeduras y Picaduras de Insectos/prevención & control , Nitrilos/farmacología , Composición Familiar , Repelentes de Insectos/farmacología
11.
Artículo en Chino | MEDLINE | ID: mdl-38802315

RESUMEN

Wasp sting refers to a series of clinical syndromes caused by the venom in the tail poison sac of the poisonous bee when attacking the attacked body, mainly manifested as local skin damage, systemic allergic reaction and multi-organ dysfunction syndrome (MODS) . Wasp venom can also act on the nervous system, and cause rare complications such as cerebral hemorrhage, subarachnoid hemorrhage, cerebral infarction, epilepsy, encephalitis, and Parkinson's disease, which can seriously affect the prognosis. This review will elaborate the above complications for clinical reference.


Asunto(s)
Mordeduras y Picaduras de Insectos , Avispas , Animales , Humanos , Mordeduras y Picaduras de Insectos/complicaciones , Venenos de Avispas , Enfermedades del Sistema Nervioso/etiología , Insuficiencia Multiorgánica/etiología
12.
PLoS One ; 19(5): e0299722, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38809841

RESUMEN

BACKGROUND: A low technology emanator device for slowly releasing vapour of the volatile pyrethroid transfluthrin was recently developed in Tanzania that provides robust protection against night biting Anopheles and Culex vectors of malaria and filariasis for several months. Here these same emanator devices were assessed in Dar es Salaam city, as a means of protection against outdoor-biting Aedes (Stegomia) aegypti, the most important vector of human arboviruses worldwide, in parallel with similar studies in Haiti and Brazil. METHODS: A series of entomological experiments were conducted under field and semi-field conditions, to evaluate whether transfluthrin emanators protect against wild Ae. aegypti, and also compare the transfluthrin responsiveness of Ae. aegypti originating from wild-caught eggs to established pyrethroid-susceptible Ae. aegypti and Anopheles gambiae colonies. Preliminary measurements of transfluthrin vapour concentration in air samples collected near treated emanators were conducted by gas chromatography-mass spectrometry. RESULTS: Two full field experiments with four different emanator designs and three different transfluthrin formulations consistently indicated negligible reduction of human landing rates by wild Ae. aegypti. Under semi-field conditions in large cages, 50 to 60% reductions of landing rates were observed, regardless of which transfluthrin dose, capture method, emanator placement position, or source of mosquitoes (mildly pyrethroid resistant wild caught Ae. aegypti or pyrethroid-susceptible colonies of Ae. aegypti and An. gambiae) was used. Air samples collected immediately downwind from an emanator treated with the highest transfluthrin dose (15g), contained 12 to 19 µg/m3 transfluthrin vapour. CONCLUSIONS: It appears unlikely that the moderate levels of pyrethroid resistance observed in wild Ae. aegypti can explain the modest-to-undetectable levels of protection exhibited. While potential inhalation exposure could be of concern for the highest (15g) dose evaluated, 3g of transfluthrin appears sufficient to achieve the modest levels of protection that were demonstrated entomologically. While the generally low levels of protection against Aedes reported here from Tanzania, and from similar entomological studies in Haiti and Brazil, are discouraging, complementary social science studies in Haiti and Brazil suggest end-users perceive valuable levels of protection against mosquitoes. It therefore remains unclear whether transfluthrin emanators have potential for protecting against Aedes vectors of important human arboviruses.


Asunto(s)
Aedes , Ciclopropanos , Fluorobencenos , Insecticidas , Control de Mosquitos , Animales , Tanzanía , Aedes/efectos de los fármacos , Ciclopropanos/farmacología , Control de Mosquitos/métodos , Insecticidas/farmacología , Mosquitos Vectores/efectos de los fármacos , Humanos , Anopheles/efectos de los fármacos , Mordeduras y Picaduras de Insectos/prevención & control , Piretrinas
13.
J Vis Exp ; (206)2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38738868

RESUMEN

Mosquitoes, notorious as the deadliest animals to humans due to their capacity to transmit diseases, pose a persistent challenge to public health. The primary prevention strategy currently in use involves chemical repellents, which often prove ineffective as mosquitoes rapidly develop resistance. Consequently, the invention of new preventive methods is crucial. Such development hinges on a thorough understanding of mosquito biting behaviors, necessitating an experimental setup that accurately replicates actual biting scenarios with controllable testing parameters and quantitative measurements. To bridge this gap, a bio-hybrid atomic force microscopy (AFM) probe was engineered, featuring a biological stinger - specifically, a mosquito labrum - as its tip. This bio-hybrid probe, compatible with standard AFM systems, enables a near-authentic simulation of mosquito penetration behaviors. This method marks a step forward in the quantitative study of biting mechanisms, potentially leading to the creation of effective barriers against vector-borne diseases (VBDs) and opening new avenues in the fight against mosquito-transmitted illnesses.


Asunto(s)
Culicidae , Microscopía de Fuerza Atómica , Animales , Microscopía de Fuerza Atómica/métodos , Culicidae/fisiología , Mordeduras y Picaduras de Insectos/prevención & control
14.
Nat Commun ; 15(1): 4626, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38816383

RESUMEN

The human infectious reservoir of Plasmodium falciparum is governed by transmission efficiency during vector-human contact and mosquito biting preferences. Understanding biting bias in a natural setting can help target interventions to interrupt transmission. In a 15-month cohort in western Kenya, we detected P. falciparum in indoor-resting Anopheles and human blood samples by qPCR and matched mosquito bloodmeals to cohort participants using short-tandem repeat genotyping. Using risk factor analyses and discrete choice models, we assessed mosquito biting behavior with respect to parasite transmission. Biting was highly unequal; 20% of people received 86% of bites. Biting rates were higher on males (biting rate ratio (BRR): 1.68; CI: 1.28-2.19), children 5-15 years (BRR: 1.49; CI: 1.13-1.98), and P. falciparum-infected individuals (BRR: 1.25; CI: 1.01-1.55). In aggregate, P. falciparum-infected school-age (5-15 years) boys accounted for 50% of bites potentially leading to onward transmission and had an entomological inoculation rate 6.4x higher than any other group. Additionally, infectious mosquitoes were nearly 3x more likely than non-infectious mosquitoes to bite P. falciparum-infected individuals (relative risk ratio 2.76, 95% CI 1.65-4.61). Thus, persistent P. falciparum transmission was characterized by disproportionate onward transmission from school-age boys and by the preference of infected mosquitoes to feed upon infected people.


Asunto(s)
Anopheles , Mordeduras y Picaduras de Insectos , Malaria Falciparum , Mosquitos Vectores , Plasmodium falciparum , Humanos , Anopheles/parasitología , Anopheles/fisiología , Animales , Plasmodium falciparum/fisiología , Plasmodium falciparum/aislamiento & purificación , Plasmodium falciparum/genética , Malaria Falciparum/transmisión , Malaria Falciparum/parasitología , Masculino , Adolescente , Niño , Preescolar , Femenino , Kenia/epidemiología , Mosquitos Vectores/parasitología , Mosquitos Vectores/fisiología , Adulto , Conducta Alimentaria , Adulto Joven , Lactante
15.
Sci Rep ; 14(1): 11476, 2024 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-38769342

RESUMEN

Entomological evaluations of vector control tools often use human landing catches (HLCs) as a standard measure of a direct human-vector contact. However, some tools have additional characteristics, such as mortality, and HLCS are not sensitive for measuring other effects beyond landing inhibition. Therefore, additional measures may need to be considered when evaluating these tools for public health use. This study has two main aims (1) the evaluate the accuracy of HLCs as a proxy for feeding and (2) to compare the predicted reduction in vectorial capacity when we do and do not consider these additional characteristics. To achieve this, we analyse previously published semi-field data from an experiment which used HLCs and another where mosquitoes were allowed to feed in the presence of different dosages of the volatile pyrethroid spatial repellent, transfluthrin. We compare results for two mathematical models: one which only considers the reduction in feeding effect and one which also considers mortality before and after feeding (using data gathered by the aspiration of mosquitoes after the semi-field feeding/landing period and 24 h survival monitoring). These Bayesian hierarchical models are parameterised using Bayesian inference. We observe that, for susceptible mosquitoes, reduction in landing is underestimated by HLCs. For knockdown resistant mosquitoes the relationship is less clear; with HLCs sometimes appearing to overestimate this characteristic. We find HLCs tend to under-predict the relative reduction in vectorial capacity in susceptible mosquitoes while over-predicting this impact in knockdown-resistant mosquitoes. Models without secondary effects have lower predicted relative reductions in vectorial capacities. Overall, this study highlights the importance of considering additional characteristics to reduction in biting of volatile pyrethroid spatial repellents. We recommend that these are considered when evaluating novel vector control tools.


Asunto(s)
Mordeduras y Picaduras de Insectos , Control de Mosquitos , Mosquitos Vectores , Animales , Humanos , Control de Mosquitos/métodos , Mosquitos Vectores/fisiología , Mosquitos Vectores/efectos de los fármacos , Mordeduras y Picaduras de Insectos/prevención & control , Conducta Alimentaria , Repelentes de Insectos/farmacología , Ciclopropanos/farmacología , Fluorobencenos/farmacología , Insecticidas/farmacología , Modelos Teóricos
16.
PLoS Biol ; 22(5): e3002625, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38771885

RESUMEN

Yersinia pestis, the causative agent of plague, is a highly lethal vector-borne pathogen responsible for killing large portions of Europe's population during the Black Death of the Middle Ages. In the wild, Y. pestis cycles between fleas and rodents; occasionally spilling over into humans bitten by infectious fleas. For this reason, fleas and the rats harboring them have been considered the main epidemiological drivers of previous plague pandemics. Human ectoparasites, such as the body louse (Pediculus humanus humanus), have largely been discounted due to their reputation as inefficient vectors of plague bacilli. Using a membrane-feeder adapted strain of body lice, we show that the digestive tract of some body lice become chronically infected with Y. pestis at bacteremia as low as 1 × 105 CFU/ml, and these lice routinely defecate Y. pestis. At higher bacteremia (≥1 × 107 CFU/ml), a subset of the lice develop an infection within the Pawlowsky glands (PGs), a pair of putative accessory salivary glands in the louse head. Lice that developed PG infection transmitted Y. pestis more consistently than those with bacteria only in the digestive tract. These glands are thought to secrete lubricant onto the mouthparts, and we hypothesize that when infected, their secretions contaminate the mouthparts prior to feeding, resulting in bite-based transmission of Y. pestis. The body louse's high level of susceptibility to infection by gram-negative bacteria and their potential to transmit plague bacilli by multiple mechanisms supports the hypothesis that they may have played a role in previous human plague pandemics and local outbreaks.


Asunto(s)
Pediculus , Peste , Yersinia pestis , Animales , Yersinia pestis/patogenicidad , Yersinia pestis/fisiología , Pediculus/microbiología , Pediculus/fisiología , Humanos , Peste/transmisión , Peste/microbiología , Insectos Vectores/microbiología , Insectos Vectores/parasitología , Mordeduras y Picaduras de Insectos/microbiología , Femenino , Masculino
18.
Malar J ; 23(1): 113, 2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38643165

RESUMEN

BACKGROUND: Microsporidia MB, an endosymbiont naturally found in Anopheles mosquitoes inhibits transmission of Plasmodium and is a promising candidate for a transmission-blocking strategy that may involve mosquito release. A rapid assessment was carried out to develop insight into sociodemographic factors, public health concerns, and malaria awareness, management, and prevention practices with the willingness to accept and participate in Microsporidia MB-based transmission-blocking strategy to develop an informed stakeholder engagement process. METHODS: The assessment consisted of a survey conducted in two communities in western Kenya that involved administering a questionnaire consisting of structured, semi-structured, and open questions to 8108 household heads. RESULTS: There was an overall high level of willingness to accept (81%) and participate in the implementation of the strategy (96%). Although the willingness to accept was similar in both communities, Ombeyi community was more willing to participate (OR 22, 95% CI 13-36). Women were less willing to accept (OR 0.8, 95% CI 0.7-0.9) compared to men due to fear of increased mosquito bites near homes. Household heads with incomplete primary education were more willing to accept (OR 1.6, 95% CI 01.2-2.2) compared to those educated to primary level or higher. Perceiving malaria as a moderate or low public health issue was also associated with a lower willingness to accept and participate. Experience of > 3 malaria cases in the family over the last six months and knowledge that malaria is transmitted by only mosquito bites, increased the willingness to accept but reduced the willingness to participate. Awareness of malaria control methods based on mosquitoes that cannot transmit malaria increases the willingness to participate. CONCLUSION: The study showed a high level of willingness to accept and participate in a Microsporidia MB-based strategy in the community, which is influenced by several factors such as community, disease risk perception, gender, education level, knowledge, and experience of malaria. Further research will need to focus on understanding the concerns of women, educated, and employed community members, and factors that contribute to the lower disease risk perception. This improved understanding will lead to the development of an effective communication strategy.


Asunto(s)
Mordeduras y Picaduras de Insectos , Malaria , Microsporidios , Masculino , Animales , Humanos , Femenino , Kenia , Malaria/prevención & control , Salud Pública , Control de Mosquitos/métodos , Mosquitos Vectores
19.
BMC Immunol ; 25(1): 23, 2024 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-38678193

RESUMEN

BACKGROUND: Flow cytometry-based basophil activation tests (BAT) have been performed with various modifications, differing in the use of distinct identification and activation markers. Established tests use liquid reagents while a new development involves the use of tubes with dried antibody reagents. The aim of this pilot study was to compare these two techniques in patients with insect venom allergy. METHODS: Seventeen patients with an insect venom allergy were included in the study. The established "BAT 1" utilizes conventional antibody solutions of anti-CCR3 for basophil identification and anti-CD63 to assess basophil activation, whereas "BAT 2" uses dried anti-CD45, anti-CD3, anti-CRTH2, anti-203c and anti-CD63 for identification and activation measurement of basophils. Negative and positive controls as well as incubations with honey bee venom and yellow jacket venom at three concentrations were performed. RESULTS: Seven patients had to be excluded due to low basophil counts, high values in negative controls or negative positive controls. For the remaining 10 patients the overall mean (± SD) difference in activated basophils between the two tests was 0.2 (± 12.2) %P. In a Bland-Altman plot, the limit of agreement (LoA) ranged from 24.0 to -23.7. In the qualitative evaluation (value below/above cut-off) Cohen's kappa was 0.77 indicating substantial agreement. BAT 2 took longer to perform than BAT 1 and was more expensive. CONCLUSION: The BAT 2 technique represents an interesting innovation, however, it was found to be less suitable compared to an established BAT for the routine diagnosis of insect venom allergies.


Asunto(s)
Basófilos , Citometría de Flujo , Humanos , Basófilos/inmunología , Femenino , Masculino , Adulto , Persona de Mediana Edad , Citometría de Flujo/métodos , Venenos de Artrópodos/inmunología , Proyectos Piloto , Animales , Hipersensibilidad/inmunología , Hipersensibilidad/diagnóstico , Mordeduras y Picaduras de Insectos/inmunología , Mordeduras y Picaduras de Insectos/diagnóstico , Venenos de Abeja/inmunología , Adulto Joven , Anciano , Anticuerpos/inmunología , Adolescente , Prueba de Desgranulación de los Basófilos/métodos , Hipersensibilidad al Veneno
20.
BMJ Case Rep ; 17(4)2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38599796

RESUMEN

A male patient in his early 40s presented to the emergency department with an acute onset of respiratory distress and facial oedema, indicative of anaphylaxis. These symptoms emerged 2 hours subsequent to a wasp sting on the left side of his face. Despite initial stabilisation, the patient's state deteriorated into somnolence and disorientation. Notably, he denied any history of seizures, sensory or motor deficits, or bowel/bladder complications. Physical examination unveiled no focal neurological deficits. Routine laboratory tests and drug screening yielded no significant findings. Subsequent brain MRI with angiography exposed bilateral thalami diffusion restriction, strongly implying an acute infarction within the artery of Percheron territory, an atypical vascular variant. The sequence of events, alongside the absence of other conclusive aetiologies, indicated a wasp sting-induced thalamic infarction driven by vasogenic and thrombogenic effects of inflammatory substances.


Asunto(s)
Mordeduras y Picaduras de Insectos , Avispas , Animales , Humanos , Masculino , Infarto Cerebral/diagnóstico por imagen , Infarto Cerebral/etiología , Mordeduras y Picaduras de Insectos/complicaciones , Imagen por Resonancia Magnética , Mesencéfalo/diagnóstico por imagen , Adulto
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