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result(s) for
"Bites and Stings - etiology"
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Clinical Features of Severe Wasp Sting Patients with Dominantly Toxic Reaction: Analysis of 1091 Cases
2013
Massive wasp stings have been greatly underestimated and have not been systematically studied. The aim of this study was to identify the clinical features and treatment strategies of severe wasp stings.
A multicenter retrospective study was undertaken in 35 hospitals and medical centers including 12 tertiary care hospitals and 23 secondary care hospitals in the Hubei Province, China. The detailed clinical data of 1091 hospitalized wasp sting patients were investigated. Over three-fourths (76.9%) of the cases had 10 or more stings and the in-hospital mortality of patients was 5.1%. Forty-eight patients died of organ injury following toxic reactions to the stings, whereas six died from anaphylactic shock. The in-hospital mortality in patients with >10 stings was higher than that of ≤10 stings (5.2% vs. 1.0%, p = 0.02). Acute kidney injury (AKI) was seen in 21.0% patients and most patients required blood purification therapy. Rhabdomyolysis was seen in 24.1% patients, hemolysis in 19.2% patients, liver injury in 30.1% patients, and coagulopathy in 22.5% patients. Regression analysis revealed that high creatinine level, shock, oliguria, and anemia were risk factors for death. Blood purification therapy was beneficial for patients with ≥20 stings and delayed hospital admission of patients (≥4 hours after sting).
In China, most patients with multiple wasp stings presented with toxic reactions and multiple organ dysfunction caused by the venom rather than an anaphylactic reaction. AKI is the prominent clinical manifestation of wasp stings with toxic reaction. High creatinine levels, shock, oliguria, and anemia were risk factors for death.
Journal Article
Impact of vector control interventions on malaria transmission intensity, outdoor vector biting rates and Anopheles mosquito species composition in Tororo, Uganda
by
Musiime, Alex K.
,
Smith, David L.
,
Kamya, Moses R.
in
Animals
,
Anopheles
,
Anopheles - physiology
2019
Background
Long-lasting insecticidal nets (LLINs) and indoor residual spraying of insecticide (IRS) are widely recommended for the prevention of malaria in endemic regions. Data from human landing catches provide information on the impact of vector control on vector populations. Here, malaria transmission indoors and outdoors, before and after mass deployment of LLINs and IRS in Uganda was compared.
Methods
The study took place in Tororo district, a historically high transmission area where universal LLIN distribution was conducted in November 2013 and May 2017 and 6 rounds of IRS implemented from December 2014 to July 2018. Human landing catches were performed in 8 houses monthly from October 2011 to September 2012 (pre-intervention period) and every 4 weeks from November 2017 to October 2018 (post-intervention period). Mosquitoes were collected outdoors from 18:00 to 22:00 h and indoors from 18:00 to 06:00 h. Female
Anopheles
were tested for the presence of
Plasmodium falciparum
sporozoites and species identification performed using gross dissection and polymerase chain reaction (PCR).
Results
The interventions were associated with a decline in human biting rate from 19.6 to 2.3 female
Anopheles
mosquitoes per house per night (p < 0.001) and annual entomological inoculation rate from 129 to 0 infective bites per person per year (p < 0.001). The proportion of mosquitoes collected outdoors increased from 11.6 to 49.4% (p < 0.001). Prior to the interventions the predominant species was
Anopheles gambiae
sensu stricto (s.s.), which comprised an estimated 76.7% of mosquitoes. Following the interventions, the predominant species was
Anopheles arabiensis,
which comprised 99.5% of mosquitoes, with almost complete elimination of
An. gambiae
s.s. (0.5%).
Conclusions
Mass distribution of LLINs and 6 rounds of IRS dramatically decreased vector density and sporozoite rate resulting in a marked reduction in malaria transmission intensity in a historically high transmission site in Uganda. These changes were accompanied by a shift in vector species from
An. gambiae
s.s. to
An. arabiensis
and a relative increase in outdoor biting.
Journal Article
Biting by Anopheles funestus in broad daylight after use of long-lasting insecticidal nets: a new challenge to malaria elimination
by
Sokhna, Cheikh
,
Ndiath, Mamadou Ousmane
,
Sougoufara, Seynabou
in
Animal behavior
,
Animals
,
Anopheles
2014
Background
Malaria control is mainly based on indoor residual spraying and insecticide-treated bed nets. The efficacy of these tools depends on the behaviour of mosquitoes, which varies by species. With resistance to insecticides, mosquitoes adapt their behaviour to ensure their survival and reproduction. The aim of this study was to assess the biting behaviour of
Anopheles funestus
after the implementation of long-lasting insecticidal nets (LLINs).
Methods
A study was conducted in Dielmo, a rural Senegalese village, after a second massive deployment of LLINs in July 2011. Adult mosquitoes were collected by human landing catch and by pyrethrum spray catch monthly between July 2011 and April 2013. Anophelines were identified by stereomicroscope and sub-species by PCR. The presence of circumsporozoite protein of
Plasmodium falciparum
and the blood meal origin were detected by ELISA.
Results
Anopheles funestus
showed a behavioural change in biting activity after introduction of LLINs, remaining anthropophilic and endophilic, while adopting diurnal feeding, essentially on humans. Six times more
An. funestus
were captured in broad daylight than at night. Only one infected mosquito was found during day capture. The mean of day CSP rate was 1.28% while no positive
An. funestus
was found in night captures.
Conclusion
Mosquito behaviour is an essential component for assessing vectorial capacity to transmit malaria. The emergence of new behavioural patterns of mosquitoes may significantly increase the risk for malaria transmission and represents a new challenge for malaria control. Additional vector control strategies are, therefore, necessary.
Journal Article
Mediator-Related Symptoms and Anaphylaxis in Children with Mastocytosis
2021
Mastocytosis is characterized by the pathological accumulation of mast cells (MC) in various organs. In these patients, MC may degranulate and thereby contribute to clinical symptoms, especially when a concomitant allergy is present. However, MC activation can not only be induced by high-affinity receptors for IgE, but also by anaphylatoxins, neuropeptides, IgG immune complexes, complement-components, drugs, products of bacteria or parasites, as well as physical factors such as heat, cold, vibration, stress, sun, or physical effort. Symptoms due to mediators released by activated MC may develop in adults suffering from systemic mastocytosis, but also evolve in children who usually have cutaneous mastocytosis (CM). Clinically, CM is otherwise characterized by typical brown, maculopapular skin lesions or mastocytoma associated with a positive Darier’s sign. Pruritus and flushing are common and blistering may also be recorded, especially in diffuse CM (DCM). Pediatric patients with mastocytosis may also have gastrointestinal, respiratory, and neurologic complaints. Although anaphylaxis is not a typical finding, pediatric patients with massive skin involvement and high tryptase levels have a relatively high risk to develop anaphylaxis. This paper reviews MC mediator-related symptoms and anaphylaxis in children with mastocytosis, with special emphasis on risk factors, triggers, and management.
Journal Article
‘A bite before bed’: exposure to malaria vectors outside the times of net use in the highlands of western Kenya
2015
Background
The human population in the highlands of Nyanza Province, western Kenya, is subject to sporadic epidemics of
Plasmodium falciparum
. Indoor residual spraying (IRS) and long-lasting insecticide treated nets (LLINs) are used widely in this area. These interventions are most effective when
Anopheles
rest and feed indoors and when biting occurs at times when individuals use LLINs. It is therefore important to test the current assumption of vector feeding preferences, and late night feeding times, in order to estimate the extent to which LLINs protect the inhabitants from vector bites.
Methods
Mosquito collections were made for six consecutive nights each month between June 2011 and May 2012. CDC light-traps were set next to occupied LLINs inside and outside randomly selected houses and emptied hourly. The net usage of residents, their hours of house entry and exit and times of sleeping were recorded and the individual hourly exposure to vectors indoors and outdoors was calculated. Using these data, the true protective efficacy of nets (P*), for this population was estimated, and compared between genders, age groups and from month to month.
Results
Primary vector species (
Anopheles funestus
s.l. and
Anopheles arabiensis
) were more likely to feed indoors but the secondary vector
Anopheles coustani
demonstrated exophagic behaviour (p < 0.05). A rise in vector biting activity was recorded at 19:30 outdoors and 18:30 indoors. Individuals using LLINs experienced a moderate reduction in their overall exposure to malaria vectors from 1.3 to 0.47 bites per night. The P* for the population over the study period was calculated as 51% and varied significantly with age and season (p < 0.01).
Conclusions
In the present study, LLINs offered the local population partial protection against malaria vector bites. It is likely that P* would be estimated to be greater if the overall suppression of the local vector population due to widespread community net use could be taken into account. However, the overlap of early biting habit of vectors and human activity in this region indicates that additional methods of vector control are required to limit transmission. Regular surveillance of both vector behaviour and domestic human-behaviour patterns would assist the planning of future control interventions in this region.
Journal Article
Effectiveness of novel fabrics to resist punctures and lacerations from white shark (Carcharodon carcharias): Implications to reduce injuries from shark bites
by
Dennis, Joshua D.
,
Whitmarsh, Sasha K.
,
Huveneers, Charlie
in
Animal behavior
,
Animal bites
,
Animals
2019
Increases in the number of shark bites, along with increased media attention on shark-human interactions has led to growing interest in preventing injuries from shark bites through the use of personal mitigation measures. The leading cause of fatality from shark bite victims is blood loss; thus reducing haemorrhaging may provide additional time for a shark bite victim to be attended to by emergency services. Despite previous shark-proof suits being bulky and cumbersome, new technological advances in fabric has allowed the development of lightweight alternatives that can be incorporated onto traditional wetsuits. The ability for these fabrics to withstand shark bites has not been scientifically tested. In this report, we compared two types of recently developed protective fabrics that incorporated ultra-high molecular weight polyethylene (UHMWPE) fibre onto neoprene (SharkStop and ActionTX) and compared them to standard neoprene alternatives. We tested nine different fabric variants using three different tests, laboratory-based puncture and laceration tests, along with field-based trials involving white sharks Carcharodon carcharias. Field-based trials consisted of measuring C. carcharias bite force and quantifying damages to the new fabrics following a bite from 3-4 m total length C. carcharias. We found that SharkStop and ActionTX fabric variants were more resistant to puncture, laceration, and bites from C. carcharias. More force was required to puncture the new fabrics compared to control fabrics (laboratory-based tests), and cuts made to the new fabrics were smaller and shallower than those on standard neoprene for both types of test, i.e. laboratory and field tests. Our results showed that UHMWPE fibre increased the resistance of neoprene to shark bites. Although the use of UHMWPE fibre (e.g. SharkStop and ActionTX) may therefore reduce blood loss resulting from a shark bite, research is needed to assess if the reduction in damages to the fabrics extends to human tissues and decreased injuries.
Journal Article
Understanding heterogeneities in mosquito-bite exposure and infection distributions for the elimination of lymphatic filariasis
by
Reimer, Lisa J.
,
Hollingsworth, T. Deirdre
,
Kazura, James W.
in
Animals
,
Anopheles - physiology
,
Aquatic insects
2018
It is well known that individuals in the same community can be exposed to a highly variable number of mosquito bites. This heterogeneity in bite exposure has consequences for the control of vector-borne diseases because a few people may be contributing significantly to transmission. However, very few studies measure sources of heterogeneity in a way which is relevant to decision-making. We investigate the relationship between two classic measures of heterogeneity, spatial and individual, within the context of lymphatic filariasis, a parasitic mosquito-borne disease. Using infection and mosquito-bite data for five villages in Papua New Guinea, we measure biting characteristics to model what impact bed-nets have had on control of the disease. We combine this analysis with geospatial modelling to understand the spatial relationship between disease indicators and nightly mosquito bites. We found a weak association between biting and infection heterogeneity within villages. The introduction of bed-nets increased biting heterogeneity, but the reduction in mean biting more than compensated for this, by reducing prevalence closer to elimination thresholds. Nightly biting was explained by a spatial heterogeneity model, while parasite load was better explained by an individual heterogeneity model. Spatial and individual heterogeneity are qualitatively different with profoundly different policy implications.
Journal Article
Small Animal Veterinarians’ Perceptions, Experiences, and Views of Common Dog Breeds, Dog Aggression, and Breed-Specific Laws in the United States
by
Kogan, Lori R.
,
Oxley, James A.
,
Schoenfeld-Tacher, Regina M.
in
Adult
,
Aggression
,
Animal bites
2019
Dog aggression directed towards humans is a common and serious behavioral and public health issue. This cross-sectional study was designed to gain insights into U.S. small animal veterinarians’ views and experiences with the most common dog breeds in the U.S., dog aggression, and breed-specific legislation. An electronic survey was distributed via email to an online veterinary community, and responses were summarized and compared by means of χ2 and Cochran–Mantel–Haenszel tests. Most respondents were concerned about the risks of dog bite injuries, but the majority were not in favor of banning specific breeds of dogs in order to enhance public safety. When participants rated the perceived bite risk associated with popular dog breeds, Chow Chows were perceived as the highest risk, with pit bull types categorized as a moderate risk. Golden Retrievers were seen as the most appropriate for families with children. Public education about animal behavior was the most frequently endorsed policy intervention to increase public safety. These findings suggest that most veterinarians feel that banning an entire dog breed is not an effective way to ensure human safety. Instead, most respondents endorsed alternative initiatives, such as public education and stricter leash laws, to reduce the risk of dog bites.
Journal Article
Attraction of Culex mosquitoes to aldehydes from human emanations
2017
Anecdotes related to preferential mosquito bites are very common, but to date there is no complete explanation as to why one out of two people systematically receives more mosquito bites than the other when both are equally accessible. Here we tested the hypothesis that two constituents of skin emanations, 6-methyl-5-heptan-2-one (6-MHO) and geranylacetone (GA), are natural repellents and may account for differential attraction in different ratios. We studied skin emanations from two human subjects, confirmed in behavioral assays that female southern house mosquitoes are significantly more attracted to subject A (attractant) than to subject N (non-attractant), and tested their 6-MHO/GA ratios in a dual-choice olfactometer. Although repelling at high doses, 6-MHO/GA mixtures were not active at the levels emitted by human skin. We found, however, differential attraction elicited by the aldehydes in the ratios produced by subjects A and N. When tested in a dose commensurate with the level released from human skin and in the ratio produced by subject A, the aldehyde mixture significantly attracted mosquitoes. By contrast, an aldehyde mixture at the same ratio released by subject N did not attract mosquitoes. We, therefore, hypothesized that aldehydes may play a role in the commonly observed differential attraction.
Journal Article
Nightly Biting Cycles of Anopheles Species in Rural Northwestern Burkina Faso
2018
The biting behavior of anophelines is an important determinant of malaria transmission. Understanding the local vector host-seeking behavior, its outdoor/ indoor biting preference, and nocturnal biting periods is essential for effectively applying and improving vector control methods, such as Long Lasting Insecticidal Nets (LLINs) and personal protective measures. To better understand the biting and host-seeking patterns of Anopheles mosquitoes in Northwestern Burkina Faso, we performed biweekly Human Landing Catches (HLC) in six villages during the period of highest mosquito abundance and malaria transmission. We applied a negative binomial regression framework to statistically analyze the host-seeking activities of Anopheles species and test for differences across hours, months, and villages, as well as for differences between indoor and outdoor capture points. Anopheles gambiae s.l. was identified as the main malaria vector in this region, representing about 90% of the total anopheline population. Biting activity was significantly different across hours and showed a peaked plateau between 2000 and 0200 hours. Differences in the pattern of biting cycles were observed between the early and late rainy season. This study shows that anopheline biting activity in Northwest Burkina Faso is high throughout the night, at indoor and outdoor posts alike. Consequently, bed nets alone may not provide sufficient protection against early biting anophelines and should be complemented with additional strategies such as indoor residual spraying (IRS) and larval source management (LSM) to meet the WHO's ambitious goals that are reflected in the global technical malaria strategy for 2030.
Journal Article