The influence of humidity and temperature on the vertical richness and abundance of blood-sucking flies (Culicidae and Ceratopogonidae) in a montane cloud forest in Mexico

Because the vertical distribution and diversity of blood-sucking flies are poorly known, we determined the diversity, structure, and composition of culicids between vertical vegetation strata. We evaluated the influence of microclimatic variables during different times of the day over a year. We used eight CDC traps baited with CO2 at a height of 1.5 m and 12-15 m. We conducted rank-abundance curves, similarity analysis (ANOSIM and SIMPER), and multivariate clustering with incidence and abundance data. We used GAM models to analyze the influence of strata (understory vs canopy), humidity, and temperature on insect richness and abundance. During the day, the difference between strata was mainly due to higher abundance of Wyeomyia arthrostigma and Wyeomyia ca. adelpha in the understory. During the night, the differences were mainly due to higher abundance of Culex stigmatosoma, Culex salinarius, and Aedes allotecnon in the canopy, and Wyeomyia arthrostigma in the understory. Seasonality played a role in the similarity between the strata. Diversity during the day was positively related to humidity and temperature, and nocturnal diversity increased with temperature but decreased with higher humidity. The effects of environmental factors on the spatiotemporal distribution of fly species are essential for epidemiological surveillance.

Filtration of environmentally sourced aquatic media impacts laboratory-colonised Aedes albopictus early development and adult bacteriome composition

Microorganisms form close associations with metazoan hosts forming symbiotic communities, known as microbiomes, that modulate host physiological processes. Mosquitoes are of special interest in exploring microbe-modulated host processes due to their oversized impact on human health. However, most mosquito work is done under controlled laboratory conditions where natural microbiomes are not present and inferences from these studies may not extend to natural populations. Here we attempt to assemble a wild-resembling bacteriome under laboratory conditions in an established laboratory colony of Aedes albopictus using aquatic media from environmentally-exposed and differentially filtered larval habitats. While we did not successfully replicate a wild bacteriome using these filtrations, we show that these manipulations alter the bacteriomes of mosquitoes, generating a unique composition not seen in wild populations collected from and near our source water or in our laboratory colony. We also demonstrate that our filtration regimens impact larval development times, as well as impact adult survival on different carbohydrate diets.

Land-cover, land-use and human hantavirus infection risk: a systematic review

Previous studies suggest that the risk of human infection by hantavirus, a family of rodent-borne viruses, might be affected by different environmental determinants such as land cover, land use and land use change. This study examined the association between land-cover, land-use, land use change, and human hantavirus infection risk. PubMed and Scopus databases were interrogated using terms relative to land use (change) and human hantavirus disease. Screening and selection of the articles were completed by three independent reviewers. Classes of land use assessed by the different studies were categorized into three macro-categories of exposure ('Agriculture', 'Forest Cover', 'Urban Areas') to qualitatively synthesize the direction of the association between exposure variables and hantavirus infection risk in humans. A total of 25 articles were included, with 14 studies (56%) conducted in China, 4 studies (16%) conducted in South America and 7 studies (28%) conducted in Europe. Most of the studies (88%) evaluated land cover or land use, while 3 studies (12%) evaluated land use change, all in relation to hantavirus infection risk. We observed that land cover and land-use categories could affect hantavirus infection incidence. Overall, agricultural land use was positively associated with increased human hantavirus infection risk, particularly in China and Brazil. In Europe, a positive association between forest cover and hantavirus infection incidence was observed. Studies that assessed the relationship between built-up areas and hantavirus infection risk were more variable, with studies reporting positive, negative or no associations.

Aedes aegypti, Ae. albopictus and Culex quinquefasciatus Adults Found Coexisting in Urban and Semiurban Dwellings of Southern Chiapas, Mexico

Tapachula, Mexico, a tropical city, is an endemic area for dengue, in addition to several outbreaks in the last decade with chikungunya and zika. As part of the migratory corridor from Central to North America and the risks of scattered infectious diseases that this implies, the identification and distribution of potential disease vectors in and around residential areas are essential in terms of entomological surveillance for the prevention of disease outbreaks. The identification of mosquito species of medical importance coexisting in houses and cemeteries in Tapachula and two semiurban sites in southern Chiapas was investigated. Adult mosquitoes were collected from May to December 2018, resting inside and outside houses and in the tombstones and fallen tree leaves in cemeteries. A total of 10,883 mosquitoes belonging to three vector species were collected across 20 sites; 6738 were from neighborhood houses, of which 55.4% were Culex quinquefasciatus, 41.6% Aedes aegypti, and 2.9% Ae. albopictus. Aedes aegypti was the most common mosquito resting inside houses (56.7%), while Ae. albopictus and Cx. quinquefasciatus were mostly found resting outside houses (75.7%). In the cemeteries, Cx. quinquefasciatus (60.8%) and Ae. albopictus (37.3%) were the most abundant, while Ae. aegypti (1.9%) was the least abundant. This is the first report to identify adults of three major disease vector species coexisting in the domestic environment of urban and semiurban sites and Ae. albopictus adult resting inside of urban houses in Mexico. It would be opportune to consider comprehensive strategies that can be applied in this region to control the three species at the same time and avoid outbreaks of the diseases they transmit.

DNA Barcodes of Mansonia (Mansonia) Blanchard, 1901 (Diptera, Culicidae)

Females of the genus Mansonia feed on the blood of humans, livestock, and other vertebrates to develop their eggs. The females' biting behavior may cause severe disturbance to blood hosts, with a negative impact on public health and economics. Certain species have been identified as potential or effective disease vectors. The accurate species identification of field-collected specimens is of paramount importance for the success of monitoring and control strategies. Mansonia (Mansonia) morphological species boundaries are blurred by patterns of intraspecific heteromorphism and interspecific isomorphism. DNA barcodes can help to solve taxonomic controversies, especially if combined with other molecular tools. We used cytochrome c oxidase subunit I (COI) gene 5' end (DNA barcode) sequences to identify 327 field-collected specimens of Mansonia (Mansonia) spp. The sampling encompassed males and females collected from three Brazilian regions and previously assigned to species based on their morphological characteristics. Eleven GenBank and BOLD sequences were added to the DNA barcode analyses. Initial morphospecies assignments were mostly corroborated by the results of five clustering methods based on Kimura two-parameter distance and maximum likelihood phylogeny. Five to eight molecular operational taxonomic units may represent taxonomically unknown species. The first DNA barcode records for Mansonia fonsecai, Mansonia iguassuensis, and Mansonia pseudotitillans are presented.

Development of an automated mosquito pupae counter

The production of mosquitoes for control programs or basic research is facilitated by the standardization of rearing conditions allowing the daily manipulation of thousands of individuals. It is crucial to develop mechanical or electronic systems for controlling the density of mosquitoes at each development stage with the aim of reducing costs, time, and human errors. We present herein an automatic mosquito counter using a recirculating water system allowing rapid and reliable counting of pupae without detectable increased mortality. Using Aedes albopictus pupae, we determined the density of pupae and the time of counting for which the device is most accurate, and evaluated the time saved using this device. Lastly, we discuss how this mosquito pupae counter can be useful in small-scale or mass-rearing contexts enabling a number of applications for research purposes as well as operational mosquito control programs.

First Isolation and Genome Sequence Analysis of West Nile Virus in Mosquitoes in Brazil

West Nile virus is a flavivirus transmitted by mosquitoes, mainly of the genus Culex. In Brazil, serological studies have already indicated the circulation of the virus since 2003, with the first human case detected in 2014. The objective of the present paper is to report the first isolation of WNV in a Culex (Melanoconion) mosquito. Arthropods were collected by protected human attraction and CDC light bait, and taxonomically identified and analyzed by viral isolation, complement fixation and genomic sequencing tests. WNV was isolated from samples of Culex (Melanoconion) mosquitoes, and the sequencing analysis demonstrated that the isolated strain belonged to lineage 1a. The finding of the present study presents the first evidence of the isolation and genome sequencing of WNV in arthropods in Brazil.

Survey of West Nile and Banzi Viruses in Mosquitoes, South Africa, 2011-2018

We collected >40,000 mosquitoes from 5 provinces in South Africa during 2011-2018 and screened for zoonotic flaviviruses. We detected West Nile virus in mosquitoes from conservation and periurban sites and potential new mosquito vectors; Banzi virus was rare. Our results suggest flavivirus transmission risks are increasing in South Africa.

Modeling Effects of Vertebrate Host Exclosures and Host-Targeted Acaricides on Lone Star Tick (Amblyomma americanum, L.) Infestations

We used a spatially explicit model to simulate the potential effects of exclosures and acaricides targeted at medium-sized mammalian hosts on the local distribution and abundance of lone star ticks (Amblyomma americanum) within forestlands of the southeastern United States. Both exclosures and acaricides were successful in markedly reducing the densities of all off-host tick life stages inside the treatment areas. Densities dropped to almost zero immediately inside the edges of the exclosures, with noticeably depressed densities extending outward 30 to 60 m from the exclosures, and the simulated exclosures maintained their effectiveness as their sizes were decreased from 4.5 to 2.25 to 0.8 ha. Densities exhibited a smooth gradient across the edges of the acaricide-treated areas, with depressed densities extending ≈100 m outward from the edges, but with perceptible densities extending ≈60 m inward from the edges; thus, the simulated acaricide areas lost their effectiveness as size was decreased to slightly less than one-half the diameter of the activity range of the targeted host. Our simulation results indicated that off-host nymph densities responded to reductions of medium-sized host densities. These results suggest that targeting acaricides at medium-sized hosts may be an effective, and currently under-utilized, method for tick suppression.

Temephos, an organophosphate larvicide for residential use: a review of its toxicity

Temephos (O,O,O',O'-tetramethyl O,O'-thiodi-p-phenylene bis(phosphorothioate)) is a larvicide belonging to the family of organophosphate pesticides used for the control of different vectors of diseases, such as dengue, Zika, chikungunya, and dracunculiasis. The aim of this review was to discuss the available published information about temephos toxicokinetics and toxicity in mammals. Temephos is quickly absorbed in the gastrointestinal tract, distributed to all organs, and then it accumulates mainly in adipose tissue. It is metabolized by S-oxidation, oxidative desulfuration, and hydrolysis reactions, with the possible participation of cytochrome P450 (CYP). Temephos is mainly eliminated by feces, whereas some of its metabolites are eliminated by urine. The World Health Organization classifies it as class III: slightly dangerous with a NOAEL (no-observed adverse effect level) of 2.3 mg/kg/day for up to 90 days in rats, based on brain acetylcholinesterase (AChE) inhibition. A LOAEL (lowest observable adverse effect level) of 100 mg/kg/day for up to 44 days in rats was proposed based on cholinergic symptoms. However, some studies have shown that temephos causes toxic effects in mammals. The inhibition of the enzyme acetylcholinesterase (AChE) is one of its main demonstrated effects; however, this larvicide has also shown genotoxic effects and some adverse effects on male reproduction and fertility, as well as liver damage, even at low doses. We performed an extensive review through several databases of the literature about temephos toxicokinetics, and we recommend to revisit current assessment of temephos with the new available data.

A Minimally Morphologically Destructive Approach for DNA Retrieval and Whole-Genome Shotgun Sequencing of Pinned Historic Dipteran Vector Species

Museum collections contain enormous quantities of insect specimens collected over the past century, covering a period of increased and varied insecticide usage. These historic collections are therefore incredibly valuable as genomic snapshots of organisms before, during, and after exposure to novel selective pressures. However, these samples come with their own challenges compared with present-day collections, as they are fragile and retrievable DNA is low yield and fragmented. In this article, we tested several DNA extraction procedures across pinned historic Diptera specimens from four disease vector genera: Anopheles, Aedes, Culex, and Glossina. We identify an approach that minimizes morphological damage while maximizing DNA retrieval for Illumina library preparation and sequencing that can accommodate the fragmented and low yield nature of historic DNA. We identify several key points in retrieving sufficient DNA while keeping morphological damage to a minimum: an initial rehydration step, a short incubation without agitation in a modified low salt Proteinase K buffer (referred to as "lysis buffer C" throughout), and critical point drying of samples post-extraction to prevent tissue collapse caused by air drying. The suggested method presented here provides a solid foundation for exploring the genomes and morphology of historic Diptera collections.

Increasing Public Health Mosquito Surveillance in Hidalgo County, Texas to Monitor Vector and Arboviral Presence

From 2016 to 2018, Hidalgo County observed the emergence of Zika virus (ZIKV) infections along with sporadic cases of Dengue virus (DENV) and West Nile virus (WNV). Due to the emergence of ZIKV and the historical presence of other mosquito-borne illnesses, Hidalgo County obtained funding to enhance mosquito surveillance and educate residents on arboviruses and travel risks. During this time period, Hidalgo County mosquito surveillance efforts increased by 1.275%. This increase resulted in >8000 mosquitoes collected, and 28 mosquito species identified. Aedes aegypti, Ae albopictus and Culex quinquefasciatus made up approximately two-thirds of the mosquitoes collected in 2018 (4122/6171). Spatiotemporal shifts in vector species composition were observed as the collection period progressed. Significantly, temperature variations (p < 0.05) accounted for associated variations in vector abundance, whereas all other climate variables were not significant.

Ixodes tropicalis (Acari: Ixodidae) infesting a human and molecular detection of Rickettsia bellii, Colombia

INTRODUCTION

Ixodes tropicalis is a little-known tick species reported parasitizing wild rodents only in Colombia and Perú.

OBJECTIVE

To report a case of I. tropicalis infesting a human in the south of the metropolitan area of the Valle de Aburrá, Antioquia, Colombia, and to report the molecular detection of Rickettsia bellii in this species.

MATERIALS AND METHODS

The tick was identified using a morphological key and sequencing of tick mitochondrial 16S rRNA. Additionally, bacterial and protozoa pathogens were evaluated using PCR for the detection of Rickettsia spp., family Anaplasmataceae, Borrelia spp., and piroplasmid.

RESULTS

We identified the tick as an I. tropicalis female according to Kohls, 1956, description and to partial 16S rRNA sequences showing a minimum of 5% divergencies compared to Ixodes sequences. We also detected the gltA gene of R. bellii in the tick with 99.87% of identity.

CONCLUSION

This is the first report in Colombia of a species of the Ixodes genus parasitizing a human and the first report of the detection of R. bellii in this tick species.

Potential for Bacillus thuringiensis and Other Bacterial Toxins as Biological Control Agents to Combat Dipteran Pests of Medical and Agronomic Importance

The control of dipteran pests is highly relevant to humans due to their involvement in the transmission of serious diseases including malaria, dengue fever, Chikungunya, yellow fever, zika, and filariasis; as well as their agronomic impact on numerous crops. Many bacteria are able to produce proteins that are active against insect species. These bacteria include Bacillus thuringiensis, the most widely-studied pesticidal bacterium, which synthesizes proteins that accumulate in crystals with insecticidal properties and which has been widely used in the biological control of insects from different orders, including Lepidoptera, Coleoptera, and Diptera. In this review, we summarize all the bacterial proteins, from B. thuringiensis and other entomopathogenic bacteria, which have described insecticidal activity against dipteran pests, including species of medical and agronomic importance.

Development of land transport connections between Asia and Europe and their possible impact on vector introductions into European Countries

The possibility of transfer of several organisms – disease vectors by land transportation Asia – Europe corridors into European countries is discussed. In Europe most alien species are of Asiatic origin. Trade and exchange of goods have developed very intensively for the beginning of the XXI century between Asia and European Union countries both by sea and land routes. Road and railway connections shorten the time of goods’ transport from China to Europe to 10,5 – 12 days. Shorter travel time and increased intensity of trade can increase the risk of introducing vector organisms from Asian countries to Europe. Existing legal international regulations (International Health Regulations, IHR) provide procedures to protect goods and persons against the carriage of organisms – vectors at every stage of transport and travel. Mass passenger and car traffic at border crossing points increase the likelihood of vector organisms entering as random stowaways; therefore it is proposed to intensify educational activities to make people aware of the danger posed by the transport of alien species of arthropods and what preventive actions to take. Unloading goods in a transit country (such as Poland) may take place at a transshipment center located near the border or inland. It is postulated to introduce a 400 m vector monitoring zone around both.

Rhipicephalus (Boophilus) microplus (Ixodida: Ixodidae) Larvae Collected From Vegetation in the Coastal Wildlife Corridor of Southern Texas and Research Solutions for Integrated Eradication

The potential for reinvasion of the United States by cattle fever ticks, Rhipicephalus (Boophilus) annulatus and Rhipicephalus microplus (Canestrini), which remain established in Mexico, threatens the viability of the domestic livestock industry because these ticks vector the causal agents (Babesia bovis and Babesia bigemina) of bovine babesiosis. The Cattle Fever Tick Eradication Program safeguards the health of the national cattle herd preventing the reemergence of bovine babesiosis by keeping the United States free of cattle fever ticks. Here, the collection of free-living southern cattle tick, R. microplus, larvae by sweeping flannel flags over vegetation in the wildlife corridor of Cameron and Willacy Counties, TX, is reported. Finding R. microplus larvae on vegetation complements reports of infestations in wildlife hosts inhabiting the southern Texas coastal plains. Land uses and environmental conditions have changed since cattle fever ticks were eradicated from the United States by 1943. These changes complicate efforts by the Cattle Fever Tick Eradication Program to keep cattle in the United States free of the cattle fever tick disease vectors. Current scientific research on technologies that could be used for area-wide management of fever tick larvae in south Texas and how this could be applied to integrated eradication efforts are discussed.

Dog-assisted therapy in the dental clinic: Part A-Hazards and assessment of potential risks to the health and safety of humans

Background

Dog-assisted therapy in the dental clinic may be an attractive alternative to sedation for anxious patients. Including a dental therapy dog in a clinical setting introduces new hazards and potential risks to health and safety for both humans and animal.

Objectives

The study aims to describe potential hazards associated with risks to humans by having a therapy dog present in the dental clinic and to provide guidance on best practices to minimise and control risks for the patients, the dentist, and the dental clinic staff.

Materials and Methods

Literature searches in Medline, http://Clinicaltrials.gov, and Google Scholar for qualitative and quantitative assessments of hazards and risks associated with the use of therapy dogs in health care settings, in combination with a review of the reference list of the included studies. Identified hazards and risks were analysed with respect for the health and welfare of humans in a dental clinic setting that involves the presence of a therapy dog.

Results

Potential risks to health and safety for humans in dental clinics that offer dog-assisted therapy can be categorised within four general categories of hazards: the dog as a source of zoonotic pathogens and human diseases, exposure to canine allergens, adverse animal behaviour, and dangers associated with high activity in a congested dental clinic operatory. Risks to humans are reduced by maintaining awareness amongst the dental clinic staff and the dog handler of all potential hazards in the dental clinic, and on how to reduce these hazards as well as adverse events that may scare the dental therapy dog.

Conclusions

Risks to the health and safety of humans in the presence of therapy dog in the clinics are present but are low if the dental clinical staff and dog handlers comply with best practices.

First report of Aedes (Stegomyia) albopictus (Skuse) in Orinoquia region of Colombia

Introducción.

Aedes albopictus es vector de arbovirus, como Flavivirus, Alphavirus, Bunyavirus, Phlebovirus, Orbivirus y Picornavirus. Muchos son agentes etiológicos de enfermedades en humanos. Actualmente, A. albopictus se encuentra en expansión geográfica por su adaptación a diversos ambientes y tipos de criaderos. En Colombia, este mosquito fue reportado por primera vez en 1998 y, hasta el momento, se ha registrado en 10 departamentos.

Objetivo.

Determinar la presencia de A. albopictus en Yopal, Casanare.

Materiales y métodos.

En una búsqueda activa de larvas de A. aegypti en la zona industrial de Yopal, se observaron por primera vez mosquitos adultos de A. albopictus. Por lo anterior, se realizó la inspección en el intradomicilio y el peridomicilio de las viviendas en ocho localidades del municipio, en la cual se recolectaron larvas y pupas al inspeccionar hábitats larvarios, y hembras adultas, mediante capturas sobre atrayente humano protegido.

Resultados.

Se identificaron 755 larvas de mosquitos, 71,5 % de A. aegypti, 24,8 % de A.albopictus, 3,2 % de Culex quinquefasciatus y 0,8 % de C. coronator y C. nigripalpus. Se capturaron 37 mosquitos adultos de A. albopictus. Los depósitos con mayor abundancia de este vector fueron las llantas.

Conclusión.

Ante la presencia de A. albopictus se sugiere intensificar el sistema de vigilancia entomológica para detectar nuevas poblaciones dentro del departamento y en las áreas cercanas. Se debe poner atención a los criaderos artificiales de las zonas cercanas a los parqueaderos de vehículos de transporte de alimentos, insumos y maquinaria, procedentes de áreas con presencia del vector.

Francisco Campos-Rivadeneira and Roberto Levi- Castillo: Their lives and contributions to the study of mosquitoes (Diptera: Culicidae) in Ecuador

The study of mosquitoes is important in the prevention of vector-borne diseases. In Ecuador, the study of local mosquito biodiversity was pioneered by two entomologists whose contributions span through the first half of the 20th century, Francisco Campos-Rivadeneira and Roberto Levi-Castillo. Both of them contributed to general aspects of Entomology and to particular insights in mosquito taxonomy. Their publications and discoveries were recognized by the international scientific community but went unnoticed in South America during their time. Today, very few citizens remember the names and contributions of these two scientists. Here, we provide an overview of their lives, a summary of their contributions, and we conclude with a broader outlook on the practice of science in Latin America during their time.

The breadth of climate change impacts on biological systems

Human activity is driving climate change. This is affecting and will affect many aspects of life on earth. The breadth of its impacts is very wide and covers human, animal and plant health, and also the planet's biodiversity and the services that deliver benefits to people from natural capital. Finding solutions to the challenge of climate change will require multidisciplinary action in which the life sciences have a major role to play as this issue of Emerging Topics in Life Sciences indicates. More process and mechanistic knowledge could underpin solutions or even provide early warning of impacts. Any solutions will need to be developed and deployed in ways that gain and maintain public support.

Ovicidal and Deleterious Effects of Cashew (Anacardium occidentale) Nut Shell Oil and Its Fractions on Musca domestica, Chrysomya megacephala, Anticarsia gemmatalis and Spodoptera frugiperda

In this work, we evaluated the ovicidal activity and the deleterious effects of cashew (Anacardium occidentale) nut shell oil and its fractions on the development of Musca domestica and Chrysomya megacephala, important vectors of several diseases. The insecticidal effects of this plant were also measured on the first and second instar larvae of Anticarsia gemmatalis and Spodoptera frugiperda, soy and maize pests, respectively. The fly eggs and the crop pest insect larvae were exposed to the cashew (Anacardium occidentale) nut shell liquid (CNSL) and its fractions: technical CNSL, anacardic acid, cardanol and cardol. The results show that the cardol fraction, for both species of flies, presented the lowest lethal concentration with LC₅₀ of 80.4 mg/L for M. domestica and 90.2 mg/L for C. megacephala. For the mortality of the larvae of A. gemmatalis and S. frugiperda, the most effective fraction was anacardic acid with LC₅₀ of 295.1 mg/L and 318.4 mg/L, respectively. In all species, the mortality rate of the commercial compounds (cypermethrin 600 mg/L and temephos 2 mg/L) was higher than that of the evaluated compounds. Despite this, the results obtained suggest their potential in field trials, once the fractions of A. occidentale presented high mortality at low lethal concentrations in laboratory conditions, with the possibility of integrated use in the control of disease vectors and agricultural pests, employing ecofriendly compounds.

Imported cutaneous leishmaniasis: a 13-year experience of a Polish tertiary center

INTRODUCTION

Leishmaniasis is a vector-borne infection endemic in 98 countries. Its cutaneous form (CL) causes skin lesions on exposed parts of the body and may lead to scarring. The numbers of imported cases of CL are increasing in Europe but the incidence of CL importation in Poland is unknown.

MATERIAL AND METHODS

A list of all patients diagnosed with CL at the Department in the years 2005-2017 was obtained. The study presents their data including age, sex, areas visited, purpose of travel, time from the onset of symptoms to correct diagnosis, appearance of lesions, results of impression smears and PCR, and superinfection, if detected, as well as treatment methods and their outcomes.

RESULTS

Altogether, 14 cases of cutaneous leishmaniasis were identified. The study demonstrates an increase in the number of cases of imported CL at our center over the last 5 years. The time to correct diagnosis was long in spite of the fact that the lesions had usually an appearance typical of CL.

CONCLUSIONS

Intensified education of physicians and travelers, as well as improvement in the access to travel medicine services and to the diagnosis and treatment methods appropriate for CL, are needed in our country. In our opinion, surveillance of leishmaniasis should be introduced in Poland.

Immunization of Experimental Dogs With Salivary Proteins From Lutzomyia longipalpis, Using DNA and Recombinant Canarypox Virus Induces Immune Responses Consistent With Protection Against Leishmania infantum

Metacyclic Leishmania promastigotes are transmitted by sand flies that inject parasites and saliva into the host's skin. Previous studies have demonstrated that DNA plasmids encoding Lutzomyia longipalpis salivary proteins LJM17 and LJL143, when used to immunize dogs, resulted in a systemic and local Th1 cell-mediated immunity that interfered in parasite survival in vitro. Here we evaluated the ability of these same salivary antigens to induce anti-Leishmania immunity and to confer protection by immunizing dogs using a novel vaccination strategy more suitable for use in the field. The strategy consisted of a single dose of plasmid followed by two doses of recombinant Canarypoxvirus (rCanarypoxvirus) expressing L. longipalpis salivary proteins (LJM17 or LJL143). Thirty days after the final immunization, dogs were intradermally challenged with 10⁷Leishmania infantum promastigotes in the presence of L. longipalpis saliva. We followed the experimentally infected dogs for 10 months to characterize clinical, parasitological, and immunological parameters. Upon vaccination, all immunized dogs presented strong and specific humoral responses with increased serum concentrations of IFN-γ, TNF, IL-7, and IL-15. The serum of dogs immunized with LJM17 also exhibited high levels of IL-2, IL-6, and IL-18. L. infantum infection was established in all experimental groups as evidenced by the presence of anti-Leishmania IgG, and by parasite detection in the spleen and skin. Dogs immunized with LJM17-based vaccines presented higher circulating levels of IFN-γ, IL-2, IL-6, IL-7, IL-15, IL-18, TNF, CXCL10, and GM-CSF post-infection when compared with controls. Results demonstrated that relevant Leishmania-specific immune responses were induced following vaccination of dogs with L. longipalpis salivary antigen LJM17 administered in a single priming dose of plasmid DNA, followed by two booster doses of recombinant Canarypox vector. Importantly, a significant increase in pro-inflammatory cytokines and chemokines known to be relevant for protection against leishmaniasis was evidenced after challenging LJM17-vaccinated dogs as compared to controls. Although similar results were observed following immunization with LJL143, the pro-inflammatory response observed after immunization was attenuated following infection. Collectively, these data suggest that the LJM17-based vaccine induced an immune profile consistent with the expected protective immunity against canine leishmaniosis. These results clearly support the need for further evaluation of the LJM17 antigen, using a heterologous prime-boost vaccination strategy against canine visceral leishmaniosis (CVL).

Novel larvicide tablets of Bacillus thuringiensis var. israelensis: Assessment of larvicidal effect on Aedes aegypti (Diptera: Culicidae) in Colombia

INTRODUCTION

Aedes (Stegomyia) aegypti is the vector for dengue, chikungunya, and Zika arboviruses. Bti-CECIF is a bioinsecticide designed and developed in the form of a solid tablet for the control of this vector. It contains Bacillus thuringiensis var. israelensis (Bti) serotype H-14.

OBJECTIVE

To evaluate under semi-field and field conditions the efficacy and residual activity of Bti-CECIF tablets on Aedes aegypti larvae in two Colombian municipalities.

MATERIALS AND METHODS

We tested under semi-field conditions in plastic tanks (Rotoplast™) four different Bti doses (0.13, 0.40, 0.66 and 0.93 mg/L) in the municipality of Apartadó, department of Antioquia, to assess Bti-CECIF efficacy (percentage of reduction of larval density) and the residual activity in water tanks containing A. aegypti third-instar larvae. The efficacy and residuality of the most lethal dose were subsequently evaluated under field conditions in cement tanks in the municipality of San Carlos, department of Córdoba.

RESULTS

Under semi-field conditions, the highest tested dose exhibited the greatest residual activity (15 days) after which larval mortality was 80%. Under field conditions, the highest tested Bti-CECIF doses showed 100% mortality and exhibited a residual activity of seven days in 90% of the tanks.

CONCLUSION

Bti-CECIF tablets effectively controlled A. aegypti larvae under field conditions for up to seven days post-treatment.

Multiband modulation spectroscopy for the determination of sex and species of mosquitoes in flight

We present a dual-wavelength polarimetric measurement method to distinguish species and sexes of disease transmitting mosquitoes in flight. By measuring co- and de-polarized backscattered light at 808 and 1550 nm, the degree of linear polarization, wingbeat frequency, reflectance, spectral ratio and glossiness of mosquitoes can be retrieved. Body and wing contributions to these signals can be separated. Whereas the optical cross section is sensitive to the aspect of observation, thus the heading direction of the insect in flight, we demonstrate that polarimetric- and spectral-band ratios are largely invariant to the aspect of observation. We show that wing glossiness, as well as wing- and body-spectral ratios are particularly efficient in distinguishing Anopheles coluzzii and Anopheles arabiensis, 2 closely related species of malaria vectors. Spectral and polarimetric ratios relate to microstructural and melanization features of the wing and body of these species. We conclude that multiband modulation spectroscopy is a useful expansion of the parameter space that can be used to improve the specificity of entomological lidars.

Dembo polymerase chain reaction technique for detection of bovine abortion, diarrhea, and respiratory disease complex infectious agents in potential vectors and reservoirs

Bovine abortion, diarrhea, and respiratory disease complexes, caused by infectious agents, result in high and significant economic losses for the cattle industry. These pathogens are likely transmitted by various vectors and reservoirs including insects, birds, and rodents. However, experimental data supporting this possibility are scarce. We collected 117 samples and screened them for 44 bovine abortive, diarrheal, and respiratory disease complex pathogens by using Dembo polymerase chain reaction (PCR), which is based on TaqMan real-time PCR. Fifty-seven samples were positive for at least one pathogen, including bovine viral diarrhea virus, bovine enterovirus, Salmonella enterica ser. Dublin, Salmonella enterica ser. Typhimurium, and Neospora caninum; some samples were positive for multiple pathogens. Bovine viral diarrhea virus and bovine enterovirus were the most frequently detected pathogens, especially in flies, suggesting an important role of flies in the transmission of these viruses. Additionally, we detected the N. caninum genome from a cockroach sample for the first time. Our data suggest that insects (particularly flies), birds, and rodents are potential vectors and reservoirs of abortion, diarrhea, and respiratory infectious agents, and that they may transmit more than one pathogen at the same time.

Citizen Science: A Gateway for Innovation in Disease-Carrying Mosquito Management?

Traditional methods for tracking disease-carrying mosquitoes are hitting budget constraints as the scales over which they must be implemented grow exponentially. Citizen science offers a novel solution to this problem but requires new models of innovation in the public health sector.

Leptospirosis in the Caribbean: a literature review

Objective

To describe leptospirosis epidemiology, seroprevalence, and serovars among humans and animals in the Caribbean from 1979 - 2013.

Methods

A retrospective study of the literature was performed on the general epidemiology, historical records, and geographical locations of leptospirosis outbreaks and cases in the Caribbean from 1979 - 2013. The primary sources of information were identified with PubMed Central, Google Scholar, CAREC, CaribVET, and The School of Veterinary Medicine at the University of the West Indies. Search terms used were: "human leptospirosis," "animal leptospirosis," "serovars," "livestock," "seroprevalence," "Caribbean countries," "risk factors," "confirmed cases," "suspected cases," "MAT," and "ELISA." Confirmed and suspected cases of human and animal leptospirosis were identified through laboratory analysis.

Results

Most cases of leptospirosis occurred during the rainy season (June - December) and had a positive correlation with flood conditions. The disease was more prevalent in males than females due to behavioral and occupational exposure. The highest incidence rates of human leptospirosis were recorded in Barbados, Trinidad and Tobago, and Jamaica. In animals, leptospirosis has been found in rodents, livestock, and dogs in many Caribbean countries. Inadequate active surveillance and misdiagnosis of human leptospirosis has contributed to under-reporting of the disease.

Conclusion

This review highlights the epidemiology and distribution of leptospirosis in the Caribbean. Prevalence rates and serovars vary greatly among the countries. Leptospirosis poses a significant health risk for humans and animals in the Caribbean and requires a "One Health" multisectoral approach to reduce incidence rates and protect at-risk individuals. Increased laboratory capacity to identify leptospirosis cases is required, along with awareness campaigns for both the public and animal and human health professionals.

Aquatic microfauna alter larval food resources and affect development and biomass of West Nile and Saint Louis encephalitis vector Culex nigripalpus (Diptera: Culicidae)

Ciliate protists and rotifers are ubiquitous in aquatic habitats and can comprise a significant portion of the microbial food resources available to larval mosquitoes, often showing substantial declines in abundance in the presence of mosquito larvae. This top‐down regulation of protists is reported to be strong for mosquitoes inhabiting small aquatic containers such as pitcher plants or tree holes, but the nature of these interactions with larval mosquitoes developing in other aquatic habitats is poorly understood. We examined the effects of these two microbial groups on lower trophic level microbial food resources, such as bacteria, small flagellates, and organic particles, in the water column, and on Culex larval development and adult production. In three independent laboratory experiments using two microeukaryote species (one ciliate protist and one rotifer) acquired from field larval mosquito habitats and cultured in the laboratory, we determined the effects of Culex nigripalpus larval grazing on water column microbial dynamics, while simultaneously monitoring larval growth and development. The results revealed previously unknown interactions that were different from the top‐down regulation of microbial groups by mosquito larvae in other systems. Both ciliates and rotifers, singly or in combination, altered other microbial populations and inhibited mosquito growth. It is likely that these microeukaryotes, instead of serving as food resources, competed with early instar mosquito larvae for microbes such as small flagellates and bacteria in a density‐dependent manner. These findings help our understanding of the basic larval biology of Culex mosquitoes, variation in mosquito production among various larval habitats, and may have implications for existing vector control strategies and for developing novel microbial‐based control methods.

[Spatial distribution of Aedes aegypti (Diptera: Culicidae) in the rural area of two municipalities of Cundinamarca, Colombia]

INTRODUCTION

It is difficult to adapt or create new strategies for dengue control in rural areas due to the dispersion of homes and the lack of knowledge about the presence and behavior of the vector in these areas. Spatial data analysis could help understand time and space dynamics related to the transmission of vector-borne diseases in rural areas and, thus, contribute to the prevention and control of dengue.

OBJECTIVE

To determine the probability of the presence of the dengue vector Aedes aegypti in the rural area of the municipalities of Anapoima and La Mesa, in the central area of Colombia.

MATERIALS AND METHODS

The probability of the presence or absence of the vector in the study area was determined by means of the kriging spatial interpolation method.

RESULTS

The region with the highest probability of the presence of the vector was located in the central part, close to the urban centers of both municipalities.

CONCLUSION

This study shows the importance of geostatistics for the surveillance of vector-borne diseases and the analysis of time and space dynamics of vector insects and of diseases transmitted by them.

Essential oils and their components as an alternative in the control of mosquito vectors of disease

More than half of the human population is exposed to mosquito-borne infections. Climate change and the emergence of strains resistant to traditionally used insecticides have motivated the search of new agents for mosquito population control. Essential oils have been effective repellents and larvicidal agents.The aim of this work was to review research studies conducted in recent years on the larvicidal activity of essential oils and their components against Aedes, Anopheles and Culex mosquitoes, as well as the latest reports about their possible mechanism of action.

Virological surveillance of Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus as support for decision making for dengue control in Medellín

INTRODUCTION

Dengue represents an important public health problem in Colombia. No treatment is available and the vaccine has not been approved in all countries, hence, actions should be strengthened to mitigate its impact through the control of Aedes aegypti, the vector mosquito. In Colombia, surveillance is done using entomological indexes and case notification, which is usually informed late, leading to untimely interventions. Viral detection in urban mosquitoes using molecular techniques provides more accurate entomological information for decision-making.

OBJECTIVE

To report results of virological surveillance in Aedes specimens collected during routine entomological activities of the Secretaría de Salud de Medellín.

MATERIALS AND METHODS

Specimens were collected during two periods in each of which we selected 18 dwellings around each one of the 250 larva traps arranged for mosquitoe surveillance, as well as 70 educational institutions and 30 health centers. Specimens were identified morphologically, and divided in pools for viral detection using reverse transcription polymerase chain reaction (RT-PCR). We calculated the minimum infection rate and the adult infestation index for each group.

RESULTS

We collected 1,507 adult mosquitoes, 10 of which were identified as A. albopictus. Out of the 407 pools, 132 (one of them Ae. albopictus) were positive, and 14.39% were A. aegypti males. The minimum infection rates for Ae. aegypti were 120.07 and 69,50 for the first and second periods, respectively, and the adult infestation index was higher in educational institutions (23.57%).

CONCLUSIONS

Using RT-PCR we identified natural infectivity and vertical transmission of dengue virus in A. aegypti and A. albopictus. We suggest the use of molecular techniques in arbovirosis surveillance and control programs in Colombia.

[Abundance, composition and natural infection of Anopheles mosquitoes from two malaria-endemic regions of Colombia]

INTRODUCTION

In Colombia there are three Anopheles species implicated in malaria transmission as primary vectors; however, the local role of some Anopheles species must still be defined.

OBJECTIVE

To determine the abundance, composition and natural infection rates for Anopheles mosquitoes with Plasmodium spp. in two malaria-endemic regions of Colombia.

MATERIALS AND METHODS

Anopheles mosquitoes were collected using the human-landing catches and while resting in livestock corrals in nine localities of two malaria-endemic regions of Colombia. Mosquitoes were morphologically identified and confirmed by PCR-RFLP-ITS2. Identified mosquitoes were processed and tested for Plasmodium parasite infection by ELISA and ssrRNA-based nested PCR.

RESULTS

We collected 1,963 Anopheles mosquitoes corresponding to nine species. The most abundant species were Anopheles nuneztovari (53.5%) and A. darlingi (34.5%), followed by A. triannulatus s.l. (6%), and other species (≈5.9%). Three species were naturally infected with Plasmodium spp.: A. darlingi, A. nuneztovari and A. triannulatus s.l.

CONCLUSIONS

Natural infection of A. darlingi and A. nuneztovari indicate that these malaria vectors continue to be effective carriers of Plasmodium in the localities under study in Valle del Cauca and Chocó. Additionally, the infected A. triannulatus s.l. collected in livestock corrals in the locality of the department of Córdoba suggests the need for further studies to define the epidemiological importance of this species given its abundance and opportunistic anthropophilic behavior.

Effects of Organic Amendments on Microbiota Associated with the Culex nigripalpus Mosquito Vector of the Saint Louis Encephalitis and West Nile Viruses

Mosquito microbiota provide important physiological and ecological attributes to mosquitoes, including an impact on their susceptibility to pathogens, fitness, and sensitivity to mosquito control agents. Culex nigripalpus mosquito populations transmit various pathogens, including the Saint Louis and West Nile viruses, and proliferate in nutrient-rich environments, such as in wastewater treatment wetlands. Our study examined whether increases in nutrients within larval mosquito developmental habitats impact microbial communities associated with C. nigripalpus mosquitoes. We characterized the effects of organic enrichments on microbiomes associated with C. nigripalpus mosquitoes and identified potential bacterial microbiota that will be further investigated for whether they alter mosquito life history traits and for their potential role in the development of microbial-based control strategies.

Pollution from nutrients in aquatic habitats has been linked to increases in disease vectors, including mosquitoes and other pestiferous insects. One possibility is that changes in mosquito microbiomes are impacted by nutrient enrichments and that these changes affect various traits, including larval development, susceptibility to larval control agents, and susceptibility of the adult mosquitoes to pathogens. We tested this hypothesis using field mesocosms supplemented with low- and high-organic-nutrient regimens and then sampled microbial communities associated with the naturally colonizing Culex nigripalpus mosquito vector. By high-throughput sequencing of 16S rRNA gene sequences, we found no significant differences in overall microbial communities associated with sampled mosquitoes, despite detecting discernible differences in environmental variables, including pH, dissolved oxygen, and nutrient amendments. Nevertheless, indicator species analysis revealed that members of the Clostridiales were significantly associated with mosquitoes that originated from high-nutrient enrichments. In contrast, members of the Burkholderiales were associated with mosquitoes from the low-nutrient enrichment. High bacterial variability associated with the life stages of the C. nigripalpus was largely unaffected by levels of nutrient enrichments that impacted larval microbial resources, including bacteria, ciliates, and flagellates in the larval environments.

IMPORTANCE Mosquito microbiota provide important physiological and ecological attributes to mosquitoes, including an impact on their susceptibility to pathogens, fitness, and sensitivity to mosquito control agents. Culex nigripalpus mosquito populations transmit various pathogens, including the Saint Louis and West Nile viruses, and proliferate in nutrient-rich environments, such as in wastewater treatment wetlands. Our study examined whether increases in nutrients within larval mosquito developmental habitats impact microbial communities associated with C. nigripalpus mosquitoes. We characterized the effects of organic enrichments on microbiomes associated with C. nigripalpus mosquitoes and identified potential bacterial microbiota that will be further investigated for whether they alter mosquito life history traits and for their potential role in the development of microbial-based control strategies.

[Diversity of Triatominae (Hemiptera: Reduviidae) in Santander, Colombia: Epidemiological implications]

INTRODUCTION

Domestic and wild triatomines in the department of Santander have an epidemiological impact, as recently they have been linked to outbreaks of acute Chagas disease. The analysis of their diversity and temporal variation contributes to the understanding of their biology and ecology in one of the most endemic areas of the country.

OBJECTIVES

To analyze triatominae diversity in two regions of Santander.

MATERIALS AND METHODS

We analyzed the triatomine records for Santander contained in the CINTROP-UIS entomology lab database. We grouped the information for two regions: the Middle Magdalena area and the Andean region, and for each one we designed species accumulation and range-abundance curves, we calculated diversity and equality indices, and we analyzed colonization and temporal variation or persistence of the community.

RESULTS

Ninety five percent of triatomines came from the Andean area and 4.57% from Magdalena Medio, with nine and ten species each. The dominant species in the Andean area were Rhodnius prolixus and Triatoma dimidiata while in Magdalena Medio they were Rhodnius pallescens and Panstrongylus geniculatus. We found a greater diversity and richness in Middle Magdalena compared to the Andean area. The temporal variation showed persistence of communities over time.

CONCLUSIONS

Results revealed differences in the diversity of the two regions and the potential of wild species to occupy artificial ecotopes. Triatomines intrusion and the recent involvement of wild species in the transmission of Trypanosoma cruzi emphasize the need to further investigate the ecology of these vectors in order to guide population control strategies.

Local and Landscape Constraints on Coffee Leafhopper (Hemiptera: Cicadellidae) Diversity

The intensification of agriculture drives many ecological and environmental consequences including impacts on crop pest populations and communities. These changes are manifested at multiple scales including small-scale management practices and changes to the composition of land-use types in the surrounding landscape. In this study, we sought to examine the influence of local and landscape-scale agricultural factors on a leafhopper herbivore community in Mexican coffee plantations. We sampled leafhopper (Hemiptera: Cicadellidae) diversity in 38 sites from 9 coffee plantations of the Soconusco region of Chiapas, Mexico. While local management factors such as coffee density, branches per coffee bush, tree species, and density were not important in explaining leafhopper abundance and richness, shade management at the landscape level and elevation significantly affected leafhoppers. Specifically, the percentage of low-shade coffee in the landscape (1,000-m radius surrounding sites) increased total leafhopper abundance. In addition, Shannon's diversity of leafhoppers was increased with coffee density. Our results show that abundance and diversity of leafhoppers are greater in simplified landscapes, thereby suggesting that these landscapes will have higher pest pressure and may be more at-risk for diseases vectored by these species in an economically important crop.

[Tick-borne diseases in Poland: Prevalence and difficulties in diagnostics]

The article presents an overview of diagnostics of tick-borne diseases in Poland, which form one of the most prevalent group of occupational illnesses in the Polish area. This is a current issue due to a constantly growing number of tick-borne infections, i.e., Lyme borreliosis, tick-borne encephalitis, tularemia, Q fever, human granulocytic anaplasmosis and babesiosis. The scale of the problem is well illustrated by the latest reports of the Polish National Institute of Public Health - National Institute of Hygiene (NIPH - NIH). The article also covers the taxonomy of vectors of etiological factors, as well as their reservoirs and possible transmission to humans. The highest risk of tick-borne infection is particularly connected with people either resting or working in the forest or meadow surroundings (i.e., foresters, farmers, hunters). The article contains up-to-date data on epidemiology, etiopathogenesis, symptomatology, laboratory medicine and factors affecting the credibility of results according to current recommendations of the Polish Society of Epidemiology and Physicians of Infectious Diseases and the Polish National Chamber of Laboratory Diagnosticians. The presented review focuses on modern laboratory techniques used in difficult diagnostics of tick-borne diseases, mainly diagnostics algorithms, pre-analytical phase (type of biological material) and analytical phase of diagnostics (reference methods, efficacy of different techniques, interfering factors, proper diagnostic procedures).

Finding Aedes aegypti in a natural breeding site in an urban zone, Sao Paulo, Southeastern Brazil

This is the description of how nine Aedes aegypti larvae were found in a natural breeding site in the Pinheiros neighborhood, city of Sao Paulo, SP, Southeastern Brazil. The record was conducted in December 2014, during an entomological surveillance program of dengue virus vectors, with an active search of potential breeding sites, either artificial or natural. FindingAe. aegypti larvae in a tree hole shows this species' ability to use both artificial and natural environments as breeding sites and habitats, which points towards the importance of maintaining continuous surveillance on this mosquito in all kinds of water-holding containers.

Prevalence of anti-Trypanosoma cruzi antibodies in women of childbearing age in Socotá, Boyacá, 2014

INTRODUCTION

Chagas' disease is a parasitic disease caused by the protozoan Trypanosoma cruzi. This condition presents epidemiological risk factors associated with socioeconomic conditions and is currently considered an important public health problem. Its presence has been reported in endemic regions at elevations of up to 2,000 meters above sea level. 

OBJECTIVE

To determine the prevalence of anti-T. cruzi antibodies and the possible risk factors associated with this condition in women of childbearing age from the town of Socotá, Boyacá. 

MATERIALS AND METHODS

An observational, descriptive cross-sectional study was conducted in a population of women of childbearing age from Socotá, Boyacá. The samples were analyzed by Chagas ELISA IgG and IgM test and indirect hemagglutination test. A univariate analysis and statistical association of variables were performed. 

RESULTS

A confirmed prevalence of 2/138 (1.4%) was found in this town. Having pets or a history of contact with vectors were possible associated risk factors although without statistical significance. 

CONCLUSIONS

From the results obtained in the present study, it is suggested that more active research be carried out for cases of Chagas' disease in non-endemic areas in Colombia that present risk factors for acquiring the disease, even when the environmental conditions and elevation differ from those described in the literature.

Our Warming Planet: Is the HIV-1-Infected Population in the Crosshairs

Global climate change exacerbated by human energy use threatens to have a profound impact on human health, including from infectious diseases. Particularly vulnerable populations include the immunocompromised, including persons with HIV infection. Global warming can be expected to increase the geographic range of pathogens such as Vibrio cholerae as well as vectors that transmit disease, including ticks and mosquitoes. Higher temperatures also contribute to increased pathogen and vector efficiency in spreading disease. Natural disasters due to climate change result in population displacement, increased population density, and living conditions conducive to the spread of infectious diseases. Political mobilization is crucial to implementing and enforcing policies for prudent energy use, reversing the drivers of global warming, and ensuring that we are prepared for the adverse health consequences of climate change. This article summarizes a presentation by Robert T. Schooley, MD, at the IAS-USA continuing education program held in Berkeley in May 2017.

The mermithid species Isomermislairdi (Nematoda, Mermithidae), previously only known in Africa, found in Europe

The present work contributs to the knowledge on the aquatic mermithids (Nematoda, Mermithidae) occurring in black flies – an insufficiently studied group of parasitic nematodes. Isomermislairdi Mondet, Poinar & Bernadou, 1977, described from larvae of Simuliumdamnosum Theobald, 1903 in Western Africa, is reported to occur in Bulgaria. The species was isolated from larvae of Simuliumornatum Meigen, 1818 in a local population of simuliids in a mountain stream near Jeleznitsa Village, Sofia district. Postparasitic juveniles of mermithids were obtained from the hosts and reared to the adult stage. The species was identified by morphological and morphometrical characters of postparasitic juveniles, and of male and female individuals. In the summer of 2012 a relatively high rate of mermithid infection in a local host population was detected (prevalence up to 44.1%). In August of the next year host abundance had considerably declined and other simuliid species, Simuliumvariegatum Meigen, 1818 and Simuliumreptans (Linnaeus, 1758), predominated in the investigated locality. In West Africa, Isomermislairdi is considered to be a potential biological agent for reducing the population density of the Simuliumdamnosum complex – the main vector of human onchocerciasis. In Europe, species of the Simuliumornatum complex are among the vectors of onchocerciasis of cattle and deer. The mermithids presumably play a certain role in the epidemiology of these diseases. A brief discussion on the taxonomy of the genus Isomermis Coman, 1953, and of the feasibility of molecular methods in mermithid taxonomy is provided. The species Isomermislairdi is reported for the first time from Europe.

Invasion biology of Aedes japonicus japonicus (Diptera: Culicidae)

Aedes japonicus japonicus (Theobald) (Diptera: Culicidae) has recently expanded beyond its native range of Japan and Korea into large parts of North America and Central Europe. Population genetic studies begun immediately after the species was detected in North America revealed genetically distinct introductions that subsequently merged, likely contributing to the successful expansion. Interactions, particularly in the larval stage, with other known disease vectors give this invasive subspecies the potential to influence local disease dynamics. Its successful invasion likely does not involve superior direct competitive abilities, but it is associated with the use of diverse larval habitats and a cold tolerance that allows an expanded seasonal activity range in temperate climates. We predict a continued but slower expansion of Ae. j. japonicus in North America and a continued rapid expansion into other areas as this mosquito will eventually be considered a permanent resident of much of North America, Europe, Asia, and parts of Hawaii.

Mosquito larval source management for controlling malaria

BACKGROUND

Malaria is an important cause of illness and death in people living in many parts of the world, especially sub-Saharan Africa. Long-lasting insecticide treated bed nets (LLINs) and indoor residual spraying (IRS) reduce malaria transmission by targeting the adult mosquito vector and are key components of malaria control programmes. However, mosquito numbers may also be reduced by larval source management (LSM), which targets mosquito larvae as they mature in aquatic habitats. This is conducted by permanently or temporarily reducing the availability of larval habitats (habitat modification and habitat manipulation), or by adding substances to standing water that either kill or inhibit the development of larvae (larviciding).

OBJECTIVES

To evaluate the effectiveness of mosquito LSM for preventing malaria.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; CABS Abstracts; and LILACS up to 24 October 2012. We handsearched the Tropical Diseases Bulletin from 1900 to 2010, the archives of the World Health Organization (up to 11 February 2011), and the literature database of the Armed Forces Pest Management Board (up to 2 March 2011). We also contacted colleagues in the field for relevant articles.

SELECTION CRITERIA

We included cluster randomized controlled trials (cluster-RCTs), controlled before-and-after trials with at least one year of baseline data, and randomized cross-over trials that compared LSM with no LSM for malaria control. We excluded trials that evaluated biological control of anopheline mosquitoes with larvivorous fish.

DATA COLLECTION AND ANALYSIS

At least two authors assessed each trial for eligibility. We extracted data and at least two authors independently determined the risk of bias in the included studies. We resolved all disagreements through discussion with a third author. We analyzed the data using Review Manager 5 software.

MAIN RESULTS

We included 13 studies; four cluster-RCTs, eight controlled before-and-after trials, and one randomized cross-over trial. The included studies evaluated habitat modification (one study), habitat modification with larviciding (two studies), habitat manipulation (one study), habitat manipulation plus larviciding (two studies), or larviciding alone (seven studies) in a wide variety of habitats and countries. Malaria incidenceIn two cluster-RCTs undertaken in Sri Lanka, larviciding of abandoned mines, streams, irrigation ditches, and rice paddies reduced malaria incidence by around three-quarters compared to the control (RR 0.26, 95% CI 0.22 to 0.31, 20,124 participants, two trials, moderate quality evidence). In three controlled before-and-after trials in urban and rural India and rural Kenya, results were inconsistent (98,233 participants, three trials, very low quality evidence). In one trial in urban India, the removal of domestic water containers together with weekly larviciding of canals and stagnant pools reduced malaria incidence by three quarters. In one trial in rural India and one trial in rural Kenya, malaria incidence was higher at baseline in intervention areas than in controls. However dam construction in India, and larviciding of streams and swamps in Kenya, reduced malaria incidence to levels similar to the control areas. In one additional randomized cross-over trial in the flood plains of the Gambia River, where larval habitats were extensive and ill-defined, larviciding by ground teams did not result in a statistically significant reduction in malaria incidence (2039 participants, one trial). Parasite prevalenceIn one cluster-RCT from Sri Lanka, larviciding reduced parasite prevalence by almost 90% (RR 0.11, 95% CI 0.05 to 0.22, 2963 participants, one trial, moderate quality evidence). In five controlled before-and-after trials in Greece, India, the Philippines, and Tanzania, LSM resulted in an average reduction in parasite prevalence of around two-thirds (RR 0.32, 95% CI 0.19 to 0.55, 8041 participants, five trials, moderate quality evidence). The interventions in these five trials included dam construction to reduce larval habitats, flushing of streams, removal of domestic water containers, and larviciding. In the randomized cross-over trial in the flood plains of the Gambia River, larviciding by ground teams did not significantly reduce parasite prevalence (2039 participants, one trial).

AUTHORS' CONCLUSIONS

In Africa and Asia, LSM is another policy option, alongside LLINs and IRS, for reducing malaria morbidity in both urban and rural areas where a sufficient proportion of larval habitats can be targeted. Further research is needed to evaluate whether LSM is appropriate or feasible in parts of rural Africa where larval habitats are more extensive.

Meeting the challenges of on-host and off-host water balance in blood-feeding arthropods

In this review, we describe water balance requirements of blood-feeding arthropods, particularly contrasting dehydration tolerance during the unfed, off-host state and the challenges of excess water that accompany receipt of the bloodmeal. Most basic water balance characteristics during the off-host stage are applicable to other terrestrial arthropods, as well. A well-coordinated suite of responses enable arthropods to conserve water resources, enhance their desiccation tolerance, and increase their water supplies by employing a diverse array of molecular, structural and behavioral responses. Water loss rates during the off-host phase are particularly useful for generating a scheme to classify vectors according to their habitat requirements for water, thus providing a convenient tool with potential predictive power for defining suitable current and future vector habitats. Blood-feeding elicits an entirely different set of challenges as the vector responds to overhydration by quickly increasing its rate of cuticular water loss and elevating the rate of diuresis to void excess water and condense the bloodmeal. Immature stages that feed on blood normally have a net increase in water content at the end of a blood-feeding cycle, but in adults the water content reverts to the pre-feeding level when the cycle is completed. Common themes are evident in diverse arthropods that feed on blood, particularly the physiological mechanisms used to respond to the sudden influx of water as well as the mechanisms used to counter water shortfalls that are encountered during the non-feeding, off-host state.

Ecology of invasive mosquitoes: effects on resident species and on human health

Investigations of biological invasions focus on patterns and processes that are related to introduction, establishment, spread and impacts of introduced species. This review focuses on the ecological interactions operating during invasions by the most prominent group of insect vectors of disease, mosquitoes. First, we review characteristics of non-native mosquito species that have established viable populations, and those invasive species that have spread widely and had major impacts, testing whether biotic characteristics are associated with the transition from established non-native to invasive. Second, we review the roles of interspecific competition, apparent competition, predation, intraguild predation and climatic limitation as causes of impacts on residents or as barriers to invasion. We concentrate on the best-studied invasive mosquito, Aedes albopictus, evaluating the application of basic ecological theory to invasions by Aedes albopictus. We develop a model based on observations of Aedes albopictus for effects of resource competition and predation as barriers to invasion, evaluating which community and ecosystem characteristics favour invasion. Third, we evaluate the ways in which invasive mosquitoes have contributed to outbreaks of human and animal disease, considering specifically whether invasive mosquitoes create novel health threats, or modify disease transmission for existing pathogen-host systems.

The availability of potential hosts as a determinant of feeding behaviours and malaria transmission by African mosquito populations

A simple model for the influence of host availability on vector bloodmeal choice is applied to estimate the relative availabilities of humans, cattle and other host populations to malaria vectors in African communities, using published human blood indices and ratios of cattle to humans. Cattle were bitten < 0.01, 0.021 +/- 0.11, 1.61 +/- 0.16 and 1.61 +/- 0.46 times as often as humans by Anopheles funestus, An. gambiae sensu stricto and An. arabiensis in Segera, Tanzania, and An. gambiae sensu lato in The Gambia, respectively. No significant feeding upon host species other than cattle or humans was detected. Even though An. gambiae s.l. in The Gambia were mostly An. gambiae s.s., they were 77 times more likely to choose cattle over humans than An. gambiae s.s. in Tanzania. The model accurately predicted cattle blood indices for the An. arabiensis population in Tanzania (predicted = 0.99 +/- 0.21 x observed + 0.00 +/- 0.10; r2 = 0.66). The potential effect of increased cattle abundance upon malaria transmission intensity was simulated using fitted relative availability parameters and assuming vector emergence rate, feeding cycle length and survivorship were unaffected. The model predicted that increased cattle populations would not affect malaria transmission in Tanzania but could drastically reduce transmission in The Gambia or where An. arabiensis is the dominant vector. We define the availability of a host as the rate at which a typical individual host-seeking vector encounters and feeds upon that host in a single feeding cycle. Mathematical models based on this definition also represent promising tools for quantifying the dependence of vector longevity, feeding cycle length and dispersal upon host availability.