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1.
Mem. Inst. Oswaldo Cruz ; 115: e200070, 2020. tab, graf
Article in English | SES-SP, LILACS, SES-SP | ID: biblio-1135278

ABSTRACT

BACKGROUND Nyssorhynchus deaneorum is a potential malaria vector because it has been shown to be competent to transmit Plasmodium vivax and Plasmodium falciparum, and because it exhibits antropophilic and endophilic behaviors in some regions of the Amazon. This profile makes Ny. deaneorum a useful mosquito for experiments that model Plasmodium-vector interactions in the Amazon. OBJECTIVE Herein we describe how a free-mating colony of Ny. deaneorum has been established using an automated light stimulation system. METHODS Mosquitoes were captured in São Francisco do Guaporé, Rondônia. The F1 generation was reared until adult emergence at which point copulation was induced using an automatic copulation induction system (ACIS). FINDINGS After four generations, natural mating and oviposition began to occur without light stimulation. The number of pupae and adult mosquitoes increased from the F5 to F10 generations. The new Ny. deaneorum colony exhibited susceptibility to P. vivax. MAIN CONCLUSIONS Automated light stimulation is an effective method for establishing an Ny. deaneorum colony under laboratory conditions as it produces enough adults to create a stenogamic colony. The establishment of a stable, P. vivax-susceptible colony of Ny. deaneorum makes it possible to model parasite-vector interactions and to test novel drug therapies that target parasite development in mosquitoes.


Subject(s)
Animals , Female , Oviposition , Copulation/physiology , Mosquito Vectors/parasitology , Insect Vectors/growth & development , Malaria , Anopheles/parasitology , Plasmodium falciparum , Plasmodium vivax , Brazil , Insect Vectors/physiology , Anopheles/physiology
2.
Mem. Inst. Oswaldo Cruz ; 115: e200043, 2020. tab, graf
Article in English | SES-SP, LILACS, SES-SP | ID: biblio-1135250

ABSTRACT

BACKGROUND The number of malaria cases in Roraima nearly tripled from 2016 to 2018. The capital, Boa Vista, considered a low-risk area for malaria transmission, reported an increasing number of autochthonous and imported cases. OBJECTIVES This study describes a spatial analysis on malaria cases in an urban region of Boa Vista, which sought to identify the autochthonous and imported cases and associated them with Anopheles habitats and the potential risk of local transmission. METHODS In a cross-sectional study at the Polyclinic Cosme e Silva, 520 individuals were interviewed and diagnosed with malaria by microscopic examination. Using a global positional system, the locations of malaria cases by type and origin and the breeding sites of anopheline vectors were mapped and the risk of malaria transmission was evaluated by spatial point pattern analysis. FINDINGS Malaria was detected in 57.5% of the individuals and there was a disproportionate number of imported cases (90.6%) linked to Brazilian coming from gold mining sites in Venezuela and Guyana. MAIN CONCLUSIONS The increase in imported malaria cases circulating in the west region of Boa Vista, where there are positive breeding sites for the main vectors, may represent a potential condition for increased autochthonous malaria transmission in this space.


Subject(s)
Humans , Animals , Male , Female , Adult , Plasmodium/isolation & purification , Travel , Miners/statistics & numerical data , Mosquito Vectors/parasitology , Malaria/diagnosis , Malaria/transmission , Anopheles/parasitology , Plasmodium/classification , Urban Population , Venezuela , Brazil/epidemiology , Cross-Sectional Studies , Geographic Information Systems , Spatial Analysis , Gold , Guyana , Malaria/parasitology , Malaria/epidemiology , Anopheles/classification , Middle Aged
3.
Rev. Soc. Bras. Med. Trop ; 52: e20190308, 2019. graf
Article in English | LILACS | ID: biblio-1057242

ABSTRACT

Abstract Malaria, a mosquito-borne infectious disease, is considered a significant global health burden. Climate changes or different weather conditions may impact infectious diseases, specifically those transmitted by insect vectors and contaminated water. Based on the current predictions for climate change associated with the increase in carbon dioxide concentrations in the atmosphere and the increase in atmospheric temperature, the Intergovernmental Panel on Climate Change predicts that in 2050, malaria may threaten some previously unexposed areas worldwide and cause a 50% higher probability of malaria cases. Climate-based distribution models of malaria depict an increase in the geographic distribution of the disease as global environmental temperatures and conditions worsen. Researchers have studied the influence of changes in climate on the prevalence of malaria using different mathematical models that consider different variables and predict the conditions for malaria distribution. In this context, we conducted a mini-review to elucidate the important aspects described in the literature on the influence of climate change in the distribution and transmission of malaria. It is important to develop possible risk management strategies and enhance the surveillance system enhanced even in currently malaria-free areas predicted to experience malaria in the future.


Subject(s)
Animals , Climate Change , Mosquito Vectors/parasitology , Malaria/transmission , Anopheles/parasitology , Population Dynamics , Models, Biological
4.
Mem. Inst. Oswaldo Cruz ; 113(2): 111-118, Feb. 2018. tab, graf
Article in English | SES-SP, LILACS, SES-SP | ID: biblio-894892

ABSTRACT

BACKGROUND In southeastern Brazil, autochthonous cases of malaria can be found near Atlantic Forest fragments. Because the transmission cycle has not been completely clarified, the behaviour of the possible vectors in those regions must be observed. A study concerning the entomological aspects and natural infection of anophelines (Diptera: Culicidae) captured in the municipalities of the mountainous region of Espírito Santo state was performed in 2004 and 2005. Similarly, between 2014 and 2015, 12 monthly collections were performed at the same area of the study mentioned above. METHODS Center for Disease Control (CDC) light traps with CO2 were set in open areas, at the edge and inside of the forest (canopy and ground), whereas Shannon traps were set on the edge. FINDINGS A total of 1,414 anophelines were collected from 13 species. Anopheles (Kerteszia) cruzii Dyar and Knab remained the most frequently captured species in the CDC traps set in the forest canopy, as well as being the vector with the highest prevalence of Plasmodium vivax/simium infection, according to molecular polymerase chain reaction techniques. CONCLUSIONS P. vivax/simium was found only in abdomens of the mosquitoes of the subgenus Nyssorhynchus, weakening the hypothesis that this subgenus also plays a role in malaria transmission in this specific region.


Subject(s)
Mosquito Vectors/parasitology , Malaria/transmission , Anopheles/classification , Anopheles/parasitology , Brazil , Forests , Population Density , Malaria
5.
Mem. Inst. Oswaldo Cruz ; 113(2): 87-95, Feb. 2018. tab, graf
Article in English | LILACS | ID: biblio-894897

ABSTRACT

BACKGROUND Studies on malaria vectors in the Pantanal biome, Central Brazil, were conducted more than half a century ago. OBJECTIVES To update anopheline records and assess receptivity and vulnerability to malaria transmission. METHODS Five-day anopheline collections were conducted bimonthly in Salobra, Mato Grosso do Sul state, for one year. Indoors, mosquitoes were collected from their resting places, while in open fields, they were captured using protected human-baited and horse-baited traps near the house and at the Miranda River margin, respectively. Hourly biting activity outdoors was also assessed. Secondary data were collected on the arrival of tourists, economic projects, and malaria cases. FINDINGS A total of 24,894 anophelines belonging to 13 species were caught. The main Brazilian malaria vector Anopheles darlingi was the predominant species, followed by An. triannulatus s.l. Hourly variation in anopheline biting showed three main peaks occurring at sunset, around midnight, and at sunrise, the first and last being the most prominent. The highest density of all species was recorded near the river margin and during the transition period between the rainy and early dry seasons. This coincides with the time of main influx of outsider workers and tourists, whose activities mostly occur in the open fields and frequently start before sunrise and last until sunset. Some of these individuals originate from neighbouring malaria-endemic countries and states, and are likely responsible for the recorded imported and introduced malaria cases. MAIN CONCLUSION Pantanal is a malaria-prone area in Brazil. Surveillance and anopheline control measures must be applied to avoid malaria re-emergence in the region.


Subject(s)
Animals , Oviposition , Malaria/transmission , Anopheles/classification , Anopheles/physiology , Mosquito Vectors , Anopheles/parasitology
6.
Rev. Soc. Bras. Med. Trop ; 50(3): 388-390, May-June 2017. graf
Article in English | LILACS | ID: biblio-1041408

ABSTRACT

Abstract INTRODUCTION: The muscoid fly Dermatobia hominis causes cutaneous myiases in mammals. Females of this species use a vector to carry their eggs to the host. This note describes Anopheles konderi acting as phoretic vector for D. hominis. METHODS: A female A. konderi carrying D. hominis was collected using light traps in Oriximiná, Pará, Brazil. The A. konderi specimen was identified at morphological and molecular levels. RESULTS: Eight eggs of D. hominis were observed on the Anopheles konderi female. CONCLUSIONS: Anopheles konderi, only the third Anopheles species recorded as a phoretic vector, may be a potential vector of D. hominis.


Subject(s)
Animals , Female , Anopheles/parasitology , Ovum , Symbiosis , Brazil , Diptera/growth & development , Anopheles/classification
7.
Mem. Inst. Oswaldo Cruz ; 111(9): 561-569, Sept. 2016. tab, graf
Article in English | LILACS | ID: lil-794724

ABSTRACT

In French Guiana, malaria vector control and prevention relies on indoor residual spraying and distribution of long lasting insecticidal nets. These measures are based on solid epidemiological evidence but reveal a poor understanding of the vector. The current study investigated the behaviour of both vectors and humans in relation to the ongoing prevention strategies. In 2012 and 2013, Anopheles mosquitoes were sampled outdoors at different seasons and in various time slots. The collected mosquitoes were identified and screened for Plasmodium infection. Data on human behaviour and malaria episodes were obtained from an interview. A total of 3,135 Anopheles mosquitoes were collected, of which Anopheles darlingi was the predominant species (96.2%). For the December 2012-February 2013 period, the Plasmodium vivax infection rate for An. darlingi was 7.8%, and the entomological inoculation rate was 35.7 infective bites per person per three-month span. In spite of high bednet usage (95.7%) in 2012 and 2013, 52.2% and 37.0% of the participants, respectively, had at least one malaria episode. An. darlingi displayed heterogeneous biting behaviour that peaked between 20:30 and 22:30; however, 27.6% of the inhabitants were not yet protected by bednets by 21:30. The use of additional individual and collective protective measures is required to limit exposure to infective mosquito bites and reduce vector densities.


Subject(s)
Humans , Animals , Female , Anopheles/physiology , Insect Bites and Stings , Insect Vectors/physiology , Anopheles/classification , Anopheles/parasitology , Forests , French Guiana , Insect Vectors/classification , Insect Vectors/parasitology , Malaria, Falciparum/transmission , Malaria, Vivax/transmission , Population Density , Seasons , Species Specificity
8.
Mem. Inst. Oswaldo Cruz ; 110(4): 573-576, 09/06/2015. tab, graf
Article in English | LILACS | ID: lil-748860

ABSTRACT

We describe a simple method for detection of Plasmodium vivax and Plasmodium falciparum infection in anophelines using a triplex TaqMan real-time polymerase chain reaction (PCR) assay (18S rRNA). We tested the assay on Anopheles darlingi and Anopheles stephensi colony mosquitoes fed with Plasmodium-infected blood meals and in duplicate on field collected An. darlingi. We compared the real-time PCR results of colony-infected and field collected An. darlingi, separately, to a conventional PCR method. We determined that a cytochrome b-PCR method was only 3.33% as sensitive and 93.38% as specific as our real-time PCR assay with field-collected samples. We demonstrate that this assay is sensitive, specific and reproducible.


Subject(s)
Animals , Anopheles/parasitology , Insect Vectors/parasitology , Plasmodium falciparum/genetics , Plasmodium vivax/genetics , Real-Time Polymerase Chain Reaction , Cytochromes b/genetics , Plasmodium falciparum/isolation & purification , Plasmodium vivax/isolation & purification , Reproducibility of Results , Sensitivity and Specificity
9.
Article in English | WPRIM | ID: wpr-130562

ABSTRACT

Wuchereria bancrofti, Dirofilaria immitis, and Dirofilaria repens are filarial nematodes transmitted by mosquitoes belonging to Culex, Aedes, and Anopheles genera. Screening by vector dissection is a tiresome technique. We aimed to screen filarial parasites in their vectors by single and multiplex PCR and evaluate the usefulness of multiplex PCR as a rapid xenomonitoring and simultaneous differentiation tool, in area where 3 filarial parasites are coexisting. Female mosquitoes were collected from 7 localities in Assiut Governorate, were microscopically identified and divided into pools according to their species and collection site. Detection of W. bancrofti, D. immitis, and D. repens using single PCR was reached followed by multiplex PCR. Usefulness of multiplex PCR was evaluated by testing mosquito pools to know which genera and species are used by filarial parasites as a vector. An overall estimated rate of infection (ERI) in mosquitoes was 0.6%; the highest was Culex spp. (0.47%). W. bancrofti, D. immitis, and D. repens could be simultaneously and differentially detected in infected vectors by using multiplex PCR. Out of 100 mosquito pools, 8 were positive for W. bancrofti (ERI of 0.33%) and 3 pools each were positive for D. immitis and D. repens (ERI 0.12%). The technique showed 100% sensitivity and 98% specificity. El-Nikhila, El-Matiaa villages, and Sahel Seleem district in Assiut Governorate, Egypt are still endemic foci for filarial parasites. Multiplex PCR offers a reliable procedure for molecular xenomonitoring of filariasis within their respective vectors in endemic areas. Therefore, it is recommended for evaluation of mosquito infection after lymphatic filariasis eradication programs.


Subject(s)
Aedes/parasitology , Animals , Anopheles/parasitology , Culex/parasitology , Dirofilaria immitis/genetics , Dirofilaria repens/genetics , Egypt , Entomology/methods , Female , Multiplex Polymerase Chain Reaction/methods , Parasitology/methods , Sensitivity and Specificity , Wuchereria bancrofti/genetics
10.
Article in English | WPRIM | ID: wpr-130555

ABSTRACT

Wuchereria bancrofti, Dirofilaria immitis, and Dirofilaria repens are filarial nematodes transmitted by mosquitoes belonging to Culex, Aedes, and Anopheles genera. Screening by vector dissection is a tiresome technique. We aimed to screen filarial parasites in their vectors by single and multiplex PCR and evaluate the usefulness of multiplex PCR as a rapid xenomonitoring and simultaneous differentiation tool, in area where 3 filarial parasites are coexisting. Female mosquitoes were collected from 7 localities in Assiut Governorate, were microscopically identified and divided into pools according to their species and collection site. Detection of W. bancrofti, D. immitis, and D. repens using single PCR was reached followed by multiplex PCR. Usefulness of multiplex PCR was evaluated by testing mosquito pools to know which genera and species are used by filarial parasites as a vector. An overall estimated rate of infection (ERI) in mosquitoes was 0.6%; the highest was Culex spp. (0.47%). W. bancrofti, D. immitis, and D. repens could be simultaneously and differentially detected in infected vectors by using multiplex PCR. Out of 100 mosquito pools, 8 were positive for W. bancrofti (ERI of 0.33%) and 3 pools each were positive for D. immitis and D. repens (ERI 0.12%). The technique showed 100% sensitivity and 98% specificity. El-Nikhila, El-Matiaa villages, and Sahel Seleem district in Assiut Governorate, Egypt are still endemic foci for filarial parasites. Multiplex PCR offers a reliable procedure for molecular xenomonitoring of filariasis within their respective vectors in endemic areas. Therefore, it is recommended for evaluation of mosquito infection after lymphatic filariasis eradication programs.


Subject(s)
Aedes/parasitology , Animals , Anopheles/parasitology , Culex/parasitology , Dirofilaria immitis/genetics , Dirofilaria repens/genetics , Egypt , Entomology/methods , Female , Multiplex Polymerase Chain Reaction/methods , Parasitology/methods , Sensitivity and Specificity , Wuchereria bancrofti/genetics
11.
Mem. Inst. Oswaldo Cruz ; 109(5): 662-667, 19/08/2014. graf
Article in English | LILACS | ID: lil-720425

ABSTRACT

Plasmodium falciparum originated in Africa, dispersed around the world as a result of human migration and had to adapt to several different indigenous anopheline mosquitoes. Anophelines from the New World are evolutionary distant form African ones and this probably resulted in a more stringent selection of Plasmodium as it adapted to these vectors. It is thought that Plasmodium has been genetically selected by some anopheline species through unknown mechanisms. The mosquito immune system can greatly limit infection and P. falciparum evolved a strategy to evade these responses, at least in part mediated by Pfs47, a highly polymorphic gene. We propose that adaptation of P. falciparum to new vectors may require evasion of their immune system. Parasites with a Pfs47 haplotype compatible with the indigenous mosquito vector would be able to survive and be transmitted. The mosquito antiplasmodial response could be an important determinant of P. falciparum population structure and could affect malaria transmission in the Americas.


Subject(s)
Animals , Humans , Anopheles/parasitology , Insect Vectors/parasitology , Plasmodium falciparum/physiology , Adaptation, Physiological/genetics , Adaptation, Physiological/immunology , Anopheles/classification , Anopheles/immunology , Host-Parasite Interactions/genetics , Immune Evasion , Insect Vectors/classification , Membrane Glycoproteins/genetics , Plasmodium falciparum/genetics , Protozoan Proteins/genetics
12.
Mem. Inst. Oswaldo Cruz ; 109(5): 668-671, 19/08/2014. graf
Article in English | LILACS | ID: lil-720428

ABSTRACT

Eicosanoids affect the immunity of several pathogen/insect models, but their role on the Anopheles gambiae response to Plasmodium is still unknown. Plasmodium berghei-infected mosquitoes were injected with an eicosanoid biosynthesis inhibitor, indomethacin (IN), or a substrate, arachidonic acid (AA), at day 7 or day 12 post-infection (p.i.). Salivary gland invasion was evaluated by sporozoite counts at day 21 p.i. IN promoted infection upon sporozoite release from oocysts, but inhibited infection when sporozoites were still maturing within the oocysts, as observed by a reduction in the number of sporozoites reaching the salivary glands. AA treatment had the opposite effect. We show for the first time that An. gambiae can modulate parasite survival through eicosanoids by exerting an antagonistic or agonistic effect on the parasite, depending on its stage of development.


Subject(s)
Animals , Anopheles/parasitology , Eicosanoids/pharmacology , Insect Vectors/parasitology , Oocysts/drug effects , Plasmodium berghei/drug effects , Salivary Glands/parasitology , Anopheles/drug effects , Arachidonic Acid/pharmacology , Indomethacin/antagonists & inhibitors , Indomethacin/pharmacology , Oocysts/growth & development , Plasmodium berghei/physiology
13.
Mem. Inst. Oswaldo Cruz ; 109(5): 644-661, 19/08/2014. graf
Article in English | LILACS | ID: lil-720429

ABSTRACT

Nearly one million people are killed every year by the malaria parasite Plasmodium. Although the disease-causing forms of the parasite exist only in the human blood, mosquitoes of the genus Anopheles are the obligate vector for transmission. Here, we review the parasite life cycle in the vector and highlight the human and mosquito contributions that limit malaria parasite development in the mosquito host. We address parasite killing in its mosquito host and bottlenecks in parasite numbers that might guide intervention strategies to prevent transmission.


Subject(s)
Animals , Humans , Anopheles/parasitology , Insect Vectors/parasitology , Life Cycle Stages/physiology , Plasmodium/growth & development , Anopheles/classification , Host-Parasite Interactions/physiology , Insect Vectors/classification , Malaria/transmission , Plasmodium/physiology
14.
Belo Horizonte; s.n; 2014. XX, 90 p.
Thesis in Portuguese | ColecionaSUS, LILACS, ColecionaSUS | ID: biblio-940884

ABSTRACT

A malária é um problema de saúde pública. O Brasil é o país sul-americano que mais casos aporta todo ano, a maioria deles ocorridos na região Amazônica. Até o presente não há nenhuma vacina eficaz contra a malária. O controle dessa doença baseia-se principalmente no combate vetorial. Um dos desafios atuais é encontrar novas moléculas úteis para bloquear a transmissão da malária no vetor, sendo necessário para isso conhecer a biologia da interação entre os parasitos e seus hospedeiros. A maioria dos grupos de pesquisa utiliza como modelos de laboratórios combinações não naturais de Anopheles – Plasmodium. Neste trabalho foi avaliada a suscetibilidade ao P. vivax em espécies Amazônicas de Anopheles, fêmeas de Anopheles darlingi, An. albitarsis s.l., An. nuneztovari s.l. e An. triannulatus s.l. e An.aquasalis foram infectadas com P. vivax utilizando um sistema de infecção experimental por membrana artificial.


Todas as espécies de Anopheles estudadas foram suscetíveis à infecção por P. vivax, porém a taxa de infecção e o numero de oocistos variaram significativamente entre elas. An. aquasalis (Spearman rho = 0.255, n = 386, p < 0.01) e An. darlingi (rho =0.518; n = 54, p < 0.01) mostraram uma correlação positiva entre o número de gametócitos e o número de oocistos formados. Também foi avaliada a via JAK/STAT de resposta imune em A. aquasalis, durante a fase tardia da infecção, e em A. darlingi, no início da infecção. A expressão dos genes STAT, PIAS e NOS foi avaliada por q-PCR. Em An. aquasalis a expressão dos genes estudados foi induzida a partir de 8 dPI (PIAS e NOS) e 12 dPI (STAT),e começou a diminuir aos 14dPI, provavelmente indicando a indução transitória desses genes na fase tardia da infecção. Em An. darlingi não foi observada a ativação dessa via imune durante a fase inicial da infecção com P. vivax. Estudos futuros devem ser realizados para saber de que forma os genes regulados pela via JAK/STAT podem modular o desenvolvimento do P. vivax em An. aquasalis, e outras vias de sinalização devem ser estudadas na resposta de An. darlingi à infecção pelo Plasmodium.


Subject(s)
Animals , Anopheles/parasitology , Host-Parasite Interactions/immunology , Malaria/prevention & control , Plasmodium vivax/pathogenicity
15.
Belo Horizonte; s.n; 2014. XX, 90 p.
Thesis in Portuguese | LILACS | ID: lil-760547

ABSTRACT

A malária é um problema de saúde pública. O Brasil é o país sul-americano que mais casos aporta todo ano, a maioria deles ocorridos na região Amazônica. Até o presente não há nenhuma vacina eficaz contra a malária. O controle dessa doença baseia-se principalmente no combate vetorial. Um dos desafios atuais é encontrar novas moléculas úteis para bloquear a transmissão da malária no vetor, sendo necessário para isso conhecer a biologia da interação entre os parasitos e seus hospedeiros. A maioria dos grupos de pesquisa utiliza como modelos de laboratórios combinações não naturais de Anopheles – Plasmodium. Neste trabalho foi avaliada a suscetibilidade ao P. vivax em espécies Amazônicas de Anopheles, fêmeas de Anopheles darlingi, An. albitarsis s.l., An. nuneztovari s.l. e An. triannulatus s.l. e An.aquasalis foram infectadas com P. vivax utilizando um sistema de infecção experimental por membrana artificial...


Todas as espécies de Anopheles estudadas foram suscetíveis à infecção por P. vivax, porém a taxa de infecção e o numero de oocistos variaram significativamente entre elas. An. aquasalis (Spearman rho = 0.255, n = 386, p < 0.01) e An. darlingi (rho =0.518; n = 54, p < 0.01) mostraram uma correlação positiva entre o número de gametócitos e o número de oocistos formados. Também foi avaliada a via JAK/STAT de resposta imune em A. aquasalis, durante a fase tardia da infecção, e em A. darlingi, no início da infecção. A expressão dos genes STAT, PIAS e NOS foi avaliada por q-PCR. Em An. aquasalis a expressão dos genes estudados foi induzida a partir de 8 dPI (PIAS e NOS) e 12 dPI (STAT),e começou a diminuir aos 14dPI, provavelmente indicando a indução transitória desses genes na fase tardia da infecção. Em An. darlingi não foi observada a ativação dessa via imune durante a fase inicial da infecção com P. vivax. Estudos futuros devem ser realizados para saber de que forma os genes regulados pela via JAK/STAT podem modular o desenvolvimento do P. vivax em An. aquasalis, e outras vias de sinalização devem ser estudadas na resposta de An. darlingi à infecção pelo Plasmodium...


Subject(s)
Animals , Anopheles/parasitology , Host-Parasite Interactions/immunology , Malaria/prevention & control , Plasmodium vivax/pathogenicity
16.
Mem. Inst. Oswaldo Cruz ; 108(8): 1057-1064, 6/dez. 2013. tab, graf
Article in English | LILACS | ID: lil-697145

ABSTRACT

On the southwest Pacific Coast of Colombia, a field study was initiated to determine the human-vector association between Anopheles (Kerteszia) neivai and fishermen, including their nearby houses. Mosquitoes were collected over 24-h periods from mangrove swamps, marshlands and fishing vessels in three locations, as well as in and around the houses of fishermen. A total of 6,382 mosquitoes were collected. An. neivai was most abundant in mangroves and fishing canoes (90.8%), while Anopheles albimanus was found indoors (82%) and outdoors (73%). One An. neivai and one An. albimanus collected during fishing activities in canoes were positive for Plasmodium vivax , whereas one female An. neivai collected in a mangrove was positive for P. vivax . In the mangroves and fishing canoes, An. neivai demonstrated biting activity throughout the day, peaking between 06:00 pm-07:00 pm and there were two minor peaks at dusk and dawn. These peaks coincided with fishing activities in the marshlands and mangroves, a situation that places the fishermen at risk of contracting malaria when they are performing their daily activities. It is recommended that protective measures be implemented to reduce the risk that fishermen will contract malaria.


Subject(s)
Animals , Female , Humans , Anopheles/physiology , Bites and Stings/epidemiology , Fisheries , Feeding Behavior/physiology , Insect Vectors/physiology , Anopheles/classification , Anopheles/parasitology , Colombia/epidemiology , Insect Vectors/classification , Insect Vectors/parasitology , Malaria/epidemiology , Malaria/transmission , Population Density , Plasmodium/isolation & purification
17.
Biomédica (Bogotá) ; 33(1): 42-52, ene.-mar. 2013. tab
Article in Spanish | LILACS | ID: lil-675131

ABSTRACT

Introducción. El departamento del Putumayo es una región endémica para malaria, o paludismo, causada principalmente por Plasmodium vivax . Los vectores en esta región incluyen Anopheles darlingi , el cual se ha encontrado solamente en el municipio de Puerto Leguízamo, y recientemente se incriminaron como vectores en Puerto Asís a las especies An. rangeli y An. oswaldoi . Objetivo. El propósito del trabajo fue determinar el papel de An. benarrochi B en la transmisión de malaria en este departamento, ya que se reporta como la especie más abundante que pica a los humanos. Materiales y métodos. Se recolectaron larvas y adultos de Anopheles spp. entre el 2006 y el 2008 en los municipios Puerto Leguízamo y Puerto Asís, y se obtuvieron secuencias del gen ITS-2 y del gen mitocondrial COI para confirmar las determinaciones taxonómicas por morfología. Se practicó la prueba ELISA para establecer la infección por P. vivax y P. falciparum. Resultados. Se identificaron 6.238 individuos correspondientes a 11 especies: An. albitarsis s.l. (1,83 %), An. benarrochi B (72,35 %), An. braziliensis (0,05 %), An. costai (0,06 %), An. darlingi (19,37 %), An. mattogrossensis (0,08 %), An. neomaculipalpus (0,13 %), An. oswaldoi s.l. (0,64 %), An. punctimacula (0,03 %), An. rangeli (5,12 %) y An. triannulatus s.l. (0,34 %). Se evaluaron 5.038 adultos por ELISA y 5 se encontraron positivos para P. vivax 210 y VK 247, todos pertenecientes a la especie An. benarrochi B. Conclusión. Los resultados sugieren que An. benarrochi B juega un papel en la transmisión de P. vivax en el departamento de Putumayo, dada su alta atracción por los humanos y su infección natural con Plasmodium spp.


Introduction: Putumayo is considered an endemic region for malaria transmission, mainly due to Plasmodium vivax. The vectors in this region are Anopheles darlingi , which has been found only in the municipality of Puerto Leguízamo, and An. rangeli and An. oswaldoi s.l. , which were recently incriminated as vectors in Puerto Asís. Objective: The purpose of this study was to determine the role of An. benarrochi B in malaria transmission in Putumayo, given that it is the most abundant species biting humans. Materials and methods: Collections of immature and adult stages of Anopheles spp. were made between 2006 and 2008 in the municipalities of Puerto Leguízamo and Puerto Asís in Putumayo, and sequences of internal transcribed spacer 2 ( ITS-2 ) of ribosomal DNA and the mitochondrial gene COI were obtained to confirm the morphological determinations. ELISA was carried out for P. vivax and P. falciparum infectivity. Results: A total of 6,238 specimens were identified, distributed in 11 species: An. albitarsis s.l. (1.83%), An. benarrochi B (72.35%), An. braziliensis (0.05%), An. costai (0.06%), An. darlingi (19.37%), An. mattogrossensis (0.08%), An. neomaculipalpus (0.13%), An. oswaldoi s.l. (0.64%), An. punctimacula (0.03%), An. rangeli (5.12%), and An. triannulatus s.l. (0.34%). A total of 5,038 adults were assessed by ELISA and 5 were found positive for P. vivax 210 and VK 247, all belonging to An. benarrochi B. Conclusion: The results suggest that An. benarrochi B plays a role in the transmission of P. vivax in Putumayo due to its high human contact and natural infection with Plasmodium sp.


Subject(s)
Animals , Female , Humans , Anopheles/parasitology , Insect Vectors/parasitology , Malaria, Falciparum/transmission , Malaria, Vivax/transmission , Plasmodium falciparum/isolation & purification , Plasmodium vivax/isolation & purification , Anopheles/classification , Anopheles/growth & development , Colombia/epidemiology , DNA, Mitochondrial/analysis , DNA, Protozoan/analysis , DNA, Ribosomal Spacer/analysis , Endemic Diseases , Enzyme-Linked Immunosorbent Assay , Insect Vectors/classification , Larva , Malaria, Falciparum/epidemiology , Malaria, Vivax/epidemiology , Phylogeography
18.
Belo Horizonte; s.n; 2013. 72 p. ilus.
Thesis in Portuguese | LILACS | ID: lil-681490

ABSTRACT

Os mosquitos da espécie Anopheles (Nyssorhynchus) aquasalis, Curry 1932 são vetores da malária humana nas Américas. Desde o ano de 2004, esse vetor tem sido mantido em colônia no Laboratório de Malária do Centro de Pesquisas René Rachou (Lamal), Fiocruz-MG, onde tem sido utilizado para estudos de interação parasito-vetor. Na natureza, as larvas desses insetos desenvolvem-se em água salobra e, no insetário de criação do Lamal utiliza-se água do mar na proporção de 1:10 em água da torneira. No ano de 2008, observou-se uma queda significativa na produção de mosquitos da colônia, devido, principalmente, à mortalidade excessiva de larvas. As larvas, de 3º e 4º estádios, apresentavam características morfológicas semelhantes àquelas relacionadas com contaminação por bacilos entomopatogênicos. Como algumas bactérias do gênero Bacillus são patogênicas às larvas de mosquitos, o objetivo do presente trabalho foi identificar a (as) espécie (es) responsável (is) pela mortalidade das larvas de Anopheles aquasalis, bem como identificar as toxinas envolvidas nessa mortalidade. Através da caracterização morfológica e molecular foi possível identificar o Bacillus sphaericus como contaminante na colônia de criação de Anopheles aquasalis. Visando uma comparação inter-insetários, analisou-se ainda amostras de três insetários distintos, sendo a presença dos bacilos identificadas em dois desses. Pela técnica de PCR buscou-se amplificar as 5 toxinas mais frequentes das estirpes de B. sphaericus (BinA, BinB, Mtx1, Mtx2 e Mtx3 ), sendo que apenas 3 (família das MTxs) foram detectadas nas amostras estudadas. Os resultados dos ensaios biológicos confirmaram a toxidade destas toxinas para as larvas de 3º e 4º estádios. Os ensaios biológicos realizados identificaram as estirpes isoladas do Laboratório de Malária como de alta toxicidade para o Anopheles aquasalis. Em resumo, este trabalho foi o primeiro a demonstrar a ocorrência de contaminação natural por bacilos entomopatogênico sem colônias de mosquitos mantidas em insetário e a caracterizar as toxinas envolvidas nesta contaminação. Espera-se que estes resultados possam contribuir para traçar estratégias de monitoramento e controle de contaminação em insetários de experimentação.


Subject(s)
Animals , Guinea Pigs , Mice , Anopheles/parasitology , Bacillus/isolation & purification , Insect Vectors/growth & development , Malaria/transmission , Plasmodium/parasitology
19.
Belo Horizonte; s.n; 2013. 72 p. ilus.
Thesis in Portuguese | ColecionaSUS, LILACS, ColecionaSUS | ID: biblio-938629

ABSTRACT

Os mosquitos da espécie Anopheles (Nyssorhynchus) aquasalis, Curry 1932 são vetores da malária humana nas Américas. Desde o ano de 2004, esse vetor tem sido mantido em colônia no Laboratório de Malária do Centro de Pesquisas René Rachou (Lamal), Fiocruz-MG, onde tem sido utilizado para estudos de interação parasito-vetor. Na natureza, as larvas desses insetos desenvolvem-se em água salobra e, no insetário de criação do Lamal utiliza-se água do mar na proporção de 1:10 em água da torneira. No ano de 2008, observou-se uma queda significativa na produção de mosquitos da colônia, devido, principalmente, à mortalidade excessiva de larvas. As larvas, de 3º e 4º estádios, apresentavam características morfológicas semelhantes àquelas relacionadas com contaminação por bacilos entomopatogênicos. Como algumas bactérias do gênero Bacillus são patogênicas às larvas de mosquitos, o objetivo do presente trabalho foi identificar a (as) espécie (es) responsável (is) pela mortalidade das larvas de Anopheles aquasalis, bem como identificar as toxinas envolvidas nessa mortalidade. Através da caracterização morfológica e molecular foi possível identificar o Bacillus sphaericus como contaminante na colônia de criação de Anopheles aquasalis.


Visando uma comparação inter-insetários, analisou-se ainda amostras de três insetários distintos, sendo a presença dos bacilos identificadas em dois desses. Pela técnica de PCR buscou-se amplificar as 5 toxinas mais frequentes das estirpes de B. sphaericus (BinA, BinB, Mtx1, Mtx2 e Mtx3 ), sendo que apenas 3 (família das MTxs) foram detectadas nas amostras estudadas. Os resultados dos ensaios biológicos confirmaram a toxidade destas toxinas para as larvas de 3º e 4º estádios. Os ensaios biológicos realizados identificaram as estirpes isoladas do Laboratório de Malária como de alta toxicidade para o Anopheles aquasalis. Em resumo, este trabalho foi o primeiro a demonstrar a ocorrência de contaminação natural por bacilos entomopatogênico sem colônias de mosquitos mantidas em insetário e a caracterizar as toxinas envolvidas nesta contaminação. Espera-se que estes resultados possam contribuir para traçar estratégias de monitoramento e controle de contaminação em insetários de experimentação


Subject(s)
Animals , Guinea Pigs , Mice , Anopheles/parasitology , Bacillus/isolation & purification , Insect Vectors/growth & development , Malaria/transmission , Plasmodium/parasitology
20.
Biomédica (Bogotá) ; 32(4): 557-569, oct.-dic. 2012. mapas, tab
Article in Spanish | LILACS | ID: lil-669103

ABSTRACT

Introducción. Pocos estudios describen los factores asociados con la dinámica de transmisión de la malaria, o paludismo, por Plasmodium vivax en las regiones endémicas de Panamá. Objetivo. Caracterizar la dinámica de transmisión de la malaria producida por P. vivax en la región fronteriza de Panamá con Costa Rica. Materiales y métodos. Se llevó a cabo un estudio observacional, descriptivo y transversal. Se evaluaron la incidencia parasitaria anual, el índice de láminas positivas y el índice anual de exámenes de sangre. Se identificaron los anofelinos vectores, y se caracterizaron sus criaderos preferenciales, densidad larvaria e índice de picada/hombre/noche. Se hizo búsqueda pasiva y activa de casos sospechosos mediante examen de gota gruesa. Resultados. De 10.401 muestras de gota gruesa, 83 resultaron positivas para P. vivax. El 84 % de los casos provenía de zonas rurales, el 79 % constituía una población económicamente activa, la mediana de edad fue de 36 años y, la media, de 30 años. El 58,5 % de los casos fueron de sexo masculino. La incidencia parasitaria anual fue de 4,1 por 1.000 habitantes; el índice de láminas positivas fue de 0,8 % y el índice anual de exámenes de sangre fue de 51,9 %. El 65,0 % de los casos diagnosticados registró entre 100 y 2.000 parásitos/μl de sangre. Se identificaron los mosquitos vectores Anopheles albimanus y An. punctimacula. Conclusión. Es necesario el seguimiento de estudios entomológicos, el fortalecimiento de la vigilancia epidemiológica, la consideración de los factores de riesgo y la realización de un trabajo en coordinación con las autoridades de salud de Costa Rica, para controlar la malaria en esta región.


Introduction. Few studies have described the factors associated with Plasmodium vivax transmission dynamics in endemic regions from Panamá. Objective. Malaria transmission dynamics produced by P. vivax were characterized at the border between Panamá and Costa Rica. Materials and methods. In the municipality of Barú, an observational, descriptive and cross-sectional study was undertaken to measure the annual parasite index (API), slide positivity index (SPR), and the annual blood examination rate (ABER). The most frequent symptoms and signs in malaria patients were recorded. The anopheline species were identified in the area and the preferred larval habitats, the density of larval populations in the larval habitats and the bites/human/night were characterized. Results. Of a total of 10,401 thick smear blood samples, 83 were positive for P. vivax. Of these, 84% came from rural areas and 79% were from economically active individuals. The median and average ages were 36 and 30 years, respectively, and 58.5% of the malaria cases were male. API was 4.1/1,000 inhabitants; SPR was 0.8% and ABER was 51.9%. Of the diagnosed cases, 54% showed blood parasitemias ranging between 100-2,000 parasites/μl. The majority of the cases were observed in May and June. Two mosquito vector species were identified-- Anopheles albimanus and An. punctimacula. Conclusion. These observations indicate the advisibility of continued entomological studies, strengthening of epidemiological surveillance, consideration of additional risk factors and evaluation of work performance in the border region. This will require coordination with health authorities of both countries to control malaria in this region.


Subject(s)
Adolescent , Adult , Aged , Animals , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Anopheles/parasitology , Disease Outbreaks , Insect Vectors/parasitology , Malaria, Vivax/transmission , Parasitemia/transmission , Plasmodium vivax/isolation & purification , Anopheles/growth & development , Antimalarials/therapeutic use , Cross-Sectional Studies , Chloroquine/therapeutic use , Costa Rica/epidemiology , Disease Reservoirs , Incidence , Insect Bites and Stings/epidemiology , Insect Bites and Stings/parasitology , Larva , Malaria, Vivax/blood , Malaria, Vivax/drug therapy , Malaria, Vivax/epidemiology , Malaria, Vivax/parasitology , Parasite Load , Panama/epidemiology , Parasitemia/blood , Parasitemia/drug therapy , Parasitemia/epidemiology , Parasitemia/parasitology , Ponds/parasitology , Primaquine/therapeutic use , Rural Population/statistics & numerical data , Species Specificity
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