Lethal effect of a bait for Rhodnius prolixus (Hemiptera: Reduviidae), the vector of Chagas' disease, containing hexachlorocyclohexane (HCH), under laboratory conditions

The lethal effect of a bait containing an aqueous hexachlorocyclohexane (HCH) suspension at the concentration of 1g/l and maintained at room temperature was studied in the laboratory over a period of 12 weeks. The suspension was placed in a latex bag hanging inside a 1000-ml beaker tightly covered with nylon netting, and left there with no changes for 85 days. Sixteen groups of R. prolixas bugs, consisting on average of 30 specimens each, were successively exposed to the bait and observed at different intervals for one week each. The mortality rate was 100% for all groups, except for the 16th, whose mortality rate was 96.7%. As the groups succeeded one another, mortality started to occur more rapidly and was more marked at the 6- and 24-h intervals. Later tests respectively started at 6:00 a.m. and 6:00 p.m. showed that diurnal and nocturnal periodicity in the offer of food had no effect on mortality. First- and 2nd- instar nymphs and adults male were more sensitive and 5th- instar nymphs were more resistant to the active principle of the bait.

Hemolymphatic components in vectors of Trypanosoma cruzi: study in several species of the subfamily Triatominae (Hemiptera: Reduviidae)

The members of the subfamily Triatominae (Hemiptera : Reduviidae) comprise a great number of species of medical importance in the transmission of the T. cruzi (American trypanosomiasis). The aim of this study was to contribute to the knowledge about the chemical composition in proteins, lipids, lipoproteins, and carbohydrates of vectors of Chagas' disease corresponding to twelve members of the subfamily Triatominae. This study was carried out in ninphs of the fifth instar and adult males of the species: T. delpontei, T. dimidiata, T. guasayana, T. infestans, T. mazzotti, T. pallidipennis, T. patagonica, T. platensis, T. rubrovaria, T. sordida of the Triatoma genus, and D. maximus and P. megistus of the Dipatalogaster and Panstrongylus genera respectively. The results show on one hand, qualitative differences in the protein composition, and on the other hand, similarity in the lipoprotein profiles. Lipids, proteins, and carbohydrates did not show significant differences between species or/and stages.

Distribucion geografica de Lutzomyia verrucarum (Townsend, 1913) (Diptera, Psychodidae, Phlebotominae), vector de la batonellosis humana en el Peru

Lutzomyia verrucarum (Townsend, 1913) (Diptera: Psychodidae), vector natural de la verruga peruana o enfermedad de Carrión es una especie propia del Perú. Su distribución geográfica esta entre los paralelos 5º y 13º25' de latitud Sur, se encuentra en los valles Occidentales e Interandinos de los Andes. La distribución altitudinal de Lu. verrucarum en los diversos valles es variable; asi: Occidentales, desde 1100 hasta 2980 msnm e Interandinos, de 1200 a 3200 msnm. En ciertas áreas verrucógenas no hay correlación entre la presencia de Lu. verrucarum y la enfermedad de Carrión lo que suguiere la existencia de vectores secundarios.

Mediterranean spotted fever and identification of new agents of rickettsioses in Portugal : epidemiological determinants, host and microbial features in portuguese patients

Resumo: a febre botonosa, também conhecida por febre escaro-nodular (FEN) é uma doença endémica nos Países da bacia do Mediterrâneo, África, Médio Oriente, Índia e Paquistão. O agente etiológico responsável por esta patologia é a bactéria Rickettsia conorii. Contudo, em alguns países, como Portugal e Itália, esta patologia é causada por duas estirpes diferentes: R conorii Malish e R conorii Israeli spotted fever strain. O principal vector e reservatório é o ixodídeo Rhipicephalus sanguineus. Mesmo com uma elevada taxa de subnotificação detectada no nosso País, a taxa incidência da FEN é de 8.4/105 habitantes (1989-2005), uma das mais altas quando comparada coom a de outros países da bacia do Mediterrâneo. De todos os distritos portugueses, Bragança e Beja são aqueles que apresentam as taxas de incidência mais elevadas, 56,8/105 habitantes e 47,4 / 105 habitantes respectivamente. Em Portugal, as alterações climáticas verificadas na última década, nomeadamente a subida das temperaturas médias anuais, parecem ter influenciado o ciclo de vida do vector e a sua dinâmica sazonal, permitindo ao R. sanguineus completar mais de um ciclo de vida por ano. Este facto, e a possibilidade deste vector se manter activo noutros meses do ano, nomeadamente nos meses de inverno, tem influenciado consequentemente o padrão de distribuição anual dos casos de FEN. A febre escaro-nodular caracteriza-se clinicamente como uma doença exantemática, com um processo de vasculite generalizado. Apesar de na generalidade ser considerada uma doença benigna (quando tratada atempadamente e com terapêutica adequada e específica)e de estarem descritos casos graves em cerca de 5-6% dos doentes, em Portugal essa percentagem aumentou e consequentemente levou a um aumento de casos fatais. Este facto tornou-se mais evidente em 1997, no Hospital Distrital de Beja e no Hospital Garcia de Orta, onde a taxa de letalidade atingiu os 32% e 18% respectivamente.Para além dos factores de co-morbilidade encontrados nos doentes mais graves, como diabetes mellitus, ou o atraso na instituição da terapêutica específica, foi colocada de que a estirpe R. conorii Israel spotted fever strain pudesse ser mais virulenta ou então estivesse associada a diferentes manifestações clínicas que dificultassem o diagnóstico clínico e a instituição atempada da terapêutica. Houve ainda a necessidade de avaliar alguns parâmetros imunológicos dos doentes e tentar identificar que factores, nomeadamente que citoquinas, poderiam estar envolvidos na resposta a uma infecção por R.conorii.Face a estas questões foi avaliada e comparada a epidemiologia, manifestações clínicas e laboratoriais de 140 doentes (71 infectados com R. conorii Malish e 69 infectados com R. conorii Israel spotted fever strain). Concluiu-se que existe uma sobreposição de manifestações clinicas entre os dois grupos de doentes, mas que a percentagem da escara de inoculação é significativamente inferior em doentes infectados com R. conorii Israel spotted fever strain. Dos resultados mais importantes encontrados neste estudo concluiu-se que a estirpe R. conorii Malish e é demonstrado, pela primeira vez, estatisticamente que o alcoolismo é um factor de risco para a morte de doentes com FEN. Associadas a factores de um mau prognósitco da doença, estão as manifestações gastrointestinais, que poderão ser ou não reflexo de alterações do sistema nervoso central, e ainda a alteração de parâmetros laboratoriais como a presença de hiperbilirubinemia e aumento dos valores da ureia.A maior parte dos estudos realizados sobre os mecanismos da resposta imunitária à infecção por R. conorii e as interacções hospedeiro - agente etiológico têm sido elucidados com base em modelos animais. Poucos estudos têm sido efectuados em doentes e nenhum estudo prévio tinha sido realizado no sentido de avaliar localmente (escara/pele) quais os mediadores ou outras moléculas envolvidas na resposta imunitária às rickettsioses. Foi avaliado o nível de expressão génica de RNA mensageiro (RNAm)de diferentes citoquinas em amostras de pele de doentes com FEN pela técnica de PCR em tempo real.Os resultados deste estudo mostraram que, quando comparado com o grupo controlo, os 23 doentes analisados apresentavam níveis estatisticamente significativos, mais elevados de expressão génica de interferão (IFN-γ, Tumor necrosis factor (TFN-α, interleucina 10 (IL-10, RANTES (regulated by activation, normal T-cell-expressed and secreted chemokine)e indolamina 2-3 desoxigenase (IDO),uma enzima envolvida no controlo e limitação do crescimento intracelular das rickettsias, através da degradação do triptofano. Seis dos 23 doentes apresentaram ainda niveis de expressão elevados de óxido nítrico indutível (iNOS)que actua como microbicida. Encontrou-se uma correlação positiva entre a expressão de RNAm de TNF-α, γ, iNOS e IDO e os casos menos graves de FEN sugerindo um tipo de resposta imunitária tipo Th1, i.e. com papel protector na resposta à infecção.Verificou-se também que os valores de expressão genética do RNAm de IL-10, estavam inversamente correlacionados com a expressão do RNAm de TNF-α e IFN-γ. Os casos menos graves de FEN parecem assim envolver um balanço entre a resposta pró-inflamatória e anti-inflamatória. Já os níveis de expressão génica do RNAm de IL-10 estavam inversamente correlacionados com a expressão RNAm de TNF-α e IFN-γ. Os casos menos graves de FEN parecem assim envolver um balanço entre uma resposta pró-inflamatória e anti-inflamatória. Já os níveis de expressão RNAm da quimoquina RANTES foram estatisticamente mais elevados em doentes graves.Nesta dissertação é ainda descrita uma nova rickettsiose presente em Portugal, causada pela bactéria R. sibirica mongolitimonae, que foi identificada laboratorialmente por isolamento do agente, e por detecção do DNA em biopsia de pele. A presença deste agente foi ainda corroborada pela detecção em paralelo do mesmo agente no ixodídeos como R. africae like e em pulgas como R. felis e R.typhi alertam para a possibilidade de existência de outras rickettsioses que possam estar diagnosticadas em Portugal. Abstract: Mediterranean spotted fever (MSF), a tick-borne disease caused by Rickettsia conorii, is widley distributed in the Old World, being endemic in the southern Europe, Africa, Middle East, India and Pakistan. In Portugal two strains cause disease: R.conorii Malish and R.conorii Israeli spotted fever.Rhipicephalus sanguineus, the brown dog tick, is considered the main vector and reservoir. MSF is characterized by seasonality, and most of cases are encountered in late spring and summer, peaking in July and August. However, CEVDI/INSA laboratory has observed that the incidence of MSF cases has changed during winter season.The increasing annual averages of air temperatures and warmer and drier winters might have influenced the dynamics of the life cycle and activity of R. sanguineus, and indirectley the number MSF cases during the so called MSF off-season.In the period of 1989-2005, the incidence rate of MSF was 8.4/105 inhabitants, one of the highest rates compared with other endemic countries. In the Portugal during the same period, the highest incidence rates were reported in the districts of Bragança, with 56.8/105 inhabitants, and Beja, with 47.4/105 inhabitants. Severe cases of MSF are reported in 6% of the patients, but it seems that this pattern of disease in Portugal has been changing.This factor became more evident in 1997, with a reported case fatality rate of 32% and 18% in patients with MSF admited at Beja and Garcia Orta Hospitals, respectively. Although it was found that diabetes mellitus and delay in therapy have been implicated as a risk factor for death, the hypothesis was considered, that the new ISF strain isolated from Portugueses patients in the same year (1997)causes different or atypical clinical conorii Malish strain. The local (skin biopsies) immune response to R. conorii infection was also evaluated.A prospective study was performed to characterized epidemiological, clinical, laboratory features and determined risk factors for a fatal outcome. One hundred forty patients (51% patients were infected with Rickettsia conorii Malish stain and 49% with Israeli spotted fever strain)with diagnosis documented with identification of the causative rickettsial strain were admitted to 13 Portugueses Hospitals during 1994-2006.Comparison of the clinical manifestations of MSF caused by Malish and ISF strains revealed tremendous overlap that would not permit clinical recognition of the strain envolved, but an eschar was observed in a significantly higher percentage of patients with Malish than ISF strain.A fatal outcome was significantly more likely for patients with ISF strain infection meaning that ISF strain was more virulent than Malish strain, and also alcoholism was a host risk factor for a fatal outcome.The pathophysiology of a fatal outcome involved significantly greater incidence of petechial rash, gastrointestinal symptoms, confusion/obtundation, dehydration, tachypnea, hepatomegaly, leukocytosis, coagulopathy, azotemia, hyperbilirubinemia, and elevated hepatic enzymes and creatine kinase. Multivariate analysis revealed that acute renal failure and hyperbilirubinemia were most strong associated with a fatal oucome of infections with both strains.The immune response to R. conorii infection determined with both strains. The immune response to R. conorii infection determined by the expression levels of inflammatory and immune mediators in skin biopsies collected from untreated patients with Mediterranean spotted fever reveal that intralesional expression of mRNA of TNF-α, IFN-γ, IL-10, RANTES, and indoleamine-2, 3-dioxygenase (IDO)an enzyme involved in limiting rickettsial growth by tryptophan degradation, were elevated in skin of MSF patients compared to controls. Six patients had elevated levels of inducible nitric oxide synthase (NOS2, a source microbicidal nitric oxide.Positive correlations among TNF-α, IFN-γ, NOS2,IDO and mild-to-moderate disease suggested that type 1 polarization plays a protective role. Significantly high levels of intralesional IL-10 were inversely correlated with IFN-γ and TNF-α. The chemokine RANTES was significantly higher in patients with several MSF. It seems that MSF patients with mild-to-moderate disease have a strong and balanced intralesional pro-inflammatory and anti-inflammatory response, while severe disease is associated with higher chemokine expression.Whether these findings are simply a correlate of mild and severe disease or contribute to anti-rickettsial immunity and pathogenesis remains to be determined.In this dissertation is also described a new rickettsiois present in Portugal caused by R.sibirica mongolitimonae strain, identified based on agent isolation and DNA detection by PCR technique in a skin biopsy.The presence of this agent corroborated by its detection also in Rhipicephalus pusillus tick. Also, pathogenic tick and flea-borne rickettsial agents such as R. africae strain detected in Rhipicephalus bursa tick, and R.felis and R.typhi detected in different fleas species raise the alert for the possible existence of other rickettsioses in Portugal that might be underdiagnosed.

The diagnostic importance of species specific and cross-reactive components of Taenia solium, Echinococcus granulosus, and Hymenolepis nana

Sera from patients infected with Taenia solium, Hymenolepis nana and Echinococcus granulosus were tested against homologous and heterologous parasite antigens using an ELISA assay, and a high degree of cross-reactivity was verified. To identify polypeptides responsible for this cross reactivity, the Enzyme Linked Immunoelectro Transfer Blot (EITB) was used. Sera from infected patients with T.solium, H.nana, and E.granulosus were assessed against crude, ammonium sulphate precipitated (TSASP), and lentil-lectin purified antigens of T.solium and crude antigens of.H.nana and E.granulosus. Several bands, recognized by sera from patients with T.solium, H.nana, and E.granulosus infections, were common to either two or all three cestodes. Unique reactive bands in H.nana were noted at 49 and 66 K-Da and in E.granulosus at 17-21 K-Da and at 27-32 K-Da. In the crude cysticercosis extract, a specific non glycoprotein band was present at 61-67 K-Da in addiction to specific glycoprotein bands of 50, 42, 24, 21, 18, 14, and 13 K-Da. None of the sera from patients with H.nana or E.granulosus infection cross reacted with these seven glycoprotein bands considered specific for T.solium infection.

Prevalence of thermotolerant species of Campylobacter and their biotypes in children and domestic birds and dogs in Southern Chile

The prevalence of thermotolerant Campylobacter in diarrhoeic and healthy children as well as in dogs, hens, ducks and pigeons was determined in Southern Chile. Campylobacter were found in 34.5% of the faecal samples examined. The isolation rate of Campylobacter in diarrhoeic and healthy children was 16.3% and 6.4% respectively. Despite C.jejuni was always more frequent than C. coli, the latter was isolated with a high frequency (29%) from patients with diarrhoea. C.jejuni and C. coli biotypes I and II were found in healthy and diarrhoeic children and were predominant in all the animals species studied. This may point out towards the possible origin of strains infecting children.

Species and serovars of enteropathogenic agents associated with acute diarrheal disease in Rosario, Argentina

We report the most frequent species and serovars of enteropathogenic organisms in Rosario from 1985 to 1993. Enteropathogenic Escherichia coli was the most prevalent agent affecting 144/570 (25.2%) children; 0111 represented 41.8%, 055: 13.6%, 0119: 12.7%. Among enterotoxigenic E. coli (ETEC) the most frequent were ETEC-ST 0128:H21 and 0153:H45. Shigella spp were isolated in 8.8%; S.flexneri: 7%, principally type 2 (59.5%); S. sonnei: 1.6%, and S. dysenteriae type 2: 0.2%. Campylobacter spp were found in 6.1% of patients; C.jejuni: 4.6%; C. coli: 1.4% and C. lari: 0.2%; except groups 0 13,50 and 0 4 (2 cases each), no predominant serogroups were found. Salmonella was isolated in 2.8% of cases, being the predominant serovar S. typhimurium until 1986, but a dramatically increase of cases due to S. enteritidis was observed since 1987. There was 1.9% of Aeromonas spp and 2 cases due to Vibrio cholerae non 0-1. No Yersinia was found. In patients with gastroenteritis due to Shigella, Campylobacter, Salmonella, or EPEC as the unique pathogen, leukocytes were observed in the faeces in 70%, 50%, 20%, and 10% of cases respectively.

Population dynamics and biting rhythm of the anthropophilic sandfly Lutzomyia cruciata (Diptera: Psychdidae) in Southeast, Mexico

Sandflies attracted by human bait were caught in an endemic focus of localized cutaneous leishmaniasis in the state of Campeche, Mexico. Catches were carried out monthly from February 1994 to January 1995 between 18:00 and 22:00 h. Lutzomyia cruciata was the only species caught. The highest population peak of Lu. cruciata was found in March with lesser peaks in February, December 1994, and January 1995. Maximum biting rate of Lu. cruciata was found between 18:00 and 19:00 h. The host-seeking females of Lu. cruciata were directly related to levels of humidity between 88 and 100%. Low and high temperature had a negative effect upon Lu. cruciata activity. The possible role of Lu. cruciata as vector of leishmaniasis in the state of Campeche, Mexico is discussed.

Schistosoma mansoni: the sex ratios of worms in animals infected with cercariae from three species of Biomphalaria

The ratios of male to female worms of Schistosoma mansoni were determined in mice infected with cercariae from LE, SJ and AL strains shed by mollusc hosts of the parasite in Brazil. The sex ratios of worms in the animals were similar with cercariae from Biomphialaria glabrata and B. tenagophila varying from 1.1:1 to 1.6:1 with LE and AL strains and 1:1.1 with SJ. In the animals infected with cercariae from B. straminea the ratio of male to female worms was similar to those obtained using cercariae shed from the other two species of molluscs, 1.5:1 with LE strain. Inoculations by AL and SJ cercariae resulted in sex ratios of 3.1:1 and 6:1 respectively. The normal sex ratios of worms established in Brazil in animals inoculated with cercariae from B. glabrata and B. tenagophila is from 1:1 to 2:1. The higher number of male worms that developed from cercariae of the AL and SJ strains obtained from B. straminea indicate a lower compatibility of the snail concerning these strains of S. mansoni.

Strategic Bidding for Electricity Markets Negotiation Using Support Vector Machines

Energy systems worldwide are complex and challenging environments. Multi-agent based simulation platforms are increasing at a high rate, as they show to be a good option to study many issues related to these systems, as well as the involved players at act in this domain. In this scope the authors’ research group has developed a multi-agent system: MASCEM (Multi- Agent System for Competitive Electricity Markets), which simulates the electricity markets environment. MASCEM is integrated with ALBidS (Adaptive Learning Strategic Bidding System) that works as a decision support system for market players. The ALBidS system allows MASCEM market negotiating players to take the best possible advantages from the market context. This paper presents the application of a Support Vector Machines (SVM) based approach to provide decision support to electricity market players. This strategy is tested and validated by being included in ALBidS and then compared with the application of an Artificial Neural Network, originating promising results. The proposed approach is tested and validated using real electricity markets data from MIBEL - Iberian market operator.

Solar Intensity Forecasting using Artificial Neural Networks and Support Vector Machines

This paper presents several forecasting methodologies based on the application of Artificial Neural Networks (ANN) and Support Vector Machines (SVM), directed to the prediction of the solar radiance intensity. The methodologies differ from each other by using different information in the training of the methods, i.e, different environmental complementary fields such as the wind speed, temperature, and humidity. Additionally, different ways of considering the data series information have been considered. Sensitivity testing has been performed on all methodologies in order to achieve the best parameterizations for the proposed approaches. Results show that the SVM approach using the exponential Radial Basis Function (eRBF) is capable of achieving the best forecasting results, and in half execution time of the ANN based approaches.

Short-term Wind Speed Forecasting using Support Vector Machines

Wind speed forecasting has been becoming an important field of research to support the electricity industry mainly due to the increasing use of distributed energy sources, largely based on renewable sources. This type of electricity generation is highly dependent on the weather conditions variability, particularly the variability of the wind speed. Therefore, accurate wind power forecasting models are required to the operation and planning of wind plants and power systems. A Support Vector Machines (SVM) model for short-term wind speed is proposed and its performance is evaluated and compared with several artificial neural network (ANN) based approaches. A case study based on a real database regarding 3 years for predicting wind speed at 5 minutes intervals is presented.

Random amplified polymorphic DNA (RAPD) analysis of Lutzomyia longipalpis laboratory populations

The phlebotomine sand fly Lutzomyia longipalpis has been incriminated as a vector of American visceral leishmaniasis, caused by Leishmania chagasi. However, some evidence has been accumulated suggesting that it may exist in nature not as a single but as a species complex. Our goal was to compare four laboratory reference populations of L. longipalpis from distinct geographic regions at the molecular level by RAPD-PCR. We screened genomic DNA for polymorphic sites by PCR amplification with decamer single primers of arbitrary nucleotide sequences. One primer distinguished one population (Marajó Island, Pará State, Brazil) from the other three (Lapinha Cave, Minas Gerais State, Brazil; Melgar, Tolima Department, Colombia and Liberia, Guanacaste Province, Costa Rica). The population-specific and the conserved RAPD-PCR amplified fragments were cloned and shown to differ only in number of internal repeats.

THERMOTOLERANT Campylobacter SPECIES ISOLATED FROM PSITTACIFORMES IN THE PERUVIAN AMAZON REGION

Foi determinada a freqüência de isolamento de campylobacters termotolerantes em Psittaciformes silvestres capturados na região amazônica do Peru. Campylobacters foram isolados em 10/142 (7.0%) dos animais estudados, sendo C. jejuni subsp. jejuni biovar I (6/10) o mais freqüente, seguido de C. coli biovar II (2/10), C. lari não foi isolado. Os resultados sugerem que estas aves podem ser importantes reservatórios destas bactérias.

Epidemiologia da malária em Cabo Verde - Factores genéticos humanos e estrutura populacional do mosquito vector

A malária, doença parasitária complexa que resulta da interacção entre parasita, hospedeiros humano e vector, constitui um dos principais problemas de saúde a nível mundial. À semelhança de outras doenças parasitárias e infecciosas a malária tem um papel importante na evolução, tendo já sido demonstrado o papel da variação genética humana na resistência à infecção. Após quase meio século de controlo, a malária persiste na ilha de Santiago onde, apesar da baixa endemicidade, os indivíduos apresentam geralmente manifestações moderadas, são diagnosticadas infecções abaixo do nível detectável pela microscopia e o vector se encontra muito próximo da população supostamente susceptível, desconhecendo-se a frequência dos principais polimorfismos genéticos humanos mais relacionados com a doença e a estrutura populacional do mosquito vector. Os objectivos gerais de trabalho desta tese assentam 1) no estudo dos dois clássicos factores genéticos do hospedeiro humano relacionados com a malária, nomeadamente os afectos à anemia das células falciformes, à deficiência em G6PD e a análise dum provável envolvimento da PK e 2) na análise genética das populações do mosquito vector, tentando contribuir para a compreensão da epidemiologia da doença na Ilha, e para a escolha de medidas de controlo apropriadas. Os trabalhos incidiram na detecção do alelo responsável pela hemoglobina S, de polimorfismos no gene da G6PD e da PK em indivíduos não aparentados (Infectados e não Infectados) com análise da sua provável associação com a infecção e, ainda, na genotipagem de loci microssatélites de Anopheles arabiensis com recurso a técnicas baseadas na PCR. Relativamente à anemia falciforme, a frequência dos portadores do traço (indivíduos HbAS) e do alelo HbS foi 6% e 5%, respectivamente, e para as variantes da G6PD, 0,8% para G6PDA- e 0,0% para a G6PDMed, não tendo sido encontrado associação entre os genótipos desses dois factores e a presença de infecção. No que concerne ao gene PKLR não foi encontrada uma associação clara entre os polimorfismos analisados e o estado de infecção, mas foi detectado um acentuado desequilíbrio de linkage entre os loci, apenas nos Não Infectados, o que pode significar que essa região do gene, aparentemente conservada, tenha sido seleccionada por fornecer protecção contra a infecção e/ou doença. A diversidade genética das populações de A. arabiensis em onze loci microssatélites foi moderada com valores médio de He, variando de 0,481 a 0,522 e a Rs de 4 a 5. O valor da diferenciação genética baseado em 7 loci polimórficos foi baixo (FST=0,012; p<0,001) mas significativo, variando entre 0,001 e 0,023 entre os pares de populações. Não foram detectados os alelos de resistência associados ao gene Kdr. A baixa frequência dos alelos associados à G6PD (A- e Med) tem implicações importantes nas estratégias de controlo definidas pelo Programa Nacional de Luta contra o Paludismo (PNLP), uma vez que a primaquina pode continuar a ser administrada como complemento aos regimes terapêuticos, em caso de necessidade. A população de A. arabiensis em Santiago revelou-se relativamente homogénea e com uma estrutura reduzida o que pode, por um lado, representar uma desvantagem por permitir uma provável dispersão dos genes de resistência. Por outro lado, essa relativa homogeneidade poderá representar uma vantagem para a introdução de um programa de controlo baseado na libertação de mosquitos transgénicos.