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Altres ajuts: This research was supported by a grant from SENACYT FID 16-201 to J. P. C. and A. V., Secretar ́ıa Nacional de Ciencia y Tecnolog ́ıa from Panama; by the grant for neglected diseases studies in Panama 1.11.1.3.703.01.55.120 from the Ministry of Economy and Finance of Panama to J. P. C. and A. V.; and by ERANet17/HLH-0271. Scott Weaver also supported this study through the World Reference Center for Emerging Viruses and Arboviruses, NIH grant R24AI120942. Dr. Lescano is sponsored by the training grant D43 TW007393 awarded by the Fogarty International Center of the US National Institutes of Health. J. L. M. is a doctoral candidate studying an Epidemiological Research Doctorate at Universidad Peruana Cayetano Heredia under FONDECYT/CIENCIACTIVA scholarship EF033-235-2015 and also supported by training grant D43 TW007393. A. V. is a member of the Sistema Nacional de Investigación de Panamá (SNI), SENACYT. E. S. was supported by the Spanish Ministerio de Ciencia Innovaci ́on y Universidades (MICINN) through a Ramon y Cajal agreement (RYC-2016-21120). Alphaviruses (Togaviridae, Alphavirus) are arthropod-borne single-stranded RNA pathogens that cause febrile and neurologic disease in much of Latin America. However, many features of Alphavirus epidemiology remain unknown. In 2011, we undertook a cross-sectional study in Nueva Esperanza, an indigenous community in the Peruvian Amazon. Here, we present the first serologic evidence of Mayaro (MAYV), Venezuelan equine encephalitis (VEE) complex alphavirus, Una (UNAV), and Madariaga (MADV) viruses reported in humans (24%, 16%, 13%, and 1.5%, respectively) from an Amazonian indigenous community in Peru. Hunting activity and cohabiting with hunters were the main risk factors for Mayaro seroconversion, but only hunting was associated with UNAV seropositivity. Our results suggest that alphavirus infection in this region is common, but we highlight the high UNAV seroprevalence found and corroborate the low MADV prevalence reported in this region. Furthermore, MAYV-neutralizing antibodies were also detected in stored samples from wild animals (18%) hunted by Nueva Esperanza inhabitants and another mestizo community located close to Iquitos. Further serological surveys of VEE complex alphaviruses, UNAV, and MADV in wild animals and assessing the ability of the MAYV seropositive species to transmit the virus will be relevant.

Background In Panama, arboviroses such as dengue fever, and more recently chikungunya fever and Zika disease, are transmitted by Aedes aegypti and Aedes albopictus. Their control is based on the elimination of breeding sites and fogging with pyrethroid insecticides. However, one of the significant issues derived from the prolonged use of pyrethroid insecticide is the development of resistance mechanisms, such as knockdown resistance or kdr. The objective of this study was to evaluate the presence of kdr mutations in a partial region of the VGSC gene in samples of wild-caught Aedes mosquitoes from different locations of the Metropolitan Region of Panama. Results Based on the analysis of 194 sequences of the VGSC gene, two kdr mutations (Ile1011Met and Val1016Gly) were detected in a specimen of Ae. aegypti. The frequency of kdr mutations in the evaluated samples of Ae. aegypti was 0.01. Conclusions This study provides evidence for a low frequency of kdr mutations in Ae. aegypti populations in Panama. It is possible that these changes have no impact on vector control interventions. To our knowledge, we report, for the first time in America the Val1016Gly mutation documented in Asia. In general terms, this result is highly relevant to the Aedes Control Programme in Panama since it constitutes a feasible approach for the timely detection of resistance as well as for the development of strategies. Electronic supplementary material The online version of this article (10.1186/s13071-019-3309-y) contains supplementary material, which is available to authorized users.

La leishmaniasis es un conjunto de enfermedades zoonóticas trasmitida a los humanos por la picadura de insectos hematófagos del género Lutzomyia. Su eco-epidemiología es compleja y los patrones de variación de su incidencia, en tendencia creciente, contradicen las propuestas anteriores de que el desarrollo socioeconómico y la urbanización eliminaría la enfermedad. Por el contrario, la vulnerabilidad de la población se ha visto afectada por los cambios demográficos y factores antropogénicos que, a su vez, transforman la dinámica y el flujo genético poblacional de los vectores y reservorios, modificando sus ciclos de transmisión. Por sus elevados números de casos y su progresiva expansión geográfica, la leishmaniasis es considerada por la Organización Mundial de la Salud (OMS) una enfermedad parasitaria de carácter emergente o reemergente de alto impacto. Las incapacidades que genera esta enfermedad por mutilaciones y deformaciones no solo se traducen en pérdida de horas de productividad, sino también tienen el impacto incapacitante de la pérdida de salud y bienestar en la población que, en la mayoría de los casos, son desestimados por el desconocimiento del comportamiento epidemiológico que presenta. En este artículo se propone una reflexión sobre los factores que inciden en el ciclo de transmisión de las Leishmania spp, y el impacto que las misma pueda tener en la región del Darién, con lo cual pretendemos intentar dilucidar aspectos para la actualización de la información para Panamá y subrayar la importancia de la reflexión teórica ante cualquier tipo de intervención práctica relacionada con este tema.ABSTRACTLeishmaniasis is a group of zoonotic diseases transmitted to humans by the bite of blood-sucking insects of the genus Lutzomyia. It has a complex eco-epidemiology and the patterns of variation of its incidence in increasing trend, contradict the previous proposals that socioeconomic development and urbanization would eliminate the disease. Contrary sensu, the vulnerability of the population has been affected by demographic changes and anthropogenic factors that, in turn, transform the dynamics and population gene flow of vectors and reservoirs, modifying their transmission cycles. Due to a high number of cases and its progressive geographical expansion, leishmaniasis is considered by World Health Organization (WHO) to be an emerging or re-emerging parasitic disease with a high impact. The disabilities generated by this disease due to mutilations and deformations translate into lost hours of productivity, but, the disabling impact of the loss of health and well-being in the population, in most cases, are dismissed due to ignorance of epidemiological behavior. This article proposes a reflection on the factors that affect the transmission cycle of Leishmania spp, and the impact that they may have in the Darien region, with which we intend to try to elucidate aspects for updating information for Panama and underline the importance of theoretical reflection before any type of practical intervention related to this topic.

Madariaga virus (MADV) has recently been associated with severe human disease in Panama, where the closely related Venezuelan equine encephalitis virus (VEEV) also circulates. In June 2017, a fatal MADV infection was confirmed in a community of Darien Province. We conducted a cross-sectional outbreak investigation with human and mosquito collections in July 2017, where sera were tested for alphavirus antibodies and viral RNA. In addition, by applying a catalytic, force-of-infection (FOI) statistical model to two serosurveys from Darien Province in 2012 and 2017, we investigated whether endemic or epidemic alphavirus transmission occurred historically. In 2017, MADV and VEEV IgM seroprevalences were 1.6% and 4.4%, respectively; IgG antibody prevalences were MADV: 13.2%, VEEV: 16.8%, Una virus (UNAV): 16.0%, and Mayaro virus: 1.1%. Active viral circulation was not detected. Evidence of MADV and UNAV infection was found near households, raising questions about its vectors and enzootic transmission cycles. Insomnia was associated withMADVand VEEV infections, depression symptoms were associated with MADV, and dizziness with VEEV and UNAV. Force-of-infection analyses suggest endemic alphavirus transmission historically, with recent increased human exposure to MADV and VEEV in Aruza and Mercadeo, respectively. The lack of additional neurological cases suggests that severe MADV and VEEV infections occur only rarely. Our results indicate that over the past five decades, alphavirus infections have occurred at low levels in eastern Panama, but that MADV and VEEV infections have recently increased-potentially during the past decade. Endemic infections and outbreaks of MADV and VEEV appear to differ spatially in some locations of eastern Panama. National Institute for Health Research Revisión por pares

BackgroundMadariaga virus (MADV), has recently been associated with severe human disease in Panama, where the closely related Venezuelan equine encephalitis virus (VEEV) also circulates. In June, 2017, a fatal MADV infection was confirmed in a community of Darien province.MethodsWe conducted a cross-sectional outbreak investigation with human and mosquito collections in July 2017, where sera were tested for alphavirus antibodies and viral RNA. Additionally, by applying a catalytic, force-of-infection statistical model to two serosurveys from Darien province in 2012 and 2017, we investigated whether endemic or epidemic alphavirus transmission occurred historically.ResultsIn 2017, MADV and VEEV IgM seroprevalence was 1.6% and 4.4%, respectively; IgG antibody prevalences were MADV: 13.2%; VEEV: 16.8%; Una virus (UNAV): 16.0%; and Mayaro virus (MAYV): 1.1%. Active viral circulation was not detected. Evidence of MADV and UNAV infection was found near households — raising questions about its vectors and enzootic transmission cycles. Insomnia was associated with MADV and VEEV infection, depression symptoms were associated with MADV, and dizziness with VEEV and UNAV. Force-of-infection analyses suggest endemic alphavirus transmission historically, with recent increased human exposure to MADV and VEEV in some regions.ConclusionsThe lack of additional neurological cases suggest that severe MADV and VEEV infections occur only rarely. Our results indicate that, over the past five decades, alphavirus infections have occurred at low levels in eastern Panama, but that MADV and VEEV infections have recently increased — potentially during the past decade. Endemic infections and outbreaks of MADV and VEEV appear to differ spatially.Author summaryPrior to 2010, it was believed that the Madariaga virus (MADV) was primarily associated with equine disease. However, an outbreak reported in Panama, in an endemic area where Venezuelan equine encephalitis virus (VEEV) also circulates, suggested a change in its epidemiological profile. We aimed to reconstruct the epidemiological dynamics of MADV and VEEV, as well as additional alphaviruses known to circulate in the region in order to understand MADV emergence. For this, cross-sectional serosurveys were used to demonstrate that the Alphaviruses MADV, VEEV and Una virus have repeatedly infected humans in eastern Panama over the past five decades. Whilst their historical transmission has been low, we confirm that the transmission has recently increased for both MADV and VEEV.

Members of the genera Alphavirus (family Togaviridae) and Flavivirus (family Flaviridae) are important zoonotic human and equine etiologic agents of neurologic diseases in the New World. In 2010, an outbreak of Madariaga virus (MADV; formerly eastern equine encephalitis virus) and Venezuelan equine encephalitis virus (VEEV) infections was reported in eastern Panamá. We further characterized the epidemiology of the outbreak by studying household contacts of confirmed human cases and of equine cases with neurological disease signs. Serum samples were screened using a hemagglutination inhibition test, and human results were confirmed using plaque reduction neutralization tests. A generalized linear model was used to evaluate the human MADV and VEEV seroprevalence ratios by age (in tercile) and gender. Overall, antibody prevalence for human MADV infection was 19.4%, VEEV 33.3%, and Mayaro virus 1.4%. In comparison with individuals aged 2-20 years, people from older age groups (21-41 and > 41 years) were five times more likely to have antibodies against VEEV, whereas the MADV prevalence ratio was independent of age. The overall seroprevalence of MADV in equids was 26.3%, VEEV 29.4%, West Nile virus (WNV) 2.6%, and St. Louis encephalitis virus (SLEV) was 63.0%. Taken together, our results suggest that multiple arboviruses are circulating in human and equine populations in Panamá. Our findings of a lack of increase in the seroprevalence ratio with age support the hypothesis of recent MADV exposure to people living in the affected region.

Phlebotomine sand flies are considered the main vectors of Leishmania, the causal agents of leishmaniasis, which is a serious emerging public health problem worldwide. The use of biological control alternatives, like endosymbiotic bacteria (Wolbachia and Rickettsia), have been proposed to decrease sand fly populations and reduce Leishmania transmissions, yet only few records on the detection of Wolbachia or Rickettsia in sand flies are available worldwide. The aim of this study was to perform the molecular detection of Rickettsial agents associated with sand flies from the last patch of a rainforest in south-eastern Mexico, where a high prevalence of Leishmania infantum has been reported. Sampling effort of sand flies covered 300 trap-nights between 2011 and 2013, and a total of 925 specimens from twelve species were morphologically identified. Using PCR techniques, we identified a new lineage of the endosymbionts Rickettsia in Psathyromyia aclydifera (prevalence of 19.54%), and Wolbachia in Psathyromyia shannoni and Lutzomyia sp. (prevalence of 25%). The detected Wolbachia lineage was similar to the wWhi strain found in Pa. shannoni from Colombia and Nyssomyia whitmani from Brazil; whereas the identified Rickettsia represents a new lineage worldwide. This is the first record of Rickettsial agents associated to sand flies from this region, yet it remains for analysed if these bacteria possibly play a role as vector control agents, capable of reducing the sand fly populations in Mexico.

American cutaneous leishmaniasis (ACL) is a common and important vector-borne parasitic zoonosis in Panam ´a. Here, we study Leishmania spp. infection rates and blood-feeding patterns among common sand flies in Trinidad de Las Minas, a rural community with hyperendemic ACL transmission, and where a deltamethrin fogging trial was performed. Sand flies were collected from April 2010 to June 2011 with light traps installed inside and in the peridomicile of 24 houses. We restricted our analysis to the most abundant species at the study site: Lutzomyia trapidoi, Lutzomyia gomezi, Lutzomyia panamensis, Lutzomyia triramula, and Lutzomyia dysponeta. We detected Leishmania spp. infection in sand flies by polymerase chain reaction (PCR) amplification of the internal transcribed spacer region 1 (ITS-1) in pooled females (1–10 females per pool). Host species of engorged sand flies were identified using a cytochrome b PCR. From 455 sand fly pools analyzed, 255 pools were positive for Leishmania spp., with an estimated infection rate (confidence interval) of 0.096 [0.080–0.115] before the deltamethrin fogging which slightly, but not significantly (P > 0.05), increased to 0.116 [0.098–0.136] after the deltamethrin fogging. Blood meal analysis suggested that pigs, goats, and birds were the most common sand fly blood sources, followed by humans and domestic dogs. DNA sequencing from a subsample of ITS-1 positive pools suggests that Leishmania panamensis, Leishmania naiffi, and other Leishmania spp. were the parasite species infecting the most common vectors at the study site. Our data confirm an association between sand fly species, humans, domestic dogs, and pigs and Leishmania spp. parasites in rural Panamá. Resumen. La leishmaniasis cutánea americana (LCA) es una zoonosis parasitaria común e importante transmitida por vectores en Panamá. Aquí estudiamos las tasas de infección por Leishmania spp. y los patrones de alimentación sanguínea entre las moscas de la arena comunes en Trinidad de Las Minas, una comunidad rural con transmisión hiperendémica de LCA, y donde se realizó un ensayo de nebulización con deltametrina. Las moscas de la arena fueron recolectadas desde abril de 2010 hasta junio de 2011 con trampas de luz instaladas dentro y en el peridomicilio de 24 casas. Restringimos nuestro análisis a las especies más abundantes en el lugar de estudio: Lutzomyia trapidoi, Lutzomyia gomezi, Lutzomyia panamensis, Lutzomyia triramula y Lutzomyia dysponeta. Se detectó la infección por Leishmania spp. en los flebótomos mediante la amplificación por reacción en cadena de la polimerasa (PCR) de la región espaciadora transcrita interna 1 (ITS-1) en hembras agrupadas (1-10 hembras por grupo). Las especies hospedadoras de las moscas de la arena engordadas se identificaron mediante una PCR del citocromo b. De los 455 grupos de moscas de la arena analizados, 255 grupos resultaron positivos a Leishmania spp., con una tasa de infección estimada (intervalo de confianza) de 0,096 [0,080-0,115] antes de la nebulización con deltametrina, que aumentó ligeramente, pero no significativamente (P > 0,05), a 0,116 [0,098-0,136] después de la nebulización con deltametrina. El análisis de la harina de sangre sugirió que los cerdos, las cabras y los pájaros eran las fuentes de sangre más comunes de la mosca de la arena, seguidos por los humanos y los perros domésticos. La secuenciación del ADN de una submuestra de grupos positivos al ITS-1 sugiere que Leishmania panamensis, Leishmania naiffi y otras Leishmania spp. fueron las especies de parásitos que infectaron a los vectores más comunes en el lugar del estudio. Nuestros datos confirman una asociación entre las especies de moscas de la arena, los seres humanos, los perros domésticos y los cerdos y los parásitos de Leishmania spp. en las zonas rurales de Panamá. Instituto Conmemorativo Gorgas de Estudios de la Salud (ICGES), Panamá Universidad de Panamá, Panamá Instituto Costarricense de Investigación y enseñanza en Nutrición y Salud (INCIENSA), Costa Rica Universidad Nacional, Costa Rica Escuela de Medicina Veterinaria

Despite the importance of Aedes, Haemagogus and Sabethes in the transmission of yellow fever virus (YFV) and the public health impacts of recent YFV epidemics in the Americas, relatively little has been reported on the biology and ecology of these vectors. Many Aedes, Haemagogus and Sabethes spp. in the American tropics inhabit and develop in the forest canopy and are difficult to sample with conventional entomological surveillance methods. We tested the utility of two previously developed phytotelmata-style oviposition traps (bamboo Guadua angustifolia) and (monkey-pot Lecythis minor), for collecting immature forms of these mosquitoes in a forest near the community of Aruza Abajo, Darien Province, Panama. Our results showed distribution of mosquito species emerging from the two types of traps was found to be significantly different (X2 = 210.23; df = 14; P

Some of the major arboviruses with public health importance, such as dengue, yellow fever, Zika and West Nile virus are mosquito-borne or mosquito-transmitted Flavivirus. Their principal vectors are from the family Culicidae, Aedes aegypti and Aedes albopictus being responsible of the urban cycles of dengue, Zika and yellow fever virus. These vectors are highly competent for transmission of many arboviruses. The genetic variability of the vectors, the environment and the viral diversity modulate the vector competence, in this context, it is important to determine which vector species is responsible of an outbreak in areas where many vectors coexist. As some vectors can transmit several flaviviruses and some flaviviruses can be transmitted by different species of vectors, through this review we expose importance of yellow fever, dengue and Zika virus in the world and the Americas, as well as the updated knowledge about these flaviviruses in their interaction with their mosquito vectors, guiding us on what is probably the beginning of a new stage in which the simultaneity of outbreaks will occur more frequently.

Background Neurotropic arboviral infections are an important cause of encephalitis. A zoonotic, vector-borne alphavirus, Madariaga virus (MADV; formerly known as South American eastern equine encephalitis virus), caused its first documented human outbreak in 2010 in Darien, Panama, where the genetically similar Venezuelan equine encephalitis virus (VEEV) is endemic. We report the results of a seroprevalence survey of animals and humans, illustrating contrasting features of MADV and VEEV ecology and epidemiology. Methods Small mammals were trapped in 42 sites in Darien, Panama, using Sherman traps, Tomahawk traps, and mist nets for bats. Blood was tested for the presence of neutralizing antibodies to MADV and VEEV. In addition, bird sera collected in 2007 in Chagres, Panama, were tested for MADV and VEEV neutralizing antibodies. Viremia was ascertained by RT-PCR. Human exposure to these two viruses was determined by IgG ELISA, followed by plaque reduction neutralization tests. To identify relevant risk factors for MADV or VEEV exposure, logistic regression analysis was performed, and the most parsimonious model was selected based on the Akaike information criterion. Results The animal survey yielded 32 bats (16 species), 556 rodents (12 species), and 20 opossums (4 species). The short-tailed cane mouse (Zygodontomys brevicauda) found abundantly in pasture and farms, had the highest MADV seroprevalence (8.3%). For VEEV, the shrub and forest-dwelling long-whiskered rice rat (Transandinomys bolivaris) had the highest seroprevalence (19.0%). Viremia was detected in one animal (Z. brevicauda). Of the 159 bird sera (50 species) tested, none were positive for either virus. In humans (n = 770), neutralizing antibodies to MADV and VEEV were present in 4.8% and 31.5%, respectively. MADV seropositivity was positively associated with cattle ranching, farming, and fishing. Having VEEV antibodies and shrubs near the house diminished risk. Age, forest work, farming and fishing were risk factors for VEEV, while having MADV antibodies, glazed windows, waste pick-up and piped water were protective. Conclusion Our findings suggest that the short-tailed cane mouse and the long-whiskered rice rat serve as hosts for MADV and VEEV, respectively. The preferred habitat of these rodent species coincides with areas associated with human infection risk. Our findings also indicate that MADV emerged recently in humans, and that the transmission cycles of these two sympatric alphaviruses differ spatially and in host utilization., Author Summary Arthropod-borne viruses are important causes of encephalitis. In 2010, the first documented human outbreak of the mosquito-borne, zoonotic Madariaga virus (MADV) occurred in the Darien region of Panama. Neither its epidemiology nor its transmission cycle is understood. In this study, the authors searched for possible animal hosts of this virus, and sought to describe its epidemiology. They contrast the findings with those for Venezuelan equine encephalitis virus (VEEV), an endemic, genetically similar virus. Zygodontomys brevicauda, the short-tailed cane mouse, had the highest seroprevalence for MADV. This rodent species is most often found in pasture and farm land. Indeed, the risk factors for human MADV exposure were cattle ranching and farming. The animal with highest seroprevalence for VEEV, the long-whiskered rice rat (Transandinomys bolivaris), commonly occurs in forest, and the epidemiological risk factors included working in the forest. Farming and fishing were risk factors for exposure to both viruses, and having antibodies to one virus diminished the risk of being positive for the other. Increasing prevalence with age was seen for VEEV, confirming that VEEV is endemic in the region. This association was absent for MADV, suggesting that this virus emerged recently to infect humans.

Background Chikungunya virus (CHIKV) typically causes explosive epidemics of fever, rash and polyarthralgia after its introduction into naïve populations. Since its introduction in Panama in May of 2014, few autochthonous cases have been reported; most of them were found within limited outbreaks in Panama City in 2014 and Puerto Obaldia town, near the Caribbean border with Colombia in 2015. In order to confirm that Panama had few CHIKV cases compared with neighboring countries, we perform an epidemiological analysis of chikungunya cases reported from May 2014 to July 2015. Moreover, to understand this paucity of confirmed CHIKV cases, a vectorial analysis in the counties where these cases were reported was performed. Methods Chikungunya cases were identified at medical centers and notified to health authorities. Sera samples were analyzed at Gorgas Memorial Institute for viral RNA and CHIKV-specific antibody detection. Results A total of 413 suspected cases of CHIKV infections were reported, with incidence rates of 0.5 and 0.7 per 100,000 inhabitants in 2014 and 2015, respectively. During this period, 38.6% of CHIKV cases were autochthonous with rash and polyarthralgia as predominant symptoms. CHIKV and DENV incidence ratios were 1:306 and 1:34, respectively. A phylogenetic analysis of E1/E2 genomic segment indicates that the outbreak strains belong to the Asian genotype and cluster together with CHIKV isolates from other American countries during the same period. Statistical analysis of the National Vector Control program at the district level shows low and medium vector infestation level for most of the counties with CHIKV cases. This index was lower than for neighboring countries. Conclusions Previous training of clinical, laboratory and vector workers allowed a good caption and detection of the chikungunya cases and fast intervention. It is possible that low/medium vector infestation level could explain in part the paucity of chikungunya infections in Panama., Author summary Chikungunya virus (CHIKV) is a mosquito borne pathogen that causes fever with rash and arthralgia, which are often confused with Dengue virus (DENV) infections. It has been reported that when CHIKV colonizes regions without previous circulation, it generally results in explosive human epidemics. In Panama, the first CHIKV infections were detected in May 2014. However, unlike many countries in the Americas, Panama presented with few autochthonous cases during the outbreak. In this study, we investigated the likely reason for the paucity of cases. Low vector infestation level, along with the surveillance programs, preparedness and early outbreak response possibly influenced the low number of cases observed during the Panamanian CHIKV outbreak.

Background Cutaneous Leishmaniasis (CL) is a neglected tropical vector-borne disease. Sand fly vectors (SF) and Leishmania spp parasites are sensitive to changes in weather conditions, rendering disease transmission susceptible to changes in local and global scale climatic patterns. Nevertheless, it is unclear how SF abundance is impacted by El Niño Southern Oscillation (ENSO) and how these changes might relate to changes in CL transmission. Methodology and Findings We studied association patterns between monthly time series, from January 2000 to December 2010, of: CL cases, rainfall and temperature from Panamá, and an ENSO index. We employed autoregressive models and cross wavelet coherence, to quantify the seasonal and interannual impact of local climate and ENSO on CL dynamics. We employed Poisson Rate Generalized Linear Mixed Models to study SF abundance patterns across ENSO phases, seasons and eco-epidemiological settings, employing records from 640 night-trap sampling collections spanning 2000–2011. We found that ENSO, rainfall and temperature were associated with CL cycles at interannual scales, while seasonal patterns were mainly associated with rainfall and temperature. Sand fly (SF) vector abundance, on average, decreased during the hot and cold ENSO phases, when compared with the normal ENSO phase, yet variability in vector abundance was largest during the cold ENSO phase. Our results showed a three month lagged association between SF vector abundance and CL cases. Conclusion Association patterns of CL with ENSO and local climatic factors in Panamá indicate that interannual CL cycles might be driven by ENSO, while the CL seasonality was mainly associated with temperature and rainfall variability. CL cases and SF abundance were associated in a fashion suggesting that sudden extraordinary changes in vector abundance might increase the potential for CL epidemic outbreaks, given that CL epidemics occur during the cold ENSO phase, a time when SF abundance shows its highest fluctuations., Author Summary In this study we analyze data on sand fly (SF) abundance and cutaneous leishmaniasis (CL) cases from Panamá. We asked whether weather patterns and climatic variability could have an impact on vector abundance that is ultimately reflected in CL transmission. We found that large epidemics of CL occur during the cold phase of El Niño Southern Oscillation (ENSO), with regular cycles coinciding with the oscillation patterns of ENSO. By contrast, and counterintuitively, we found that during the hot and cold phase of ENSO the average number of SF was reduced when compared with the normal phase of ENSO. Nevertheless, the cold ENSO phase also shows the largest variability in vector abundance, which is a likely indicative of sudden and extraordinary increases in SF abundance. We, therefore, propose that marked SF abundance changes, triggered by anomalous weather patterns associated with ENSO, likely play a major role in shaping CL interannual transmission cycles in Panamá.

Background Insecticide thermal fogging (ITF) is a tool to control vector borne diseases. Insecticide application success for vector control has been associated with housing materials and architecture. Vector abundance is correlated with weather changes. Nevertheless, housing quality and weather impacts on vector abundance have been unaccounted for in most New World insecticide control trials for leishmaniasis vectors. Methods We conducted a 15 month insecticide control trial that included two deltamethrin [6 mg a.i.m-2] based ITF interventions in 12 of 24 monitored houses at Trinidad de Las Minas, a hyperendemic cutaneous leishmaniasis transmission village in western Panamá. During the study we followed sand fly (SF) abundance, keeping track of rainfall and quantified housing quality using an index based on architecture and construction materials. Results We found a 50 to 80% reduction in SF density in the fogged houses when compared with control houses, while controlling for seasonal changes in SF abundance associated with rainfall. We found heterogeneities in the reductions, as abundance changed according to SF species: Lutzomyia gomezi, Lu. panamensis, Lu. dysponeta and Lu. triramula reduced in density between 40% and 90% after ITF. In contrast, Lu. trapidoi density increased 5% after ITF. Differences in the impact of ITF were associated with housing quality, the most destitute houses, i.e., those with features that ease insect entrance, had a disproportionally larger SF abundance, in some cases with increased domiciliary SF density following the ITF. Conclusion Our results suggest the potential of insecticide application to control SF density and leishmaniasis transmission could depend on housing quality beyond insecticide efficiency., Parasites & Vectors, 6(1), 164; 2013

American Cutaneous Leishmaniasis, ACL, is a zoonotic disease with a large richness of co-occurring vector species in transmission foci. Here, we describe changes in patterns of phlebotomine sand fly (Diptera: Psychodidae: Phlebotominae) species composition at the village of Trinidad de Las Minas, Capira, Panamá, a hyperendemic focus of ACL transmission, subjected to a vector control intervention with insecticide thermal fogging (ITF). Our study setting consisted of 24 houses, 12 subjected to two rounds of ITF and 12 kept as control. During 15 months (April 2010- June 2011) we monitored sand fly species composition and abundance with modified HP light traps inside (domicile) and outside (peridomicile) the studied houses. From 5628 sand flies collected, we were able to identify 5617 of the samples into 24 species, a number of species close to 25±1.6, the estimate from the Chao2 Index. The most abundant species were Lutzomya trapidoi (20%), Lu. gomezi (20%) and Lu. triramula (20%). Cluster analyses showed that most of the 24 houses had high similarity in relative abundance patterns of the six most common species, with only few peripheral houses not following the main cluster pattern. We also found that species richness was decreased to 22 species in the fogged houses, of which only 19 were found in the domiciliary environment. Changes in species richness were especially notorious at the end of the wet season. Our results suggest that species richness can decrease following ITF in domiciliary environments, primarily affecting the less common species. La leishmaniosis cutánea americana (LCA) es una enfermedad zoonótica con una gran riqueza de especies de vectores que coexisten en focos de transmisión. Aquí describimos los cambios en los patrones de composición de las especies de moscas de arena flebotominas (Diptera: Psychodidae: Phlebotominae) composición de especies en el pueblo de Trinidad de Las Minas, Capira, Panamá', un foco hiperendémico de transmisión del LAC, sometido a una intervención de control vectorial con nebulización térmica insecticida (ITF). Nuestro escenario de estudio consistió en 24 casas, 12 sometidas a dos rondas de ITF y 12 mantenidas como control. Durante 15 meses (abril de 2010 - junio de 2011) se monitoreó la composición y abundancia de de la mosca de la arena y su abundancia con trampas de luz HP modificadas en el interior (domicilio) y en el exterior (peridomicilio) de las casas estudiadas. casas estudiadas. De 5628 moscas de la arena recogidas, pudimos identificar 5617 de las muestras en 24 especies, un número de especies cercano a 2561,6, la estimación del índice Chao2. Las especies más abundantes fueron Lutzomya trapidoi (20%), Lu. gomezi (20%) y Lu. triramula (20%). Los análisis de conglomerados mostraron que la mayoría de las 24 casas tenían una gran similitud en los patrones de abundancia relativa de las seis especies más comunes, y sólo unas pocas casas periféricas no seguían el patrón de agrupación principal. También encontramos que la riqueza de especies se redujo a 22 especies en las casas empañadas, de las cuales sólo 19 se encontraron en el entorno domiciliario. Los cambios en la riqueza de especies fueron especialmente notorios al final de la estación húmeda. Nuestros resultados sugieren que la riqueza de especies puede disminuir tras la ITF en entornos domiciliarios, afectando principalmente a las especies menos comunes. especies menos comunes. Universidad Nacional, Costa Rica Escuela de Medicina Veterinaria

Lutzomyia longipalpis is the primary vector of the parasite responsible for visceral leishmaniasis in the Americas. In the present study, Lu. longipalpis was found in a domiciliary area in Limon, a district in Capira, a region in which cutaneous leishmaniasis is endemic in Panama. Previously, this species has been found in a humid forest in this same region. Finding Lu. longipalpis in domiciliary areas indicates that this species may be adapting to new habitats and that it may play a role in the transmission of leishmaniasis in Panama.

In Panama, species of the genus Lutzomyia are vectors of American cutaneous leishmaniasis (ACL). There is no recent ecological information that may be used to develop tools for the control of this disease. Thus, the goal of this study was to determine the composition, distribution and diversity of Lutzomyia species that serve as vectors of ACL. Sandfly sampling was conducted in forests, fragmented forests and rural environments, in locations with records of ACL. Lutzomyia gomezi, Lutzomyia panamensis and Lutzomyia trapidoi were the most widely distributed and prevalent species. Analysis of each sampling point showed that the species abundance and diversity were greatest at points located in the fragmented forest landscape. However, when the samples were grouped according to the landscape characteristics of the locations, there was a greater diversity of species in the rural environment locations. The Kruskal Wallis analysis of species abundance found that Lu. gomezi and Lu. trapidoi were associated with fragmented environments, while Lu. panamensis, Lutzomyia olmeca bicolor and Lutzomyia ylephiletor were associated with forested environments. Therefore, we suggest that human activity influences the distribution, composition and diversity of the vector species responsible for leishmaniasis in Panama.

Algunas especies del género Lutzomyia França son transmisores de la leishmaniasis cutánea y mucocutánea en Panamá. Su distribución está relacionada con la incidencia de casos en lugares ruralescolindantes a zonas boscosas, sin embargo la presencia de los vectores puede registrarse en algunas zonas, sin que existan reportes de enfermos. Este estudio se realizó en las localidades de Gamboa, Altos de Campana y Altos Chagres, sitios ubicados dentro de la Cuenca del Canal de Panamá, durante los años del 2000 al 2001. Los ejemplares se capturaron con trampas CDC miniatura y se trasladaron al Instituto Conmemorativo Gorgas donde se realizaron las identificaciones de las especies y el conteo del número de individuos. Fueron capturados 8,213 individuos del género Lutzomyia, predominando L. ylephiletor (Fairchild & Hertig) (1097 individuos) siendo también la especie más abundante en Altos de Campana, seguida de L.carpenteri (Fairchild & Hertig) (610 individuos), y L. dysponeta (Fairchild & Hertig) (595 individuos). Mediante un análisis de correspondencia simple se relacionaron las especies de Lutzomyia con los tipos de bosques característicos de las áreas de estudios, resultando correspondencia de algunas especies por el tipo de hábitat. En la similitud entre las tres áreas los resultados mostraron que la composición de especies de Phlebotominae en Altos de Campana y Altos Chagres tiene una afinidad de SSo= 0.503. Esta investigación también ha permitido actualizar la información ecológica de las especies de interés médico, con el propósito de tomar medidas preventivas y de control para evitar la proliferación de la Leishmaniasis en estas áreas.