The principal objective of this study was to assess a modeling approach to Lu. longipalpis distribution in an urban scenario, discriminating micro-scale landscape variables at microhabitat and macrohabitat scales and the presence from the abundance of the vector. For this objective, we studied vectors and domestic reservoirs and evaluated different environmental variables simultaneously, so we constructed a set of 13 models to account for micro-habitats, macro-habitats and mixed-habitats. We captured a total of 853 sandflies, of which 98.35% were Lu. longipalpis. We sampled a total of 197 dogs; 177 of which were associated with households where insects were sampled. Positive rK39 dogs represented 16.75% of the total, of which 47% were asymptomatic. Distance to the border of the city and high to medium density vegetation cover ended to be the explanatory variables, all positive, for the presence of sandflies in the city. All variables in the abundance model ended to be explanatory, trees around the trap, distance to the stream and its quadratic, being the last one the only one with negative coefficient indicating that the maximum abundance was associated with medium values of distance to the stream. The spatial distribution of dogs infected with L. infantum showed a heterogeneous pattern throughout the city; however, we could not confirm an association of the distribution with the variables assessed. In relation to Lu. longipalpis distribution, the strategy to discriminate the micro-spatial scales at which the environmental variables were recorded allowed us to associate presence with macrohabitat variables and abundance with microhabitat and macrohabitat variables. Based on the variables associated with Lu. longipalpis, the model will be validated in other cities and environmental surveillance, and control interventions will be proposed and evaluated in the microscale level and integrated with socio-cultural approaches and programmatic and village (mesoscale) strategies.

No abstract

SUMMARY The first Argentinian autochthonous human case of visceral leishmaniasis (VL) was confirmed in Posadas (Misiones) in 2006. Since then, the disease has increased its incidence and geographical distribution. In the 2006-2012 period, 107 human cases were detected (11 deaths). The presence of Lutzomyia longipalpis was detected in peridomiciles in Puerto Iguazú urban area in 2010; some of these findings were associated with households where cases of canine VL had already been reported. The objective of this study was to ascertain the abundance and spatial distribution of Lu. longipalpis in Puerto Iguazú City, on the Argentina-Brazil-Paraguay border. Lu. longipalpis proved to be exclusively urban and was found in 31% of the households sampled (n = 53), 67% of which belonged to areas of low abundance, 20% to areas of moderate abundance and 13% to areas of high abundance. Nyssomyia whitmani was the only species found both in urban and peri-urban environments, and Migonemyia migonei was registered only on the outskirts of the city. Due to the fact that Puerto Iguazú is considered to be at moderate risk at the moment, it is necessary to intensify human and canine case controls, as well as take integrated prevention and control measures regarding the environment, vectors and reservoirs on the Argentina-Brazil-Paraguay border area.

No abstract

The objective of this study was to evaluate the presence of Lutzomyia longipalpis in the Argentine city of Concordia, in the province of Entre Rios, without record of this species despite previous samplings, but with canine cases of visceral leishmaniasis and Lu. longipalpis reports both, from Northern Argentine localities and from the city of Salto, Uruguay, located just across the river and the international border. This study confirms the presence of Lu. longipalpis and Nyssomyia whitmani, related to the risk of visceral and tegumentary leishmaniasis, respectively, in Concordia-Entre Rios. The presence of Lu. longipalpis confirms the ongoing dispersal along the Uruguay river basin. The presence of these species in the study area alerts about the risk of transmission of Leishmania spp.

The aim of this study was to evaluate the effectiveness of insecticide-impregnated curtains against the entry of phlebotomine (Diptera: Psychodidae) flies into experimental slatted hen houses in an area endemic for American cutaneous leishmaniasis (ACL). Three treatments in experimental dwellings containing three chickens each were applied using, respectively, an impregnated curtain (IC), a non-impregnated curtain (NIC) and no curtain (NC). A control site without chickens (WC) was included. The study used permethrin at 0.05 g/m . During each month for 1 year, each experimental hen house randomly received all treatments. Phlebotomine sandflies were captured using REDILA BL traps placed inside the hen house. Significant differences in abundances of phlebotomine flies/trap/night were observed between treatments (χ = 17853.58, d.f. = 3, P < 0.0001): 59.7% of phlebotomines were captured in the NC treatment, 26.3% in the NIC treatment, 8.0% in the IC treatment and 6.1% in the WC condition. Nyssomyia whitmani (Antunes & Coutinho) was the most abundant species in all collections (89.9%). These results showed a lower abundance of phlebotomines in the experimental hen house in the IC condition than in the hen house in the NC condition (P < 0.05) and that the presence of NIC represents an effective physical barrier against phlebotomines (P < 0.05). Therefore, the use of curtains may be an alternative eco-friendly method for the prevention of indoor ACL transmission in slatted dwellings, which represent a common house type in northeast Argentina.

No abstract

NO2 is a mainly anthropogenic gas that affects population health and its exposure is associated with several respiratory diseases. Its tropospheric concentration is associated with vehicle emissions. During 2020, COVID-19 lockdowns have impeded population's mobility, hence constructing an almost ideal situation to study their relationship with tropospheric NO2 concentration. We used TROPOMI satellite images, Google mobility reports and vehicule count in order to study these relationships in six big Latin American metropolitan areas. In all of them, tropospheric NO2 concentration decreased during 2020 compared to 2019, particularly during April 2020. The daily vehicle count in Buenos Aires was a significantly important variable in order to explain NO2 concentration variations. This study strengthens previous research findings about NO2 concentration reduction during COVID-19 lockdowns and shows the relationship between human mobility and air pollution in the particular context of Latin America big cities.