Performance of the Health System Network in Formosa, Argentina, in the Diagnosis of Leprosy.

Leprosy is a chronic, neglected tropical infectious disease, currently endemic in Formosa, a province in northwestern Argentina. To analyze the performance, distribution, and effectiveness of the health system in leprosy diagnosis in Formosa, we estimated the trend of the number of new cases of leprosy diagnosed between 2002 and 2019 and estimated a forecast for 2022 at the primary health care centers (PHCCs) of at the first level of care (1stLC), at district hospitals (DHs) of the second level of care (2ndLC), high-complexity hospitals at the third level of care (3rdLC), and in rural and urban areas. The general trend was calculated based on the new cases detection rate (NCDR) using the autoregressive-moving average model (ARMA). The 1stLC, 2ndLC, and 3rdLC and the rural/urban variables were assessed using a proportional Bayesian trend ARMA (TrARMA) model. A predictive model was used for estimated forecasts. Markov-Monte Carlo chains were applied with A Metropolis-Hastings's algorithm. The highest median proportion (Mp) of new cases of leprosy was diagnosed at the 2ndLC (Mp, 0.67; 97.5% credibility interval [CI] [0.56-0.77]), at the 3rdLC (Mp, 0.11; 97.5% CI [0.08-0.15]), and in urban areas (urban median proportion (uMp), 0.86; 97.5% CI [0.83- 0.88]), whereas the lowest proportion of new cases was diagnosed at the 1stLC (Mp, 0.082; 97.5% CI [0.061-0.108]) and in rural areas (rural median proportion (rMp), 0.13; 97.5% CI [0.11-0.16]). Our model predicts for 2022 that a median number of new cases of leprosy of 19.70 will be diagnosed in urban areas (97.5% CI [15.94-23.80]), and will continue to be diagnosed at the 2ndLC (median number of cases, 15.33; 97.5% CI [12.40-10.52]) and 3rdLC (median number of cases, 2.43; 97.5% CI [1.97-2.94]).

Status and forecast of leprosy in the still endemic province of Formosa in northern Argentina.

BACKGROUND: The province of Formosa, Argentina, is endemic for leprosy. In the present paper, we assessed the trend (T, 2002-2016 time series) and the forecast for 2022 of new case detection rate (NCDR) and determined the spatial distribution of new cases detected (NCD) of leprosy. METHODOLOGY/PRINCIPAL FINDINGS: This is a descriptive observational study of 713 NCD of leprosy from provincial medical records between January 2002 and December 2016. The whole dataset from the provincial medical record was used to independently estimate the NCDR trends of the general population, age groups, sexes and Departments. This same database was used to estimate the NCDR forecast of the general population for 2022, applying a dynamic linear model with a local linear trend, using the MCMC algorithm. The NCDR was higher in men (p<0.05), increased with age (0.20, 8.17, 21.04, and 29.49 for the 0-14, 15-44, 45-64 and over 65-year-old age groups, respectively; p<0.05) and showed a downward trend (negative values) of estimated slopes for the whole province and each Department. Bermejo Department showed the highest (T:-1.02, 95%CI: [-1.42, -0.66]) and Patiño the lowest decreasing trend (T:-0.45, 95%CI: [-0.74, -0.11]). The NCDR trend for both sexes was similar (T:-0.55, 95%CI: [-0.64, -0.46]), and age groups showed a decreasing trend (S15-44:-103, S45-64:-81, S>65:-61, p<0.05), except for the 0-14 age group (S:-3, p>0.05), which showed no trend. Forecasts predicted that leprosy will not be eliminated by 2022 (3.64, 95%CI: [1.22, 10.25]). CONCLUSIONS/SIGNIFICANCE: Our results highlight the status of leprosy in Formosa and provide information to the provincial public health authorities on high-risk populations, stressing the importance of timely detection of new cases for further elimination of the disease in the province.

Optimization of DNA Extraction from Individual Sand Flies for PCR Amplification.

Numerous protocols have been published for extracting DNA from phlebotomines. Nevertheless, their small size is generally an issue in terms of yield, efficiency, and purity, for large-scale individual sand fly DNA extractions when using traditional methods. Even though this can be circumvented with commercial kits, these are generally cost-prohibitive for developing countries. We encountered these limitations when analyzing field-collected Lutzomyia spp. by polymerase chain reaction (PCR) and, for this reason, we evaluated various modifications on a previously published protocol, the most significant of which was a different lysis buffer that contained Ca2+ (buffer TESCa). This ion protects proteinase K against autolysis, increases its thermal stability, and could have a regulatory function for its substrate-binding site. Individual sand fly DNA extraction success was confirmed by amplification reactions using internal control primers that amplify a fragment of the cacophony gene. To the best of our knowledge, this is the first time a lysis buffer containing Ca2+ has been reported for the extraction of DNA from sand flies.

Is autumn the key for dengue epidemics in non endemic regions? The case of Argentina.

BACKGROUND: Dengue is a major and rapidly increasing public health problem. In Argentina, the southern extreme of its distribution in the Americas, epidemic transmission takes place during the warm season. Since its re-emergence in 1998 two major outbreaks have occurred, the biggest during 2016. To identify the environmental factors that trigger epidemic events, we analyzed the occurrence and magnitude of dengue outbreaks in time and space at different scales in association with climatic, geographic and demographic variables and number of cases in endemic neighboring countries. METHODS: Information on dengue cases was obtained from dengue notifications reported in the National Health Surveillance System. The resulting database was analyzed by Generalized Linear Mixed Models (GLMM) under three methodological approaches to: identify in which years the most important outbreaks occurred in association with environmental variables and propose a risk estimation for future epidemics (temporal approach); characterize which variables explain the occurrence of local outbreaks through time (spatio-temporal approach); and select the environmental drivers of the geographical distribution of dengue positive districts during 2016 (spatial approach). RESULTS: Within the temporal approach, the number of dengue cases country-wide between 2009 and 2016 was positively associated with the number of dengue cases in bordering endemic countries and negatively with the days necessary for transmission (DNT) during the previous autumn in the central region of the country. Annual epidemic intensity in the period between 1999-2016 was associated with DNT during previous autumn and winter. Regarding the spatio-temporal approach, dengue cases within a district were also associated with mild conditions in the previous autumn along with the number of dengue cases in neighboring countries. As for the spatial approach, the best model for the occurrence of two or more dengue cases per district included autumn minimum temperature and human population as fixed factors, and the province as a grouping variable. Explanatory power of all models was high, in the range 57-95%. DISCUSSION: Given the epidemic nature of dengue in Argentina, virus pressure from endemic neighboring countries along with climatic conditions are crucial to explain disease dynamics. In the three methodological approaches, temperature conditions during autumn were best associated with dengue patterns. We propose that mild autumns represent an advantage for mosquito vector populations and that, in temperate regions, this advantage manifests as a larger egg bank from which the adult population will re-emerge in spring. This may constitute a valuable anticipating tool for high transmission risk events.

[Visceral leishmaniasis in Argentina. Cases notification and distribution of vectors (2006-2012)]. / Leishmaniasis visceral en la Argentina. Notificación y situación vectorial (2006-2012).

Visceral leishmaniasis (VL) is a notifiable disease in Argentina. Every new case diagnosed must be reported to the National Health Surveillance System. In the period 2006-2012, a total of 103 cases have been notified in four provinces: Entre Rios, Santa Fe, Misiones and Santiago del Estero. Misiones has the largest amount of cases: a total of 80, detected in 15 towns from May 2006 to July 2012. The highest incidence is observed in children (less than 15 years of age). In 2004 the vector Lutzomyia longipalpis was detected for the first time in Formosa Province. Cases of human and canine VL, as well as the presence of the canine vector were reported in 2006 in the province of Misiones, and in 2008-2009 in the province of Corrientes. In Santiago del Estero cases of human and canine VL (2008) were possibly associated with secondary vectors. In 2010 Lu longipalpis was found in Entre Rios, showing its dispersal to the south. Between January and April 2011 a systematic search of the VL vector was carried out in 13 towns, in Entre Ríos, Santa Fe and Santiago del Estero Provinces (275 traps/night). The colonization of the vector Lu longipalpis was proved in Chajarí town (Entre Rios), but not in Santiago del Estero Province, where Migonemyia migonei appears as a putative LV vector.

Leishmaniasis visceral en la Argentina: Notificación y situación vectorial (2006-2012) / Visceral leishmaniasis in Argentina: Cases notification and distribution of vectors (2006-2012)

La leishmaniasis visceral (LV) en la Argentina se notifica obligatoriamente a través del Sistema Nacional de Vigilancia de la Salud (SNVS). El análisis de la notificación muestra un total de 103 casos distribuidos en cuatro provincias, siendo Misiones la de mayor casuística con un total de 80 casos en 15 localidades, desde mayo 2006 hasta julio de 2012. Los niños de 0 a 15 años de edad son el grupo con mayor incidencia. En el año 2004 fue registrado por primera vez el riesgo de LV urbana endémica en la provincia de Formosa tras el hallazgo del vector Lutzomyia longipalpis. En el año 2006 la provincia de Misiones registra casos de LV humana, LV canina, y la provincia de Corrientes en el verano 2008-2009. En Santiago del Estero los casos de LV humana y LV canina en el año 2008 estuvieron asociados posiblemente a vectores secundarios. En el año 2010 Lu. longipalpis fue hallado en Chajarí, Entre Ríos, mostrando su dispersión hacia el sur. Por ello, para conocer la distribución del riesgo, entre enero y abril del 2011 se realizó búsqueda sistemática del vector de LV en 13 localidades de las provincias de Entre Ríos, Santa Fe y Santiago del Estero, totalizando 275 trampas/noche. Se comprobó la colonización de Lu. longipalpis, en la localidad de Chajarí. En Santiago del Estero no se encontró Lu. longipalpis por lo que Migonemyia migonei sigue incriminada como vector putativo de LV en esta región.(AU)

Visceral leishmaniasis (VL) is a notifiable disease in Argentina. Every new case diagnosed must be reported to the National Health Surveillance System. In the period 2006-2012, a total of 103 cases have been notified in four provinces: Entre Rios, Santa Fe, Misiones and Santiago del Estero. Misiones has the largest amount of cases: a total of 80, detected in 15 towns from May 2006 to July 2012. The highest incidence is observed in children (less than 15 years of age). In 2004 the vector Lutzomyia longipalpis was detected for the first time in Formosa Province. Cases of human and canine VL, as well as the presence of the canine vector were reported in 2006 in the province of Misiones, and in 2008-2009 in the province of Corrientes. In Santiago del Estero cases of human and canine VL (2008) were possibly associated with secondary vectors. In 2010 Lu longipalpis was found in Entre Rios, showing its dispersal to the south. Between January and April 2011 a systematic search of the VL vector was carried out in 13 towns, in Entre Ríos, Santa Fe and Santiago del Estero Provinces (275 traps/night). The colonization of the vector Lu longipalpis was proved in Chajarí town (Entre Rios), but not in Santiago del Estero Province, where Migonemyia migonei appears as a putative LV vector.(AU)

Leishmaniasis visceral en la Argentina: Notificación y situación vectorial (2006-2012) / Visceral leishmaniasis in Argentina: Cases notification and distribution of vectors (2006-2012)

La leishmaniasis visceral (LV) en la Argentina se notifica obligatoriamente a través del Sistema Nacional de Vigilancia de la Salud (SNVS). El análisis de la notificación muestra un total de 103 casos distribuidos en cuatro provincias, siendo Misiones la de mayor casuística con un total de 80 casos en 15 localidades, desde mayo 2006 hasta julio de 2012. Los niños de 0 a 15 años de edad son el grupo con mayor incidencia. En el año 2004 fue registrado por primera vez el riesgo de LV urbana endémica en la provincia de Formosa tras el hallazgo del vector Lutzomyia longipalpis. En el año 2006 la provincia de Misiones registra casos de LV humana, LV canina, y la provincia de Corrientes en el verano 2008-2009. En Santiago del Estero los casos de LV humana y LV canina en el año 2008 estuvieron asociados posiblemente a vectores secundarios. En el año 2010 Lu. longipalpis fue hallado en Chajarí, Entre Ríos, mostrando su dispersión hacia el sur. Por ello, para conocer la distribución del riesgo, entre enero y abril del 2011 se realizó búsqueda sistemática del vector de LV en 13 localidades de las provincias de Entre Ríos, Santa Fe y Santiago del Estero, totalizando 275 trampas/noche. Se comprobó la colonización de Lu. longipalpis, en la localidad de Chajarí. En Santiago del Estero no se encontró Lu. longipalpis por lo que Migonemyia migonei sigue incriminada como vector putativo de LV en esta región.

Visceral leishmaniasis (VL) is a notifiable disease in Argentina. Every new case diagnosed must be reported to the National Health Surveillance System. In the period 2006-2012, a total of 103 cases have been notified in four provinces: Entre Rios, Santa Fe, Misiones and Santiago del Estero. Misiones has the largest amount of cases: a total of 80, detected in 15 towns from May 2006 to July 2012. The highest incidence is observed in children (less than 15 years of age). In 2004 the vector Lutzomyia longipalpis was detected for the first time in Formosa Province. Cases of human and canine VL, as well as the presence of the canine vector were reported in 2006 in the province of Misiones, and in 2008-2009 in the province of Corrientes. In Santiago del Estero cases of human and canine VL (2008) were possibly associated with secondary vectors. In 2010 Lu longipalpis was found in Entre Rios, showing its dispersal to the south. Between January and April 2011 a systematic search of the VL vector was carried out in 13 towns, in Entre Ríos, Santa Fe and Santiago del Estero Provinces (275 traps/night). The colonization of the vector Lu longipalpis was proved in Chajarí town (Entre Rios), but not in Santiago del Estero Province, where Migonemyia migonei appears as a putative LV vector.

Leishmaniasis visceral en la Argentina. Notificación y situación vectorial (2006-2012). / [Visceral leishmaniasis in Argentina. Cases notification and distribution of vectors (2006-2012)].

Visceral leishmaniasis (VL) is a notifiable disease in Argentina. Every new case diagnosed must be reported to the National Health Surveillance System. In the period 2006-2012, a total of 103 cases have been notified in four provinces: Entre Rios, Santa Fe, Misiones and Santiago del Estero. Misiones has the largest amount of cases: a total of 80, detected in 15 towns from May 2006 to July 2012. The highest incidence is observed in children (less than 15 years of age). In 2004 the vector Lutzomyia longipalpis was detected for the first time in Formosa Province. Cases of human and canine VL, as well as the presence of the canine vector were reported in 2006 in the province of Misiones, and in 2008-2009 in the province of Corrientes. In Santiago del Estero cases of human and canine VL (2008) were possibly associated with secondary vectors. In 2010 Lu longipalpis was found in Entre Rios, showing its dispersal to the south. Between January and April 2011 a systematic search of the VL vector was carried out in 13 towns, in Entre Ríos, Santa Fe and Santiago del Estero Provinces (275 traps/night). The colonization of the vector Lu longipalpis was proved in Chajarí town (Entre Rios), but not in Santiago del Estero Province, where Migonemyia migonei appears as a putative LV vector.

[Distribution of Lutzomyia longipalpis in the Argentine Mesopotamia, 2010]. / Distribución de Lutzomyia Longipalpis en la Mesopotamia Argentina, 2010.

The first case of visceral leishmaniasis (VL) in Argentina was reported in 2006 in Posadas, Misiones. During the summer 2008-2009 Lutzomyia longipalpis, the VL vector, and canine VL cases were already spread along the province of Corrientes. In order to know the distribution of VL risk, systematic captures of the vector were performed between February and March 2010, in 18 areas of the provinces of Entre Ríos and Corrientes, and the city of Puerto Iguazú, Misiones, with a total of 313 traps/night. We confirmed the presence of Lu. longipalpis, for the first time in Chajarí (Entre Ríos), Alvear, La Cruz, Curuzú Cuatiá and Bella Vista (Corrientes), and Puerto Iguazú (Misiones). In Santo Tome and Monte Caseros (Corrientes), where the vector had been previously reported, traps with more samples were obtained with 830 and 126 Lu. Longipalpis trap/site/night respectively. These results show that the vector of urban VL continues spreading in the Argentine territory. Simultaneously, the spread of the parasite and the resulting human VL cases are associated with the dispersion of reservoirs, infected dogs, with or without clinical symptoms or signs, due to human transit.

Distribución de Lutzomyia longipalpis en la Mesopotamia Argentina, 2010 / Distribution of Lutzomyia longipalpis in the Argentine Mesopotamia, 2010

El primer caso autóctono de leishmaniasis visceral (LV) en la Argentina se notificó en el año 2006 en Posadas, Misiones, y en el verano 2008-2009 se comprobó la dispersión del vector de LV, Lutzomyia longipalpis y casos de LV canina en la provincia de Corrientes. Para conocer la distribución del riesgo, entre febrero y marzo del 2010 se realizó la búsqueda sistemática del vector de LV en 18 localidades de las provincias de Entre Ríos, Corrientes y en la ciudad de Puerto Iguazú, Misiones, totalizando 313 trampas/noche. Se comprobó la presencia de Lu. longipalpis, por primera vez, en las localidades de Chajarí (Entre Ríos), Alvear, La Cruz, Curuzú Cuatiá y Bella Vista (Corrientes), y en Puerto Iguazú (Misiones). En Santo Tomé y Monte Caseros (Corrientes) se volvió a registrar la presencia del vector, y se obtuvieron las trampas con más ejemplares, 830 y 126 Lu. longipalpis trampa/sitio/noche respectivamente. Los resultados muestran que el vector de la LV urbana, continúa dispersándose en el territorio argentino. Simultáneamente, la propagación del parásito, y los consecuentes casos de LV humana se asocian al aumento de reservorios, perros infectados con o sin clínica, debidos al tránsito humano.

The first case of visceral leishmaniasis (VL) in Argentina was reported in 2006 in Posadas, Misiones. During the summer 2008-2009 Lutzomyia longipalpis, the VL vector, and canine VL cases were already spread along the province of Corrientes. In order to know the distribution of VL risk, systematic captures of the vector were performed between February and March 2010, in 18 areas of the provinces of Entre Ríos and Corrientes, and the city of Puerto Iguazú, Misiones, with a total of 313 traps/night. We confirmed the presence of Lu. longipalpis, for the first time in Chajarí (Entre Ríos), Alvear, La Cruz, Curuzú Cuatiá and Bella Vista (Corrientes), and Puerto Iguazú (Misiones). In Santo Tome and Monte Caseros (Corrientes), where the vector had been previously reported, traps with more samples were obtained with 830 and 126 Lu. Longipalpis trap/site/night respectively. These results show that the vector of urban VL continues spreading in the Argentine territory. Simultaneously, the spread of the parasite and the resulting human VL cases are associated with the dispersion of reservoirs, infected dogs, with or without clinical symptoms or signs, due to human transit.