Intermolecular base-pairing interactions, a unique topology and exoribonuclease-resistant noncoding RNAs drive formation of viral chimeric RNAs in plants.

In plants, exoribonuclease-resistant RNAs (xrRNAs) are produced by many viruses. Whereas xrRNAs contribute to the pathogenicity of these viruses, the role of xrRNAs in the virus infectious cycle remains elusive. Here, we show that xrRNAs produced by a benyvirus (a multipartite RNA virus with four genomic segments) in plants are involved in the formation of monocistronic coat protein (CP)-encoding chimeric RNAs. Naturally occurring chimeric RNAs, we discovered, are composed of 5'-end of RNA 2 and 3'-end of either RNA 3 or RNA 4 bearing conservative exoribonuclease-resistant 'coremin' region. Using computational tools and site-directed mutagenesis, we show that de novo formation of chimeric RNAs requires intermolecular base-pairing interaction between 'coremin' and 3'-proximal part of the CP gene of RNA 2 as well as a stem-loop structure immediately adjacent to the CP gene. Moreover, knockdown of the expression of the XRN4 gene, encoding 5'→3' exoribonuclease, inhibits biogenesis of both xrRNAs and chimeric RNAs. Our findings suggest a novel mechanism involving a unique tropology of the intermolecular base-pairing complex between xrRNAs and RNA2 to promote formation of chimeric RNAs in plants. XrRNAs, essential for chimeric RNA biogenesis, are generated through the action of cytoplasmic Xrn 4 5'→3' exoribonuclease conserved in all plant species.

Modeling potential risk areas of Orthohantavirus transmission in Northwestern Argentina using an ecological niche approach.

BACKGROUND: Hantavirus Pulmonary Syndrome (HPS) is a rodent-borne zoonosis in the Americas, with up to 50% mortality rates. In Argentina, the Northwestern endemic area presents half of the annually notified HPS cases in the country, transmitted by at least three rodent species recognized as reservoirs of Orthohantavirus. The potential distribution of reservoir species based on ecological niche models (ENM) can be a useful tool to establish risk areas for zoonotic diseases. Our main aim was to generate an Orthohantavirus risk transmission map based on ENM of the reservoir species in northwest Argentina (NWA), to compare this map with the distribution of HPS cases; and to explore the possible effect of climatic and environmental variables on the spatial variation of the infection risk. METHODS: Using the reservoir geographic occurrence data, climatic/environmental variables, and the maximum entropy method, we created models of potential geographic distribution for each reservoir in NWA. We explored the overlap of the HPS cases with the reservoir-based risk map and a deforestation map. Then, we calculated the human population at risk using a census radius layer and a comparison of the environmental variables' latitudinal variation with the distribution of HPS risk. RESULTS: We obtained a single best model for each reservoir. The temperature, rainfall, and vegetation cover contributed the most to the models. In total, 945 HPS cases were recorded, of which 97,85% were in the highest risk areas. We estimated that 18% of the NWA population was at risk and 78% of the cases occurred less than 10 km from deforestation. The highest niche overlap was between Calomys fecundus and Oligoryzomys chacoensis. CONCLUSIONS: This study identifies potential risk areas for HPS transmission based on climatic and environmental factors that determine the distribution of the reservoirs and Orthohantavirus transmission in NWA. This can be used by public health authorities as a tool to generate preventive and control measures for HPS in NWA.

[Tegumentary leishmaniasis and sandflies in Colonia Santa Rosa locality in northern Argentina]. / Leishmaniasis tegumentaria y flebótomos en la localidad de Colonia Santa Rosa del norte de Argentina.

Tegumentary leishmaniasis (TL) is caused by parasites of the genus Leishmania and transmitted by the sandfly species, insects belonging to the order Diptera, family Psychodidae. Historically, the most endemic area of TL in Argentina has been the northern region. The aim of this work was to analyze the presence and temporal variation of TL cases reported between 1985 and 2019 in Colonia Santa Rosa locality, northern Argentina. Furthermore, its clinical forms were characterized and sandflies were captured. Patients were diagnosed by smear and the Montenegro skin test. For sampling, CDC light traps were placed at 14 sites from 7pm to 7am. The correlation between vegetation cover and sandfly abundance was also studied. One hundred and twenty TL cases were diagnosed and the overall prevalence was 0.75% (≈16 000 inhabitants). Patients presented simple and multiple cutaneous leishmaniasis (88.79%) and the mucocutaneous form (10.83%). Skin lesions were more frequent on the lower extremities (46.73%). Of the total number of sandflies, Nyssomyia neivai (95%) was the predominant species followed by Migonemyia migonei (1.9%), cortelezzii complex (1.3%) and Evandromyia sallesi (0.09%). The persistent occurrence of cases and the presence of sandflies in the locality suggest the existence of endemic transmission in the area. This highlights the need to design prevention and control measures for TL in northern Argentina.

Potato Mop-Top Virus Co-Opts the Stress Sensor HIPP26 for Long-Distance Movement.

Virus movement proteins facilitate virus entry into the vascular system to initiate systemic infection. The potato mop-top virus (PMTV) movement protein, TGB1, is involved in long-distance movement of both viral ribonucleoprotein complexes and virions. Here, our analysis of TGB1 interactions with host Nicotiana benthamiana proteins revealed an interaction with a member of the heavy metal-associated isoprenylated plant protein family, HIPP26, which acts as a plasma membrane-to-nucleus signal during abiotic stress. We found that knockdown of NbHIPP26 expression inhibited virus long-distance movement but did not affect cell-to-cell movement. Drought and PMTV infection up-regulated NbHIPP26 gene expression, and PMTV infection protected plants from drought. In addition, NbHIPP26 promoter-reporter fusions revealed vascular tissue-specific expression. Mutational and biochemical analyses indicated that NbHIPP26 subcellular localization at the plasma membrane and plasmodesmata was mediated by lipidation (S-acylation and prenylation), as nonlipidated NbHIPP26 was predominantly in the nucleus. Notably, coexpression of NbHIPP26 with TGB1 resulted in a similar nuclear accumulation of NbHIPP26. TGB1 interacted with the carboxyl-terminal CVVM (prenyl) domain of NbHIPP26, and bimolecular fluorescence complementation revealed that the TGB1-HIPP26 complex localized to microtubules and accumulated in the nucleolus, with little signal at the plasma membrane or plasmodesmata. These data support a mechanism where interaction with TGB1 negates or reverses NbHIPP26 lipidation, thus releasing membrane-associated NbHIPP26 and redirecting it via microtubules to the nucleus, thereby activating the drought stress response and facilitating virus long-distance movement.

[Soil transmitted helminthiasis in Argentina. A systematic review]. / Geohelmintiasis en la Argentina. Una revisión sistemática.

A systematic review of surveys performed between 1980 and 2011 (published in MEDLINE/Pubmed and/or LILACS indexed journals, available in the baseline data from a Mass Deworming National Program (MDNP, 2005) was used to identify the prevalence, distribution and detection of risk areas for soil transmitted helminth infections (STH) in Argentina. We found 310 publications in the database using the pre-defined key-words (medical subject headings) for research purposes. Only 24 articles with 26 surveillance sites in 8 provinces and a total of 5495 surveyed individuals fulfilled the inclusion criteria. Frequency rates for STH had a wide range: Ascaris lumbricoides: 0-67%, hookworms: 0-90%, Trichuris trichiura: 0-24.6 and Strongyloides stercoralis: 0-83%. The estimated combined incidence varied from 0.8% to 88.6%. Baseline surveys from the MDNP reporting on 1943 children from 12 provinces confirmed the heterogeneity, with combined STH frequency rates ranging from 0 to 42.7%. Surveys included in this review showed that the distribution of STH in Argentina is not homogeneous, with areas of high incidence (> 20%) in the northeastern and northwestern provinces where mass deworming activities would be highly beneficial. In several surveys, the high overall incidence was mostly due to hookworms and S. stercoralis, a situation to be considered when selecting diagnostic and therapeutic control strategies. The scarcity or absence of data from various provinces and the availability of less than 8000 surveyed individuals should be considered.

First detection of V410L kdr mutation in Aedes aegypti populations of Argentina supported by toxicological evidence.

BACKGROUND: Aedes aegypti (L.) is the main vector of dengue, yellow fever, Zika, and chikungunya viruses in many parts of the world, impacting millions of people worldwide each year. Insecticide-based interventions have been effective in controlling Aedes mosquito populations for several years, but in recent times, resistance to these compounds has developed, posing a global threat to the control of this mosquito. METHODS: Ovitraps were used to collect A. aegypti eggs in the cities of Tartagal and San Ramón de la Nueva Orán (Salta), Puerto Iguazú (Misiones), and Clorinda (Formosa). World Health Organization (WHO)-impregnated papers with the discriminating concentration (DC) of permethrin, 5X, 10X and pirimiphos methyl were used for the toxicological bioassays. We also genotyped each sample for the three kdr single nucleotide polymorphisms (SNP): V410L, V1016I, and F1534C in individual TaqMan quantitative PCR (qPCR) reactions. RESULTS: All investigated A. aegypti populations were highly resistant to permethrin, as the mortality percentage with the permethrin 10×DC remained below 98%. However, all populations were 100% susceptible to pirimiphos-methyl. Kdr genotyping demonstrated the presence of the V410L mutation for the first time in Argentina in all the populations studied. A prevalence of the triple mutant genotype (LL + II + CC) was observed in the northeastern cities of Clorinda (83.3%) and Puerto Iguazú (55.6%). CONCLUSIONS: This study demonstrates for the first time the presence and intensity of resistance to permethrin in different populations from Argentina, and correlates the observed phenotype with the presence of kdr mutations (genotype).

Clustering Health Behaviors in Mexican Adolescents: The HELENA-MEX Study.

Purpose: The prevalence of excess weight within the adolescent population is rapidly increasing in Mexico, especially in areas with lower socioeconomic status. The present study aimed to identify lifestyle clustered patterns in adolescents and analyze the associations among these clusters and body composition. Method: A final sample of n=259 participants (13 to 17 years old, 58.7% girls), residents in rural and urban areas, were included. Hierarchical and k-means clusters analyses included moderate to vigorous physical activity (MVPA), cardiorespiratory fitness (CRF), handgrip strength, screen time, sleep time, and diet. The associations between cluster membership and body composition were analyzed through general linear models (ANCOVA), including sex, age, place of residence, and socioeconomic status as covariates. Results: Three different clusters were identified: Cluster 1, [Unhealthy] (low values in all lifestyle patterns), Cluster 2, [Low Physical Fitness] (low values in CRF and handgrip strength) and Cluster 3, [High Physical Activity and CRF] (highest values in CRF, handgrip strength and MVPA). Clusters 2 and 3 showed high values in screen time and industrialized food consumption. There were no differences in sleep between the 3 Clusters. ANCOVA analysis revealed that participants belonging to Cluster 3 showed significantly lower adiposity and a higher Fat Free Mass compared with the other two clusters (p < 0.05). Conclusion: Our findings suggest that a lifestyle characterized by high levels of physical activity and physical fitness and low consumption of industrialized food may be protective against the problem of obesity, which could be helpful to develop interventions to reduce excess weight in Mexican adolescents.

Performance of different Trypanosoma cruzi antigens in the diagnosis of Chagas disease in patients with American cutaneous leishmaniasis from a co-endemic region in Argentina.

OBJECTIVE: To determine the ability of recombinant antigens to detect cases of infection with Trypanosoma cruzi among cases of infection with Leishmania spp. by serological methods. METHODS: Sera from 41 patients infected with Leishmania spp. were evaluated with ELISA using single (FRA, CP1 and TSSAVI) or pooled (commercial Rec-ELISA) recombinant proteins or homogenate antigens (commercial H-ELISA). As there is no gold standard antigen to discriminate Chagas disease from leishmaniasis, the correlation of results between defined antigens and the homogenate was made with Kappa Index (KI), the level of correlation considered being used as a criterion of specificity. RESULTS: Single recombinant antigens and Rec-ELISA showed good correlation (KI > 0.8). A low correlation (KI < 0.66) was observed between the results from single recombinant antigens or the commercial recombinant kit and H-ELISA. CONCLUSIONS: The highly correlated results between T. cruzi single or pooled recombinant proteins are indicative of the usefulness of recombinant antigens for Chagas diagnosis. Our results also indicate that in the city of Oran in Argentina, between 12% and 17% of patients with leishmaniasis are also infected with Chagas disease. The high KI values between TSSAVI and the other recombinant proteins suggest that in these patients, the infection may be caused by T. cruzi II and/or V and/or VI lineages.

Analysis of the tick communities associated to domestic mammals in rural areas of the Yungas montane forest from Argentina.

The aim of this work was to describe the tick community associated to domestic mammals in rural areas from the Yungas lower montane forest of Argentina. The circulation of tick-borne pathogens was also analyzed. Samples of ticks parasitizing cattle, horses, sheep and dogs were carried out in different seasons, and questing ticks were collected from vegetation and analyzed to detect the presence of Rickettsia, Ehrlichia, Borrelia and Babesia by a battery of different PCRs. The structure of the tick communities was analyzed through the Chao1 species richness estimator, the Shannon-Wiener index and the Horn index of community similarity. Eight tick species were collected in the study area: Amblyomma sculptum, Rhipicephalus microplus, Amblyomma hadanii, Dermacentor nitens, Amblyomma ovale, Haemaphysalis juxtakochi, Ixodes pararicinus and Rhipicephalus sanguineus sensu stricto. However, A. sculptum was by far the dominant species in the tick assemblages analyzed, and this was reflected in the low diversity values obtained. Dermacentor nitens, A. sculptum and R. microplus were the three species associated to horses. The predominance of A. sculptum was also observed in the tick samples obtained from dogs, even on two tick species, namely A. ovale and R. sanguineus s.s., which have dogs as the principal domestic host. Rhipicephalus microplus and A. sculptum were the most abundant ticks on cattle, while few specimens of I. pararicinus, A. hadanii and D. nitens were found on bovines. Dermacentor nitens ticks were found to be infected with B. caballi, which indicate the circulation of this pathogen of horses in the Yungas area. The detection of a strain of Borrelia sp. belonging to the B. burgdorferi s.l. complex in I. pararicinus is consistent with previous findings made in Argentina, but the public health relevance of this vector-microorganism association is far from being similar to that occurs in the northern hemisphere because there are practically no records of these tick species parasitizing humans in South America. The tick community of rural areas of the Yungas lower montane forest is composed by species which are potential vectors of pathogenic microorganism with veterinary and public health importance, circulating in a human-wildlife-livestock interface.

The impact of point source pollution on shallow groundwater used for human consumption in a threshold country.

Many developing and threshold countries rely on shallow groundwater wells for their water supply whilst pit latrines are used for sanitation. We employed a unified strategy involving satellite images and environmental monitoring of 16 physico-chemical and microbiological water quality parameters to identify significant land uses that can lead to unacceptable deterioration of source water, in a region with a subtropical climate and seasonally restricted torrential rainfall in Northern Argentina. Agricultural and non-agricultural sources of nitrate were illustrated in satellite images and used to assess the organic load discharged. The estimated human organic load per year was 28.5 BOD(5) tons and the N load was 7.5 tons, while for poultry farms it was 9940-BOD(5) tons and 1037-N tons, respectively. Concentrations of nitrates and organics were significantly different between seasons in well water (p values of 0.026 and 0.039, respectively). The onset of the wet season had an extraordinarily negative impact on well water due in part to the high permeability of soils made up of fine gravels and coarse sand. Discriminant analysis showed that land uses had a pronounced seasonal influence on nitrates and introduced additional microbial contamination, causing nitrification and denitrification in shallow groundwater. P-well was highly impacted by a poultry farm while S-well was affected by anthropogenic pollution and background load, as revealed by Principal Component Analysis. The application of microbial source tracking techniques is recommended to corroborate local sources of human versus animal origin.

[Immunoenzymatic evaluation of the recombinant SAPA protein of Trypanosoma cruzi in naturally infected dogs]. / Evaluación inmunoenzimática del antígeno recombinante SAPA en perros infectados naturalmente por Trypanosoma cruzi.

We evaluated the recombinant antigen SAPA (Shed Acute Phase Antigen) for the detection of Trypanosoma cruzi antibodies in sera from naturally infected dogs. The technique used was ELISA and the antigens were a homogenate of parasite T. cruzi (ELISA-H) and the recombinant SAPA (ELISA-SAPA). We analyzed 93 sera from dogs by ELISA-H and ELISA-SAPA, which were grouped as follows: G1: 11 negative control sera from the city of Salta, G2: 11 positive control sera from dogs naturally infected with T. cruzi and G3: 71 samples of dogs belonging to a Chagas disease-endemic area. The sensitivity and specificity of ELISA-SAPA were 100 %. The kappa index between ELISA-H and ELISA-SAPA was 0,85. These results confirm the use of SAPA antigen in the diagnosis of infection with T. cruzi in dogs.

Use of Aedes aegypti Oviposition Surveillance and a Geographic Information System for Planning Anti-Vectorial Measures.

Arboviruses transmitted by Aedes aegypti pose a threat to global public health. Because there are no vaccines or drugs available, the prevention of these diseases in Argentina is based on integrated vector control. In this work, the spatiotemporal dynamics of the vector distribution was analyzed by monitoring oviposition. This information allowed the planning of anti-vector interventions and the evaluation of their effect on the relative abundance of mosquito populations in San Ramón de la Nueva Orán. Observed data were compared with the eggs expected via a statistical model based on meteorological variables. The oviposition substrate preference of mosquito females was also evaluated, and the possible relationship between the relative abundance of the vector and sociodemographic and environmental variables (normalized difference vegetation index and normalized difference water index) was explored. A total of 4,193 eggs of Ae. aegypti were collected, and spatial clusters were detected for all months for which the presence of the mosquito was reported. The observed number of eggs was significantly less than the expected-corrected egg abundance. A significant correlation of oviposition activity was found with three sociodemographic variables, whereas no significant correlation was found with mean or median values of the environmental variables studied. This monitoring strategy made it possible to address the interventions and evaluate them, proposing them as good complementary tools for the control of Ae. aegypti in northern Argentina.

High Adherence to the Mediterranean Diet is Associated with Higher Physical Fitness in Adults: a Systematic Review and Meta-Analysis.

Although prior research has synthesized the relationships between the Mediterranean diet (MD) and components of physical fitness (PF) in adults, they are limited and inconclusive. This study aimed to synthesize the associations between high (compared with low) MD adherence and PF levels with each of its components (cardiorespiratory, motor, and musculoskeletal) in adulthood. We conducted a systematic search in 5 databases from inception to January 2022. Observational studies and randomized controlled trials were included. Pooled odds ratios (ORs) and effect sizes (Cohen d index) with their 95% CIs were calculated via a random effects model. A total of 30 studies were included (19 cross-sectional in young, middle-aged, and older adults; 10 prospective cohort in older adults; and 1 randomized controlled trial in young adults) involving 36,807 individuals (mean age range: 20.9-86.3 y). Pooled effect sizes showed a significant cross-sectional association between higher MD adherence scores (as a continuous variable) and overall PF (d = 0.45; 95% CI: 0.14, 0.75; I2 = 91.0%, n = 6). The pooled ORs from cross-sectional data showed that high adherence to MD was associated with higher cardiorespiratory fitness (OR: 2.26; 95% CI: 2.06, 2.47; I2 = 0%, n = 4), musculoskeletal fitness (OR: 1.26; 95% CI: 1.05, 1.47; I2 = 61.4%, n = 13), and overall PF (OR: 1.44; 95% CI: 1.20, 1.68; I2 = 83.2%, n = 17) than low adherence to MD (reference category: 1). Pooled ORs from prospective cohort studies (3- to 12-y follow-up) showed that high adherence to MD was associated with higher musculoskeletal fitness (OR: 1.20; 95% CI: 1.01, 1.38; I2 = 0%, n = 4) and overall PF (OR: 1.14; 95% CI: 1.02, 1.26; I2 = 9.7%, n = 7) than low adherence to MD (reference category: 1). Conversely, no significant association was observed between MD and motor fitness. High adherence to MD was associated with higher PF levels, a crucial marker of health status throughout adulthood. This trial was registered at PROSPERO as CRD42022308259.

[Role of three ELISA tests using promastigote homogenates of Leishmania braziliensis, L. amazonensis and L. guyanensis in the diagnosis of tegumentary leishmaniasis]. / El rol de tres pruebas de ELISA con antígenos de promastigotes de Leishmania braziliensis, L. amazonensis y L. guyanensis en el diagnóstico de leishmaniasis tegumentaria.

It is important to know whether the variability of species of Leishmania parasites circulating in a region affects the performance of the ELISA test for the diagnosis of leishmaniasis. Therefore, the aim of this study was to analyze the reactivity of the ELISA using homogenates of promastigotes of Leishmania (V.) braziliensis (ELISAb), Leishmania (L) amazonensis (ELISAa) and Leishmania (V.) guyanensis (ELISAg) against different sera groups. Samples from individuals with cutaneous leishmaniasis (n = 37), mucocutaneous leishmaniasis (n = 8), healthy controls (n = 52), persons infected with Trypanosoma cruzi (n = 11) and mixed infections (n = 14) were included in the study. We calculated sensitivities, specificities, cut offs, and predictive values for the three tests and compared them using ANOVA, kappa index, ROC curves comparison, and confidence intervals calculated by the bootstrap method. Significant differences were found when comparing the OD levels of sera from patients with cutaneous leishmaniasis against healthy controls, but there were no differences when comparing the different ELISAs. The sensitivities calculated for ELISAb and ELISAa were 84.6 and of 88.5% for ELISAg, while the value of specificity for the three tests was 96.2. The kappa index (0.87) and comparison of ROC curves showed similar performance for the three ELISAs (p = 0.225). The high reactivity obtained for these ELISAs in sera of patients with mucocutaneous leishmaniasis indicates this test as an important complement in the diagnosis of the disease.

Ivermectin-related adverse clinical events in patients treated for Mansonella ozzardi infections.

We report the occurrence of serious reactions after treatment with oral ivermectin in two patients with Mansonella ozzardi infections. Both had systemic and respiratory symptoms and recovered without sequelae. Follow-up revealed clearance of microfilaremia in both cases, with relapse in one of them. These reactions are well described in the treatment of other filarial infections, but have not yet been reported in the treatment of M. ozzardi. We are now reporting the first such known reactions with this helminthiasis.

Viruses in Extreme Environments, Current Overview, and Biotechnological Potential.

Virus research has advanced significantly since the discovery of the tobacco mosaic virus (TMV), the characterization of its infection mechanisms and the factors that determine their pathogenicity. However, most viral research has focused on pathogenic viruses to humans, animals and plants, which represent only a small fraction in the virosphere. As a result, the role of most viral genes, and the mechanisms of coevolution between mutualistic viruses, their host and their environment, beyond pathogenicity, remain poorly understood. This review focuses on general aspects of viruses that interact with extremophile organisms, characteristics and examples of mechanisms of adaptation. Finally, this review provides an overview on how knowledge of extremophile viruses sheds light on the application of new tools of relevant use in modern molecular biology, discussing their value in a biotechnological context.

Assessment of Influential Factors for Scours Associated with Cryptosporidium sp., Rotavirus and Coronavirus in Calves from Argentinean Dairy Farms.

Scours is the most common disease in dairy calves, and it is a multifactorial syndrome complex. Cryptosporidium sp. (C. sp.), rotavirus group A (RVA), and bovine coronavirus (BCoV) are the three main pathogens associated with scours. The objective of this study was to identify potential factors associated with scours, C. sp., RVA, and BCoV infections in preweaned dairy calves from Lerma Valley in Salta Province, Argentina. A total of 488 preweaned calves from 19 dairy farms located in the Lerma Valley were enrolled in this observational study. One fecal sample was collected from each calf between one week and two months of age for assessment of C. sp., RVA, and BCoV infection status. Cryptosporidium sp. oocysts and RVA and BCoV antigens in fecal samples were assessed using microscopic observation and indirect enzyme-linked immune sorbent assay (iELISA), respectively. A voluntary questionnaire was developed and used to collect data regarding management practices from the participants' farms. The data were analyzed using multivariable logistic regression models. Scours incidence was 35.4%, and a greater proportion of calves younger than 20 days were affected. Of the fecal samples, 18% and 9.5% tested were positives for C. sp. and RVA, respectively, while BCoV was detected only in two calves. Furthermore, 84.2% and 63.1% of the farms tested positive for Cryptosporidium sp. and RVA, respectively. In addition, the following variables were associated with higher odds of having scours: (1) herd size (>300 milking cows; OR = 1.7), (2) calf age (<20 days of age; OR = 2.2), (3) RVA and C. sp. test (positive test; RVA OR = 2.6; C. sp. OR = 3), calf feeding practices (feeding milk replacer; OR = 1.81), and newborn calf management practices (calf moved from maternity pen <6 h after calving; OR = 1.7). Concerning RVA infection, calves less than 20 days of age (OR = 2.6) had a higher chance of testing positive for RVA, while calves that remained in the calving pen for less than 6 h after calving had a lower chance (OR = 0.3). On the other hand, for C. sp. infection, large farm size (>300 milking cows; OR = 1.2) and young calf age (<20 days of age; OR = 4.4) indicated a higher chance of testing positive for C. sp., while calves belonging to farms that fed frozen colostrum (OR = 0.2) had a lower chance of becoming infected with C. sp. The result of this study indicated that scours is a prevalent disease in farms of the Lerma Valley, Salta, Argentina, and that RVA and C. sp. infections, along with specific farm management practices, might be important contributing factors that could increase the chance of NCS in dairy farms.

Tegumentary leishmaniasis and sand flies in a border area between Argentina and Bolivia.

Background: Some sand flies are of medical importance because they are vectors of Leishmania parasites that are responsible for leishmaniasis. The aim of this study was to make a retrospective epidemiological analysis of tegumentary leishmaniasis (TL), to identify Leishmania spp. from patient isolates and to describe the diversity of sand flies from a border area between Bolivia and Argentina. Methods: TL cases included in the study were diagnosed in an endemic area of the north of Argentina from 1985 to 2017. The parasites isolated were characterized by the cytochrome B method. Sand flies were captured with Centers for Disease Control traps in Aguas Blancas and Media Luna-Algarrobito localities. Results: A total of 118 cases of TL were analysed. Eight isolates were characterized as Leishmania (Viannia) braziliensis. A total of 1291 sand flies were captured, including Nyssomyia neivai, Cortelezzii complex, Evandromyia sallesi, Migonemyia migonei and Micropygomyia quinquefer. Within the area, sand flies were found in the backyards of houses. Conclusions: In this region there exists the possibility of peridomestic transmission of TL in the neighbourhoods peripheral to the urban area and in rural environments as well as the risk of transmission to travellers that pass through the customs offices.

TcTASV Antigens of Trypanosoma cruzi: Utility for Diagnosis and High Accuracy as Biomarkers of Treatment Efficacy in Pediatric Patients.

The discovery and characterization of novel parasite antigens to improve the diagnosis of Trypanosoma cruzi by serological methods and for accurate and rapid follow-up of treatment efficiency are still needed. TcTASV is a T. cruzi-specific multigene family, whose products are expressed on the parasite stages present in the vertebrate host. In a previous work, a mix of antigens from subfamilies TcTASV-A and TcTASV-C (Mix A + C) was sensitive and specific to identify dogs with active infection of high epidemiological relevance. Here, TcTASV-A and TcTASV-C were assayed separately as well as together (Mix A + C) in an ELISA format on human samples. The Mix A + C presented moderate sensitivity (78%) but high diagnostic accuracy with a 100% of specificity, evaluated on healthy, leishmaniasic, and Strongyloides stercoralis infected patients. Moreover, antibody levels of pediatric patients showed-2 years posttreatment-diminished reactivity against the Mix A + C (P < 0.0001), pointing TcTASV antigens as promising tools for treatment follow-up.

Vegetation Cover and Microspatial Distribution of Sand Flies (Diptera: Psychodidae) in an Endemic Locality for Cutaneous Leishmaniasis in Northern Argentina.

The sand fly fauna in Hipólito Yrigoyen, Argentina, a locality where cutaneous leishmaniasis cases occur, was surveyed with zones of higher abundance of sand flies correlated to vegetation cover estimated through normalized difference vegetation index (NDVI). Sand flies were collected with 10 CDC traps during six nights, from December 2009 to January 2010. A map was built of expected sand flies abundance in which levels of NDVI were categorized. In total, 1,392 Phlebotominae (Diptera: Psychodidae) specimens were collected, comprised of the following species: Nyssomyia neivai (Pinto 1926), Migonemyia migonei (França 1920), species of the cortelezzii complex (Brèthes 1923), Evandromyia sallesi (Galvão & Coutinho 1940), and Psathyromyia shannoni (Dyar 1929). Positive correlations were found between the abundance of sand flies and the NDVI (P < 0.05) for buffer areas of <150 m radii from the trap location points, i.e., the sand fly abundance was greater where vegetation cover and density were greater. In this context, plant cover should be taken into account to prioritize surveillance and control areas within the program of sand flies control in northern Argentina.