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Both HIV-1 and Toxoplasma gondii are able to invade central nervous system and affect its functionality. Advanced HIV-1 infection has been associated with defects in immune response to T. gondii, leading to reactivation of latent infections and the appearing of toxoplasmic encephalitis. This study evaluated changes in the immune response to T. gondii in different stages of HIV infection. Immune response to T. gondii was assessed studying cytokine production in response to parasite antigens in HIV-1-infected/T. gondii-non-infected (P1), HIV-1/T. gondii co-infected (P2), HIV-1-non-infected/T. gondii-non-infected (C1) and HIV-1-non-infected/T. gondii-infected (C2) individuals. Patients (P1 and P2) were divided in early/asymptomatic (P1A, P2A) or late/symptomatic (P1B/C, P2B/C) according to peripheral blood CD4+ T lympho-cyte counts (>350 or

La enfermedad de Chagas (ECh) es una parasitosis del grupo de enfermedades desatendidas de la OMS. Endémica del continente americano, la transmisión se realiza en ciclos selvático, peridomiciliario y domiciliario. Epidemiológicamente, los caninos y felinos constituyen una fuente importante de infección y son centinelas de la transmisión. El perro es un hospedador común e importante del parásito ya que la presencia y número de caninos infectados en la vivienda del hombre constituyen factores de riesgo de transmisión doméstica de Trypanosoma cruzi. El presente estudio reporta la seroprevalencia de la infección por T. cruzi en la bioregión centro norte de Venezuela (Distrito Capital, Chichiriviche de la Costa del Estado La Guaira y parte del Estado Miranda), en 301 perros y 49 gatos empleando el ensayo inmunoenzimatico (ELISA). La prevalencia global en perros fue del 30,2 % en las tres zonas estudiadas mientras que en gatos fue de 40,8 %. Con relación al sexo de los animales, se encontró una prevalencia general de perros hembras del 27,6 % y para los perros machos del 33,1%. Los gatos machos presentaron una prevalencia mayor que las hembras en todas las localidades. Tanto en perros como en gatos la distribución de seropositividad fue mayor en animales intradomicilio. Se evidenció diferencia en los valores de ELISA-IgG para las poblaciones de perros muestreados en la localidad de Petare comparado con perros presentes en la localidad de Aricagua (perros de caza), (p=0,006). En líneas generales, esta última localidad presentó una media de densidad óptica para la prueba de ELISA-IgG de 0,959 [0,369 - 1,975]. La presencia de perros y gatos infectados es un factor de riesgo actual de infección por T. cruzi para el hombre tanto en el medio rural como en el urbano.

In the past 5–10 years, Venezuela has faced a severe economic crisis, precipitated by political instability and declining oil revenue. Public health provision has been affected particularly. In this Review, we assess the impact of Venezuela's health-care crisis on vector-borne diseases, and the spillover into neighbouring countries. Between 2000 and 2015, Venezuela witnessed a 359% increase in malaria cases, followed by a 71% increase in 2017 (411 586 cases) compared with 2016 (240 613). Neighbouring countries, such as Brazil, have reported an escalating trend of imported malaria cases from Venezuela, from 1538 in 2014 to 3129 in 2017. In Venezuela, active Chagas disease transmission has been reported, with seroprevalence in children ( less than 10 years), estimated to be as high as 12·5% in one community tested (n=64). Dengue incidence increased by more than four times between 1990 and 2016. The estimated incidence of chikungunya during its epidemic peak is 6975 cases per 100 000 people and that of Zika virus is 2057 cases per 100 000 people. The re-emergence of many vector-borne diseases represents a public health crisis in Venezuela and has the possibility of severely undermining regional disease elimination efforts. National, regional, and global authorities must take action to address these worsening epidemics and prevent their expansion beyond Venezuelan borders. © 2019 Elsevier Ltd

Accurate diagnostics tools and surrogate markers of parasitological response to treatment are priority needs for management of Chagas disease. Quantitative real-time PCR (qPCR) is used for treatment monitoring, but variability in copy dosage and sequences of molecular target genes among different Trypanosoma cruzi strains limit the precision of quantitative measures. To improve qPCR quantification accuracy, we designed and evaluated a synthetic DNA molecule containing a Satellite DNA (satDNA) repeat unit as standard for quantification of T. cruzi loads in clinical samples, independently of the parasite strain. Probit regression analysis established for Dm28c (Tc I) and CL-Brener (Tc VI) stocks similar LOD95 values (0.903 (0.745-1.497) and 0.667 (CI 0.113-3.927) copy numbers/μL, respectively), when synthetic DNA was the standard for quantification, thus allowing direct comparison of loads in samples infected with different DTUs. This standard curve was evaluated in 205 samples from 38 acute oral and 19 chronic CD patients from different geographical areas infected with different genotypes, including samples obtained during treatment follow-up, and high agreement with parasitic load trends using standard curves based on DNA extracted from spiked blood with counted parasites was obtained. This qPCR-based quantification strategy will be a valuable tool in phase III clinical trials, to follow-up patients under treatment or at risk of reactivation and in experimental models using different parasite strains. Fil: Muñoz Calderon, Arturo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Silva Gomess, Natalia Lins. Fundación Oswaldo Cruz; Brasil Fil: Apodaca, Sofia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Alarcón de Noya, Belkisyolé. Universidad Central de Venezuela; Venezuela Fil: Díaz Bello, Zoraida. Universidad Central de Venezuela; Venezuela Fil: Quintino Souza, Leticia Rocha. Fundación Oswaldo Cruz; Brasil Fil: Tavares Costa, Alexandre Dias. Fundación Oswaldo Cruz; Brasil Fil: Britto, Constança. Fundación Oswaldo Cruz; Brasil Fil: Moreira, Otacilio Cruz. Fundación Oswaldo Cruz; Brasil Fil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina

Chagas disease is one of the parasitic infections with the greatest socio-economic impact in Latin America. In Venezuela, epidemiological data has shown different sources of infection, such as the vectorial route by oral transmission. Given the importance of the TLR4 gene in the innate immune response triggered by infection with Trypanosoma cruzi, this work analyses the role of TLR4 polymorphisms and its possible effect on cytokine expression. Genomic DNA was extracted from the peripheral blood of patients from the main outbreak of oral Chagas disease in Venezuela (n = 90), as well as from a group of healthy individuals (n = 183). Subsequently, peripheral blood was also extracted from individuals with different TLR4 haplotypes and then stimulated with LPS to determine the cytokine concentration by ELISA. The internalization of TLR4 was evaluated by flow cytometry. In comparison to healthy individuals, the analysis showed a significantly increased frequency of the Asp/Gly genotype in symptomatic patients. Also, observed a correlation of the 299/399 haplotype with a significant decrease in cytokine concentration and disease severity. Finally, the parasites' trypomastigotes cause the internalization or negative regulation of TLR4. The variants of TLR4 associated with low production of cytokines may be a risk factor for chronicity and severity (cardiac involvement) in oral vectorial Chagas disease.

Several diagnostic tools have been developed for clinical and epidemiological assays. RT-PCR and antigen detection tests are more useful for diagnosis of acute disease, while antibody tests allow the estimation of exposure in the population. Currently, there is an urgent need for the development of diagnostic tests for COVID-19 that can be used for large-scale epidemiological sampling. Through a comprehensive strategy, potential 16 mer antigenic peptides suited for antibody-based SARS-CoV-2 diagnosis were identified. A systematic scan of the three structural proteins (S,N and M) and the non-structural proteins (ORFs) present in the SARS-CoV-2 virus was conducted through the combination of immunoinformatic methods, peptide SPOT synthesis and an immunoassay with cellulose-bound peptides (Pepscan). The Pepscan filter paper sheets with synthetic peptides were tested against pools of sera of COVID-19 patients. Antibody recognition showed a strong signal for peptides corresponding to the S, N and M proteins of SARS-CoV-2 virus, but not for the ORFs proteins. The peptides exhibiting higher signal intensity were found in the C-terminal region of the N protein. Several peptides of this region showed strong recognition with all three immunoglobulins in the pools of sera. The differential reactivity observed between the different immunoglobulin isotypes (IgA, IgM and IgG) within different regions of the S and N proteins, can be advantageous for ensuring accurate diagnosis of all infected patients, with different times of exposure to infection. Few peptides of the M protein showed antibody recognition and no recognition was observed for peptides of the ORFs proteins.

Trypanosoma cruzi uses various mechanisms of infection to access humans. Since 1967, food contaminated with metacyclic trypomastigotes has triggered several outbreaks of acute infection of Chagas disease by oral transmission. Follow-up studies to assess the effectiveness of anti-parasitic treatment of oral outbreaks are rather scarce. Here, we report a 10-year laboratory follow-up using parasitological, serological, and molecular tests of 106 individuals infected in 2007 of the largest known outbreak of orally transmitted Chagas disease, which occurred in Caracas city, Venezuela. Before treatment (2007), specific IgA, IgM and IgG, were found in 71% (75/106), 90% (95/106) and 100% (106/106), respectively, in addition to 21% (9/43) parasitemia, Complement Mediated Lysis (CML) in 98% (104/106) and 79% (34/43) parasitic DNA for PCR. Blood culture detected parasitemia up to 18 months post-treatment in 6% (6/106) of the patients. In 2017, the original number of cases in the follow-up decreased by 46% and due to the country's economic situation, not all the trials could be carried out in the entire population. During follow-up, IgA and IgM disappeared promptly, with IgM persisting in 19% (20/104) of the patients three years after treatment. The anti-T. cruzi IgG remained positive 10 years later in 41% (20/49) of the individuals evaluated. CML remained positive seven years later in 79% (65/82) of the cases. PCR positive cases decreased after treatment but progressively recovered, being positive in 69% (32/46) of the individuals evaluated in 2017. The group of children (under 18 years of age) showed the highest PCR positivity with 76% (26/34) of the cases, but their parasitic load tended to diminish, while in adults the parasitic load regained their initial values. The simultaneous evaluation of serological tests and PCR of the patients allowed us to separate patients among responders and non-responders to the anti-parasitic treatment, and this information prompted us to apply a second anti-parasitic treatment in the group of non-responders. In this population not subjected to the like lihood of re-infection, adult patients were more likely to be non-responders when compared to children. These results suggest that rigorous laboratory follow-up with T. cruzi infectious biomarkers is essential to detect cases of parasite persistence.

Chagas disease, caused by the protozoan Trypanosoma cruzi, affects more than 6 million people worldwide. Following a mostly asymptomatic acute phase, the disease progresses to a long-lasting chronic phase throughout which life-threatening disorders to the heart and/or gastrointestinal tract will manifest in about 30% of those chronically infected. During the chronic phase, the parasitemia is low and intermittent, while a high level of anti-T. cruzi antibodies persist for years. These two features hamper post-chemotherapeutic follow-up of patients with the tools available. The lack of biomarkers for timely assessment of therapeutic response discourages a greater use of the two available anti-parasitic drugs, and complicates the evaluation of new drugs in clinical trials. Herein, we investigated in a blinded case-control study the serological reactivity over time of a group of parasite-derived antigens to potentially address follow up of T. cruzi chronically infected subjects after treatment. We tested PFR2, KMP11, HSP70, 3973, F29 and the InfYnity multiplexed antigenic array, by means of serological assays on a multi-national retrospective collection of samples. Some of the antigens exhibited promising results, underscoring the need for further studies to determine their potential role as treatment response biomarkers.

The cryptic parasite Sparganum proliferum proliferates in humans and invades tissues and organs. Only scattered cases have been reported, but S. proliferum infection is always fatal. However, S. proliferum’s phylogeny and life cycle remain enigmatic. To investigate the phylogenetic relationships between S. proliferum and other cestode species, and to examine the mechanisms underlying pathogenicity, we sequenced the entire genomes of S. proliferum and a closely related non–life-threatening tapeworm Spirometra erinaceieuropaei. Additionally, we performed larvae transcriptome analyses of S. proliferum plerocercoid to identify genes involved in asexual reproduction in the host. The genome sequences confirmed that the S. proliferum has experienced a clearly distinct evolutionary history from S. erinaceieuropaei. Moreover, we found that nonordinal extracellular matrix coordination allows asexual reproduction in the host, and loss of sexual maturity in S. proliferum are responsible for its fatal pathogenicity to humans. Our high-quality reference genome sequences should be valuable for future studies of pseudophyllidean tapeworm biology and parasitism., Kikuchi et al. sequence the genome of the fatal tapeworm Sparganum proliferum and a closely related non–life-threatening tapeworm Spirometra erinaceieuropaei, and describe its genomic features suggesting the natural history and molecular mechanisms underlying pathogenicity. Their findings indicate that nonordinal extracellular matrix coordination is important for its asexual reproduction, and suggest that loss of sexual maturity contributes to the fatal pathogenicity of S. proliferum to humans.

En este artículo se revisan las infecciones parasitarias de mayor impacto a la gestante en el trópico latinoamericano, con repercusiones para la madre y el niño. Algunas de estas afecciones se deben tomar en cuenta para el diseño de medidas preventivas de la población en general, ya que aquellas debilitan el estado general de la gestante y también pueden tener un efecto directo sobre la placenta y afectar al feto ”. Las mujeres tienen, por tanto, una morbilidad añadida derivada del embarazo y el parto, con una cifra estimada en 2017, de unos 80 millones de casos relacionados con más de 800.000 años vividos con discapacidad. En paralelo, 16 infecciones parasitarias causan casi un millón de muertes, 3 millones de casos y 96 millones de años de vida ajustados por discapacidad, AVAD, anualmente. De estos 16 parásitos, 5 pueden transmitirse verticalmente al feto (malaria, toxoplasmosis, enfermedad de Chagas, leishmaniasis visceral y tripanosomiasis africana) o durante el parto (tricomoniasis). Los 10 restantes (protozoos intestinales y helmintos) pueden debilitar a la madre con consecuencias de diversa intensidad para el feto (anemia, bajo peso al nacer, mortinatos). En los trópicos, también existen condiciones especiales que agravan este cuadro nocivo durante el embarazo

In Venezuela, Chagas disease (ChD) is considered a serious health problem, with about 6 million people at risk; and acute outbreaks due to oral transmission of Chagas Disease (OChD) are becoming increasingly important. In 2007 there was a major outbreak of OChD and although patients from this episode were treated with nifurtimox (Lampit®-Bayer), about 70% therapeutic failure was registered. These results led us to examine whether parasite's drug susceptibility was related to this therapeutic failure.The Trypanosoma cruzi parasites were isolated by haemoculture of the peripheral blood drawn from the pre- and post-nifurtimox treated patients infected in the 2007 OChD outbreak at Caracas, Venezuela. The in vitro assays for drug testing were performed by the MTT methodology followed by calculation of inhibitory concentration-50 (ICParasite isolates obtained from the infected patients prior and after nifurtimox treatment when subjected to variable concentrations of the drug showed great heterogeneity in susceptibility with ICThe high heterogeneity in nifurtimox IC

BackgroundThe cryptic parasite Sparganum proliferum proliferates in humans and invades tissues and organs. Only scattered cases have been reported, but S. proliferum infection is always fatal. However, the S. proliferum phylogeny and lifecycle are still an enigma.ResultsTo investigate the phylogenetic relationships between S. proliferum and other cestode species, and to examine the underlying mechanisms of pathogenicity, we sequenced the entire S. proliferum genome. Additionally, S. proliferum plerocercoid larvae transcriptome analyses were performed to identify genes involved in asexual reproduction in the host. The genome sequences confirmed that the S. proliferum genetic sequence is distinct from that of the closely related Spirometra erinaceieuropaei. Moreover, nonordinal extracellular matrix coordination allows for asexual reproduction in the host and loss of sexual maturity in S. proliferum is related to its fatal pathogenicity in humans.ConclusionsThe high-quality reference genome sequences generated should prove valuable for future studies of pseudophyllidean tapeworm biology and parasitism.

descripción no proporcionada por scopus, ISGlobal work is supported by the Departament d’Universitats i Recerca de la Generalitat de Catalunya, Spain (AGAUR; 017SGR00924) and by the Instituto de Salud Carlos III (ISCIII) RICET Network for Cooperative Research in Tropical Diseases (ISCIII; RD16/0027/0004 - PI1290) and FEDER. MJP research is supported by the Ministry of Health, Government of Catalonia (PERIS 2016-2010 SLT008/18/00132). ICA, JG, and FT are supported by the grant number U01AI129783 from the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH). ICA is also partly supported by the grant number 5U54MD007592 from the National Institute on Minority Health and Health Disparities (NIMHD), NIH. MCL and MCT were supported by ISCIII RICET grant RD16/0027/0005 - PI1290 and FEDER and by grants SAF2016-81003-R and SAF2016-80998-R from the Spanish “Programa Estatal I+D+i (MINECO)”. AA's work was supported by the Italian Ministry of Health “Fondi Ricerca Corrente - Linea 3, progetto 9” to IRCCS Sacro Cuore Don Calabria Hospital. JR was supported by CONACyT Fossis grant #261006. The Drugs for Neglected Diseases initiative (DNDi) is grateful to its donors, public and private, who have provided funding to DNDi since its inception in 2003. A full list of DNDi's donors can be found at http://www.dndi.org/donate/donors/. FIND is grateful to its donors, public and private, who have helped bring innovative new diagnostics for diseases of poverty. A full list of FIND’s donors can be found at: https://www.finddx.org/partners-donors/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Chagas disease (CD) epidemiology is rapidly evolving in the context of human, socioeconomic, and environmental changes. Until the mid-twentieth century, CD was exclusively present in rural parts of the American continent, considered a disease of poverty associated with potentially lethal heart disease and was usually incurable. Since then, an increasing number of sporadic cases and evidence of congenital, post-transfusional and transplanted-related transmission have been identified first in urban regions of Latin America and more recently in other continents. This happens as a consequence of enhanced human mobility both within countries (rural to urban migration) and across borders in the context of socioeconomic and political development along with globalization. In parallel, hematophagous triatomines, the vectors of Trypanosoma cruzi, were increasingly identified in peri-urban regions of Latin America but also in other latitudes, such as in the United States, Australia, and in some Asian countries. Outbreaks of human cases following food-borne transmission have highlighted the risk of the development of emergent routes of transmission potentially affecting large numbers of people. Another example pertains to the global dissemination of Cimex lectularius (bedbugs) as a worldwide pest, difficult to control and with demonstrated susceptibility to T. cruzi infection.

Background & objectives: In Venezuela, Chagas disease (ChD) is considered a serious health problem, with about 6 million people at risk; and acute outbreaks due to oral transmission of Chagas Disease (OChD) are becoming increasingly important. In 2007 there was a major outbreak of OChD and although patients from this episode were treated with nifurtimox (Lampit®—Bayer), about 70% therapeutic failure was registered. These results led us to examine whether parasite’s drug susceptibility was related to this therapeutic failure. Methods: The Trypanosoma cruzi parasites were isolated by haemoculture of the peripheral blood drawn from the pre- and post-nifurtimox treated patients infected in the 2007 OChD outbreak at Caracas, Venezuela. The in vitro assays for drug testing were performed by the MTT methodology followed by calculation of inhibitory concentration-50 (IC50) values. Results: Parasite isolates obtained from the infected patients prior and after nifurtimox treatment when subjected to variable concentrations of the drug showed great heterogeneity in susceptibility with IC50 values ranging from 4.07 ± 1.82 to 94.92 ± 7.24 µM. Interpretation & conclusion: The high heterogeneity in nifurtimox IC50 values in the isolates and clones from the OChD patients, suggests that the therapeutic failure to nifurtimox could be due in part to a phenotypic variability that existed in the wild parasite population at the original source of contamination. Though, further pharmacological studies are needed to confirm the existence of natural nifurtimox resistance in the parasite. Fil: Muñoz Calderon, Arturo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Central de Venezuela; Venezuela Fil: Diaz Bello, Zoraida. Universidad Central de Venezuela; Venezuela Fil: Ramirez, José Luis. Fundacion Instituto de Estudios Avanzados Idea; Venezuela Fil: Noya, Oscar. Universidad Central de Venezuela; Venezuela. Ministerio del Poder Popular para la Salud; Venezuela Fil: Alarcón de Noya, Belkisyolé. Universidad Central de Venezuela; Venezuela

Two old drugs are the only choice against Trypanosoma cruzi and little is known about their secondary effects in the acute stage of oral-transmitted Chagas disease (ChD).A cross-sectional analytical surveillance study was conducted in a sizable cohort of patients seen during the largest acute foodborne ChD microepidemic registered so far. Individuals were treated with benznidazole (BNZ) or nifurtimox (NFX). 'Common Terminology Criteria for Adverse Events' was assessed to categorize side effects according to severity.Out of 176 treatments applied, 79% had one or more adverse effects, which predominated in adults (97.8%) as compared to children (75.5%). Risk of side effects with NFX was significantly higher than BNZ. Four adults and a child treated with NFX had severe side effects (pulmonary infarction, facial paralysis, neutropenia, blurred vision, bone marrow hypoplasia) warranting hospitalization, and drug suspension. Adverse effects frequently reported with NFX were abdominal pain, hyporexia, weight loss, headache, nausea and lymphocytosis, whereas skin rash, neurosensory effects, hyporexia, fatigue, pyrosis, abdominal pain and eosinophilia were observed with BNZ.Frequency and severity of side effects during treatment of acute oral infection by T. cruzi demand direct supervision and close follow-up, even in those asymptomatic, to prevent life-threatening situations.

Oral transmission of Trypanosoma cruzi is a frequent cause of acute Chagas disease (ChD). In the present cross-sectional study, we report the epidemiological, clinical, serological and molecular outcomes of the second largest outbreak of oral ChD described in the literature. It occurred in March 2009 in Chichiriviche de la Costa, a rural seashore community at the central littoral in Venezuela. The vehicle was an artisanal guava juice prepared at the local school and Panstrongylus geniculatus was the vector involved. TcI genotype was isolated from patients and vector; some showed a mixture of haplotypes. Using molecular markers, parasitic loads were high. Eighty-nine cases were diagnosed, the majority (87.5%) in school children 6–15 years of age. Frequency of symptomatic patients was high (89.9%) with long-standing fever in 87.5%; 82.3% had pericardial effusion detected by echocardiogram and 41% had EKG abnormalities. Three children, a pregnant woman and her stillborn child died (5.6% mortality). The community was addressed by simultaneous determination of specific IgG and IgM, confirmed with indirect hemagglutination and lytic antibodies. Determination of IgG and IgA in saliva had low sensitivity. No individual parasitological or serological technique diagnosed 100% of cases. Culture and PCR detected T. cruzi in 95.5% of examined individuals. Based on the increasing incidence of oral acute cases of ChD, it appears that food is becoming one of the most important modes of transmission in the Amazon, Caribbean and Andes regions of America., Graphical abstract Image 1

A Trypanosoma cruzi Loopamp kit was recently developed as a ready-to-use diagnostic method requiring minimal laboratory facilities. We evaluated its diagnostic accuracy for detection of acute Chagas disease (CD) in different epidemiological and clinical scenarios. In this retrospective study, a convenience series of clinical samples (venous blood treated with EDTA or different stabilizer agents, heel-prick blood in filter paper or cerebrospinal fluid samples (CSF)) from 30 infants born to seropositive mothers (13 with congenital CD and 17 noninfected), four recipients of organs from CD donors, six orally–infected cases after consumption of contaminated guava juice and six CD patients coinfected with HIV at risk of CD reactivation (N = 46 patients, 46 blood samples and 1 CSF sample) were tested by T. cruzi Loopamp kit (Tc LAMP) and standardized quantitative real-time PCR (qPCR). T. cruzi Loopamp accuracy was estimated using the case definition in the different groups as a reference. Cohen’s kappa coefficient (κ) was applied to measure the agreement between Tc LAMP (index test) and qPCR (reference test). Sensitivity and specificity of T. cruzi Loopamp kit in blood samples from the pooled clinical groups was 93% (95% CI: 77–99) and 100% (95% CI: 80–100) respectively. The agreement between Tc LAMP and qPCR was almost perfect (κ = 0.92, 95% CI: 0.62–1.00). The T. cruzi Loopamp kit was sensitive and specific for detection of T. cruzi infection. It was carried out from DNA extracted from peripheral blood samples (via frozen EDTA blood, guanidine hydrochloride-EDTA blood, DNAgard blood and dried blood spots), as well as in CSF specimens infected with TcI or TcII/V/VI parasite populations. The T. cruzi Loopamp kit appears potentially useful for rapid detection of T. cruzi infection in congenital, acute and CD reactivation due to HIV infection., Author summary The aim of this study was to evaluate a kit prototype (T. cruzi Loopamp or Tc LAMP) based on loop-mediated isothermal amplification (LAMP) for molecular diagnosis of acute Chagas disease in well-characterized individuals, collected in real life conditions, such as newborns or infants born to Chagas disease mothers aiming to detect congenital Chagas disease, recipients of organs from Chagas disease donors who acquired T. cruzi infection after transplantation, persons with oral Chagas disease acquired after consumption of a contaminated meal, and HIV/T. cruzi coinfected patients at risk of Chagas disease reactivation due to immunosuppression. Different types of clinical samples were tested; peripheral blood samples treated with ethylenediamine tetraacetic acid (EDTA) as anticoagulant or with guanidine hydrochloride or DNAgard stabilizer agents, as well as dried blood spots and cerebrospinal fluid samples. The performance of Tc LAMP was estimated using the case definition in the different groups as a reference and all test kit results were compared to those obtained using standardized duplex real-time PCR (qPCR) in the same clinical samples. Sensitivity and specificity of Tc LAMP in blood samples from the pooled clinical groups were 93% (95% CI: 77–99) and 100% (95% CI: 80–100) respectively. The agreement between Tc LAMP and qPCR was almost perfect (κ index of Cohen = 0.92, 95% CI: 0.62–1.00). Tc LAMP was sensitive and specific for detection of T. cruzi infection in the tested samples, encouraging prospective field studies to validate its use for rapid detection of T. cruzi infection in congenital, acute and CD reactivation due to HIV infection.

Chagas disease (ChD), caused by the protozoan parasite Trypanosoma cruzi, affects millions of people worldwide. Chemotherapy is restricted to two drugs, which are partially effective and may cause severe side effects, leading to cessation of treatment in a significant number of patients. Currently, there are no biomarkers to assess therapeutic efficacy of these drugs in the chronic stage. Moreover, no preventive or therapeutic vaccines are available. In this chapter, we describe the purification of Trypanosoma cruzi trypomastigote-derived glycosylphosphatidylinositol (GPI)-anchored mucins (tGPI-mucins) for their use as antigens for the reliable primary or confirmatory diagnosis and as prognostic biomarkers for early assessment of cure following ChD chemotherapy. We also describe, as an example, the synthesis of a potential tGPI-mucin-derived α-Gal-terminating glycan and its coupling to a carrier protein for use as diagnostic and prognostic biomarker in ChD.

Chagas disease has been one of the great neglected infectious pathologies, affecting not only developing countries but also the most vulnerable sectors of the population with greater intensity. In the spectrum of its mechanisms of infection, the most forgotten, unknown, and underestimated is the oral infection. Despite being the usual form of infection among mammals and the increasing frequency of oral Trypanosoma cruzi-transmitted outbreaks since 1967, many aspects about the physiopathology, the histotropism, clinical evolution, evasion mechanisms of Trypanosoma cruzi, the consequent host immune response, and the therapeutic efficacy are still unknown. However, nowadays we already know, and are discussed in this chapter, the risk factors, the clinical aspects, the incriminated vectors, the ideal diagnostic methods, and the therapeutic approach primarily applicable to the acute phase.

Toxoplasmosis serodiagnosis was analyzed in the Instituto de Medicina Tropical in Caracas during 1999–2013. Subjects for toxoplasmosis diagnosis were grouped into five categories: pregnancy, human immunodeficiency virus (HIV)/acquired immune deficiency syndrome, ocular pathology, lymphadenopathy, and others. Testing for specific anti-Toxoplasma IgM/IgG antibodies, as well as IgG avidity, was performed. Analysis of 68,622 individuals resulted in an overall prevalence of 50.9%, with 50.9% in pregnant women, 63.8% in patients with eye lesions, 53.1% in HIV-positive individuals, 33.3% in patients with lymphadenopathy, and 49% in other individuals. Toxoplasma gondii infection in pregnant women aged ≤15 years was 32%, which increased to 64% in the middle age category. Diagnostic tests detected 54 recent infections in pregnant women and their follow-up showed no congenital infection. The present age-related and comorbidity prevalence data should be used to design control measures to prevent congenital transmission, coinfection in immunosuppressed patients, and eye lesions in children.

We describe the eleventh major outbreak of foodborne Trypanosoma cruzi transmission in urban Venezuela, including evidence for vertical transmission from the index case to her fetus. After confirming fetal death at 24 weeks of gestation, pregnancy interruption was performed. On direct examination of the amniotic fluid, trypomastigotes were detected. T. cruzi specific-polymerase chain reaction (PCR) also proved positive when examining autopsied fetal organs. Finally, microscopic fetal heart examination revealed amastigote nests. Acute orally transmitted Chagas disease can be life threatening or even fatal for pregnant women and unborn fetuses owing to vertical transmission. There is therefore an urgent need to improve national epidemiologic control measures.

Oral outbreaks of Chagas disease are increasingly reported in Latin America. The transitory presence of Trypanosoma cruzi parasites within contaminated foods, and the rapid consumption of those foods, precludes precise identification of outbreak origin. We report source attribution for 2 peri-urban oral outbreaks of Chagas disease in Venezuela via high resolution microsatellite typing.