Prevalence and Transmission of Trypanosoma cruzi in People of Rural Communities of the High Jungle of Northern Peru

A Trypanosoma cruzi Trans-Sialidase Peptide Demonstrates High Serological Prevalence Among Infected Populations Across Endemic Regions of Latin America

Infection by Trypanosoma cruzi, the agent of Chagas disease, can irreparably damage the cardiac and gastrointestinal systems during decades of parasite persistence and related inflammation in these tissues. Diagnosis of chronic disease requires confirmation by multiple serological assays due to the imperfect performance of existing clinical tests. Current serology tests utilize antigens discovered over three decades ago with small specimen sets predominantly from South America, and lower test performance has been observed in patients who acquired T. cruzi infection in Central America and Mexico. Here, we attempt to address this gap by evaluating antibody responses against the entire T. cruzi proteome with phage display immunoprecipitation sequencing comprised of 228,127 47-amino acid peptides. We utilized diverse specimen sets from Mexico, Central America and South America, as well as different stages of cardiac disease severity, from 185 cases and 143 controls. We identified over 1,300 antigenic T. cruzi peptides derived from 961 proteins between specimen sets. A total of 67 peptides were reactive in 70% of samples across all regions, and 3 peptide epitopes were enriched in ≥90% of seropositive samples. Of these three, only one antigen, belonging to the trans-sialidase family, has not previously been described as a diagnostic target. Orthogonal validation of this peptide demonstrated increased antibody reactivity for infections originating from Central America. Overall, this study provides proteome-wide identification of seroreactive T. cruzi peptides across a large cohort spanning multiple endemic areas and identified a novel trans-sialidase peptide antigen (TS-2.23) with significant potential for translation into diagnostic serological assays.

Chagas Disease and Leishmaniasis, Sympatric Zoonoses Present in Human from Rural Communities of Venezuela

PURPOSE

Trypanosoma cruzi and Leishmania spp. coexist in several endemic areas, and there are few studies of Chagas disease and leishmaniasis coinfection worldwide; for this reason, the objective of this work was to determine the Chagas disease and leishmaniasis coinfection in several rural communities co-endemic for these diseases.

METHODS

A total of 1107 human samples from six co-endemic rural communities of Cojedes state, Venezuela, were analyzed. Serum samples were evaluated by ELISA, indirect hemagglutination, and indirect immunofluorescence for Chagas disease diagnosis, and individuals were evaluated for leishmaniasis by leishmanin skin test (LST). Approximately, 30% of the individuals were also analyzed by PCR (blood clot samples) for T. cruzi and for Leishmania spp.

RESULTS

The 14.7% of the individuals were positive to Trypanosoma cruzi infection by serology, and 25.8% were positive to Leishmania spp. current or past infection by LST. Among the group with PCR results, 7.8% were positive for T. cruzi, and 9.4% for Leishmania spp. The coinfection T. cruzi/Leishmania spp. was 6.5%. The T. cruzi DTUs of the positive blood clot samples were TcI, revealed using the molecular markers: (i) intergenic region of the miniexon, (ii) D7 divergent domain of the 24Sα rDNA, (iii) size-variable domain of the 18S rDNA, and (iv) hsp60-PCR-RFLP (EcoRV). The Leishmania species identified were L. (Leishmania) mexicana and L. (Viannia) braziliensis.

CONCLUSION

A high prevalence was found for T. cruzi and Leishmania spp. single and coinfections in almost all communities studied, being these results of relevance for the implementation of control programs in co-endemic areas.

Human Trypanosoma cruzi infection in the Argentinean Chaco: risk factors and identification of households with infected children for treatment

BACKGROUND

Chagas disease is a neglected tropical disease (NTD). Cost-effective strategies for large-scale implementation of diagnosis and etiological treatment are urgently needed to comply with NTD control goals. We determined the seroprevalence of Trypanosoma cruzi infection and associated risk factors in a well-defined rural population of Pampa del Indio municipality including creole and indigenous (Qom) households and developed two indices to identify houses harboring infected children.

METHODS

We serodiagnosed and administered a questionnaire to 1337 residents (48.2% of the listed population) in two sections of the municipality (named Areas II and IV) 6-9 years after deploying sustained vector control interventions. Multiple logistic regression models were used to evaluate the relationship between human infection and a priori selected predictors. Two risk indices were constructed based on environmental and serostatus variables, and we used spatial analysis to test whether households harboring T. cruzi-seropositive children were randomly distributed.

RESULTS

The global seroprevalence of T. cruzi infection was 24.8%. Human infection was positively and significantly associated with exposure time to triatomines, the household number of seropositive co-inhabitants, maternal seropositivity for T. cruzi, recent residence at the current house and the presence of suitable walls for triatomine colonization in the domicile. The pre-intervention mean annual force of infection (FOI) was 1.23 per 100 person-years. Creoles from Area IV exhibited the highest seroprevalence and FOI; Qom people from both areas displayed intermediate ones and creoles from Area II the lowest. Three hotspots of infected children were spatially associated with hotspots of triatomine abundance at baseline and persistent house infestation. No child born after vector control interventions was T. cruzi seropositive except for one putative transplacental case. Two simple risk indices (based on self-reported inhabiting an infested house and suitable walls for triatomines or maternal serostatus) identified 97.3-98.6% of the households with at least one T. cruzi-seropositive child.

CONCLUSIONS

We showed strong heterogeneity in the seroprevalence of T. cruzi infection within and between ethnic groups inhabiting neighboring rural areas. Developed indices can be used for household risk stratification and to improve access of rural residents to serodiagnosis and treatment and may be easily transferred to primary healthcare personnel.

A review of neurological health disparities in Peru

Peru is a historically unique and culturally diverse Latin American country. As a low-to-middle-income country (LMIC), Peru faces health implications from the spread of communicable diseases as well as a growing rate of noncommunicable diseases, both of which have been worsened by the recent COVID-19 pandemic's impact on the national health system. Over the past two decades, the country has aimed to improve health access for its population through various efforts described in this review. Despite this, there are notable neurological health disparities that exist today. This narrative review investigates such disparities through the leading neurological contributors to the national burden of disease in the country, including migraine headaches, cerebrovascular disease, and dementia. Public health disparities that contribute to other major neurological diseases in the country, including epilepsy, neurocysticercosis, Chagas disease, multiple sclerosis, traumatic brain injury, traumatic and non-traumatic spinal cord injuries are also investigated. We also explore potential solutions for overcoming the various neurological health disparities covered in this review that may be applied through public policies, as well as in similar LMICs in Latin America. By overcoming such disparities, the country may be able to successfully address the major contributors of neurological disease burden and create a healthcare environment that can sustainably and equitably improve health outcomes for Peruvian people.

Chagas disease control-surveillance in the Americas: the multinational initiatives and the practical impossibility of interrupting vector-borne Trypanosoma cruzi transmission

Chagas disease (CD) still imposes a heavy burden on most Latin American countries. Vector-borne and mother-to-child transmission cause several thousand new infections per year, and at least 5 million people carry Trypanosoma cruzi. Access to diagnosis and medical care, however, is far from universal. Starting in the 1990s, CD-endemic countries and the Pan American Health Organization-World Health Organization (PAHO-WHO) launched a series of multinational initiatives for CD control-surveillance. An overview of the initiatives’ aims, achievements, and challenges reveals some key common themes that we discuss here in the context of the WHO 2030 goals for CD. Transmission of T. cruzi via blood transfusion and organ transplantation is effectively under control. T. cruzi, however, is a zoonotic pathogen with 100+ vector species widely spread across the Americas; interrupting vector-borne transmission seems therefore unfeasible. Stronger surveillance systems are, and will continue to be, needed to monitor and control CD. Prevention of vertical transmission demands boosting current efforts to screen pregnant and childbearing-aged women. Finally, integral patient care is a critical unmet need in most countries. The decades-long experience of the initiatives, in sum, hints at the practical impossibility of interrupting vector-borne T. cruzi transmission in the Americas. The concept of disease control seems to provide a more realistic description of what can in effect be achieved by 2030.

Chagas Disease in Pregnant Women in the Peruvian Amazon Basin. Cross-Sectional Study

Aims: To assess the prevalence of Chagas disease in pregnant women in Iquitos City, Peru.

Material and Methods: Cross-sectional survey in 300 pregnant women in Iquitos (Peru) from 1 May 2019 to 15 June 2019. Women were tested using an ELISA serology test.

Results: Serology was positive in one case (prevalence: 0.33%; 95% confidence interval: 7.1–13.9%), of a 25-year-old woman who lived in a wooden house with a leaf roof in a periurban area of Iquitos. She was familiar with kissing bugs and had chronic, asymptomatic Chagas disease.

Conclusion: The prevalence of Chagas disease is low in the urban and peri-urban area of the city of Iquitos.

INFECCIÓN NATURAL POR Trypanosoma cruzi (TRYPANOSOMATIDAE) EN TRIATOMINOS INTRADOMÉSTICOS DEL DEPARTAMENTO DE GUAINÍA

La búsqueda continua de triatominos forma parte de los programas de vigilancia de la enfermedad de Chagas en zonas con características ecológicas apropiadas para la presencia del vector, permitiendo priorizar y definir las acciones de intervención. El objetivo del presente trabajo fue determinar la presencia y estado de infección de triatominos en viviendas del municipio de Inírida (Guainía). El estudio se realizó entre 2018 y 2019mediante vigilancia comunitaria y búsqueda activa. Los vectores se identificaron y evaluaron por PCR. Se recolectaron cinco triatominos (un Panstrongylus lignariusy cuatro P. geniculatus). Se evidenció la infección natural en ambas especies. La genotipificación mostró la presencia de TcI Dom.Se actualiza así la presencia e infección P. lignarius, así como la infección de P. geniculatuspara Inírida.

Human Trypanosoma cruzi infection is driven by eco-social interactions in rural communities of the Argentine Chaco

The transmission of Trypanosoma cruzi to humans is determined by multiple ecological, socio-economic and cultural factors acting at different scales. Their effects on human infection with T. cruzi have often been examined separately or using a limited set of ecological and socio-demographic variables. Herein, we integrated the ecological and social dimensions of human infection risk with the spatial distribution patterns of human and vector (Triatoma infestans) infection in rural communities of the Argentine Chaco composed of indigenous people (90% Qom) and a creole minority. We conducted serosurveys in 470 households aiming at complete population enumeration over 2012–2015. The estimated seroprevalence of T. cruzi prior to the implementation of an insecticide spraying campaign (2008) was 29.0% (N = 1,373 in 301 households), and was twice as large in Qom than creoles. Using generalized linear mixed models, human seropositive cases significantly increased with infected triatomine abundance, having a seropositive household co-inhabitant and household social vulnerability (a multidimensional index of poverty), and significantly decreased with increasing host availability in sleeping quarters (an index summarizing the number of domestic hosts for T. infestans). Vulnerable household residents were exposed to a higher risk of infection even at low infected-vector abundances. The risk of being seropositive increased significantly with house infestation among children from stable households, whereas both variables were not significantly associated among children from households exhibiting high mobility within the communities, possibly owing to less consistent exposures. Human infection was clustered by household and at a larger spatial scale, with hotspots of human and vector infection matching areas of higher social vulnerability. These results were integrated in a risk map that shows high-priority areas for targeted interventions oriented to suppress house (re)infestations, detect and treat infected children, and thus reduce the burden of future disease.

Chagas disease is one of the main neglected tropical diseases (NTDs) affecting vulnerable communities in Latin America where transmission by triatomine vectors still occurs. Access to diagnosis and treatment is one of the remaining challenges for sustainable control of Chagas disease in endemic areas. In this study, we integrated the ecological and social determinants of human infection with the spatial component to identify individuals, households and geographic sectors at higher risk of infection. We found that human infection was more prevalent in indigenous people compared to creoles and increased with the abundance of infected vectors and with household social vulnerability (a multidimensional index of poverty). We also found that the social factors modulated the effect of the abundance of infected vectors: vulnerable-household residents were exposed to a higher risk of infection even at low infected-vector abundance, and human mobility within the area determined a lower and more variable exposure to the vector over time. These results were integrated in a risk map that showed high-priority areas, which can be used in designing cost-effective serological screening strategies adapted to resource-constrained areas.

Trypanosoma cruzi transmission dynamics in a synanthropic and domesticated host community

Trypanosoma cruzi is the causative agent of Chagas disease, a Neglected Tropical Disease affecting 8 million people in the Americas. Triatomine hematophagous vectors feed on a high diversity of vertebrate species that can be reservoirs or dead-end hosts, such as avian species refractory to T. cruzi. To understand its transmission dynamics in synanthropic and domesticated species living within villages is essential to quantify disease risk and assess the potential of zooprophylaxis. We developed a SI model of T. cruzi transmission in a multi-host community where vector reproduction and parasite transmission depend on a triatomine blood-feeding rate accounting for vector host preferences and interference while feeding. The model was parameterized to describe T. cruzi transmission in villages of the Yucatan peninsula, Mexico, using the information about Triatoma dimidiata vectors and host populations accumulated over the past 15 years. Extensive analyses of the model showed that dogs are key reservoirs and contributors to human infection, as compared to synanthropic rodents and cats, while chickens or other domesticated avian hosts dilute T. cruzi transmission despite increasing vector abundance. In this context, reducing the number of dogs or increasing avian hosts abundance decreases incidence in humans by up to 56% and 39%, respectively, while combining such changes reduces incidence by 71%. Although such effects are only reached over >10-years periods, they represent important considerations to be included in the design of cost-effective Integrated Vector Management. The concomitant reduction in T. cruzi vector prevalence estimated by simulating these zooprophylactic interventions could indeed complement the removal of colonies from the peridomiciles or the use of insect screens that lower vector indoor abundance by ~60% and ~80%. These new findings reinforce the idea that education and community empowerment to reduce basic risk factors is a cornerstone to reach and sustain the key objective of interrupting Chagas disease intra-domiciliary transmission.

Severity of Chagasic Cardiomyopathy Is Associated With Response to a Novel Rapid Diagnostic Test for Trypanosoma cruzi TcII/V/VI

Background

Trypanosoma cruzi causes Chagas disease in the Americas. The outcome of infection ranges from lifelong asymptomatic status to severe disease. Relationship between T. cruzi lineage (TcI-TcVI) infection history and prognosis is not understood. We previously described peptide-based lineage-specific enzyme-linked immunosorbent assay (ELISA) with trypomastigote small surface antigen (TSSA).

Methods

A novel rapid diagnostic test (RDT; Chagas Sero K-SeT) that incorporates a peptide that corresponds to the TSSA II/V/VI common epitope was developed and validated by comparison with ELISA. Patients from Bolivia and Peru, including individuals with varying cardiac pathology, and matched mothers and neonates, were then tested using Chagas Sero K-SeT.

Results

Chagas Sero K-SeT and ELISA results, with a Bolivian subset of cardiac patients, mothers, and neonates, were in accord. In adult chronic infections (n = 121), comparison of severity class A (no evidence of Chagas cardiomyopathy) with class B (electrocardiogram suggestive of Chagas cardiomyopathy) and class C/D (decreased left ventricular ejection fraction; moderate/severe Chagas cardiomyopathy) revealed a statistically significant increase in Chagas Sero K-SeT reactivity with increasing severity (χ2 for trend, 7.39; P = .007). In Peru, Chagas Sero K-SeT detected the sporadic TcII/V/VI infections.

Conclusions

We developed a low cost RDT that can replace ELISA for identification of TSSA II/V/VI immunoglobulin G. Most importantly, we show that response to this RDT is associated with severity of Chagas cardiomyopathy and thus may have prognostic value. Repeated challenge with T. cruzi infection may both exacerbate disease progression and boost the immune response to the TSSApep-II/V/VI epitope.

Giardia Infection and Trypanosoma Cruzi Exposure in Dogs in the Bosawás Biosphere Reserve, Nicaragua

Indigenous Mayangna and Miskitu inhabit Nicaragua's remote Bosawás Biosphere Reserve, located in the North Caribbean Coast Autonomous Region. They are sedentary horticulturists who supplement their diet with wild game, hunting with the assistance of dogs. To test whether hunting dogs increased the risk of human exposure to protozoal zoonotic neglected tropical diseases (NTDs), we sampled dogs from three communities varying in population size and level of contact with other communities. We screened dog feces (n = 58) for Giardia and Cryptosporidium DNA and sera (n = 78) for Trypanosoma cruzi antibodies and DNA. Giardia DNA was detected in 22% (13/58) of samples; sequencing revealed the presence of both zoonotic genotypes (assemblages A and B) and dog-specific genotypes (assemblages C and D). Giardia shedding was associated with community and age. Older dogs and those in the two, more accessible communities had greater odds of shedding parasites. Seroprevalence of T. cruzi antibodies, indicating prior exposure, was 9% (7/78). These results contribute to the limited literature on NTDs in indigenous populations, and suggest hunting dogs can both serve as sentinels of environmental NTDs and pose zoonotic risk for their owners and communities.

Immigration and establishment of Trypanosoma cruzi in Arequipa, Peru

Changing environmental conditions, including those caused by human activities, reshape biological communities through both loss of native species and establishment of non-native species in the altered habitats. Dynamic interactions with the abiotic environment impact both immigration and initial establishment of non-native species into these altered habitats. The repeated emergence of disease systems in urban areas worldwide highlights the importance of understanding how dynamic migratory processes affect the current and future distribution and abundance of pathogens in urban environments. In this study, we examine the pattern of invasion of Trypanosoma cruzi-the causative agent of human Chagas disease-in the city of Arequipa, Peru. Phylogenetic analyses of 136 T. cruzi isolates from Arequipa and other South American locations suggest that only one T. cruzi lineage established a population in Arequipa as all T. cruzi isolated from vectors in Arequipa form a recent monophyletic group within the broader South American phylogeny. We discuss several hypotheses that may explain the limited number of established T. cruzi lineages despite multiple introductions of the parasite.

A review on the occurrence of companion vector-borne diseases in pet animals in Latin America

Companion vector-borne diseases (CVBDs) are an important threat for pet life, but may also have an impact on human health, due to their often zoonotic character. The importance and awareness of CVBDs continuously increased during the last years. However, information on their occurrence is often limited in several parts of the world, which are often especially affected. Latin America (LATAM), a region with large biodiversity, is one of these regions, where information on CVBDs for pet owners, veterinarians, medical doctors and health workers is often obsolete, limited or non-existent. In the present review, a comprehensive literature search for CVBDs in companion animals (dogs and cats) was performed for several countries in Central America (Belize, Caribbean Islands, Costa Rica, Cuba, Dominican Republic, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Puerto Rico) as well as in South America (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guiana, Guyana (British Guyana), Paraguay, Peru, Suriname, Uruguay, Venezuela) regarding the occurrence of the following parasitic and bacterial diseases: babesiosis, heartworm disease, subcutaneous dirofilariosis, hepatozoonosis, leishmaniosis, trypanosomosis, anaplasmosis, bartonellosis, borreliosis, ehrlichiosis, mycoplasmosis and rickettsiosis. An overview on the specific diseases, followed by a short summary on their occurrence per country is given. Additionally, a tabular listing on positive or non-reported occurrence is presented. None of the countries is completely free from CVBDs. The data presented in the review confirm a wide distribution of the CVBDs in focus in LATAM. This wide occurrence and the fact that most of the CVBDs can have a quite severe clinical outcome and their diagnostic as well as therapeutic options in the region are often difficult to access and to afford, demands a strong call for the prevention of pathogen transmission by the use of ectoparasiticidal and anti-feeding products as well as by performing behavioural changes.

Considering Dogs as Complementary Targets of Chagas Disease Control

This review describes the role that dogs play in Latin American countries where Chagas disease is endemic. Multiple studies determined the high frequency with which canine populations are infected with Trypanosoma cruzi. The infection prevalence of dogs is greater than that of humans and the presence of infected dogs in households is associated with a higher risk of human infection. Dog infectiousness to triatomine vectors is several-fold higher than that of humans, thereby underscoring their major role in the domestic transmission of T. cruzi. Insecticide spraying of houses is in most cases efficacious but the lack of sustainability hinders this vector-focused strategy. Multi-pronged approaches have been adopted to improve control measures but dog intervention was never included. Experimental evaluation of systemic insecticides or deltamethrin-impregnated collars suggested that dog intervention leading to triatomine killing could curb domestic transmission of T. cruzi. Larger field studies are required to determine its applicability and efficacy. However, the implementation of dog intervention could complement other control measures currently in place, mostly in periods when vector spraying has been interrupted.

Electrocardiographic abnormalities in Chagas disease in the general population: A systematic review and meta-analysis

BACKGROUND

Chagas disease (CD) is a major public health concern in Latin America and a potentially serious emerging threat in non-endemic countries. Although the association between CD and cardiac abnormalities is widely reported, study design diversity, sample size and quality challenge the information, calling for its update and synthesis, which would be very useful and relevant for physicians in non-endemic countries where health care implications of CD are real and neglected. We performed to systematically review and meta-analyze population-based studies that compared prevalence of overall and specific ECG abnormalities between CD and non-CD participants in the general population.

METHODS

Six databases (EMBASE, Ovid Medline, Web of Science, Cochrane Central, Google Scholar and Lilacs) were searched systematically. Observational studies were included. Odds ratios (OR) were computed using random-effects model.

RESULTS

Forty-nine studies were selected, including 34,023(12,276 CD and 21,747 non-CD). Prevalence of overall ECG abnormalities was higher in participants with CD (40.1%; 95%CIs=39.2-41.0) compared to non-CD (24.1%; 95%CIs=23.5-24.7) (OR=2.78; 95%CIs=2.37-3.26). Among specific ECG abnormalities, prevalence of complete right bundle branch block (RBBB) (OR=4.60; 95%CIs=2.97-7.11), left anterior fascicular block (LAFB) (OR=1.60; 95%CIs=1.21-2.13), combination of complete RBBB/LAFB (OR=3.34; 95%CIs=1.76-6.35), first-degree atrioventricular block (A-V B) (OR=1.71; 95%CIs=1.25-2.33), atrial fibrillation (AF) or flutter (OR=2.11; 95%CIs=1.40-3.19) and ventricular extrasystoles (VE) (OR=1.62; 95%CIs=1.14-2.30) was higher in CD compared to non-CD participants.

CONCLUSIONS

This systematic review and meta-analysis provides an update and synthesis in this field. This research of observational studies indicates a significant excess in prevalence of ECG abnormalities (40.1%) related to T. cruzi infection in the general population from Chagas endemic regions, being the most common ventricular (RBBB and LAFB), and A-V B (first-degree) node conduction abnormalities as well as arrhythmias (AF or flutter and VE). Also, prevalence of ECG alterations in children was similar to that in adults and suggests earlier onset of cardiac disease.

Acute Chagas disease in the state of Pará, Amazon Region: is it increasing?

Acute Chagas disease (ACD) has a distinct epidemiological profile in the Amazon Region, with cases and outbreaks of Trypanosoma cruzi infection being possibly related to the ingestion of contaminated food. Data on ACD in the state of Pará retrieved from 2000 to 2016 from the Brazilian Notifiable Diseases Information System (SINAN) were evaluated. During this period, 2,030 of the 16,807 reported cases were confirmed, with a higher incidence between the months of August and December, thus characterising a seasonal pattern of acute infection, and coinciding with the higher production of “açaí”, one fruit likely involved in the oral transmission of the disease. Evaluation of the absolute numbers of confirmed ACD cases secondary to oral infection suggests that infection through this route increased during the 2010-2016 period, differing from what was recorded in terms of vectorial or other infection routes. These findings point to the need of intensifying strategies to prevent or substantially reduce oral transmission.

An insight into the salivary gland and fat body transcriptome of Panstrongylus lignarius (Hemiptera: Heteroptera), the main vector of Chagas disease in Peru

Triatomines are hematophagous arthropod vectors of Trypanosoma cruzi, the causative agent of Chagas Disease. Panstrongylus lignarius, also known as Panstrongylus herreri, is considered one of the most versatile triatomines because it can parasitize different hosts, it is found in different habitats and countries, it has sylvatic, peridomestic and domestic behavior and it is a very important vector of Chagas disease, especially in Peru. Molecules produced and secreted by salivary glands and fat body are considered of important adaptational value for triatomines because, among other functions, they subvert the host haemostatic, inflammatory and immune systems and detoxify or protect them against environmental aggressors. In this context, the elucidation of the molecules produced by these tissues is highly valuable to understanding the ability of this species to adapt and transmit pathogens. Here, we use high-throughput sequencing techniques to assemble and describe the coding sequences resulting from the transcriptome of the fat body and salivary glands of P. lignarius. The final assembly of both transcriptomes together resulted in a total of 11,507 coding sequences (CDS), which were mapped from a total of 164,676,091 reads. The CDS were subdivided according to their 10 folds overexpression on salivary glands (513 CDS) or fat body (2073 CDS). Among the families of proteins found in the salivary glands, lipocalins were the most abundant. Other ubiquitous families of proteins present in other sialomes were also present in P. lignarius, including serine protease inhibitors, apyrase and antigen-5. The unique transcriptome of fat body showed proteins related to the metabolic function of this organ. Remarkably, nearly 20% of all reads mapped to transcripts coded by Triatoma virus. The data presented in this study improve the understanding on triatomines' salivary glands and fat body function and reveal important molecules used in the interplay between vectors and vertebrate hosts.

Antiprotozoal activity of medicinal plants used by Iquitos-Nauta road communities in Loreto (Peru)

ETHNOPHARMACOLOGICAL RELEVANCE

In the Peruvian Amazon, the use of medicinal plants is a common practice. However, there is few documented information about the practical aspects of their use and few scientific validation. The starting point for this work was a set of interviews of people living in rural communities from the Peruvian Amazon about their uses of plants. Protozoan diseases are a public health issue in the Amazonian communities, who partly cope with it by using traditional remedies. Validation of these traditional practices contributes to public health care efficiency and may help identify new antiprotozoal compounds.

AIMS OF STUDY

to inventory and validate the use of medicinal plants by rural people of Loreto region.

MATERIALS AND METHODS

Rural mestizos were interviewed about traditional medication of parasite infections with medicinal plants. Ethnopharmacological surveys were undertaken in two villages along Iquitos-Nauta road (Loreto region, Peru), namely 13 de Febrero and El Dorado communities. Forty-six plants were collected according to their traditional use for the treatment of parasitic diseases, 50 ethanolic extracts (different parts for some of the plants) were tested in vitro on Plasmodium falciparum (3D7 sensitive strain and W2 chloroquine resistant strain), Leishmania donovani LV9 strain and Trypanosoma brucei gambiense. Cytotoxic assessment (HUVEC cells) of the active extracts was performed. Two of the most active plants were submitted to preliminary bioguided fractionation to ascertain and explore their activities.

RESULTS

From the initial plants list, 10 were found to be active on P. falciparum, 15 on L. donovani and 2 on the three parasites. The ethanolic extract from Costus curvibracteatus (Costaceae) leaves and Grias neuberthii (Lecythidaceae) bark showed strong in vitro activity on P. falciparum (sensitive and resistant strain) and L. donovani and moderate activity on T. brucei gambiense.

CONCLUSIONS

The Amazonian forest communities in Peru represents a source of knowledge on the use of medicinal plants. In this work, several extracts with antiprotozoal activity were identified. This work contributes to validate some traditional uses and opens subsequent investigations on active compounds isolation and identification.

First report of Panstrongylus lignarius , Walker, 1873 (Hemiptera, Reduviidae, Triatominae), in the State of Rondônia, Brazil

INTRODUCTION:

This study reports, for the first time, the presence of Panstrongylus lignarius in the State of Rondonia, Brazil.

METHODS:

Specimen of P. lignarius was collected from a flat in an urban area of the municipality of Porto Velho, Western Amazon.

RESULTS:

With this finding of P. lignarius, the number of Triatominae species in the State of Rondonia has increased from six to seven.

CONCLUSIONS:

The occurrence of P. lignarius is worrisome, because this species has been found to be naturally infected with Trypanosoma cruzi and there has been evidence of its domiciliation capabilities in other countries of South America.

Assessment of the anti-feeding and insecticidal effects of the combination of dinotefuran, permethrin and pyriproxyfen (Vectra® 3D) against Triatoma infestans on rats

This study, based on the rat model, was designed to explore the anti-feeding and insecticidal efficacy of a topical ectoparasiticide, dinotefuran-permethrin-pyriproxyfen (DPP), against Triatoma infestans (Hemiptera: Reduviidae), a vector of Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae), for which dogs are domestic reservoir hosts. Twenty rats were divided into two equal groups: untreated and treated. Each rat was exposed under sedation to 16 T. infestans of mixed life stages for 1 h on days 1, 7, 14, 21 and 28 post-treatment. The anti-feeding and insecticidal effects of DPP were estimated after 1 h of exposure. Insecticidal efficacy was also assessed after incubation of the insects for 24 h post-exposure. Anti-feeding efficacy was 96.7, 84.7, 80.5, 81.5 and 42.6% on days 1, 7, 14, 21 and 28, respectively. Insecticidal efficacy evaluated at 1 and 24 h after exposure on days 1, 7, 14, 21 and 28 was 100, 91.2, 82.5, 80.0 and 29.1, and 100, 100, 100, 96.0 and 49.9%, respectively. This study demonstrates that a single administration of DPP spot-on treatment at a dose equivalent to the minimal recommended dose in rats has a powerful effect against T. infestans starting from day 1 that lasts for at least 3 weeks.

Identifying Trypanosoma cruzi discreet typing units in triatomines collected in different natural regions of Perú

INTRODUCTION

Trypanosoma cruzi has been divided by international consensus into six discrete typing units (DTU): TcI, TcII, TcIII, TcIV, TcV y TcVI. The factors determining the dynamics of T. cruzi genotypes vector transmission of Chagas' disease in the different geographical regions of Perú are still unknown.

OBJECTIVE

To detect and type T. cruzi DTUs from the faeces of seven species of triatomines (Panstrongylus chinai, P. geniculatus, P. herreri, Rhodnius robustus, R. pictipes, Triatoma carrioni and T. infestans) captured in eight departments from different natural regions of Perú.

MATERIALS AND METHODS

We examined 197 insects for detecting trypanosomes. DNA was extracted from each insect intestinal contents and PCR amplification of kDNA, SL-IR, 24Sα rRNA and 18Sα RNA was performed for detecting T. cruzi DTUs.

RESULTS

Five T. rangeli and 113 T. cruzi infections were detected; 95 of the latter were identified as TcI (two in P. chinai, one in P. geniculatus, 68 in P. herreri, four in R. pictipes, seven in R. robustus, one in T. carrioni, 12 in T. infestans), five as TcII (four in P. herreri, one in T. infestans), four as TcIII (three in P. herreri, one in R. robustus) and four TcIV infections in P. herreri.

CONCLUSIONS

This is the first study which has attempted a large-scale characterization of T. cruzi found in the intestine of epidemiologically important vectors in Perú, thus providing basic information that will facilitate a better understanding of the dynamics of T. cruzi vector transmission in Perú.

Comprehensive Survey of Domiciliary Triatomine Species Capable of Transmitting Chagas Disease in Southern Ecuador

BACKGROUND

Chagas disease is endemic to the southern Andean region of Ecuador, an area with one of the highest poverty rates in the country. However, few studies have looked into the epidemiology, vectors and transmission risks in this region. In this study we describe the triatomine household infestation in Loja province, determine the rate of Trypanosoma cruzi infection in triatomines and study the risk factors associated with infestation.

METHODOLOGY/PRINCIPAL FINDINGS

An entomological survey found four triatomine species (Rhodnius ecuadoriensis, Triatoma carrioni, Panstrongylus chinai, and P. rufotuberculatus) infesting domiciles in 68% of the 92 rural communities examined. Nine percent of domiciles were infested, and nymphs were observed in 80% of the infested domiciles. Triatomines were found in all ecological regions below 2,200 masl. We found R. ecuadoriensis (275 to 1948 masl) and T. carrioni (831 to 2242 masl) mostly in bedrooms within the domicile, and they were abundant in chicken coops near the domicile. Established colonies of P. chinai (175 to 2003 masl) and P. rufotuberculatus (404 to 1613 masl) also were found in the domicile. Triatomine infestation was associated with surrogate poverty indicators, such as poor sanitary infrastructure (lack of latrine/toilet [w = 0.95], sewage to environment [w = 1.0]). Vegetation type was a determinant of infestation [w = 1.0] and vector control program insecticide spraying was a protective factor [w = 1.0]. Of the 754 triatomines analyzed, 11% were infected with Trypanosoma cruzi and 2% were infected with T. rangeli.

CONCLUSIONS/SIGNIFICANCE

To date, only limited vector control efforts have been implemented. Together with recent reports of widespread sylvatic triatomine infestation and frequent post-intervention reinfestation, these results show that an estimated 100,000 people living in rural areas of southern Ecuador are at high risk for T. cruzi infection. Therefore, there is a need for a systematic, sustained, and monitored vector control intervention that is coupled with improvement of socio-economic conditions.