Texas and Mexico: sharing a legacy of poverty and neglected tropical diseases

Optimization of DNA Extraction from Field-Collected Mammalian Whole Blood on Filter Paper for Trypanosoma cruzi (Chagas Disease) Detection

Blood filter paper strips are cost-effective materials used to store body fluid specimens under challenging field conditions, extending the reach of zoonotic pathogen surveillance and research. We describe an optimized procedure for the extraction of parasite DNA from whole blood (WB) stored on Type I Advantec Nobuto strips from both experimentally spiked and field-collected specimens from canine and skunks, respectively. When comparing two commercial kits for extraction, Qiagen's DNeasy Blood & Tissue Kit performed best for the detection of parasite DNA by PCR from Trypanosoma cruzi-spiked canine WB samples on Nobuto strips. To further optimize recovery of β-actin from field-collected skunk WB archived on Nobuto strips, we modified the extraction procedures for the Qiagen kit with a 90 °C incubation step and extended incubation post-addition of proteinase K, a method subsequently employed to identify a T. cruzi infection in one of the skunks. Using this optimized extraction method can efficaciously increase the accuracy and precision of future molecular epidemiologic investigations targeting neglected tropical diseases in field-collected WB specimens on filter strips.

Temperatures Influence Susceptibility to Insecticides in Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Mosquitoes

Aedes aegypti and Aedes albopictus (Diptera: Culicidae) are vectors for several arboviruses, including dengue, Zika virus and chikungunya virus. The primary method of controlling these diseases is controlling the vector population, often with insecticides. Insecticide resistance may impact the success of these efforts. We tested the effect of variable temperature exposures on susceptibility to insecticides by exposing adult A.aegypti and A. albopictus to different temperatures and tested their susceptibility to insecticides. We hypothesized that adults maintained at high temperatures would show increased susceptibility to insecticides relative to lower temperatures. Colony mosquitoes were hatched, reared to adulthood and then maintained in three temperature regimes that reflect average seasonal temperatures in the Rio Grande Valley, TX. Susceptibility to permethrin and deltamethrin was assessed using the CDC bottle bioassay method. Overall Aedes albopictus had higher susceptibility to all insecticides than Aedes aegypti. Mosquitoes kept at different temperatures exhibited differential susceptibility to insecticides. Low temperature exposed mosquitoes had decreased susceptibility while high temperature conditions resulted in increased mortality. Our results suggest public health officials must consider temperature effects when controlling mosquitoes with insecticides.

Parasitic infections represent a significant health threat among recent immigrants in Chicago

Parasitic infections are likely under-recognized among immigrant populations in the USA. We conducted a cross-sectional study to evaluate if such infections have health impacts among recent immigrants in Chicago and to identify predictive factors for parasitic infections. A total of 133 recent immigrants were enrolled, filling out a standardized medical questionnaire and providing blood and stool samples. Appriximately 12% of subjects (15/125) who provided a blood or stool sample for testing were found to have evidence of current or prior infection with a pathogenic parasite, of which Toxocara spp. (8 subjects, 6.4%) and Strongyloides stercoralis (5 subjects, 4%) were most commonly identified. Parasitic infection was more likely among subjects who had immigrated within the previous 2 years and those with a self-reported history of worms in the stool. The most useful surrogate markers identified for parasitic infections were an elevated immunoglobulin E level (seen in 46.7% (7/15) of subjects with parasitic infections and 20% (22/110) of uninfected individuals, p = 0.04) and the presence of Blastocystis hominis cysts on Ova & Parasite exam (detected in 38.5% (5/13) of subjects with parasitic infections who provided a stool sample and 5.1% (5/98) of uninfected subjects, p = 0.002). Our study found that parasitic infections may be common in recent US immigrants, which highlights an important health disparity among a vulnerable population that merits further study. Additionally, clinical risk factors, symptoms, and laboratory findings traditionally thought to be associated with parasites were commonly found but not predictive of infection in this study population.

The rise of neglected tropical diseases in the "new Texas"

Within the last five years, the State of Texas has experienced either transmission or outbreaks of Ebola, chikungunya, West Nile, and Zika virus infections. Autochthonous transmission of neglected parasitic and bacterial diseases has also become increasingly reported. The rise of such emerging and neglected tropical diseases (NTDs) has not occurred by accident but instead reflects rapidly evolving changes and shifts in a “new” Texas beset by modern and globalizing forces that include rapid expansions in population together with urbanization and human migrations, altered transportation patterns, climate change, steeply declining vaccination rates, and a new paradigm of poverty known as “blue marble health.” Summarized here are the major NTDs now affecting Texas. In addition to the vector-borne viral diseases highlighted above, there also is a high level of parasitic infections, including Chagas disease, trichomoniasis, and possibly leishmaniasis and toxocariasis, as well as typhus-group rickettsiosis, a vector-borne bacterial infection. I also highlight some of the key shifts in emerging and neglected disease patterns, partly due to an altered and evolving economic and ecological landscape in the new Texas, and provide some preliminary disease burden estimates for the major prevalent and incident NTDs.

Assessing the Prevalence of Risk Factors for Neglected Tropical Diseases in Brazos County, Texas

INTRODUCTION

Although more than one billion people live at risk of neglected tropical diseases (NTDs) in areas of Asia, sub-Saharan Africa, and Latin America, the degree to which they burden countries like the U.S. is unclear. Even though many NTDs such as dengue, leishmaniasis, and Chagas disease are typically not endemic to the U.S., the possibility of their emergence is noteworthy, especially in states like Texas with high levels of poverty, large immigrant populations, geographic proximity to endemic areas, and a climate amenable to the vectors for these diseases. Despite the health threat that emerging NTDs may pose, little is known about the prevalence of risk factors for NTDs in the U.S.

METHODS

We tested the Community Assessment for Public Health Emergency Response (CASPER) method to assess the prevalence of risk factors for NTDs in Brazos County, Texas.Results: We found relatively low prevalence of risk factors related to travel (5.2% of respondents visited an endemic area in the previous 3 months); however, few respondents reported adherence to mosquito prevention, such as wearing long sleeves and long pants (14.1%, 95% CI: 13.9,14.4) and repellant containing DEET (13.5%, 95% CI: 13.2,13.7). Between 5.4% and 35.8% of respondents had a visible container (e.g., pet water dishes, flower pots, bird baths) that could support mosquito breeding.

DISCUSSION

CASPER findings present public health authorities with potential avenues for implementing health education and other interventions aimed at reducing exposure to risk factors for NTDs among Texas residents.

Impacting Binational Health through Leadership Development: A Program Evaluation of the Leaders across Borders Program, 2010-2014

Background

Workforce and leadership development is imperative for the advancement of public health along the U.S./Mexico border. The Leaders across borders (LaB) program aims to train the public health and health-care workforce of the border region. The LaB is a 6-month intensive leadership development program, which offers training in various areas of public health. Program curriculum topics include: leadership, border health epidemiology, health diplomacy, border public policies, and conflict resolution.

Methods

This article describes the LaB program evaluation outcomes across four LaB cohort graduates between 2010 and 2014. LaB graduates received an invitation to participate via email in an online questionnaire. Eighty-five percent (n = 34) of evaluation participants indicated an improvement in the level of binationality since participating in the LaB program. Identified themes in the evaluation results included increased binational collaborations and partnerships across multidisciplinary organizations that work towards improving the health status of border communities. Approximately 93% (n = 37) of the LaB samples were interested in participating in future binational projects while 80% (n = 32) indicated interest in the proposal of other binational initiatives. Participants expressed feelings of gratitude from employers who supported their participation and successful completion of LaB.

Discussion

Programs such as LaB are important in providing professional development and education to a health-care workforce along the U.S./Mexico border that is dedicated to positively impacting the health outcomes of vulnerable populations residing in this region.

Ecology of phlebotomine sandflies and putative reservoir hosts of leishmaniasis in a border area in Northeastern Mexico: implications for the risk of transmission of Leishmania mexicana in Mexico and the USA

Leishmaniases are a group of important diseases transmitted to humans through the bite of sandfly vectors. Several forms of leishmaniases are endemic in Mexico and especially in the Southeast region. In the Northeastern region, however, there have only been isolated reports of cases and scanty records of sandfly vectors. The main objective of this study was to analyze the diversity of sandflies and potential reservoir hosts of Leishmania spp. in the states of Nuevo León and Tamaulipas. Species richness and abundances of sandflies and rodents were recorded. A fraction of the caught sandflies was analyzed by PCR to detect Leishmania spp. Tissues from captured rodents were also screened for infection. Ecological Niche Models (ENMs) were computed for species of rodent and their association with crop-growing areas. We found 13 species of sandflies, several of which are first records for this region. Medically important species such as Lutzomyia anthophora, Lutzomyia diabolica, Lutzomyia cruciata, and Lutzomyia shannoni were documented. Leishmania spp. infection was not detected in sandflies. Nine species of rodents were recorded, and Leishmania (Leishmania) mexicana infection was found in four species of Peromyscus and Sigmodon. ENMs showed that potential distribution of rodent pest species overlaps with allocated crop areas. This shows that Leishmania (L.) mexicana infection is present in the Northeastern region of Mexico, and that previously unrecorded sandfly species occur in the same areas. These findings suggest a potential risk of transmission of Leishmania (L.) mexicana.

Temporal Variation in the Abundance and Timing of Daily Activity of Chagas Disease Vector Triatoma gerstaeckeri (Stål, 1859) in a Natural Habitat in the Lower Rio Grande Valley, South Texas

Chagas disease caused by Trypanosoma cruzi is a burden to millions of people in South and Central America. A sylvatic life cycle of the parasite exists in the Southern United States, but recent studies indicate an active peri-domestic life cycle of T. cruzi in Texas. The United States-Mexico border region in Texas displays areas of high poverty and sub-standard housing conditions which are important risk factors for a potential spill-over transmission to a domestic life cycle including humans. The objectives of the study were to examine short- and long-term temporal variation in vector activity and to evaluate the effect of different combinations of attractants on the capture of potential triatomine vectors. We collected local triatomine vectors (all of them identified as Triatoma gerstaeckeri) from a natural habitat in South Texas during the course of a year. The exact time of collection was recorded to examine the timing of flight activity of the triatomine vector. We also conducted a comparative study of the efficiency of 2 commonly used attractants (light and CO₂) and the combination of those on the capture rate of Tr. gerstaeckeri. Our study indicates a short season of dispersal of Tr. gerstaeckeri (April/May) and it suggests a unimodal distribution of activity peaking between 2 and 3 hr after sunset. Ultra-violet light served as the main attractant of Tr. gerstaeckeri while CO₂ from dry ice did not significantly contribute to the collection of vectors. The pronounced timing of activity in Tr. gerstaeckeri reported in this study contributes to our understanding of the epidemiology of T. cruzi in wildlife and its potential as a Chagas disease vector to humans in the Rio Grande Valley, South Texas.

Pediatric Neglected Tropical Diseases in a Major Metropolitan Children's Hospital in the United States, 2004-2013

We conducted a retrospective study of neglected tropical diseases (NTDs) diagnosed at Texas Children's Hospital between 2004 and 2013. Forty-three patients with an NTD were identified; 47% had never traveled outside of the United States. The results of this study highlight the importance of physician awareness of NTDs in children in the United States.

Mucocutaneous manifestations of helminth infections: Nematodes

In the 21st century, despite increased globalization through international travel for business, medical volunteerism, pleasure, and immigration/refugees into the United States, there is little published in the dermatology literature regarding the cutaneous manifestations of helminth infections. Approximately 17% of travelers seek medical care because of cutaneous disorders, many related to infectious etiologies. This review will focus on the cutaneous manifestations of helminth infections and is divided into 2 parts: part I focuses on nematode infections, and part II focuses on trematode and cestode infections. This review highlights the clinical manifestations, transmission, diagnosis, and treatment of helminth infections. Nematodes are roundworms that cause diseases with cutaneous manifestations, such as cutaneous larval migrans, onchocerciasis, filariasis, gnathostomiasis, loiasis, dracunculiasis, strongyloidiasis, ascariasis, streptocerciasis, dirofilariasis, and trichinosis. Tremadotes, also known as flukes, cause schistosomiasis, paragonimiasis, and fascioliasis. Cestodes (tapeworms) are flat, hermaphroditic parasites that cause diseases such as sparganosis, cysticercosis, and echinococcus.

Cost-Effectiveness of Blood Donation Screening for Trypanosoma cruzi in Mexico

An estimated 2 million inhabitants are infected with Chagas disease in Mexico, with highest prevalence coinciding with highest demographic density in the southern half of the country. After vector-borne transmission, Trypanosoma cruzi is principally transmitted to humans via blood transfusion. Despite initiation of serological screening of blood donations or donors for T. cruzi since 1990 in most Latin American countries, Mexico only finally included mandatory serological screening nationwide in official Norms in 2012. Most recent regulatory changes and segmented blood services in Mexico may affect compliance of mandatory screening guidelines. The objective of this study was to calculate the incremental cost-effectiveness ratio for total compliance of current guidelines from both Mexican primary healthcare and regular salaried worker health service institutions: the Secretary of Health and the Mexican Institute for Social Security. We developed a bi-modular model to analyze compliance using a decision tree for the most common screening algorithms for each health institution, and a Markov transition model for the natural history of illness and care. The incremental cost effectiveness ratio based on life-years gained is US$ 383 for the Secretary of Health, while the cost for an additional life-year gained is US$ 463 for the Social Security Institute. The results of the present study suggest that due to incomplete compliance of Mexico’s national legislation during 2013 and 2014, the MoH has failed to confirm 15,162 T. cruzi infections, has not prevented 2,347 avoidable infections, and has lost 333,483 life-years. Although there is a vast difference in T. cruzi prevalence between Bolivia and Mexico, Bolivia established mandatory blood screening for T.cruzi in 1996 and until 2002 detected and discarded 11,489 T. cruzi -infected blood units and prevented 2,879 potential infections with their transfusion blood screening program. In the first two years of Mexico’s mandated program, the two primary institutions failed to prevent due to incomplete compliance more potential infections than those gained from the first five years of Bolivia’s program. Full regulatory compliance should be clearly understood as mandatory for the sake of blood security, and its monitoring and analysis in Mexico should be part of the health authority’s responsibility.

Chagas disease continues to be a neglected disease in Mexico and Latin-American. Although an estimated 96% of Trypanosoma cruzi transmission to humans occurs via 32 triatomine vector species, the only transmission prevention in Mexico has been sparse and based on heterogeneous blood donation screening. Despite mandating serological screening of blood donations or donors for T. cruzi since 1990 in most Latin American countries, Mexico only finally included mandatory serological screening nationwide in official Norms in 2012. In 2005, a survey of blood donor centers in Mexico was conducted to compare T. cruzi prevalence in donations with that of Mexican migrants in the US. Since there was little coincidence between data from that survey and official screening or confirmed case rates, and screening for the social security system only initiated in 2010, the objective of this study was to calculate the incremental cost-effectiveness ratio for total compliance of current guidelines from both Mexican primary healthcare (the Secretary of Health) and regular salaried worker health services (the Mexican Institute for Social Security). A bi-modular model to analyze compliance was developed using a decision tree for the most common documented screening algorithms for the two principal health institution, and a Markov transition model for the natural history of illness and care. The incremental cost effectiveness ratio based on life-years gained is US$ 383 for the Secretary of Health (MoH), while the cost for an additional life-year gained is US$ 463 for the Social Security Institute (IMSS). Using survey compliance data for MoH, and that published by IMSS, failure to detect current infections, to avoid new infections, and life-years lost were calculated for 2013 and 2014 for both institutions. The MoH has failed to confirm 15,162 T. cruzi infections, did not prevent 2,347 avoidable infections, and lost 333,483 life-years over the two year period. Full regulatory compliance should be mandatory and timely monitoring should be part of the health authority’s responsibilities for the sake of blood security in Mexico.

Bibliometric analysis of medicine-related publications on poverty (2005-2015)

BACKGROUND

Poverty is a global problem. The war against poverty requires not only financial support, but also poverty-related research to pinpoint areas of high need of intervention. In line with international efforts to fight poverty and negative consequences, we carried out this study to give a bibliometric overview of medicine-related literature on poverty. Such a s study is an indicator of the extent of interaction of various international key players on the war against poverty-related health problems.

METHODS

Scopus was used to achieve the objective of this study. The time span set for this study was 2005-2015. Poverty-related articles under the subject area "Medicine" were used to give bibliometric indicators such as annual growth of publications, international collaboration, highly cited articles, active countries, institutions, journals, and authors.

RESULTS

The total number of retrieved articles was 1583. The Hirsh-index of retrieved articles was 56. A modest and fluctuating increase was seen over the study period. Visualization map of retrieved articles showed that "HIV", infectious diseases, mental health, India, and Africa were most commonly encountered terms. No significant dominance of any particular author or journal was observed in retrieved articles. The United States of America had the largest share in the number of published articles. The World Health Organization and Centers for Disease Prevention and Control were among top active institutions/organizations. International collaboration was observed in less than one third of publications. Top cited articles focused on three poverty-related health issues, mainly, infectious diseases, malnutrition, and child development/psychology. Most of top articles were published in high impact journals.

CONCLUSIONS

Data indicated that articles on poverty were published in high influential medical journals indicative of the importance of poverty as a global health problem. However, the number publications and the extent of international collaborations was lower than expected given the huge burden of poverty-related health problems.

Preventive health screening utilization in older Mexicans before and after healthcare reform

OBJECTIVE

To assess changes in preventive screening utilization in older Mexicans, pre- and post-Seguro Popular.

MATERIALS AND METHODS

Data from the Mexican Health and Aging Study (MHAS/Enasem) 2001 and 2012 were used. Logistic and ordinary least squares regression adjusted models were used to predict preventive care in 2012 by insurance status categories in 2001-2012, as the focus explanatory variable.

RESULTS

Participants who were uninsured in 2001 and had Seguro Popular in 2012 were significantly more likely to be tested for diabetes, high blood pressure and receive a tetanus shot than the continually uninsured.

CONCLUSIONS

While disparities in preventive screening between the insured and uninsured continue to exist in Mexico, Seguro Popular seems to have provided better access to health services to prevent chronic and infectious diseases for the otherwise uninsured population.

Gene-deleted live-attenuated Trypanosoma cruzi parasites as vaccines to protect against Chagas disease

Chagas disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. This illness is now becoming global, mainly due to congenital transmission, and so far, there are no prophylactic or therapeutic vaccines available to either prevent or treat Chagas disease. Therefore, different approaches aimed at identifying new protective immunogens are urgently needed. Live vaccines are likely to be more efficient in inducing protection, but safety issues linked with their use have been raised. The development of improved protozoan genetic manipulation tools and genomic and biological information has helped to increase the safety of live vaccines. These advances have generated a renewed interest in the use of genetically attenuated parasites as vaccines against Chagas disease. This review discusses the protective capacity of genetically attenuated parasite vaccines and the challenges and perspectives for the development of an effective whole-parasite Chagas disease vaccine.

Aedes aegypti and Aedes albopictus Habitat Preferences in South Texas, USA

The South Texas region has a historical record of occasional dengue outbreaks. The recent introduction of chikungunya virus to the Caribbean suggests that this disease may be a concern as well. Six different cities and three field habitat types (residential, tire shops, and cemeteries) were examined for evidence of habitat and longitudinal preference of two vector species, Aedes aegypti and Aedes albopictus. A. aegypti was more prevalent in tire shop sites, while A. albopictus was more prevalent in cemetery sites. In residential sites, the relative abundance of the two species varied with longitude, with A. albopictus being more abundant near the coast, and A. aegypti being more abundant inland. There was also a temporal variation, with A. aegypti declining in frequency over time in residential sites. These results have implications for control strategies and disease risk and suggest a greater need for increased surveillance and research in the region.

Pathogenic Landscape of Transboundary Zoonotic Diseases in the Mexico-US Border Along the Rio Grande

Transboundary zoonotic diseases, several of which are vector borne, can maintain a dynamic focus and have pathogens circulating in geographic regions encircling multiple geopolitical boundaries. Global change is intensifying transboundary problems, including the spatial variation of the risk and incidence of zoonotic diseases. The complexity of these challenges can be greater in areas where rivers delineate international boundaries and encompass transitions between ecozones. The Rio Grande serves as a natural border between the US State of Texas and the Mexican States of Chihuahua, Coahuila, Nuevo León, and Tamaulipas. Not only do millions of people live in this transboundary region, but also a substantial amount of goods and people pass through it everyday. Moreover, it occurs over a region that functions as a corridor for animal migrations, and thus links the Neotropic and Nearctic biogeographic zones, with the latter being a known foci of zoonotic diseases. However, the pathogenic landscape of important zoonotic diseases in the south Texas-Mexico transboundary region remains to be fully understood. An international perspective on the interplay between disease systems, ecosystem processes, land use, and human behaviors is applied here to analyze landscape and spatial features of Venezuelan equine encephalitis, Hantavirus disease, Lyme Borreliosis, Leptospirosis, Bartonellosis, Chagas disease, human Babesiosis, and Leishmaniasis. Surveillance systems following the One Health approach with a regional perspective will help identifying opportunities to mitigate the health burden of those diseases on human and animal populations. It is proposed that the Mexico-US border along the Rio Grande region be viewed as a continuum landscape where zoonotic pathogens circulate regardless of national borders.

Analysis of children's perception of triatomine vectors of chagas disease through drawings: opportunities for targeted health education

BACKGROUND

Chagas disease is a tropical parasitic disease affecting about 10 million people, mostly in the Americas, and transmitted mainly by triatomine bugs. Insect vector control with indoor residual insecticides and the promotion of housing improvement is the main control intervention. The success of such interventions relies on their acceptance and appropriation by communities, which depends on their knowledge and perceptions of both the disease and the vector. In this study, we investigated school-aged children's knowledge and perception on triatomine vectors and Chagas disease to further understand how communities view this vector and the disease in Yucatan, Mexico.

METHODOLOGY/PRINCIPAL FINDINGS

We performed an analysis of children's drawings on the theme of triatomines and their house in several rural villages, to explore in an open-ended manner their views, understanding and misconceptions. A total of 261 drawings were collected from children ages 6-12 from four villages. We found that children are very familiar with triatomine vectors, and know very well many aspects of their biology and ecology, and in particular their blood-feeding habits. On the other hand, their drawings suggest that the role of triatomines as vectors of a chronic and severe cardiac disease is less understood, and the main perceived health threat appears limited to the bite itself, as previously observed in adults.

CONCLUSIONS/SIGNIFICANCE

These results have important implications for the specific design of future education materials and campaigns, and for the promotion of the inclusion of children in raising Chagas disease awareness in these endemic communities.

The Impact of Nurses on Neglected Tropical Disease Management

Although Neglected Tropical Diseases (NTDs) are largely endemic in the developing nations of Africa, Asia, and South and Central America, they are reemerging with increasing frequency in developed countries. Their diagnosis, treatment, and control are an increasing public health concern that requires a different awareness by health care providers. Neglected tropical diseases (NTDs) are chronic infectious diseases which disproportionately burden poor, rural, and marginalized populations with significant mortality and high morbidity (disability, disfigurement, impaired childhood growth and cognitive development, increased vulnerability to coinfection) that reinforces their poverty. What can we learn from the nurses in developing countries already battling NTD's that could be useful in the developed world? This article provides an overview of distribution, pathophysiology, symptoms, and management of 13 NTDs, with particular attention to the role of nurses in delivering cost-effective integrated interventions. Case studies of schistosomiasis, Chagas disease, and leishmaniasis address recognition and treatment of infected individuals in developed nations where NTD infection is limited primarily to immigrants and travelers.

High prevalence of soil-transmitted helminths in Southern Belize-highlighting opportunity for control interventions

OBJECTIVE

To assess prevalence and intensity of soil-transmitted helminths (STH) in school age children of two southern districts as baseline information prior to implement a deworming program against intestinal parasites as part of an integrated country development plan.

METHODS

Children randomly selected from urban and rural schools in Southern Belize provided one stool sample each, analysed by the Kato-Katz method to assess prevalence and intensity of STH infections. Epi Info software was used for data analysis; Chi-square test and Fischer exact test were applied to compare group proportions; P<0.05 was considered of statistical significance; descriptive statistics were expressed as percentages.

RESULTS

A total of 500 children from 10 schools participated in the study from May to December 2005. Prevalence of STH ranged between 40% and 82% among schools, with a median of 59.2%; the majority of light intensity, and with 2.2% high intensity infection. Trichuris and Ascaris infections presented similar frequency in children aged from 6 to 9 years old; hookworm infections tended to be more frequent in the older group 10 to 12 years old. Statistical significances (P≤0.01) were found in children in rural schools infected with any species of STH, in moderate Trichuris infections, in hookworm infections in rural areas with strong Mayan presence and in Ascaris infections in children of Mayan origin.

CONCLUSIONS

High prevalence of STH in Southern Belize provided sound ground for implementing an integrated deworming control program.

Dengue vectors, human activity, and dengue virus transmission potential in the lower Rio Grande Valley, Texas, United States

Dengue virus is an emerging disease of concern in the Americas. Recent outbreaks in Florida highlight the potential for the virus to return to the United States. The Lower Rio Grande Valley region of Texas directly borders Mexico, and has experienced dengue transmission in the past concurrent with outbreaks in Mexico along the border region. We examined the potential for dengue virus transmission by examining the vectors in the region, as well as assessing human behavior. We further hypothesized that dengue vector abundance would influence human behavior. Two dengue vectors, Aedes aegypti (L.) and Aedes albopictus (Skuse), were found in the region in high abundance. More mosquitoes were collected in rural sites and sites with high vegetation. Of the two species, only Ae. albopictus showed any significant habitat preferences, being more common in rural site. While there was no correlation between human behavior and mosquito abundance, the results support a significant correlation between knowledge of mosquitoes and dengue virus and behavioral practices that might reduce risk of disease transmission. Dengue risk may be higher in certain regions of the Lower Rio Grande Valley based on socioeconomic conditions, specifically in economically poor regions such as the undeveloped colonias found in the region. Because of the proximity of this region to an area with endemic dengue, continued surveillance and risk assessment is suggested.

Projected future distributions of vectors of Trypanosoma cruzi in North America under climate change scenarios

BACKGROUND

Chagas disease kills approximately 45 thousand people annually and affects 10 million people in Latin America and the southern United States. The parasite that causes the disease, Trypanosoma cruzi, can be transmitted by insects of the family Reduviidae, subfamily Triatominae. Any study that attempts to evaluate risk for Chagas disease must focus on the ecology and biogeography of these vectors. Expected distributional shifts of vector species due to climate change are likely to alter spatial patterns of risk of Chagas disease, presumably through northward expansion of high risk areas in North America.

METHODOLOGY/PRINCIPAL FINDINGS

We forecast the future (2050) distributions in North America of Triatoma gerstaeckeri and T. sanguisuga, two of the most common triatomine species and important vectors of Trypanosoma cruzi in the southern United States. Our aim was to analyze how climate change might affect the future shift of Chagas disease in North America using a maximum entropy algorithm to predict changes in suitable habitat based on vector occurrence points and predictive environmental variables. Projections based on three different general circulation models (CCCMA, CSIRO, and HADCM3) and two IPCC scenarios (A2 and B2) were analyzed. Twenty models were developed for each case and evaluated via cross-validation. The final model averages result from all twenty of these models. All models had AUC >0.90, which indicates that the models are robust. Our results predict a potential northern shift in the distribution of T. gerstaeckeri and a northern and southern distributional shift of T. sanguisuga from its current range due to climate change.

CONCLUSIONS/SIGNIFICANCE

The results of this study provide baseline information for monitoring the northward shift of potential risk from Chagas disease in the face of climate change.

Seroprevalence of T. cruzi infection in blood donors and Chagas cardiomyopathy in patients from the coal mining region of Coahuila, Mexico

Context and Objective: Chagas disease is considered a worldwide emerging disease; it is endemic in Mexico and the state of Coahuila and is considered of little relevance. The objective of this study was to determine the seroprevalence of T. cruzi infection in blood donors and Chagas cardiomyopathy in patients from the coal mining region of Coahuila, Mexico.

Design and Setting: Epidemiological, exploratory and prospective study in a general hospital during the period January to June 2011.

Methods: We performed laboratory tests ELISA and indirect hemagglutination in three groups of individuals: 1) asymptomatic voluntary blood donors, 2) patients hospitalized in the cardiology department and 3) patients with dilated cardiomyopathy.

Results: There were three levels of seroprevalence: 0.31% in asymptomatic individuals, 1.25% in cardiac patients and in patients with dilated cardiomyopathy in 21.14%.

Conclusions: In spite of having detected autochthonous cases of Chagas disease, its importance to local public health remains to be established as well as the details of the dynamics of transmission so that the study is still in progress.

Crowd-funded micro-grants for genomics and "big data": an actionable idea connecting small (artisan) science, infrastructure science, and citizen philanthropy

Biomedical science in the 21(st) century is embedded in, and draws from, a digital commons and "Big Data" created by high-throughput Omics technologies such as genomics. Classic Edisonian metaphors of science and scientists (i.e., "the lone genius" or other narrow definitions of expertise) are ill equipped to harness the vast promises of the 21(st) century digital commons. Moreover, in medicine and life sciences, experts often under-appreciate the important contributions made by citizen scholars and lead users of innovations to design innovative products and co-create new knowledge. We believe there are a large number of users waiting to be mobilized so as to engage with Big Data as citizen scientists-only if some funding were available. Yet many of these scholars may not meet the meta-criteria used to judge expertise, such as a track record in obtaining large research grants or a traditional academic curriculum vitae. This innovation research article describes a novel idea and action framework: micro-grants, each worth $1000, for genomics and Big Data. Though a relatively small amount at first glance, this far exceeds the annual income of the "bottom one billion"-the 1.4 billion people living below the extreme poverty level defined by the World Bank ($1.25/day). We describe two types of micro-grants. Type 1 micro-grants can be awarded through established funding agencies and philanthropies that create micro-granting programs to fund a broad and highly diverse array of small artisan labs and citizen scholars to connect genomics and Big Data with new models of discovery such as open user innovation. Type 2 micro-grants can be funded by existing or new science observatories and citizen think tanks through crowd-funding mechanisms described herein. Type 2 micro-grants would also facilitate global health diplomacy by co-creating crowd-funded micro-granting programs across nation-states in regions facing political and financial instability, while sharing similar disease burdens, therapeutics, and diagnostic needs. We report the creation of ten Type 2 micro-grants for citizen science and artisan labs to be administered by the nonprofit Data-Enabled Life Sciences Alliance International (DELSA Global, Seattle). Our hope is that these micro-grants will spur novel forms of disruptive innovation and genomics translation by artisan scientists and citizen scholars alike. We conclude with a neglected voice from the global health frontlines, the American University of Iraq in Sulaimani, and suggest that many similar global regions are now poised for micro-grant enabled collective innovation to harness the 21(st) century digital commons.

Childhood parasitic infections endemic to the United States

Endemic parasitic infections in the United States are more frequent than is commonly perceived. Intestinal parasitic infection with Cryptosporidium, Dientamoeba, and Giardia occurs most often in children in northern states during the summer months. Zoonotic Toxocara and Toxoplasma parasitic infections are more frequent in southern states, in African Americans, and in populations with lower socioeconomic status. Approximately 300, 000 people in the United States have Trypanosoma cruzi infection. Local, vector-borne transmission of T cruzi and Leishmania infections has been documented in southern states. Parasitic diseases endemic to the United States are not uncommon but are understudied.

Accelerating the development of a therapeutic vaccine for human Chagas disease: rationale and prospects

Chagas disease is a leading cause of heart disease affecting approximately 10 million people in Latin America and elsewhere worldwide. The two major drugs available for the treatment of Chagas disease have limited efficacy in Trypanosoma cruzi-infected adults with indeterminate (patients who have seroconverted but do not yet show signs or symptoms) and determinate (patients who have both seroconverted and have clinical disease) status; they require prolonged treatment courses and are poorly tolerated and expensive. As an alternative to chemotherapy, an injectable therapeutic Chagas disease vaccine is under development to prevent or delay Chagasic cardiomyopathy in patients with indeterminate or determinate status. The bivalent vaccine will be comprised of two recombinant T. cruzi antigens, Tc24 and TSA-1, formulated on alum together with the Toll-like receptor 4 agonist, E6020. Proof-of-concept for the efficacy of these antigens was obtained in preclinical testing at the Autonomous University of Yucatan. Here the authors discuss the potential for a therapeutic Chagas vaccine as well as the progress made towards such a vaccine, and the authors articulate a roadmap for the development of the vaccine as planned by the nonprofit Sabin Vaccine Institute Product Development Partnership and Texas Children's Hospital Center for Vaccine Development in collaboration with an international consortium of academic and industrial partners in Mexico, Germany, Japan, and the USA.

Neglected infections of poverty in Texas and the rest of the United States: management and treatment options

In the poorest regions of the United States, especially along the Gulf Coast and in South Texas, are a group of endemic parasitic and related infections known as the neglected infections of poverty. Such infections are characterized by their chronicity, disabling features, and disproportionate impact on the estimated 46 million people who live below the U.S. poverty line. Today more Americans live in poverty than ever before in the half-century that the Census Bureau has been recording poverty rates. In association with that poverty, a group of major neglected infections of poverty have emerged in the United States. Here we describe the major neglected infections of poverty in the United States, with a brief overview of their significant epidemiological features, their links with poverty, and our approaches to their diagnosis, management, and treatment.