Zoonotic and Viral Diseases

The Laboratory for Zoonotic and Viral Diseases is primarily focused on clinical research of human vector-borne diseases and emerging pathogens.

Current activities include the following clinical/research projects:

SARS-COV-2 virus is an emerging pathogen that results in the clinical disease known as COVID-19. As a new pathogen, there are substantial gaps in our knowledge of the natural history and long-term clinical outcomes related to infection. There are also new concerns regarding the potential for reactivation of infection and lack of robust, long-acting immune response that would confer longer protection. Please detail the overall purpose and goal of the project. The purpose of this study is to understand the epidemiology of the disease, examine the long-term clinical outcomes, document the natural history of infection by monitoring viral shedding and the humoral immune response, and evaluate biomarkers of infection predictive of severe disease.

We have created a nationwide Acute Febrile Illness (AFI) surveillance network to detect and diagnose vector-borne, respiratory, and enteric pathogens within sentinel hospitals and clinics throughout Belize. This AFI sentinel surveillance system will work in tandem with vector and animal reservoir surveillance to create a One Health approach to detecting and combating disease threats. In collaboration with the Belize Ministry of Health and the US Centers for Disease Control and Prevention, we are implementing surveillance at 11 clinics representing all districts of Belize. Patients presenting to the surveillance sites with acute onset fever and meeting inclusion criteria will be screened for vector-borne pathogens (ZIKV, WNV, DENV, CHIKV, Rickettsia spp., Trypanosoma cruzi, and Plasmodium spp.), 21 respiratory pathogens, and 22 gastrointestinal pathogens. Results from this study will be used to understand, detect, and respond to infectious disease threats in this high-risk region and be used for public health planning and policy-making. Due to the outbreak of SARS-CoV-2 causing COVID-10, this study is especially valuable. We are working directly with the Ministry of Health to increase capacity for COVID-19 testing.

Through our collaboration with the University of the Philippines in Manila and USAID, we recently screened more than 5,000 children in Bohol, Philippines for tuberculosis (TB). The goal of this study is to understand the impact of the large earthquake in 2013 had on TB transmission in vulnerable populations. By understanding the prevalence and risk factors for TB exposure in children, we can create interventions and develop programs for disease prevention and control.

We are conducting a study to determine the long-term clinical outcomes of chronic West Nile virus infection. Since 2002, the study has followed a cohort of more than 200 West Nile virus survivors with the goal of gaining insight into the long-term renal and neurological effects of West Nile virus. The research study has conducted annual renal and neurological evaluations including neurological exams, MRIs, nerve and muscle studies, and lumbar punctures of persistently infected West Nile patients. Now, our efforts focus on acute aspects of infection and evaluating what makes individuals sick. We also work to identify potential treatments for West Nile virus infections. These studies are currently supported by a shared U19 grant in collaboration with Yale University, The Brockman Foundation, and The Chao Foundation. The study was formerly funded by an R01 through the National Institutes of Health, the Gillson Longenbaugh Foundation, and the Mike Hogg Foundation.

Our laboratory is working to better understand the transmission dynamics and epidemiology of vector-borne and neglected tropical disease in Texas. We work to analyze vector distribution, pathogen prevalence in reservoir animals, and conduct active screening of high-risk populations. Our effort to characterize autochthonous Chagas disease transmission in Texas are described here. Our effort to characterize autochthonous Chagas disease transmission in Texas has included a search for kissing bugs throughout the state of Texas, enrollment and testing of high-risk Texans such as hunters, testing of local wildlife, and evaluation of individuals presenting with dilated cardiomyopathy for Chagas disease.

Collaborative Projects:

Working with Dr. Flor Munoz-Rivas, we are developing a predictive model for pandemic H1N1 influenza using patient data from the 2013 outbreak. Additionally, we are performing a toxoplasmosis chart abstraction study to understand the emergence of pediatric cases at Texas Children’s and its implication for future disease outbreaks.

With Dr. Julie Boom and Leila Sahni at Texas Children’s, we performed a surveillance project screening febrile children in the Emergency Department for Chikungunya, Dengue and West Nile virus infection. We currently have enrolled over 900 children into this febrile surveillance cohort.

Since the 1990’s, an epidemic of acute kidney failure in Central America has been affecting mostly young, healthy sugarcane workers who lack typical risk factors for kidney disease. Despite a large number of deaths (approximately 20,000 people have already died from this disease) the etiology remains a mystery. Based the patterns of this disease, its clinical characteristics, and what we have observed of the local environment, we hypothesize that an infectious organism could be at the root of the outbreak.

Since 2014, the team has been leading efforts to collect samples from people, key animal species, and the environment at our research site in Nicaragua in order to look for evidence of infectious pathogens. Understanding the agent-host-environment model of this disease is central to our investigation as we look for interventions and treatment strategies to interrupt this unrelenting epidemic of acute kidney failure.