- Infectious Disease
Instructor, Medicine - Infectious Diseases
Boards, Advisory Committees, Professional Organizations
Senior Fellow, Center for Innovation in Global Health (CIGH) at Stanford University School of Medicine (2015 - Present)
Fellowship, Stanford University Medical Center, Infectious Diseases, Adult (2015)
Board Certification: Infectious Disease, American Board of Internal Medicine (2013)
Board Certification: Internal Medicine, American Board of Internal Medicine (2012)
Residency:Stanford University Medical Center (2011) CA
Internship:Stanford University Medical Center (2009) CA
Medical Education:University of Pennsylvania (2008) PA
Current Research and Scholarly Interests
I am interested in the intersection between infectious disease and ecology and my current research is on detecting emerging zoonotic pathogens. Zoonotic disease represents a major burden to human health: from the bubonic plague of the middle ages, to the 1918 flu pandemic that infected one third of the world’s population, to the modern Human immunodeficiency virus (HIV) epidemic which affects 34 million people living today. My current work aims to detect viral spillover events from animals to humans with the hope of eventually understanding the ecology that drives this process and better defining the steps that will be required to stop the emergence of these pathogens. I currently work in Bangladesh, China, and Costa Rica.
Detection of Emerging Zoonotic Pathogens in Humans, Bangladesh
A surveillance platform for the detection of novel pathogens and emerging infectious diseases. Currently the platform is running throughout Bangladesh and has collected hundreds of samples from high-risk acutely ill individuals. Collaboration with Stanford University, the International Centre for Diarrhoeal Disease Research, Bangladesh, and Columbia University.
Developing Interventions to End Cycles of Poverty Caused by Taenia solium and Neurocysticercosis, China
Neurocysticercosis is a neglected infectious disease caused by larval forms of the pig tapeworm, Taenia solium, infecting people's brains. In our exploratory work in impoverished areas of Western China focusing on disease prevalence and burden in children, we have identified widespread disease, including brain infections and resulting cognitive deficits. We hope to identify transmission pathways and pilot interventions that will reduce transmission.
Spillover of Zoonotic Diseases in a Fragmented Landscape, Costa Rica
Structural Equation Modeling (SEM) of Cysticercosis in School-Aged Children in Tibetan Rural Farming Areas of Western China: Implications for Intervention Planning.
International journal of environmental research and public health
2019; 16 (5)
Neurocysticercosis (NCC) significantly contributes to morbidity in developing countries. We recently published a study of prevalence and risk factors in school-aged children in three mountainous areas in Sichuan province of western China. Using structural equation modeling (SEM) on data from that study to guide intervention planning, here we examine risk factors grouped into three broad interventional categories: sociodemographics, human behavior, and sources of pork and pig husbandry. Because neuroimaging is not easily available, using SEM allows for the use of multiple observed variables (serological tests and symptoms) to represent probable NCC cases. Data collected from 2608 students was included in this analysis. Within this group, seroprevalence of cysticercosis IgG antibodies was 5.4%. SEM results showed that sociodemographic factors (beta = 0.33, p < 0.05), sources of pork and pig husbandry (beta = 0.26, p < 0.001), and behavioral factors (beta = 0.33, p < 0.05) were all directly related to probable NCC in school-aged children. Sociodemographic factors affected probable NCC indirectly via sources of pork and pig husbandry factors (beta = 0.07, p < 0.001) and behavioral variables (beta = 0.07, p < 0.001). Both sociodemographic factors (beta = 0.07, p < 0.05) and sources of pork and pig husbandry factors (beta = 0.10, p < 0.01) affected probable NCC indirectly via behavioral variables. Because behavioral variables not only had a large direct effect but also served as a critical bridge to strengthen the effect of sociodemographics and sources of pork and pig husbandry on probable NCC, our findings suggest that interventions targeting behavioral factors may be the most effective in reducing disease.
View details for DOI 10.3390/ijerph16050780
View details for PubMedID 30836642
Prevalence and risk factors for Taenia solium cysticercosis in school-aged children: A school based study in western Sichuan, People's Republic of China.
PLoS neglected tropical diseases
2018; 12 (5): e0006465
Taenia solium cysticercosis affects millions of impoverished people worldwide and can cause neurocysticercosis, an infection of the central nervous system which is potentially fatal. Children may represent an especially vulnerable population to neurocysticercosis, due to the risk of cognitive impairment during formative school years. While previous epidemiologic studies have suggested high prevalence in rural China, the prevalence in children as well as risk factors and impact of disease in low-resource areas remain poorly characterized.Utilizing school based sampling, we conducted a cross-sectional study, administering a questionnaire and collecting blood for T. solium cysticercosis antibodies in 2867 fifth and sixth grade students across 27 schools in west Sichuan. We used mixed-effects logistic regression models controlling for school-level clustering to study associations between risk factors and to characterize factors influencing the administration of deworming medication. Overall prevalence of cysticercosis antibodies was 6%, but prevalence was significantly higher in three schools which all had prevalences of 15% or higher. Students from households owning pigs (adjusted odds ratio [OR] 1.81, 95% CI 1.08-3.03), from households reporting feeding their pigs human feces (adjusted OR 1.49, 95% CI 1.03-2.16), and self-reporting worms in their feces (adjusted OR 1.85, 95% CI 1.18-2.91) were more likely to have cysticercosis IgG antibodies. Students attending high prevalence schools were more likely to come from households allowing pigs to freely forage for food (OR 2.26, 95% CI 1.72-2.98) and lacking a toilet (OR 1.84, 95% CI 1.38-2.46). Children who were boarding at school were less likely to have received treatment for gastrointestinal worms (adjusted OR 0.58, 95% CI 0.42-0.80).Our study indicates high prevalences of cysticercosis antibodies in young school aged children in rural China. While further studies to assess potential for school-based transmission are needed, school-based disease control may be an important intervention to ensure the health of vulnerable pediatric populations in T. solium endemic areas.
View details for DOI 10.1371/journal.pntd.0006465
View details for PubMedID 29738570
View details for PubMedCentralID PMC5959190
High prevalence of Taenia solium taeniasis and cysticercosis in Tibetan schoolchildren in western Sichuan, China: a cross-sectional study
ELSEVIER SCIENCE INC. 2017: S89
View details for Web of Science ID 000440459400090
TAENIA SOLIUM AND NEUROCYSTICERCOSIS BURDEN AND DECREASED ACADEMIC PERFORMANCE ASSOCIATED WITH BRAIN INFECTION IN SCHOOL AGED CHILDREN, SOUTHWEST CHINA
AMER SOC TROP MED & HYGIENE. 2017: 139–40
View details for Web of Science ID 000412851501447
Reduction in bacterial contamination of hospital textiles by a novel silver-based laundry treatment
AMERICAN JOURNAL OF INFECTION CONTROL
2016; 44 (12): 1705-1708
Treating hospital patient textiles with ionic silver after each washing results in a significant decrease in microbial contamination. Although further study is needed to better understand the role textiles play in hospital-acquired infections and to quantify the influence of silver textile treatment on health care-associated infection risk and patient outcomes, ionic silver treatment of textiles may prove useful in hospital-acquired infection reduction strategies.
View details for DOI 10.1016/j.ajic.2016.06.021
View details for Web of Science ID 000392626300057
View details for PubMedID 27561434
Bat Hunting and Bat-Human Interactions in Bangladeshi Villages: Implications for Zoonotic Disease Transmission and Bat Conservation.
Transboundary and emerging diseases
Bats are an important reservoir for emerging zoonotic pathogens. Close human-bat interactions, including the sharing of living spaces and hunting and butchering of bats for food and medicines, may lead to spillover of zoonotic disease into human populations. We used bat exposure and environmental data gathered from 207 Bangladeshi villages to characterize bat exposures and hunting in Bangladesh. Eleven percent of households reported having a bat roost near their homes, 65% reported seeing bats flying over their households at dusk, and 31% reported seeing bats inside their compounds or courtyard areas. Twenty percent of households reported that members had at least daily exposure to bats. Bat hunting occurred in 49% of the villages surveyed and was more likely to occur in households that reported nearby bat roosts (adjusted prevalence ratio [aPR] 2.3, 95% CI 1.1-4.9) and villages located in north-west (aPR 7.5, 95% CI 2.5-23.0) and south-west (aPR 6.8, 95% CI 2.1-21.6) regions. Our results suggest high exposure to bats and widespread hunting throughout Bangladesh. This has implications for both zoonotic disease spillover and bat conservation.
View details for DOI 10.1111/tbed.12505
View details for PubMedID 27125493
View details for PubMedCentralID PMC5086320
Increased Morbidity and Mortality in Domestic Animals Eating Dropped and Bitten Fruit in Bangladeshi Villages: Implications for Zoonotic Disease Transmission.
2016; 13 (1): 39-48
We used data on feeding practices and domestic animal health gathered from 207 Bangladeshi villages to identify any association between grazing dropped fruit found on the ground or owners directly feeding bat- or bird-bitten fruit and animal health. We compared mortality and morbidity in domestic animals using a mixed effects model controlling for village clustering, herd size, and proxy measures of household wealth. Thirty percent of household heads reported that their animals grazed on dropped fruit and 20% reported that they actively fed bitten fruit to their domestic herds. Household heads allowing their cattle to graze on dropped fruit were more likely to report an illness within their herd (adjusted prevalence ratio 1.17, 95% CI 1.02-1.31). Household heads directly feeding goats bitten fruit were more likely to report illness (adjusted prevalence ratio 1.35, 95% CI 1.16-1.57) and deaths (adjusted prevalence ratio 1.64, 95% CI 1.13-2.4). Reporting of illnesses and deaths among goats rose as the frequency of feeding bitten fruit increased. One possible explanation for this finding is the transmission of bat pathogens to domestic animals via bitten fruit consumption.
View details for DOI 10.1007/s10393-015-1080-x
View details for PubMedID 26668032
- Bat hunting and bat-human interactions in Bangladeshi villages: implications for zoonotic disease transmission and bat conservation Transboundary & Emerging Disease 2016
- Increased morbidity and mortality in domestic animals fed ground and bitten fruit in Bangladeshi villages: implications for bat borne zoonotic disease transmission EcoHealth 2015
- Rocky mountain spotted fever in the United States, 2000-2007: interpreting contemporary increases in incidence. American journal of tropical medicine and hygiene 2010; 83 (1): 174–182
- Eczema vaccinatum resulting from the transmission of vaccinia virus from a smallpox vaccinee: an investigation of potential fomites in the home environment Vaccine 2009; 27 (3): 375-7
- Human Ehrlichiosis: Clinical and Ecological Challenges Southern Medical Journal 2007; 100 (8): 769-770
- Purple Glove Syndrome Following Intravenous Phenytoin Administration Vascular Medicine 2007; 12: 29-31
- Rickettsia parkeri rickettsiosis and its clinical distinction from Rocky Mountain spotted fever Clin Infect Dis. 2006; 47 (9): 1188-96