program for enhancing the health and productivity of livestock
Catherine Herzog
Catherine studies the transmission dynamics of peste des petits ruminants virus in multi-host systems in Northern Tanzania
About Me
Catherine holds a Bachelor of Science in Neuroscience from the University of Michigan and a Master of Public Health degree in Epidemiology and Global Health Certificate from the University of Michigan School of Public Health. Her master’s thesis was a descriptive epidemiological study of the prevalence and geographical distribution of blood cancers in Gharbiah Province, Egypt. After graduation, she worked as an Allan Rosenfield Global Health fellow of Health Informatics at the Centers for Disease Control in Lusaka, Zambia with the national electronic healthcare record system SmartCare. In the US, she worked as an epidemiologist at the Air Force Medical Support Agency for approximately four years completing projects on descriptive chronic disease epidemiology, quality of care metrics, and health informatics. Still interested in infectious disease research, she returned to academia to pursue her PhD and is now a Biology PhD candidate at Penn State University. At the highly interdisciplinary Center for Infectious Disease Dynamics, she pursues research at the intersection of disease ecology and epidemiology. In her free time Catherine likes to dance (ballroom dancing and west coast swing), sing, cook, and read.
Transmission dynamics of peste des petits ruminants virus in a multi-host system in Northern Tanzania
Thesis Research Project
Research
I work with Drs. Ottar Bjørnstad, Peter Hudson, Isabella Cattadori, and Vivek Kapur in collaboration with Tanazanian colleagues Dr. Lughano Kusiluka (Mzumbe University), Dr. Emmanuel Mpolya, and Dr. Joram Buza at the Nelson Mandela African Institute of Science and Technology to study the multi-host disease dynamics and persistence of peste des petits ruminants virus (PPRV) in Tanzania. The livestock-wildlife interface in northern Tanzania, especially areas near Serengeti National Park and Ngorongoro Crater, is species rich with pastoralists and agropastoralists herding cattle, sheep, and goats on grazing grounds shared with wildlife including African buffalo, wildebeest, and various antelope, bat, and rodent species. I am developing a multi-host model that will describe the system and allow me to test the impact of various seasonal forces on disease dynamics. This model will be informed by a large, age structured serosurvey among sheep and goats in Northern Tanzania. PPRV has been selected as the next disease for eradication, but currently there is not even a basic understanding of its transmission dynamics in multi-host systems such as those found in Tanzania. The role of each livestock species and of regional wildlife species in transmission and persistence of PPRV needs to be better understood to help guide eradication campaign efforts.
PPRV is an important pathogen of ruminant livestock worldwide
PPRV infects sheep, goats, and cattle as will as wild ruminant species such as antelope and buffalo. PPRV threatens ~80% of the global small ruminant population of nearly 2 billion animals. Globally, over 330 million farmers’ livelihoods rely directly on small ruminants and demand for meat and milk will rise 137-177% by 2030. PPRV has spread to > 70 countries in Asia, the Middle East, and Africa. The virus is transmitted by direct contact and causes high morbidity and mortality in domesticated sheep and goats. PPRV is now endemic in Tanzania and its distribution and risk factors among sheep, goats and cattle are unknown.
Using Serosurveys, Questionnaires, and Modeling to Learn More about PPRV in Tanzania
Serosurveys and questionnaires can help improve knowledge of PPRV distribution and provide parameters for statistical and mathematical models. These models describe the data and its structure and model dynamics are evaluated against field data to validate mechanistic assumptions about PPRV transmission in the field. Insights from models improve understanding of PPRV dynamics in small ruminant herds and effect of PPRV on capital. My project aims to better understand the distribution and risk factors for PPRV transmission in Tanzania and create models whose outputs can inform PPR 2030 Eradication campaign efforts.
Research in Action
Catherine tested sheep, goat, and cattle serum samples in the lab using a competitive enzyme linked immunosorbent assay (cELISA) which detects antibodies in the serum. Here, she explains and demonstrates the technique and how she is using it to further her research on peste des petits ruminants virus.