The diseases we study

COVID-19 is a highly contagious respiratory disease caused by the SARS-CoV-2 virus. Beginning in 2019, this novel virus started spreading globally, causing severe illness and death, and overwhelming health care systems in many areas.

We study COVID-19 from numerous angles, including transmission dynamics; evaluating vaccine effectiveness, waning immunity, infection-acquired immunity and how the virus evolves; balancing health equity, epidemiology, and modeling in vaccine prioritization; and the role of viral, pharmaceutical, and social factors in transmission across settings. Our work provides quantitative and qualitative analyses to inform control methods and understand the population-level impacts of interventions. 

Drug resistant infections are caused by bacteria, parasites, viruses etc. that evade the drugs commonly used to treat them. This resistance makes infections harder to treat and increases the risk of disease spread, severe illness and death. Our research aims to better understand and address this growing challenge of drug resistance.

We model the population genetics of bacteria like Neisseria gonorrhoeae, Escherichia coli, Streptococcus pneumoniae, and Staphylococcus aureus to study the emergence and spread of resistance. We also estimate how antimicrobial stewardship—the appropriate use of antimicrobials—and new diagnostics could help reduce antibiotic exposure and slow resistance. Leveraging large health care datasets, we assess factors influencing trends in transmission and resistance in healthcare-associated infections. We also explore new tools and strategies to combat resistant bacteria including diagnostics and vaccines. 

Gonorrhea is one of the most prevalent sexually transmitted infections and an urgent public health threat because of its extensive antibiotic resistance, with increasing rates of resistance to the last-line antibiotic. Left untreated, it can cause severe sequelae, including reproductive health complications and increased risk of HIV infection.

Our research seeks to understand the biology and epidemiology of Neisseria gonorrhoeae, the cause of gonorrhea, to develop a roadmap for methods and management principles that may be generalized to drug resistant pathogens. Our work extends from molecular microbiology and genetics to mathematical modeling and the design of strategies to improve clinical management and public health policy. 

HIV is a virus that attacks the body’s immune system, and over time, if untreated, can lead to AIDS, which leaves the body vulnerable to life-threatening diseases and infections. Since the early 1980s, HIV has claimed more than 40 million lives worldwide and continues to be a major public health challenge without a cure, but with highly effective lifelong treatment.

We use quantitative modeling and analysis to better understand HIV epidemics, evaluate prevention strategies, and provide evidence to guide policies around HIV treatment and care, particularly in sub-Saharan Africa. In partnership with ministries of health and national HIV programs in Malawi, South Africa, and others in the region, our research helps to identify HIV incidence trends, develop district-level HIV estimates, and track progress towards HIV testing and treatment targets.  

Diseases transmitted via mosquito bites like malaria and dengue contribute to a large disease burden globally. Using genomic data and information on human mobility, we aim to understand real-time transmission and how human patterns of movement affect disease spread. We use models and data to help national control programs optimize their limited resources for control and elimination of malaria, and work with communities to support vector control and screening. Our group has a focus on malaria in the Amazon region in the context of gold mining.  

Our ability to respond rapidly to COVID-19 showed the value of ongoing work on pathogens that could flare up and cause outbreaks or even pandemics. Longstanding research at CCDD monitors and models pathogens that pose serious threats to public health, including influenza, Mpox, and mumps, among others.

We study the patterns and drivers of seasonality of these infections to develop predictions of future disease burden and principles for understanding seasonality in new infections. We develop new methods to evaluate vaccines against these pathogens to identify how vaccination policy can stop outbreaks before they start. Through ethical and policy work we advocate for better regulation of research on potential pandemic pathogens. 

Pneumococcus (Streptococcus pneumoniae) is the leading cause of bacterial pneumonia and among the most common sources of vaccine-preventable disease and death. We have been tracking the effects of vaccination against this pathogen since the first modern vaccine was introduced in 2000. Our work focuses on basic understanding of how pneumococcal populations persist and vary genetically, as well as developing applications that can predict how vaccination will change the bacterial population and how to deploy vaccination to minimize new infections. Fewer infections mean better public health outcomes and less opportunity for the bacteria to evolve and find new ways to evade our vaccines and treatments.