Modeling "The Perfect Storm": Natural Disasters and Infectious Disease

2011 saw an incredible range of natural disasters throughout the globe. Earthquakes shook the ground the world over, from minor (if unexpected) ones in the eastern states of the US, to the 8.9-magnitude quake and its subsequent after-shocks that ravaged Japan and the 7.6-quake in New Zealand along with several others in Southeast Asia, just barely more than a year after the 7.0- magnitude quake hit Haiti in 2010. Read more... >>

Defining a "Contact"

According to the Merriam-Webster dictionary, a contact is defined as "a union or junction of surfaces; direct experience through the senses" ( However when it comes to the transmission of infectious diseases, a contact can mean so much more. Read more... >>

Modeling Vector Control

In Phoenix, a program is in place to eradicate one of the pests associated with high levels of damage to cotton crops – the pink bollworm, the larval form of a grey moth that thrives in cotton producing areas of the United States, Mexico, Egypt and India. This pest-control program actually breeds these moths, then sterilizes them via radiation exposure, and releases them by the millions from planes flying over cotton fields. Read more... >>

Modeling Travel and Infectious Disease

As the school year draws to a close, most families start thinking about what to do over the summer – and for many people this means travel. It could be as simple as a road-trip to see family, or as extravagant as flying to Europe for a month, but the one thing all travel scenarios have in common, from a modeling perspective, is the sudden expansion of contact matrices. Read more... >>

Q&A: What to do when there's not enough data?

Q: There isn’t enough data on some of the parameters for the disease / system we’re looking at – is it even worth pursuing the development of a mathematical transmission model at this point, or is it better to wait for more research? A: Yes… and yes. Read more... >>

The Disease Impacts of Monsoons

The formal definition of monsoon is a “seasonal reversing wind accompanied by corresponding changes in precipitation” (see Wikipedia for more), but most people, when they think of “monsoon”, think RAIN. Monsoon weather patterns are prevalent in several regions of the globe, including parts of Africa, South and East Asia, Australia, and the desert Southwestern United States. Read more... >>

An Ecological Perspective on Individual Disease

The Merriam-Webster dictionary defines health as freedom from physical disease or pain. Human health, including disease resistance, is driven in numerous ways by an individual’s microbiome – the inner ecosystem of human gut bacteria and their genes. The microbiome is a vast internal ecosystem which influences and is influenced by environmental conditions in the human digestive system. Read more... >>

Setting Up for Success With Modeling

Mathematics is a beautiful and elegant field of science, and many of the theorems that have developed over the centuries have involved years and years of deep thought and intense exploration in their construction. However for most people mathematics is a tool meant to be applied to other fields of study, and for these individuals the beauty and elegance of a mathematical equations isn’t nearly as important as how well it answers the question at hand. Read more... >>

How to Make Mathematical Models More Accessible

Mathematical modeling is a fabulous tool for solving problems in almost every field of scientific study, from genetics to astrophysics and everything in between. And yet, so many times the very models that can be of most use to these fields are mysterious black-boxes within which who-knows-what goes on. And sometimes, it must be admitted, the mathematicians behind these models like it this way. Read more... >>

Mathematical Experiments and Modeling Scenarios

Many people feel mathematics is a field in which experimentation doesn’t really come into play. The term “experiment” generally conjures up images of chemistry, biology, physics and so on, i.e. what the average person considers “science” (though I personally would argue that math is absolutely a science). Read more... >>

Modeling the Seasonal Epidemic - Part 1

It’s fairly easy to recognize that influenza has a “season” – a time of year in which transmission is exceptionally high, counterbalanced by the opposite time of year in which incidence is low to almost-nil in a given location. This is the case with a wide variety of diseases – vector-borne, food-borne, water-borne, respiratory, parasitic, and so on. Read more... >>

Modeling the Seasonal Epidemic - Part 2

Last month we discussed the various ways that seasonality can impact infectious disease transmission; this month we’re looking into the techniques to incorporate these periodic effects into mathematical models. A function is said to be periodic if its behavior repeats over constant intervals. Read more... >>

Modeling the Seasonal Epidemic - Part 3

In the first part of this series we discussed the existence of short- and long-term seasonality in epidemiology, and its impact on disease transmission; in the second part, we addressed ways in which to incorporate these seasonal effects into mathematical models. For this final installment we’ll be looking into the implications of seasonality and longer-term periodicity for the control and eradication of infectious diseases. Read more... >>