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Deadly bacteria are spreading through the oceans as waters warm up, and are increasing infection risks, according to a new study. Multiple species of rod-shaped Vibrio bacteria live in the world's oceans, and their populations rise and fall based on many different variables, changing the likelihood of making people sick.

This case study centers on an active teaching game that simulates a cholera outbreak among five villages along a river, similar to the Haitian outbreak of 2010. By enacting the behaviors of fictional villagers, students learn how trade, travel, sanitation practices and geographic location contribute to the spread of diarrheal disease. Documenting various contamination events of village water supplies allows students to trace the progression of the disease and illustrates how adequate sanitation facilities provide protection against the bacteria Vibrio cholera. Originally designed for an undergraduate upper-division biology course focusing on the epidemiology of diseases, the simulation is also appropriate for microbiology and public health courses, as well as lower division undergraduate biology courses and high school. Biology or epidemiology components of the case study can be highlighted depending on the emphasis of the course being taught. The game can be completed within a 45- to 60-minute class period. Playing cards are available from the Supplemental Materials tab; detailed instructions are found in the teaching notes.

Iona Twaddell looks at the science of the waterborne disease cholera There are an estimated 3-5 million cases of cholera, a disease caused by the bacterium Vibrio cholera, each year. It is passed on through drinking water that has been contaminated with faeces from someone infected with the bacteria. Cholera causes vomiting and diarrhoea, leading to severe dehydration.

Vibrio harveyi is a marine bacteria that emits light only at high population density. The bacterial bioluminescence is controlled by a system called quorum sensing. In this system, signaling molecules are secreted, and when they bind to cell surface receptors, they turn on many genes, including those that produce bioluminescence.