Pathogen top-trumps: Helicobacter pylori

Updating the childhood game for the biologist. Each week I will publish a new card on a new pathogen, the following categories will be included

Annual Death Rate- Based on WHO statistics or equivalent.
Disease Severity- severity of symptoms and manifest disease; 0= mild discomfort, 10= death
Treatability- Disease treatability; 0=no treatment 10=fully treatable
Published Papers- Based on pubmed hits.
Lab Category – Containment category of the lab needed to work on the pathogen.

I will also include a brief introduction and summary of the organism.
This week I thought it would be best to start with the disease I know best, the subject of my thesis.
Helicobacter pylori is a gram negative, micro-aerobic, spiral rod bacterium that colonises the stomach First identified in 1983 by Marshal and Warren (1), and subsequently classified as a type one carcinogen by WHO. H. pylori is the cause of 80% of peptic ulcer disease and an important determining factor in the development of gastric adenocarcinoma (which leads to up to one million deaths globally each year (2,3) and mucosal-associated lymphoid tissue (MALT) lymphoma. About 50% of the global population is infected, however, only around 15% of these will develop gastric ulceration in their lifetime and only 0.5-2% develop gastric adenocarcinoma (4). H. pylori is passed between individuals by the oral-oral route and due to the intimacy required for disease passage, infection is familial in nature spreading from parent to child (5) (though in less developed countries horizontal transmission is also common). Once infection is identified it can be quickly cleared using triple therapy of 2 antibiotics and a proton pump inhibitor. However, if infection leads to gastric cancer only about one patient in five survives longer than five years after diagnosis.

1. Marshall BJ, & Warren JR. 1984. Lancet 1: 1311-5
2. Covacci A et al., 1999. Science 284: 1328-33
3. Figura N et al., 1998. Gut 42: 772-8
4. Solnick JV, & Schauer DB. 2001. Clin Microbiol Rev 14: 59-97
5. Delport W et al., 2006. Genetics 174: 2107-18