Plagues create business opportunities and the worried well in any era present a commercial opportunity. In the Middle Ages, the Black Death and the Great Plague saw brisk sales in fumigators, herbal remedies, and the plague suit – predecessor of the DuPont TK555T HazMat suit, and equally unsettling for nervous patients. Quacks (from the old Dutch word Quacksalver, for one who boasts or “quacks” about his or her salves) thrived in an era unchallenged by scientific evidence and online Cochrane reports.

The flu business today is brisk – swine, avian and “normal” – and the market in vaccine development, delivery systems, information sources and flu gurus is worth billions. Let me look at two areas – epidemic monitoring and gadgets designed to prevent you from getting flu.

Epidemic monitoring is now embedded in social networking technology. Healthmap tracks flu worldwide via news reports, and social media guide Mashable lists a range of ways to track the virus. Information and links to useful websites are being shared on Twitter, the micro-blogging service, while social networking website Facebook is tracking swine flu discussion among users.

There are also more controversional projects. The blog waves reverberated this summer, announcing that Japan’s Ministry of Internal Affairs and Communications had launched a study to see if a mobile phone based GPS tracking system can alert people who had come into contact with someone who later became infected. The blog waves went quiet over whether this has actually been completed, but the issues raised are considerable: a requirement for massive population coverage, an acceptance of personal location monitoring, and challenges to personal data privacy.

I like this quirky list of ten gadgets designed to prevent you from getting flu, which includes an electric toothbrush with a built-in uv sanitiser, a mounted door knob disinfectant spray and a USB airfiltering system for use at your office computer. But my favourite flu gadget so far this year is the Anti Swine Flu Holy Water Dispenser.

Many churches are suspending the use of shared fonts at church entrances. Luciano Marabese, from the Italian town of Fornaci di Briosco, has designed a terracotta motion-activated model that works like an automatic soap dispenser – devout Catholics wave their hands and a few drops of blessed water spurt out, they can then bless themselves safely. I wonder if the automatic fonts proliferate is there is a risk of associated Legionella outbreaks?

Does social networking offer public health gains or does it merely breed erstatz armchair epidemiologists and fuel flu paranoia? Also, if we assume that gadgets will survive or die based to a great extent on the logic of the commercial market how do we ensure the customer, judgement perhaps clouded by flu fear fever, is not being conned?

Mary E Black, is a public health physician in Serbia, and a co-owner of implementek.com, an internet consulting company based in Belgrade, Los Angeles, Munich, and Dublin.