Not so long ago, doctors were being encouraged to treat women with uncomplicated urinary tract infections with just three days of antibiotics. Anecdotal evidence suggests this isn't always effective, and a population based retrospective cohort study from the Netherlands backs this up. Treatment failure after three days of trimethoprim and nitrofurantoin was 14.4%, and it was 9.6% in those treated with norfloxacin. Further analysis of the data from more than 16 000 women points to five day and seven day courses being more effective (British Journal of Clinical Pharmacology 2004;58: 184-9).

Mobile and cordless phones use microwaves to transmit and receive telephone calls. As the parotid gland is in a position where it gains high exposure to these waves, a Swedish team set up a case-control study to assess the association between the use of mobile phones and the risk of salivary gland tumours. No association was identified, but few people reported having used such phones for more than 10 years and no conclusions could be drawn about long term heavy use (Occupational and Environmental Medicine 2004;61: 675-9).

People at high risk of tuberculosis are sometimes the very people who don't present in a typical way. People with HIV, for example, may have normal chest radiographs and their sputum …