In late 2006, diseased fish of a variety of species began to appear in the Chobe and upper Zambezi rivers in southern Africa. In April 2007, investigations showed that the levels of pesticides and heavy metals in the tissues of the fish were very low, discounting pollution as an underlying cause for the disease. However, histological evidence showed that the disease closely resembled the epizootic ulcerative syndrome caused by the oomycete Aphanomyces invadans, a serious aquatic pathogen that has been isolated from freshwater and estuarine fish in Japan, south-east Asia, Australia and the usa since the 1970s, but not previously recorded in Africa.

We documented a 6-fold increase in the frequency of nontuberculous mycobacteria isolated from clinical samples in Botswana during 2011–2014. Because antituberculosis treatment is often initiated only on the basis of acid-fast bacilli smear-positive microscopy results, some patients with nontuberculous mycobacterial infections might have received inappropriate treatment.