in the pietermaritzburg region, the river occasionally contains counts of "e. coli" bacteria as high as 50 000 per 100 ml. this results in a fairly high incidence (64% of respondents in one survey) of health issues in canoeists using the river. these include diarrhea (colloquially referred to as "dusi guts"), as well as eye and ear infections, and septic cuts. the poor quality of water is believed to be caused by sewers near the river overflowing during heavy rains, and illegal dumping. these health risks threaten the annual canoe marathon. in effective terms, the water quality of the msunduzi river is undesirable and can pose as a serious health threat for those who brave its waters.