Public health officials in the US state of Texas are investigating a recent surge in reported cases of infection with the single-celled protozoan parasite Cyclospora concentrated around the city of Austin.
According to the Texas Department of State Health Services 70 cases have been recorded so far this year, but 58 were reported in the last week alone. It is suspected that the sudden increase in cases is the result of infections from a common source and investigations are now under way to identify it.
Cyclospora cayatanensis is the only species of the parasite known to infect humans and causes watery diarrhoea and other acute gastrointestinal symptoms that may last for a month or more. Infections in adults are typically self-limiting, but may be more serious in children and the elderly. The incubation time before symptoms appear can be up to 14 days, making tracing the source of infection more difficult.
Contaminated food and water are the usual vehicles of contamination and previous Cyclospora outbreaks were recorded in Texas in 2013 and 2014. The most recent outbreak affected at least 126 people across the state and was linked to contaminated cilantro (coriander) grown in Mexico.
More information about the current outbreak can be found here.