Five people in Heyuan Guangdong Province in southern China, developed rhabdomyolysis after eating wild red tailed carp with four meeting the clinical criteria for Haff disease, according to a report published by China CDC Weekly.
The incident occurred in April and marks China’s second documented cluster of Haff disease associated with carp Science and Technology Daily reported. All five patients recovered following medical treatment.
According to the report, a hospital in Longchuan county, Heyuan reported the cases on April 25. Five members of the same family, aged between 35 and 69, developed vomiting, abdominal pain and limb soreness after a family gathering the previous day.
Medical tests revealed that all five patients had significantly elevated creatine kinase levels, ranging from six to 65 times the upper limit of normal. Four patients met the clinical criteria for Haff disease.
Investigators found that seven people had shared the family meal which included a 2.5 kilogram wild red tailed carp caught in a small bay of a local reservoir. The five people who ate the fish developed rhabdomyolysis, while the two who did not consume it showed no abnormalities.
Researchers identified red tailed carp as another potential source of Haff disease. In China, most reported cases have been associated with crayfish while outbreaks linked to freshwater fish are relatively uncommon.
Haff disease is a foodborne condition characterised by rhabdomyolysis a syndrome in which damaged muscle tissue releases substances into the bloodstream that can potentially harm the kidneys. Symptoms may include muscle pain weakness and dark coloured urine.
Wei Guo a doctor in the nutrition department at Dongfang Hospital of Beijing University of Chinese Medicine, said the condition typically develops within 24 hours of consuming freshwater aquatic products. Consuming large quantities of aquatic products alongside alcohol may increase the risk according to Science and Technology Daily.
Despite being identified nearly a century ago, the exact cause of Haff disease remains unknown. Researchers have retained the remaining fish samples for further testing to investigate the possible source of contamination.
The investigation has prompted recommendations for public health campaigns to raise awareness of the potential risks associated with consuming wild caught freshwater fish.
Authorities and researchers continue to investigate the disease, as identifying its cause remains important for preventing further outbreaks.