Scrombrotoxic fish poisoning.
Sanjiv Rughooputh (Dip MLT, GIBiol, FIBMS, MSc)
Molecular and Microbial Glycobiology research group
University of Westminster
Food poisoning usually results as a consequence of improper food preparation, handling and also storage. In most cases the causative organisms are either not destroyed during cooking and preparation, or else are introduced after the food has been prepared. Once such instance is Scrombrotoxic fish poisoning. Scrombotoxic fish poisoning is quite rare and sporadic cases have been documented. There was a peak in reported case in 1979, when 200 cases were reported both in the UK ( Gilbert et al, 1980) and Italy ( Molinari et al, 1989). A Recent Communicable Disease Report ,UK (CDR Weekly, 12/05/2000) reported that Scrombrotoxic fish poisoning is responsible for 65% of outbreaks of food poisoning associated with the consumption of fish in England and Wales ( sorry folks !). But the number of cases nowadays has regressed. Approximately 40 cases were reported in 1999 as opposed to 200 two decades ago.
Scrombrotoxic fish poisoning usually occurs after the consumption of fish of the Scrombridae and Scromeresocidae family, particularly tuna, mackerel, Skipjack, bonito (Sabroe and Kobza Black, 1998) or other fish like pilchards, sardines, anchovies, herring and salmon (CDR, 12/05/00). These fishes naturally contain high levels of the amino acid L-Histidine. Fish poisoning occurs when L- Histidine is converted to Histamine by the enzyme Histidine Decarboxylase, produced by 20 genera of bacteria that are part of the normal fish flora. The Enterobacteriacea members like Klebsiella, Morganella and Hafnia also produce Histidine Decarboxylase. Contamination occurs mainly if the fish has not been properly stored. After fish has been caught, accumulation of histamine can continue, even at 4°C. Normal cooking or canning temperatures does not affect the concentration of histamine.
Symptoms can occur even at low concentration as low as 5 mg histamine/ 100 g fish. But at this concentration only 38% reported incidents were distinctive ( Bartholemew et al, 1987). But concentration higher that 20 mg/ 100 g fish, symptoms can be visible within a few minutes up to 2 h after consumption of contaminated fish. Symptoms vary from burning sensation in the mouth, rash on the face, neck, upper chest, flushing, sweating, headache, tightness of chest, palpitations, anxiety, dizziness, diarrhoea and vomiting. The illness is generally not serious ( Gilbert et al, 1980) and can resolve within 2-3 h or can take up to 24 h.
This type of food poisoning is rare and seldom sample would be sent for microbiological investigation. However, if sent for investigation, the causative organisms may not detected, as most Food Microbiology laboratories would be investigating for faecal Eschrerichia coli and therefore miss organisms like Klebsiella sp. . But if the type of fish consumed is known, then the level of Histamine can be determined, as well as other organisms of the Enterobacteriacea investigated.
Although, Scrombrotoxic fish poisoning is very rare,Scrombrotoxic fish poisoning can be prevented, by proper fish handling, storage, whereby, contamination is minimised and causative bacteria’s growth greatly reduced.
Bartholomew, B.A; Berry, P.R; Rodhouse, J.C; Gilbert, R.J; Murray, C.K. (1987) Scrombrotoxic fish poisoning in Britain: features of over 250 suspected incidents from 1976 to 1986. Epidemiol Infect Dec 99(3) 775- 82.
Communicable Disease Report ( CDR Weekly), 12 May 2000 10 (19).176
Gilbert R.J; Hobbs, G; Murray, C.K; Cruickshank J.G; Young, S.E. (1980) Scrombrotoxic fish poisoning : features of the first 50 incidents to be reported in Britain (1976-9). Br Med J 5; 281 (6232) 71-2.
Molinari, G; Montagnoli, G; Pelligrini, G; Caroli, G. (1989) Hygiene and health importance of histamine as an unhealthy factor in several food products. Ann Ig May- Aug (3-4) 637-46.
Sabroe, R. A; Kobza Black, A. (1998) Scrombrotoxic fish poisoning. Clin Exp Dermatol Nov ;23 (6) 258-9