Sodium nitrite food poisoning in one family

Abstract

Sodium nitrite is used as a coloring agent or preservative in food, as well as an antimicrobial agent in meat and fish and some cheeses. In high amounts it can be toxic for humans, causing methemoglobinemia. This is an unusual and potentially fatal condition in which hemoglobin is oxidized to methemoglobin (MHb), reducing the amount of oxygen that is released from hemoglobin, similar to carbon monoxide poisoning. MHb levels of 70% are generally lethal, but the existence of underlying anemia, acidosis, respiratory compromise, and cardiac disease may exacerbate the toxicity of MHb. We present a case of poisoning with sodium nitrite in three family members after eating homemade sausages given to them by their neighbor who was a butcher. According to the findings of the veterinary inspectorate in charge of food control in this case, the concentration of sodium nitrite in the homemade sausages was about 3.5 g per 1 kg of meat, almost 30 times higher than allowed according to legislation. In this case report, a 70-year-old man died about 7 h after consuming the meal, while two women, 53 and 67 years of age, respectively, were admitted to a toxicology clinic the following day due to food poisoning, with the maximum concentration of MHb in blood of 33.7 and 20.4%, respectively. They were discharged 3 days later. The autopsy of the deceased man showed sodium nitrite poisoning with a relatively low concentration of MHb in his blood – 9.87%. Death was attributed to the exacerbation of hypertensive and ischemic heart disease, resulting from accidental sodium nitrite poisoning. The presented cases illustrate the necessity of close cooperation between the authorities, medical staff, veterinary inspectorate, and forensic pathologists in determining the source of poisoning, the cause of death of the victim, and preventing the outbreak of poisoning among a greater number of consumers.