Title 20. FOOD POISONINGS.pdf ✅

PHARMD GURU Page 1  Food poisoning is an acute illness, usually of sudden onset, brought about by eating contaminated or poisonous food.  The symptoms normally include abdominal pain, diarrhoea, nausea, vomiting and fever.  Food poisoning can occur in many ways, and may be isolated instances, or may constitute an epidemic (mass food poisoning).  The latter bristles with medico-social implications and necessitates prompt reporting to public health authorities who must take effective steps to contain the epidemic.  Food borne illnesses are among the commonest health problems encountered world- wide, and are particularly rampant in third world countries such as India, mainly due to a relative lack of sanitation and public hygiene. CAUSES: 1. Microbes: bacteria, viruses, protozoa 2. Parasites 3. Fungi 4. Plants 5. Fish 6. Chemical additives DIAGNOSIS:  History.  Clinical picture.  Stool analysis  Suspect food/agent analysis.  Measurement of serum electrolytes FOOD POISONINGS
PHARMD GURU Page 2 GENERAL TREATMENT MEASURES:  Oral Rehydration Therapy (ORT) - This is resorted to only in the presence of mild dehydration (3 to 5% fluid deficit), or moderate dehydration (6 to 10% fluid deficit).  Limitations of ORT - ORT Es not sufficient therapy in the presence of dysentery (bloody diarrhoea), shock, intestinal ileus, intractable vomiting, high stool output (>10 ml/kg/hr), monosaccharide malabsorption and lactose intolerance.  Intravenous Rehydration - This is necessary when dehydration is severe (> 10% fluid deficit or shock). 20 mlikg boluses of Ringer's lactate, normal saline, or similar solution is administered until pulse, perfusion, and mental status return to normal.  Non-specific anti-diarrhoeal agents - Use of such agents such as kaolin-pectin, antimotility drugs (e.g. loperamide), antisecretory drugs, or toxin binders (e.g. cholestyramine), is controversial. Available data do not demonstrate significant beneficial effects. Instead, serious adverse effects can occur, including ileus and anticholinergic syndrome. MICROBIAL FOOD POISONING: Bacteria: Bacterial food poisoning is most frequently caused by Staphylococcus, followed by Clostridium perfringens, Salmonella, Shigella, and Streptococcus in descending order of frequency. 1. BACILLUS CEREUS: Bacillus cereus is an endemic, soil-dwelling, Gram-positive, rod shaped, beta haemolytic bacterium that is well known to cause food-borne illness. It is a facultative aerobe, and like other members of the genus B.  Source: Fried and cooked rice, pasta, pastry, and noodles. Meat and vegetables. Other potential sources of infection include spices, pasteurized fresh or powdered milk, and reconstituted milk-based infant formula.  Clinical Features: Nausea, vomiting, Diarrhoea (watery), abdominal pain. Fever is uncommon.
PHARMD GURU Page 3  Diagnosis: Stool culture and growth in MYPA (mannitol, egg yolk, phenol red, polymyxin agar) medium. Diagnosis can be confirmed by detecting the organisms in the suspected food item.  Treatment: Supportive measures. The disease is usually mild and self-Limiting, Monitor fluid and electrolyte status and hepatic enzymes as indicated. Significant nausea and vomiting in adults may be controlled with a suitable antiemetic agent. For wound infections Chloramphenicol, tetracycline, kanamycin, gentamicin, clindamycin, vancomycin, and erythromycin are generally effective. 2. STAPHYLOCOCCUS AUREUS: It is said to be the commonest cause of bacterial food poisoning.  Source: Previously cooked, proteinaceous food: meat, fish, milk, and milk products. Staphylococcal toxins are formed within a few hours when food is kept at room temperature.  Clinical Features: Nausea and vomiting with violent retching, diarrhoea, crampy abdominal pain. Diarrhoea is usually mild, while vomiting is severe. Inhalation of the toxins can cause sudden onset of fever, headache, chills, myalgia, non-productive cough, dyspnoea.  Diagnosis: Staphylococcal food poisoning is usually a self limited illness; often no laboratory evaluation is required. Monitor electrolytes and fluid balance in patients with significant volume loss from vomiting and diarrhoea, Serological tests are usually very sensitive, for e.g. latex agglutination and ELISA,.  Treatment: All persons with significant toxicity, dehydration, abnormal electrolyte levels, or a history of poor compliance should be admitted for intravenous fluid therapy. Significant nausea and vomiting can be controlled with an antiemetic agent. However, antiemetics are not usually required if alteration of the diet is successful. 3. SHELLFISH POISONING: Shellfish poisoning is a general term used to indicate poisoning that occurs when shellfish (mainly oysters, clams, scallops or mussels) are eaten by humans. Shellfish are usually associated with saltwater habitats, but some species inhabit freshwater. Both freshwater and
PHARMD GURU Page 4 saltwater shellfish may cause poisoning_ Because the symptoms of shellfish poisoning are somewhat similar and patients often did not know exactly what type of shellfish they ate, the tendency of the medical community was to simply lump the symptoms together and diagnose "shellfish poisoning" for any shellfish-related problem. However, more recent clinical studies have separated the group of shellfish poisonings into four groups: 1. Amnesic shellfish poisoning (ASP) 2. Diarrheal shellfish poisoning (DSP) 3. Neurotoxic shellfish poisoning (NSF) 4. Paralytic shellfish poisoning (PSP) SHELLFISH POISONS SHELLFISH POISONING TYPE SYMPTOMS CAUSE Amnestic Permanent Short Term Memory Loss, Brain Damage. Death Domoic Acid Diarrheal Diarrhea, Nausea, Vomiting Okadaic acid, Azaspiracid Neurotoxic Slurred Speech, Nausea, Vomiting Brevetoxins Paralytic Parathesias, Coordination Loss, Speech Defects, Nausea, Vomiting, Death Saxitoxin Neosaxiton and Gonyautoxins-I to IV. SOURCE:  Shellfish (especially oysters, clams, mussels, and scallops) contaminated by dinoflagellates. Other source includes univalve mollusks, starfish, limpets, sand crabs, whelks, turban shells, top shells, xanthid crabs and various fish.