Food poisonings are non-contagious, more often acute and mass diseases, caused by the use of substandard food, containing microorganisms or toxins of various origin.

Their difference from the intestinal infections (dysentery, cholera, etc.) is non-contagiousness (absence of transfer of the disease from a patient to a healthy person).

Food poisoning may occur only in persons, who eat food containing harmful substances or microbes.

Classification of Food Poisonings

v Food poisonings of a microbe etiology:

Ø Toxoinfections are caused by entry of living microbes into organism with nutrition (E.coli, Proteus, Cl.perfringens, Bac.cereus, etc.).

Ø Bacterial toxicoses occur at entry of microbial toxins with nutrition into organism:

§ staphylococcal toxicosis (Staphylococcus aureus)

§ botulism (Clostridium botulinum).

v Food poisonings of a non-microbe etiology:

Ø with toxic products:

§ toxic mushrooms (death-cup, fly-agaric, etc.)

§ toxic plants (belladonna, etc.)

§ toxic weeds (heliotrope)

§ toxic parts of some fish

Ø with foodstuffs sometimes or partially toxic:

§ stone-fruits (amygdalin)

§ haricot (phasing)

§ potatoes (solanine)

Ø with chemicals:

§ heavy metals — lead, copper, zinc, hydrargyrum, etc.

§ pesticides

§ nitrates and nitrites

§ food additives.

 

v Mycotoxicoses

Table 24

Type of fungi	Mycotoxins	Foodstuffs	Pathology
Aspergillus	Aflatoxins	Nuts, coffee	Cirrhosis and primary cancer of the liver
Aspergillus	Ochrotoxins	Grain, coffee	Balkan epidemic nephropathy
Fusarium	Trichocetenes	Grain	1. Fusariotoxicosis (poisoning with “drunk bread”) 2. Alimentary-toxic aleukia
Claviceps	Alkaloids of ergot	Grain	Ergotism
Penicillium	Patulin	Juices, mashed potatoes	Malignant tumours

 

v Food poisonings of non-investigated etiology:

Ø Alimentary paroxysmal toxic myoglobinuria (Gaffen disease)

Ø Poisoning with quail meat

Ø Kashin-Beck disease (now it is referred to as strontium, manganese and fluorine hyperpolymicroelementosis)

Food Poisonings of a Microbe Etiology

These include the following:

· Toxicoinfections are caused by entry into organism of food containing living microorganisms. The specific causative agents are Salmonellas, potentially pathogenic microflora — E. Coli, Proteus, etc.

· Bacterial toxicoses (former — food intoxications) occur on entry into organism of foodstuffs containing bacterial toxins formed in them. The examples are staphylococcal toxicosis, botulism.

· Those of mixed etiology — when food contains both living microbes and toxins, for example, Salmonellas + staphylococcal toxin.

Toxicoinfections

Foods-sources:meat products, especially minced meat (pies with minced meat), eggs (frequently infected with Salmonellas), fish (stuffed, cooked and hot smoked), sour milk products (sour cream).

Conditions when products become dangerous in respect of toxicoinfection include the following:

v The reasons of entry of causative agents into foodstuffs:

Ø slaughter of diseased and tired animals, improper cutting of animal carcass,

Ø improper storage and transportation of foodstuffs, processing raw and cooked foodstuffs on the same cutting board, with one and the same knife, etc.,

Ø non-observance by the personnel of nutrition units of rules of personal hygiene, absence of regular medical examinations of personnel, attraction of unknown or ill people to work in the kitchen.

v The reasons of reproduction and preservation of causative agents in foodstuffs:

Ø improper storage — non-observance of storage temperature and terms of realization,

Ø insufficient thermal processing.

Signs and Symptoms of Toxicoinfections

There are 5 clinical forms:

v Gastroenteric form: nausea, vomiting, diarrhea, stomach pains. It may be of a

Ø mild degree — 80% of all cases;

Ø moderate degree — 20% of cases (increase of temperature up to 38°C);

Ø severe degree — 2% (body temperature is 38-40°С, decrease of arterial blood pressure, severe intoxication).

v Typhus-like form — severe intoxication with intermittent fever

v Choleroid form — severe intoxication with profuse diarrhea

v Dysentery form — diarrhea with blood in faecal masses

v Grippe-like form — signs and symptoms of grippe, gastroenteritis is slightly expressed.

Prevention of Toxicoinfections

It includes elimination of reasons of entry and reproduction of causative agents of toxoinfections in foodstuffs (see above).

Bacterial Toxicoses

This is a group of food poisonings of a microbe etiology caused by the microbe toxins which have accumulated in foodstuffs.

1. Staphylococcal Toxicosis

Its cause is a golden staphylococcus, capable of producing exotoxin in products. Food-sources are: dairy products, creams, pies, cakes, fish and meat products.

The conditions of a staphylococcus entry into foodstuffs and producing exotoxin are the following:

· Staphylococcal diseases of personnel of nutrition units, such as quinsy, pustular diseases of the hand skin,

· Improper storage of foodstuffs — at room temperature, non-observance of expiration date.

Clinical signs and symptoms: gastroenteritis at a normal temperature, infrequent diarrhea, in severe cases — cardiac abnormalities, dehydration of organism.

Prevention: physical examinations and dismissal of personnel from work, proper storage of products, especially cakes and pies in a hot season.

2. Botulism

The reason of botulism is the formation of exotoxin in food products by botulinic bacillus Clostridium botulinum. Features of the causative agent are as follows:

· a spore formation — spores withstand boiling for 4-5 hours, (the bacillus itself in a vegetative form dies in 15 minutes), they survive at temperature of 16ºС for 14 months, resist the action of preservatives, e.g. salt, vinegar, sugar for a long time;

· an obligate anaerobe microbe — it develops without access of oxygen (canned food);

· Under certain conditions (+10-30ºС without oxygen) it forms the strongest neurotropic exotoxin, which lethal dose for a person is 35 μg.

Foods-sources: in the 19th century in Germany they included cooked and blood sausages (poisoning with "sausage poison"), dried and cold smoked fish, nowadays these are most frequently tinned goods (household preserved mushrooms and vegetables — it is difficult to destroy spores in home conditions), sometimes — dried and smoked meat, canned meat.