E. Krasnitskaya and L. Rogachevskaya

Food Poisoning in the RSFSR in 1946

From the Chief State Sanitary Inspectorate of the Ministry of Health of the RSFSR

Compared with the war years, 1946 saw a substantial decline in the number of cases of food poisoning.

Records of food poisoning in the RSFSR show that the major industrial regions in the East Siberian part of the federation were relatively well off in this respect, whereas a number of agricultural regions—Vladimir, Yaroslavl, and Oryol—saw some increase in food poisoning.

The proportion of food poisoning cases recorded at public catering establishments remained high. Nevertheless, it was considerably lower than in the preceding war years. At the same time, an increase in the number of food poisoning cases attributable to children’s summer health facilities, factory training schools, and vocational schools should be noted.

The distribution of food poisoning by main etiological group, compared with 1945, is as follows (Table 1).

Table 1

Poisoning of bacterial etiology

Children accounted for 11% of all those affected, compared with 4.6% in 1945.

Among the foods whose consumption was the principal cause of foodborne toxicoinfections, meat products ranked first, accounting for 71% of outbreaks. More than half of the toxicoinfections caused by meat products arose from various products made from offal. Among offal products, the largest number of toxicoinfections was associated with the consumption of meat jelly (40%); goulash ranked second. Liver sausage (Munich-style), unlike in previous years, was a considerably less frequent source of poisoning (21.5% versus 39.3% in 1945). Fish products were associated with 13.2% of poisonings of bacterial origin.

Dairy products ranked third (milk, milk kissel, and bryndza cheese). Omelet should also be noted as a source of poisoning.

Bacteriological examinations were performed in 75.4% of registered toxicoinfections, with positive results in 61.4% of cases. The following causative organisms were isolated: B. botulinus, opportunistic bacteria, salmonellae, staphylococci, and, in one case, the Sonne dysentery bacillus. Opportunistic microbes were isolated most frequently.

Botulism. Recent years have been characterized by the absence of large outbreaks of botulism. In 1946, all cases of botulism arose from the consumption of fish, predominantly caught by the individuals themselves, and occurred as isolated cases.

Salmonelloses. It is noteworthy that the number of cases in which microbes of the salmonella group are isolated increases each year.

The percentage of positive findings of microbes in this group relative to the total number of bacterial poisonings over the past three years, and their relationship to the unregulated slaughter of animals, are presented in Table 2.

This finding may be directly linked to the increase in toxicoinfections caused by meat from animals slaughtered outside organized facilities.

The total number of people affected in salmonellosis outbreaks constitutes 31.4% of those affected by poisoning of bacterial etiology.

Bacteriological examinations found Salmonella enteritidis Gärtner in almost half of the cases. In equal numbers

Table 2

…cases, Salmonella typhi murium and B. paratyphi B were isolated. In one outbreak, Salmonella cholerae suis was found.

In a few cases, the species of paratyphoid organism was not identified because the isolated strains showed group agglutination with various members of that group of microorganisms. Opportunistic microorganisms were also isolated relatively frequently alongside salmonellae.

The overwhelming majority of salmonellosis cases were, of course, caused by the consumption of meat products.

In more than half of the cases, bacteriological investigations were accompanied by serological testing. Sometimes this was the only evidence implicating a particular microorganism.

One particularly illustrative case was that in which the rise in agglutination titre was monitored. Initially, agglutination tests using blood from recovered patients and the isolated strain were positive in 4 patients at dilutions of 1:100, 1:200 and 1:400. On repeat testing, blood from 13 patients yielded positive results, at higher titres.

Staphylococcal flora was isolated in 5% of cases. However, it was not possible in every case to determine with certainty the etiological role of staphylococci, since the toxigenic properties of the isolated strains were generally not studied and, moreover, in three cases other microorganisms were isolated alongside staphylococci (Escherichia coli, streptococci, etc.).

The staphylococcal etiology of these illnesses could be inferred indirectly from the fairly typical clinical symptoms.

Opportunistic bacteria. As already noted, opportunistic microorganisms were isolated most frequently in cases of bacterial poisoning. Proteus was isolated in nearly half of the cases. A substantial group comprised cases in which E. coli was found, sometimes together with Proteus.

In the overwhelming majority of cases, these microorganisms were isolated only from the product that caused the poisoning, which, given their ubiquity, is wholly insufficient to establish their etiological role.

Nevertheless, compared with the previous year, the proportion of illnesses in which Proteus was also isolated from other sources associated with the poisoning—patients’ excreta, swabs from equipment, and so forth—increased to 50%. However, the number of illnesses whose investigation included an agglutination test remains small; a positive result would have provided the strongest confirmation of the etiological role of the isolated microorganisms.

Epidemiological links in bacterial food poisoning. Investigations of bacterial food poisoning cases in recent years make it possible to conclude that the foremost among the immediate epidemiological links…

…leading to outbreaks of foodborne toxicoinfection, a prominent place is occupied by violations of processing regulations and storage time limits for perishable foods. These violations may be considered responsible for 74% of illnesses of bacterial origin.

A closer examination of violations in the processing and storage of perishable foods shows that, recurring year after year, they consist of the following: prolonged storage of finished products and their consumption without reheating; inadequate heat treatment of perishable foods or its complete absence; failure to follow the rules for soaking salted products (fish and meat); and preparation of raw and cooked products on the same table or cutting boards. As a rule, several of these violations occur together rather than singly.

Judging by the investigation reports, meat-processing plants continue to play a significant role in the epidemiological chains of bacterial food poisoning. Unsanitary conditions were observed at some meat-processing plants, as well as violations in the production of meat products and in the rules governing their storage and sale. These included the release of perishable products without certificates or information on their date of manufacture, and sales through kiosks attached to meat-processing plants (Altai Krai and Smolensk, Vladimir, and Moscow Oblasts).

The investigation reports on foodborne toxicoinfections draw attention to the lack of effective refrigeration at sites where perishable foods are produced, stored, and sold. This leads to extensive bacterial contamination of products, which cannot always be eliminated by heat treatment.

A prominent factor in the epidemiology of foodborne toxicoinfections in 1946 was the consumption of meat from livestock slaughtered outside organized channels. This was facilitated to a considerable extent by weak local veterinary oversight, particularly at some auxiliary farms operated by industrial enterprises and at state farms.

Poisoning of Nonbacterial Origin

In 1946, poisoning of nonbacterial origin accounted for a larger proportion of all food-poisoning incidents than in 1945 (29.5% versus 20.2%), but a somewhat smaller proportion than in 1944 (30.5%).

The increase was due mainly to a rise in poisoning caused by poisonous mushrooms, adulterated vegetable oils, and flour products. The number of people affected by nonbacterial poisoning more than doubled compared with 1945, owing to the substantial numbers affected by consumption of flour products and mineral oils. Deaths also increased somewhat because of the number of poisonings by poisonous mushrooms, which usually have a high fatality rate. More than half of these poisonings were individual cases.

Flour products caused 33.5% of nonbacterial food-poisoning incidents. Poisonous mushrooms accounted for almost the same proportion (32%). Adulterated vegetable oils caused a comparatively large proportion of poisonings (16.5%). Isolated cases were caused by adulterated salt, roots of poisonous plants, dulcin, and other substances.

Among the etiological factors responsible for nonbacterial poisoning, arsenical preparations ranked first. In 40.6% of cases, poisoning was associated with the consumption of bread, flour products, and other products containing arsenic. It was not possible to establish how the arsenic entered the food in every case. Nevertheless, it was established that in the overwhelming majority of cases, poisoning resulted from the consumption of products made from treated grain, as well as from grain contaminated…

…contaminated with arsenical preparations as a result of being stored together.

Improper preparation of false morels was the main cause of mushroom poisoning.

Poisoning by the roots of poisonous plants, which had been prominent during the war years, occurred in 1946 only in isolated cases, predominantly among children. Poisonings caused by the poisonous seeds of weeds (bitterweed, jimsonweed, etc.) and fungal diseases of grain (ergot) accounted for a small number of cases.

Poisonings attributed to vegetable oils were associated with their contamination by mineral oils and, in some cases, with the consumption of mineral oils in pure form. The oil was generally purchased at markets from private sellers.

Failure to observe the rules for transporting tetraethyl lead resulted in isolated cases of household poisoning through contamination of food. These illnesses were severe because of the high toxicity of tetraethyl lead, which causes a distinctive illness predominantly affecting the central nervous system.

The curve of poisonings in 1946 shows two peaks, one in spring and one in the summer–autumn period. The first peak was due to an increase in poisonings of nonbacterial origin (mushrooms, etc.); the second was due mainly to bacterial poisonings.

Conclusions

1. In 1946, the number of food poisonings fell substantially compared with the war years, and the number of people affected declined somewhat compared with 1945.

2. The proportion of food poisonings occurring in public catering establishments declined.

3. The principal causes of foodborne toxicoinfections were violations of the rules for processing and storing perishable foods.

4. The rise in the proportion of foodborne salmonellosis among all food poisonings was due mainly to an increase in cases of unregulated livestock slaughter. Some improvement in the quality of bacteriological testing should also be taken into account.

5. The growing epidemiological importance of unregulated livestock slaughter indicates inadequate sanitary and veterinary oversight, particularly on subsidiary farms of industrial enterprises and on state farms.

6. Meat-processing plants, slaughterhouses, and slaughtering points continue to play a major role in the occurrence of bacterial food poisoning.

7. The rise in the proportion of nonbacterial food poisonings resulted from an increase in poisonings by mushrooms, adulterated vegetable oils, and flour products containing arsenic.

8. The quality of sanitary and epidemiological investigations of food poisonings improved compared with previous years.