Dr. A. M. Babenko (Novosibirsk)

“Boiled” Drinking Water and Its Bacteriological Indicators

Water and food play a significant role in the spread of gastrointestinal diseases (typhoid fever, paratyphoid fevers, dysentery, and enterocolitis).

When investigating the routes by which waterborne infections spread in particular cases, attention is usually directed to water from natural or artificial bodies of water. Neither specialist instructional literature on hygiene nor epidemiological literature mentions the possibility that infections may spread through “boiled” water. The periodical literature contains only isolated, fragmentary reports on this question.

To determine the extent to which water may be polluted and infected, we conducted bacteriological analyses of “boiled” drinking water collected from institutions, stations, depots, dining halls, hospitals, and other premises along the section of the Tomsk Railway between Chulymskaya and Oyash stations. Observations were conducted from November 1934 to September 1935.

Of 170 samples, the coli titer¹ showed the water to be of doubtful quality and unhealthy in 14 cases, or 8.2%. Judged by colony count, the water was found unsuitable in 52% of 166 samples; individual samples (8.2%) also contained E. coli in impermissible quantities—in other words, they were contaminated with human excrement.

We give the most characteristic cases.

On 2 December 1934, water was taken from a carafe in the restaurant at Novosibirsk I station. In 1 cm³ of this water, the following was found: microbial colony growth was so abundant that it could not be counted.² A sample of water taken on 2 February 1935

¹ The coli titer was assessed according to Whipple’s classification, and colonies were counted according to Miquel’s scheme, with some modification to frame the question more clearly and obtain more definite answers.

² Samples were taken only from carafes and other vessels in continuous use.

The water from the tank in the district workers’ supply department canteen proved to be the same. A repeat examination on 16 February gave the same result. On 17 September, at the Novosibirsk factory apprenticeship school, the water in the tank and samovar of the same school’s first dormitory contained so many microbial colonies that they could not be counted, and coliform bacteria were found in 0.01 cm³ of the first sample—the water was entirely unfit.¹ On 31 May, a water sample taken from a tub in the passenger building at Chulymskaya station contained 4,650 microbial colonies per 1 cm³; coliform bacteria were found even in 0.1 cm³. On 16 April, the station attendant’s carafe proved to be a veritable aquarium for the cultivation of microorganisms. It contained more than 100,000 colonies per 1 cm³ of water. A water sample taken on 15 May from a tank in the passenger station at Oyash contained 30,000 colonies per 1 cm³ and coliform bacteria in 0.1 cm³ of water. A water sample taken on 26 April from the canteen of the rolling-stock section at Novosibirsk station contained 300,000 colonies. Water taken on 19 September from a barrel at School No. 35 contained 27,000 colonies per 1 cm³. In every case, the water was entirely unfit. Nevertheless, of all the samples taken, 48% were judged satisfactory by colony count and 91.8% by coli titer. For example, seven water samples from Novosibirsk School No. 34 contained between 10 and 80 microbial colonies, and no coliform bacteria were found at all. Water from the tank in the women’s dormitory of Track Maintenance Section No. 2 was also judged entirely fit. The same was true in the surgical department of the railway hospital and at other institutions.

In considering the causes of heavy microbial contamination of boiled water, such factors as temperature, dust, humidity, bacteriological contamination of the air, and so forth must also be taken into account.

Overall, the indicators of water unfitness (clean, very unclean, and mediocre) based on colony counts are much higher in every month than the indicator of water unfitness based on coli titer. Moreover, seasonal fluctuations do not at all times of the year coincide with seasonal maxima or minima in coli titers and with waterborne infections.

Conclusions

1. Boiled water is an excellent medium for the rapid growth of microorganisms and, under unsanitary conditions, can also be a source of transmission of gastrointestinal diseases, including infectious diseases.
2. The most careful supervision of boiled “drinking” water at enterprises, stations, and public places must be established by both sanitary and administrative authorities.
3. The coli titer of boiled water rises or falls according to the time (month) of the year.
4. Experimental laboratory observations are needed on the growth of microorganisms, particularly coliform bacteria, in boiled water under varying conditions of temperature, dust, atmospheric humidity, and so forth.

¹ Three cases of paratyphoid A were registered at the factory apprenticeship school in August and September.