Home Print this page Email this page Small font size Default font size Increase font size
Users Online: 2792
Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 

 Table of Contents 
Year : 2020  |  Volume : 9  |  Issue : 6  |  Page : 3131-3135  

A survey of public restrooms microbial contamination in Tehran city, capital of Iran, during 2019

1 Department of Medical, Islamic Azad University, Tehran Medical Sciences Branch, Tehran, Iran
2 Department of Paramedicine, Islamic Azad University, Tehran Medical Sciences Branch, Tehran, Iran
3 Department of Modern Science, Islamic Azad University, Tehran Medical Sciences Branch, Tehran, Iran
4 Department of Basic Science, Islamic Azad University, Science and Research Branch, Tehran, Iran
5 Department of Paramedicine, Varastegan Private University, Mashhad Medical Sciences Branch, Tehran, Iran, India

Date of Submission22-Feb-2020
Date of Decision14-Mar-2020
Date of Acceptance25-Apr-2020
Date of Web Publication30-Jun-2020

Correspondence Address:
Dr. Javad Nematian
Faculty of Medicine, Tehran Medical Sciences, Islamic Azad University, Tehran
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jfmpc.jfmpc_300_20

Rights and Permissions

Introduction: Daily use of public restrooms may have a significant impact on spreading infectious diseases. Human society could be affected by spreading of transitional infectious diseases through feces, urinary tract infection and poor personal hygiene. According to the World Health Organization reports, plenty of people's developed diseases caused by contaminated public restrooms that may result in severe health problems. Methods: This descriptive cross-sectional study was conducted on 7,482 samples that were collected randomly in 6 months (spring and summer 2019) in different regions of Tehran. The Data were obtained by analyzing 804 restroom's indoor and outdoor handles, 1062 toilet faucet, 826 washbasin taps, 1,062 toilet hoses, 804 flush tank levers, 643 soap dispenser bottoms, 643 liquid soaps, 99 bar soaps, 169 toilet papers and paper towels, and 50 hand dryer machines. Samples which were tested, based on bacteriology standard methods. Result: 7,482 samples were gathered of which 6,678 contaminated cases (89.25%) were observed and 804 cases (10.75%) were found non-contaminated. Escherichia coli with 28.48% and Pseudomonas with 0.39% were the most and the least common bacteria, respectively, in this study. Conclusion: The required tests to identify the bacteria that cause contamination through the use of public restrooms have been done. It is essential to inform the public of the mentioned items and teach how to prevent infectious diseases.

Keywords: Bacterial contamination, hand dryer soaps, public restrooms

How to cite this article:
Matini E, Shayeghi F, Vaghar ME, Nematian J, Hosseini SS, Mojri N, Taherabadi NT, Hakimi R, Ahmadi N, Badkoubeh N, Esmaeili H, Akhlaghi M, Vaseghnia H. A survey of public restrooms microbial contamination in Tehran city, capital of Iran, during 2019. J Family Med Prim Care 2020;9:3131-5

How to cite this URL:
Matini E, Shayeghi F, Vaghar ME, Nematian J, Hosseini SS, Mojri N, Taherabadi NT, Hakimi R, Ahmadi N, Badkoubeh N, Esmaeili H, Akhlaghi M, Vaseghnia H. A survey of public restrooms microbial contamination in Tehran city, capital of Iran, during 2019. J Family Med Prim Care [serial online] 2020 [cited 2020 Sep 18];9:3131-5. Available from: http://www.jfmpc.com/text.asp?2020/9/6/3131/287864

  Introduction Top

Using public restrooms on a regular basis could have a significant effect on the transmission and diffusion of infectious diseases and other bacterial contamination. Due to many people using public toilets or washbasins and touching doorknobs several times a day, it can cause transmission of such contamination and pathogenic infectious disease. Therefore, the importance of toilets and washbasins as a source of transmission of bacterial contamination becomes more evident. It's obvious that if people's awareness of transitional contamination and related diseases enhances, it can be good for better social health and prevention of various infections. The purpose of this research is to boost health care in public services. In this study, by the survey of bacteriology and sampling of every facility that exist in restrooms and public services, we have measured the kind and amount of contamination that may be transferred by one to another people while they are using this places.

It seems that public services and home services must be more sanitized; absolutely in order to use public services and preventing problem for public health, more care of these services are recommended. Public services such as cinemas, hotels, hospitals, libraries, parks, etc., are more intended to be polluted because of severe public usage this should be done repeatedly to prevent transmission of disease and not to establish various illnesses such as skin disease, digestive disease, genital and venereal disease to the public. Such diseases are commonly transferable to public services because of sharing the same spaces of usage. All the points that are touchable for publics such as door handles, toilet paper, flush tanks, water hoses, valve handles, sink, liquid and solid soap, tissues, electrical driers, etc., subjects to be cleaned properly. The ventilation of public services areas is a very important factor to keep health care for public services.[1] Per annum, many cases of disease from public places occur to the people who are using these services, because of lack of sanitizing procedure; furthermore, by being infected with multidrug-resistant (MDR) bacteria or a harmful one, the process of recovery will become more complicated; this causes many economic and mental consequences to these people. Knowing the variety of contamination and checking infected facilities (such as an important one, toilet papers) that are existing in such services and have an important role in publishing the infection, McCusky et al.[2] and Robinton et al.[3] can help us to find means of preventing or diminishing infectious diffusion.

Recognizing the transmittal ways of”germs” and the means, help us to prevent establishing of contamination and to decrease the prevalence rate of disease that we expect to come after use of these facilities.. Also, making people aware of the bad consequences of poor health services and encouraging them to keep their personal belongings clean will cause social behavior more confident in their health. This study examines whether electric driers, liquid or solid soaps, toilet paper and toilet valves, outdoor, and indoor handles etc., and whether they can play a positive or negative role in the transmission of diseases. In this article, we tried to answer this question by determining the type of microorganisms that we presume to exist. By the 7,482 samples we had taken from different points of many services, we get rich to achieve the trustful answer to the question. Definitely, by the numerous numbers of samples taken, its precision, accuracy, and reliability would be also higher.

  Materials and Methods Top

This descriptive cross-sectional study was conducted in different areas of Tehran during 2019. The subjects which were sampled are indoor and outdoor handles, taps, flush tank bottoms and levers, liquid and bar soaps. For bacterial type detecting, we have used of principals scientific sources and standard methods of bacteriology. For a bacterial sampling of cases mentioned above, first provided wet sterile swabs which after sampling, transported on transport culture media and then as soon as possible it was transferred to the laboratory for passaging them on culture medias such as nutrient agar (HIMEDIA, LOT45114591), blood agar (HIMEDIA, LOT45114591), MacConkey agar (HIMEDIA, LOTWe215), and EMB (HIMEDIA, LOT00000015320) which had been prepared before and were keeping on the refrigerator. Before passaging the samples on culture media, the prepared media were brought out from the refrigerator in order to reach room temperature. After passage, in order to bacterial growth, the culture media which were passaged on were put into the incubator on 37 centigrade degrees (for 24–48 h). Finally, in order to assess the bacterial growth and colony-formation, the preserved culture media were examined precisely. When it manifested that the bacterial colonies had been grown on culture media, the Gram-staining method used to determine Gram-positive and Gram-negative bacteria.

Generally, all the species with their bacterial load of up to 100,000 CFU/g were designated detrimental even though those between 50,000 and 100,000 CFU/g were repeated for sampling and reassessed. Although, less than 50,000 colonies of bacteria/g are also considered normal and were excluded from the samples.

We realized that all the bacteria (whether Gram-positive and Gram-negative) could be able to grow on Nutrient agar media; also Gram-positive bacteria were grown on blood agar media and Gram-negative bacteria were grown on EMB and MacConkey agar media. For determining the specious of bacteria, these biochemical tests had been done; as mentioned below: For detecting the specious of Gram-negative bacilli such as Shigella,  Salmonella More Details, Pseudomonas, etc., Catalase, oxidase, urease test and triple sugar iron agar (TSI) (HIMEDIA, LOT00000015312) culture media were used. For detecting the specious of Gram-positive bacteria such as Enterococcus faecalis, Staphylococcus aureus, etc., Catalase, coagulase, and MSA culture media (HIMEDIA, LOT0000287212) were used, too.

  Result Top

In the above study, we sampled 1,062 restrooms that in this survey: 2,124 restroom indoor and outdoor handles, 1,062 toilet faucet, 826 washbasin taps, 1,062 toilet hoses, 804 flush bottoms, 643 soap dispenser bottoms, 643 liquid soaps, 99 bar soaps, 169 toilet papers and paper towels, and 50 hand dryer machines. In total 7482 samples were tested from which 6,678 samples (89.25%) were contaminated and 804 samples (10.75%) uncontaminated.

  Discussion Top

In this study, 7,482 samples were taken from various cases. According to [Table 1], there were 6,678 contaminated specimens, of which the highest rate was found in toilet hoses and taps with 99.72% (Out of 1,062 samples, 1,058 specimens were contaminated), followed by toilet outdoor handles with 99.62% (out of 1,062 samples, 1,058 specimens were contaminated). Flush tank levers with 99.14% (out of 804 samples, 781 samples were contaminated), toilet indoor handles with 95.52%, soap dispenser bottoms with 97.82%, washbasin taps with 95.52%, bar soaps with 91.92%, hand dryer with 56% and towel papers with 20.12% were placed in terms of the amount of contamination.
Table 1: Absolute and relative frequency table of contaminated and non-contaminated public restrooms

Click here to view

According to results of [Table 2]. E. coli (28.5%) and Klebsiella (1.51%) were the most and least present bacteria in toilet indoor handles, respectively. On toilet outdoor handles, E. coli was the most (28.54%) and Pseudomonas was the least (1.32%). On flush tank levers, maximum bacteria was E. coli (35.08%) and Pseudomonas (0.26%) was the minimum. E. coli (30.6%) and Salmonella (1.52%) were the most and the least bacteria on washbasin taps, respectively. In soap dispenser bottoms, E. coli was the most (29.73%) and Pseudomonas was the least (0.32%). The most and the least bacteria that were found in liquid soaps were Proteus vulgaris (27.78%) and Enterococcus (1.85%). The most bacteria in bar soaps was E. coli (17.58%) and the least was Klebsiella (1.1%). On toilet papers, Staphylococcus epidermidis and mix bacteria were the most with (29.41%) and Proteus spp. and Bacillus spp. with (11.76%) were the least and finally in hand dryer machines S. epidermidis (35.71%) was the most and S. aureus and Bacillus spp. (7.14%) were the least.
Table 2: Absolute and relative frequency table of microorganisms isolated from public restrooms

Click here to view

In general, E. coli is the highest rate of contamination related to flush tank levers or bottoms and Pseudomonas is the lowest rate of contamination. It seems that after using the bathroom, flush tank levers can be effective in transmitting bacterial infectious diseases due to non-adherence in health care. It seems that E. coli, which is an intestinal bacteria, causes various parts of restroom contamination during the use of toilets, which is a sign of non-adherence in health care. Also, E. coli bacteria are very sensitive to drying on the contaminated hands; so the high potential of this bacteria for cross-contamination is expected due to soppy hands.[4] Pseudomonas in liquid soap and the other parts of restrooms, which were contaminated by these bacteria, is a sign that subjects and materials are not used correctly. People are infected, and they transmit diseases.

A study performed by Buffet-Bataillon et al.,[5] has questioned the outbreak of Serratia marcescens and its investigation and control in the neonatal intensive care unit (NICU). In this study, during 3 months period, five infants were colonized by a single strain of Serratia marcescens. The researchers of this study achieved that a bottle soap dispenser can be a reservoir of this nosocomial pathogenic bacteria. So, these microorganisms can be easily transferred to newborns by healthcare workers. Conversely, P. vulgaris (27.78%) were the most bacteria sampled from liquid soaps as well as E. coli (29.73%), Bacillus subtilis (17.65%), and Entrococcus faecalis (14.63%) liquid soap dispenser bottoms. Although some researchers have proved that washing hands with non-antibacterial soaps and water are more effective than with water alone, Burton et al.,[6] basically by regarding the contamination of soap dispensers, we suggest using of alcoholic hand antiseptic instead of liquid or solid soaps.

In the study of microbial biogeography of public restroom surfaces which have been done by Flores et al.,[7] the communities were clustered into three general categories: those found on surfaces associated with toilets, those on the restroom floor, and those found on the surface routinely touched with hands. However, by comparison to our study, the sample items and bacterial diversity were almost alike, also vagina-associated Lactobacillaceae were wildly distributed in female restrooms.

In the study of Kanayama et al.,[8] 252 samples were contaminated from 292 specimens, taken from toilets and warm water taps. S. aureus, Streptococcus spp, Enterococcus spp, Enterobacteriaceae and other negative bacteria had been found. From the above items, Enterobacteriaceae were isolated as 84 (%28.8) bidets and E. coli, Enterobacter spp. Klebsiella, Citrobacter spp, and Enterobacteriaceae by 38 (13.0%), 22 (7.5%), 13 (4.5%), 5 (1.7%) and 6 (2.1%) were isolated in toilet bidets warm water, respectively.

In the study of McCusky et al., Bacillus licheniformis was the most isolated bacteria with 20.2% that shows a remarkable difference to compare with our study.[2] Also, in the study of Harrison et al., Micrococcus luteus and some strains of Serratia marcescens were the two specious of bacteria found in paper towel specimens.[9] In addition, Robinton et al.,[3] showed that paper towels have substantially fewer viable bacteria on them than cloth towels, although in the opposite of cloth towels, the number of bacteria found on paper towels does not seem to be a variable appreciably influenced by geographic and/or climatic differences. In the above study, Bacillus spp were the most bacterial species found in both kinds of towels. This is in contrast to our results in which S. epidermidis was common. There is no difference in the type of infectious bacteria in the above study compared with our study, but there is a significant difference in the percentage of contamination.[10] In a study by Sabra in Egypt in 2011,[11] the contamination of the women's public toilets were examined. 71.9% of the samples being positively infected. Toilets door handles (91.3%), toilet doors (73.8%), toilet sinks (63.3%), and flush tank levers (50%) were contaminated. S. aureus (40.6%) and E. coli (22.5%) were the most isolated bacteria from positive samples and P. vulgaris was the least one. There is no significant difference to compare with our study.

In the study of Alharbi et al.,[12] five different bacterial isolations were sampled from the airflow of 15 warm air dryers used in washrooms; including Staphylococcus haemolyticus, Micrococcus luteus, Pseudomonas alcaligenes, Bacillus cereus, and Brevandimonad diminuta (vascularis). In this survey, the most bacterial isolates were due to S. haemolyticus with 95% pathogenicity; however, in our study, hand dryer machines were highly contaminated by S. epidermidis (35.71%). It is obvious that hot air dryers can deposit the pathogenic bacteria onto the hands and body of users as well as distributing them into the general environment whenever dryers are running. Also, some microorganisms could be inhaled by users and nonusers alike. So, it is imperative to recommend the sanitization of this machines several times a day. It is notable that in some studies it's manifested by which using warm air dryers or some jet dryers, we actually have augmented the aerosolization of bacteria and facilitating the microbial cross-contamination via airborne dissemination to the environment.[1] Best et al. reported that higher levels of contamination were due to washrooms using a jet air dryers compared with those using paper towels.[13] The hand-drying method can affect the risk of (airborne) dissemination of bacteria in real-world settings. JADs may not be suitable for settings where microbial cross-contamination risks are high, including hospitals.

The study that was conducted by Zapka et al., in 2011,[14] the K. pneumoniae was isolated from samples after the bacteria were recovered and transferred by hand after washing with liquid soap which had been spontaneously infused and liquid soaps which were contaminated without control.

A study of bacteriological assessment of door handles/knobs of toilets and washrooms was conducted by Frank Ngonda in a hospital setting in 2017,[15] which revealed some bacteriological similar results. Among the total of 442 samples, 184 cases (41.6%) were contaminated and also S. aureus was the most bacteria had isolated. The male toilet handles were most contaminated than the females (35.5% beside 19.4%), followed by general sets (9.7%). Whilst the washroom was less contaminated in general, the highest contamination being observed in the male washroom 19.4% as compared to the female washroom at 9.7%.

In the study of Ogba et al.,[16] the researchers have checked on 151 samples of public toilet seats. Out of the 151 samples examined, E. coli 70 (46.4%) was the most prevalent isolate followed by Salmonella spp. 45 (29.8%) while Staphylococcus aureus 15 (9.9%) was the least encountered isolate. Nevertheless, most of the samples and isolates were from hostels 41 (44.0%). This study demonstrates that public toilet seats that have been washed still harbor a high number of bacterial organisms and may serve as a potential source of infections.

  Conclusion Top

The results of this study and other similar related studies, that have been presented, demonstrate that illnesses such as genitourinary tract infections as well as gastrointestinal diseases can be found in children and adults by using contaminated services. In females, some genitourinary tract disorders such as vulvovaginocistitis, acute and chronic pregnancy, premature rupture of membrane (PROM), and acute pyelonephritis would arise mostly due to E. coli. In males, acute and chronic urethritis, cystitis, and prostatitis are most likely. Also, E. coli contamination is principally qualified to lead on Infertility in males and females. Acute cystitis, urethritis, and vaginal discharges are the main problems that occur in children are affected by this bacteria, therefore, enhancing personal hygiene, sanitizing public restrooms regularly and correctly, and using public toilets safely can prevent the transmission, diffusion, and spread of bacterial infections.


We would like to show our gratitude, to “the Medical department of Tehran University” for providing us well equipped “parasitology and mycology” laboratories.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Suen LK, Siu GK, Guo YP, Yeung SK, Lo KY, O'Donoghue M. The public washroom-friend or foe? An observational study of washroom cleanliness combined with microbiological investigation of hand hygiene facilities. Antimicrob Resist Infect Control 2019;8:47.  Back to cited text no. 1
McCusky Gendron L, Trudel L, Moineau S, Duchaine C. Evaluation of bacterial contaminants found on unused paper towels and possible postcontamination after handwashing: A pilot study. Am J Infect Control [Internet] 2012;40:e5-9.  Back to cited text no. 2
Robinton ED, Mood EW. A study of bacterial contaminants of cloth and paper towels. Am J Public Heal Nations Heal [Internet] 1968;58:1452-9.  Back to cited text no. 3
Gerhardts A, Hammer TR, Balluff C, Mucha H, Hoefer D. A model of the transmission of micro-organisms in a public setting and its correlation to pathogen infection risks. J Appl Microbiol 2012;112:614-21.  Back to cited text no. 4
Buffet-Bataillon S, Rabier V, Bétrémieux P, Beuchée A, Bauer M, Pladys P, et al. Outbreak of serratia marcescens in a neonatal intensive care unit: Contaminated unmedicated liquid soap and risk factors. J Hosp Infect 2009;72:17-22.  Back to cited text no. 5
Burton M, Cobb E, Donachie P, Judah G, Curtis V, Schmidt WP. The effect of handwashing with water or soap on bacterial contamination of hands. Int J Environ Res Public Health 2011;8:97-104.  Back to cited text no. 6
Flores GE, Bates ST, Knights D, Lauber CL, Stombaugh J, Knight R, et al. Microbial biogeography of public restroom surfaces. PLoS One 2011;6:e28132.  Back to cited text no. 7
Kanayama Katsuse A, Takahashi H, Yoshizawa S, Tateda K, Nakanishi Y, Kaneko A, et al. Public health and healthcare-associated risk of electric, warm-water bidet toilets. J Hosp Infect [Internet] 2017;97:296-300.  Back to cited text no. 8
Harrison WA, Griffith CJ, Ayers T, Michaels B. Bacterial transfer and cross-contamination potential associated with paper-towel dispensing. Am J Infect Control 2003;31:387-91.  Back to cited text no. 9
Tsunoda A, Otsuka Y, Toguchi A, Watanabe K, Nishino R, Takahashi T. Survey on bacterial contamination of bidet toilets and relation to the interval of scrubbing these units. J Water Health 2019;17:863-9. doi: https://doi.org/10.2166/wh.2019.234  Back to cited text no. 10
Sabra SMM. Bacterial public health hazard in the public female restrooms at Taif, KSA. Middle-East J Sci Res 2013;14:63-8.  Back to cited text no. 11
Alharbi SA, Salmen SH, Chinnathambi A, Alharbi NS, Zayed ME, Al-Johny BO, et al. Assessment of the bacterial contamination of hand air dryer in washrooms. Saudi J Biol Sci 2016;23:268-71.  Back to cited text no. 12
Best E, Parnell P, Couturier J, Barbut F, Le Bozec A, Arnoldo L, et al. Multicentre study to examine the extent of environmental contamination by potential bacterial pathogens, including antibiotic resistant bacteria, in hospital washrooms according to hand-drying method. J Hosp Infect 2018; doi: 10.1016/j.jhin. 2018.07.002.  Back to cited text no. 13
Zapka CA, Campbell EJ, Maxwell SL, Gerba CP, Dolan MJ, Arbogast JW, et al. Bacterial hand contamination and transfer after use of contaminated bulk-soap-refillable dispensers. Appl Environ Microbiol 2011;77:2898-904.  Back to cited text no. 14
Ngonda F. Assessment of bacterial contamination of toilets and bathroom doors handle/knobs at Daeyang Luke hospital. Pharm Biol Evaluations 2017;4:193-7.  Back to cited text no. 15
Ogba OM, Obio OM. Microbial spectrum on public toilet seats. Ann Microbiol Infect Dis 2017;1:58-62.  Back to cited text no. 16


  [Table 1], [Table 2]


Similar in PUBMED
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  In this article
   Materials and Me...
   Article Tables

 Article Access Statistics
    PDF Downloaded45    
    Comments [Add]    

Recommend this journal