Use of masks to control the spread of infection: more than a century of confusion

Jayant Radhakrishnan
Darien, Illinois, United States

 

A masked surgical team operates while onlookers wear no masks
The above photograph is from the archives of the Cook County Hospital when it closed. It was taken in the surgical amphitheater in the main building. The year is not known. The photograph demonstrates an operation being carried out by masked and gowned surgeons and the scrub nurse however, the anesthesiologist, the circulating nurse, and the audience in the galleries are not masked. Image courtesy of Dr. Bohdan Iwanetz.

Johann von Mickulicz-Radecki (1850-1905) was an ardent advocate of the one-time novel concept of aseptic surgery. To improve his results, he began working with a hygienist and bacteriologist, Carl Flugge (1847-1923), who pointed out possible sources of infection for the surgical patient, including droplets dispersed from the nose and mouth of the surgeon.1 Mickulicz altered his practices and reported on them in 1897 in a paper entitled “Das operieren in steriliserten zwirnhandschuren und mit mundbinde. Zentrabl Chir” (“Operating with sterilized woven/fabricated gloves and mouth covering”—zwirn is an ultrafine tailoring thread that yields a tight fabric, and mundbinde literally means “mouth tie”).2

In 1897 Alice Hamilton (1869-1970) was also appointed Professor of Pathology at the Woman’s Medical School of Northwestern University in Chicago after graduating from the University of Michigan Medical School. She resided at Hull House on 800 S. Halstead Street for her entire twenty-two-year stay in Chicago and her interest in occupational health and industrial toxicology arose from her experiences there.

When the Woman’s Medical School closed in 1902, she moved to the Memorial Institute of Infectious Diseases, which was established that year by Mr. and Mrs. Harold F. McCormick in memory of their son who had died of scarlet fever the previous year.3 Here she worked with the eminent pathologist Ludvig Hektoen (1863-1951) who suggested that she study the spread of scarlet fever in addition to her studies on typhoid and tuberculosis. At a time when people doubted that streptococci caused scarlet fever, she not only proved that to be the case but also demonstrated that streptococci were present in the droplets of sputum expelled from the mouths of fifty scarlet fever patients from the Memorial Institute, Cook County Hospital, and the Scarlet Fever Hospital of the New York Department of Health. The droplets were expelled upon coughing, crying, or even breathing heavily with the mouth open.4 She postulated that the streptococcus might pass from one patient to another and that one patient may become a source of danger to other patients in the same ward. Interestingly, she also stated: “I was told by a student in a large medical college in Chicago that he had often noticed at the clinics of a certain surgeon that, when the light was from a certain direction, he could see from his seat in the amphitheater, a continuous spray of saliva coming from the mouth of the surgeon while he discoursed to the class and conducted his operation.” She credited Dr. Mendes de Leon for studying this subject, determining that antiseptic mouthwashes created a thin watery saliva which worsened the problem and for creating a mouth guard that held back salivary droplets.4

She studied individuals who were either healthy or had slight sore throats but came to work. By placing culture plates at varying distances from their mouths while they counted to one hundred, she found colonies in thirty-three plates when they coughed and in twenty-six when they spoke. In addition, she found streptococci in forty-six of the fifty throat cultures. She determined that streptococci were expelled to at least 24 cm when speaking and a minimum of 36 cm when coughing. Furthermore, forced expiration while whispering produced more sputum than when speaking normally.

George Weaver was a contemporary of Hamilton’s who worked at the fifty-bed Durand Hospital for Infectious Diseases at 637 South Wood Street, Chicago. Recognizing the importance of droplets as a source of infections, he instituted a policy that all nurses and physicians working at the hospital must wear masks of “double thickness of gauze, so shaped as to fit closely over the face from the chin well up over the nose, and held in place by two tapes tied behind the head.”5 Masks were never worn twice unless sterilized and washed and were immediately replaced by a fresh one if it was contaminated or became moist. This practice immediately curtailed the transmission to hospital personnel not only of diphtheria, meningitis, and scarlet fever but also of tonsillitis, pharyngitis, and rhinitis. Weaver stated that “the mask not only protects the healthy person from infection and from becoming a carrier, but also prevents a carrier from spreading infection to others.”5

Soon after Weaver’s report, the influenza pandemic struck and masks were considered invaluable in preventing its spread. However, different types of masks were used and their efficacy as barriers to the transmission of infections was not known. Doust and Lyon6 were one of the teams that chose to experimentally study the mask. They introduced an organism into the mouth of test subjects wearing different types of masks and placed agar culture plates at various distances to capture the organism while the subjects spoke for varying lengths of time and also when they coughed. Bacillius prodigiosus was the agent chosen “because of its innocuous character, and because its pigment formation makes its recognition easy on agar plates.”6 B. prodigiosus is now known as Serratia marcescens. As expected, they found gauze masks of up to ten layers to be worthless but three-layer buttercloth masks were effective in obstructing bacteria.

Even though influenza is a droplet-borne infection, use of cloth and cotton masks by patient care workers and the general public were useless in preventing infections during the 1918-1919 influenza pandemic. An experimental study by Kellogg and MacMillan in 1919, also with B. prodigious,7 found that gauze face masks did not control the droplets. Other factors that probably contributed to the failure in controlling the 1918-19 pandemic were improperly made masks, use of masks that were too small and covered only the mouth or the nose, continuing to wear them when contaminated, removing them improperly and thus infecting the hands, not wearing the mask when in close proximity to others, passage of droplets around the edges of the mask, and not wearing a mask out of sheer obstinacy. In addition, as we know now, cloth masks are not effective against organisms <5µm in size.

A 2019 paper based on the influenza seasons between September 2011 and May 2015 discussed the value of masks and respirators.8 There was no significant difference in the incidence of laboratory-confirmed influenza among the two groups in outpatient health care personnel (8.2% for the N95 respirator and 7.2% for masks). When asked whether they wore the device “always” or “sometimes,” 89.4% of the respirator group did and 90.2% of the mask group did. Reasons for poor compliance when using respirators were that they were uncomfortable and hot, the inside rapidly became wet, it was nearly impossible to speak with them on, and when properly fitted it was extremely difficult to breathe.9

It appears that along with hand washing, avoiding contact with the face, and using a well-fitting mask as required, handling it properly, and changing it as advised should control droplet dispersion of coronavirus. Social distancing of six feet to prevent the spread of droplets >5µm in size seems to be adequate but SARS-CoV-2 also appears to spread as an aerosol and may travel for considerable distances following the airflow, as evident from the case in the Guangzhou restaurant.10

It seems that matters are not as straightforward as believed by Mickulicz. The German philosopher and poet Friedrich Wilhelm Nietzsche (1844-1900) was indeed correct when he said “Der Teufl steckt im Detail”—the devil is in the detail.

 

References:

  1. Schlich T 2012. Asepsis and bacteriology: A realignment of surgery and laboratory science. Med Hist 56(3):308-334
  2. Mickulicz J 1897. Das operieren in steriliserten zwirnhandschuren und mit mundbinde. Zentrabl Chir 24(26):713-717
  3. Billings F 1904. The memorial institute for infectious diseases. JAMA 42(26):1676-1677
  4. Hamilton A 1905. Dissemination of streptococci through invisible sputum. JAMA 44(14):1108-1111
  5. Weaver GH 1918. The value of the face mask and other measures. In prevention of diphtheria, meningitis, pneumonia etc. JAMA 70(2):76-78
  6. Doust BC, Lyon AB 1918. Face masks in infections of the respiratory tract. JAMA 71(15):1216-1219
  7. Kellogg WH, MacMillan G 1920. An experimental study of the efficiency of gauze face masks. Am J Public Health. 10(1):34-42.
  8. Radonovich LJ Jr, Simberkoff MS, Bessesen MT, Brown AC, Cummings DAT, Gaydos CA, Los JG, Krosche AE, Gibert CL, Gorse GJ, Nyquist A-C, Reich NG, Rodriguez-Barradas MC, Savor Price C, Perl TM 2019. N95 respirators vs medical masks for preventing influenza among health care personnel: A randomized clinical trial. JAMA 322(9):824-833
  9. Radonovich LJ, Wizner K, LaVela SL, Lee ML, Findley K, Yorio P 2019. A tolerability assessment of new respiratory protective devices developed for health care personnel: A randomized simulated clinical study. PLoS ONE 14(1):e0209559 . https://doi.org/10.1371/journal. pone.0209559
  10. Lu J, Gu J, Li K, Xu C, Su W, Lai Z, Zhou D, Yu C, Xu B, Yang Z 2020. COVID-19 Outbreak Associated with Air Conditioning in Restaurant, Guangzhou, China, 2020. EID Journal 26(7):Research letter DOI: 10.3201/eid2607.200764

 


 

JAYANT RADHAKRISHNAN, MB, BS, MS (Surg), FACS, FAAP, completed a Pediatric Urology Fellowship at the Massachusetts General Hospital, Boston following a Surgery Residency and Fellowship in Pediatric Surgery at the Cook County Hospital. He returned to the County Hospital and worked as an attending pediatric surgeon and served as the Chief of Pediatric Urology. Later he worked at the University of Illinois, Chicago from where he retired as Professor of Surgery & Urology, and the Chief of Pediatric Surgery & Pediatric Urology. He has been an Emeritus Professor of Surgery and Urology at the University of Illinois since 2000.

 

Summer 2020 |  Sections  |  Infectious Diseases