Table 1.
NoV aerosol transmission cases.
| Location | Number of Cases | Setting | Time | Infection Source | Mode of Transmission | Aerosol Transmission Evidence | References |
|---|---|---|---|---|---|---|---|
| Philadelphia, Pennsylvania, USA | NA | Medical College | 1945 | The patient’s gargle and stool suspension | airborne, fecal–oral | Of the 32 volunteers who inhaled gargles aerosol, 17 developed symptoms. | [47] |
| Toronto, Ontario, Canada | 635 | Hospital | 01/11/1985–22/11/1985 | NA | airborne | 1. Among those who visited the emergency department from November 11 to 12, there was no correlation between the incidence and indirect contact behavior or diet, but there was a correlation with the length of stay in the emergency department. 2. The risk of illness for housekeepers who visited the emergency room was four times greater than those who did not. |
[48] |
| Los Angeles, USA | NA | Geriatric convalescent institution | 12/1988–01/1989 | Infection may originate from hospitals and may be transmitted to the convalescent facility via cross-staff | multiple routes of transmission, including airborne transmission | 1. Fourteen cases had no contact with patients or their stool. 2. Foodborne and waterborne transmission were ruled out. |
[49] |
| UK | 126 | Nursing home | 14/11/1992–03/12/1992 | The virus was likely introduced from the community by staff or patients | airborne (aerosol-vomitus); environmental contamination | 1. Exposure to nearby vomiting was the only risk factor. 2. No significant correlation was found between cleaning the patient’s vomit and feces and gastroenteritis among nurses. |
[50] |
| UK | 52 | Hotel Restaurant | 07/12/1998–11/12/1998 | A guest who attended a party vomited at the restaurant | airborne (aerosol-vomitus) | 1. None of the foods served at the dinner party were likely to be a vector of virus transmission. 2. The attendant who cleaned up the vomit did not fall ill. 3. There was a significant correlation between the distance between other guests and the vomiting location and their risk of illness. 4. No one at the restaurant became ill after the incident. |
[24] |
| Derbyshire, England | 153 | Schools (including primary schools and nurseries for children aged 4 to 11) |
25/06/2001–16/07/2001 | NA | airborne (aerosol-vomitus); environmental contamination | 1. Cleaned up immediately after vomiting. 2. Incidence increased with the number of exposures to vomiting. 3. In classrooms where three vomiting events occurred on the same day, the median time from exposure to onset was significantly shorter than those in the other two classrooms where vomiting occurred only once. |
[25] |
| Japan | 444 | Hotel | 02/12/2006–10/12/2006 | The index case vomited in corridors on the 3rd and 25th floors | airborne (aerosol-vomitus); contact with fomites | 1. NoV was detected in the contaminated carpet and also in the environment samples that were unlikely to be touched, such as mantels or light fittings. 2. Eighteen guests did not eat any of the party food, were still sick and were infected with the same NoV genotype as those who ate the party food. 3. Foodborne transmission was ruled out. |
[51] |
| Salzburg Province, Austria | 176 | Youth hostel (holiday for teachers and students of 4 schools) |
08/12/2007–17/12/2007 | The first case vomited several times on a bus from Vienna to Salzburg Province on 8 December 2007, and vomited again in the hotel lobby after arrival | airborne (aerosol-vomitus); subsequent person-to-person transmission or exposure to a contaminated environment | 1. A day-by-day analysis of specific foods showed that no food was associated with the risk of infection between 8 and 12 December. 2. Other transmission modes were ruled out. |
[52] |
| Changzhou City, China | 207 | Primary school | 22/11/2011–02/12/2011 | The earliest cases vomited repeatedly in public places such as classrooms, bathrooms and staircases | airborne (aerosol-vomitus); person-to-person transmission or exposure to a contaminated environment | 1. Exposure to vomiting and contact with patients were associated with an increased risk of NoV gastroenteritis. 2. Foodborne and waterborne transmission were ruled out. 3. Within the first 48 h, students closer to the site of vomiting fell ill earlier than those farther away. |
[53] |
| Quebec City, Canada | NA | Eight medical facilities | 2012 | NA | airborne, other routes of transmission cannot be ruled out | 1. NoV GII genomes were detected in 23 air samples from six healthcare facilities, with concentrations ranging from 1.35 × 101 to 2.35 × 103 genomes/m3. 2. In vitro experiments showed that MNV remained intact and infectious in aerosols. |
[30] |
| Gothenburg, Sweden | NA | Sahel Greska University Hospital | 2012 | NA | multiple routes of transmission, including airborne transmission | The gene sequences of NoV GII.4 strains detected in dust, virus trap sampling device and air vents in the ward were the same or highly similar to those from the patients. | [54] |
| Yiyang City, Hunan Province, China | 105 | Senior high school | 18/02/2014–02/03/2014 | NA | airborne (aerosol-vomitus); contact with fomites | 1. The student vomited on the floor of the classroom or the bathroom sink, and did not disinfect and clean up in time. The student washed the mop in the bathroom sink and moped the classroom floor. 2. Classrooms were grouped according to their distance from the bathroom; the farther the classroom was from the bathroom, the lower the incidence of illness. |
[55] |
| Ningbo City, Zhejiang Province, China | 46 | Primary school | 03/01/2015–13/01/2015 | The first case may were infected by consuming oysters contaminated with NoV | airborne (aerosol-vomitus); person-to-person transmission | 1. The vomit of the first case was not treated in a timely and standardized manner, and the vomit was only removed without disinfection. 2. Due to the rainy and cold weather, the classroom was not ventilated by opening windows. |
[56] |
| Zhongshan City, Guangdong Province, China | 39 | Primary school | 23/02/2016–29/02/2016 | The indicative case vomited in the school hallway | airborne (aerosol-vomitus); person-to-person transmission | 1. Passing through the vomit site was a risk factor. 2. The low wind in the vomit-contaminated area was not conducive to the rapid dispersal of aerosols. |
[57] |
| Shanghai City, China | 19 | Primary school | 07/03/2017–10/03/2017 | The first case vomited at the playground | airborne (aerosol-vomitus) | 1. The epidemic curve was unimodal, indicating the occurrence of point source exposure. 2. The first case vomited in the playground during physical education class, and the vomit was not disinfected in time. |
[58] |
| Lianyungang, China | 20 | Kindergarten | 09/06/2017–29/06/2017 | The first case vomited on the top bunk of a bunk bed in the lunch break room | airborne (aerosol-vomitus) | 1. The beds of all cases were located in the fan-shaped area covered by air conditioning exhaust. 2. Teachers and children who were not in the lunch break room on that day were not infected with NoV. 3. The outbreak occurred in only one class, and investigations showed lunch and drinking water were not risk factors. |
[59] |
| Sweden | 26 | Hospitals (13 wards in 3 hospitals) |
03/2017–05/2018 | NA | airborne transmission; other transmission routes were not ruled out | 1. Detection of NoV RNA in the air was associated with a shorter time from vomiting. 2. The concentration of NoV RNA in the air ranged from 5 to 215 copies/m3, with an average of 31 copies/m3, and NoV RNA was detected in aerosols with particle sizes of <0.95 µm and >4.51 µm. |
[13] |
| Shenzhen City, Guangdong Province, China | 16 | Kindergarten | 10/09/2018–12/09/2018 | The first case vomited in the classroom during the nap time of young children | airborne (aerosol-vomitus) | 1. The outbreak was characterized by point-source exposure. 2. During naptime, windows and doors were closed, and air conditioners were turned on; therefore, children and staff were in an enclosed space, and most cases were in the fan-shaped area covered by air conditioning exhaust. 3. The cleaning of vomit was not standardized. |
[60] |
| Wenzhou City, Zhejiang Province, China | 28 | Junior high school | 14/12/2018–24/12/2018 | The first case vomited in the classroom |
airborne (aerosol-vomitus); person-to-person transmission | 1. The vomit from the first case was simply swept up and was not disinfected, and the cleaning tools were also not disinfected. 2. Cases were mainly concentrated around the first case and the vomit. 3. Cleaning up vomit and staying less than 2 m away from vomit are risk factors. |
[61] |
| Wuhan City, Hubei Province, China | 17 | Kindergarten | 16/11/2020–18/11/2020 | The first case vomited in the classroom |
airborne (aerosol-vomitus); person-to-person transmission | 1. The vomit was not disposed of properly, and the disinfection concentration was not enough. 2. Students did not leave the classroom and were not ventilated before cleaning up the vomit. 3. The closer the student was to the vomit of the first case, the greater the risk of infection. |
[62] |
| Xi’an City, Shaanxi Province, China | 31 | Kindergarten | 26/05/2021–28/05/2021 | The first case vomited in the classroom |
airborne (aerosol-vomitus) | 1. The risk of illness in children close exposed to vomit was 3.98 times higher than in children exposed at a distance, and 102 times higher than in unexposed children. 2. Vomit cleanup was not standardized, and the garbage bag containing the vomit was not sealed. 3. Contaminated areas were not disinfected, children were not immediately evacuated and cases were not isolated. |
[63] |