This article is more than 5 years old. Information may no longer be current.
Hand washing may be effective as HFMD control measure
Ruan F. Pediatrics. 2011;127:e898-e904.
Click Here to Manage Email Alerts
Emphasizing proper hand washing during outbreaks of hand, foot and mouth disease and herpangina caused by the human enterovirus 71 infection may help to control the outbreak, according to a study published online.
Researchers from the Chinese Field Epidemiology Training Program of the CDC in Beijing submitted a questionnaire to parents of children living in the Qiaosi Township of the Zhejiang province of China during the outbreak, which began in late April and ended at the end of June 2008.
The case-control study involved 176 children aged 6 years or younger who had tested positive for hand, foot and mouth disease (HFMD) or herpangina as the test case; another 201 children served as the controls. The children or their caregivers were asked four questions about their hand washing habits during the time of the outbreak (April 30 to June 26, 2008). Each question was scored on a 0-3 basis, with 3 being almost always washed, and 0 being never washed.
The researchers said half of the children who had contracted HFMD or herpangina scored poorly on the questionnaire (score 1 to 3), whereas only 2.5% of the control group reported poor hand hygiene habits. Conversely, 78% of the control group had high scores (7 or higher) vs. only 12% of the test group.
In summarizing their findings, the researchers said, “Hand washing by preschool-aged children and their caregivers had an important mitigating effect and was highly protective at the individual level.”
The Chinese CDC recommended that local health officials stress the importance of proper hand washing to intervene before outbreaks of these types of illnesses occur.
Disclosure: The researchers report no relevant financial disclosures.
Eickhoff
This study illustrates the enormous difficulty in obtaining reliable data on hand-washing and its efficacy in preventing transmission of infectious agents. It's difficult enough in the hospital setting, where hospital staff can be watched somewhat closely, but it's far, far more difficult in the community setting where direct observation is virtually impossible and reliance must be placed on subject recall. Furthermore, each setting introduces its own particular set of potential biases. There are several biases to worry about in this report. Two such biases are mentioned in the paper by Ruan et al; first, the simple recall bias; and second, in the case of actual HFMD patients, or others with herpangina, the questionnaire covered only a 1-week period before illness onset; for control patients, the interval was the entire 8-week study interval. However, the bias I am most concerned about was not mentioned by the authors, and that is the apparent lack of blinding of the questioners. In other words, the questioners knew whether they were questioning a patient or a control parent. The possibility of "observer bias" being introduced here is, frankly, enormous. I think it is quite likely that there was indeed a preventive effect of hand-washing, but I seriously doubt that it was really of the magnitude reported by the investigators.
– Theodore C. Eickhoff, MD
Infectious Diseases in Children Editorial Board member
 |
Follow the PediatricSuperSite.com on Twitter. |