An MMWR analysis of six outbreaks of adenovirus-associated epidemic keratoconjunctivitis from 2008 through 2010 provides lessons on infection control in healthcare settings. Epidemic keratoconjunctivitis is a severe form of viral conjunctivitis with symptoms that can last up to 21 days and may be associated with common ophthalmologic procedures.
The healthcare-associated outbreaks occurred in Florida, Illinois, Minnesota, and New Jersey. Healthcare providers were likely sources of transmission in four of the outbreaks, and infection control breaches occurred in all. Over 400 patients were infected.
MMWR‘s editors recommend the following infection-control measures:
- Use strict hand hygiene.
- Wear disposable gloves for potential contact with eye secretions.
- Disinfect ophthalmologic instruments after every use, or use disposable instruments.
- Ensure patients with suspected conjunctivitis have a separate waiting room, sign-in area, and exam room.
- Bar from work any staff members with signs of epidemic keratoconjunctivitis.
In addition, the editors note, isopropyl alcohol is not sufficient for disinfecting ophthalmologic instruments that contact typically sterile body sites; rather, staff should follow equipment manufacturer’s instructions.
Source: MMWR article
Multidrug-resistant Mycobacterium abscessus is frequently transmitted between patients with cystic fibrosis, suggesting that current infection control is not adequate, according to a Lancet study.
Researchers analyzed 168 isolates from 31 patients with pulmonary M. abscessus infection at a U.K cystic fibrosis center. Within clusters ofM. abscessus subspecies massiliense, isolates from different patients were often more closely related to each other than were isolates from within a single individual, suggesting transmission of the bacteria between patients. In addition, some isolates were resistant to macrolides and aminoglycosides in patients previously unexposed to those antibiotics, supporting the notion of cross-infection. The authors say transmission is likely occurring indirectly, such as through fomite contamination or lung function testing.
The authors conclude that their findings raise “several important questions about current infection control measures used in treatment centers, the potential for cross-infection in other patient groups and with other … species, and whether mandatory notification of infections with M. abscessus complex and routine whole genome sequencing might be required to identify and control the spread.”
Using a novel method, investigators revealed marked heterogeneity in healthcare worker interactions and in the potential consequences of their hand hygiene.
Attempts to understand disease transmission in healthcare settings have generally assumed that healthcare workers (HCWs) move and interact uniformly. However, observational studies have suggested the possibility of peripatetic “superspreaders” who have greater-than-average mobility and interactivity — and thus more opportunity to spread infection. In a recent study conducted in the medical intensive care unit of a university hospital, researchers assessed this possibility.
The researchers used small electronic badges worn by HCWs, together with fixed-position beacons, to determine patterns of HCW movement and interactions within this 20-bed unit. They then used these data to mathematically model the effect of HCW hand hygiene on pathogen transmission.
During the 48-hour period of analysis, the average number of contacts (HCW–HCW and HCW–patient) per HCW was 80.1 for day shifts and 76.1 for night shifts. However, a few HCWs were responsible for a disproportionately large share of the contacts. Modeling the effect of hand-hygiene activity on disease transmission showed that spread of a pathogen would be significantly greater with noncompliance of a few high-contact staff members than with noncompliance of an equal number of low-contact workers.
Comment: Hand hygiene is a central tenet of infection control, yet since the original work of Semmelweis, there has been relatively little research on the direct effects of hand-hygiene behavior on disease transmission. Hornbeck and colleagues have provided new insights into HCW contacts, which can help us to understand the role of hand hygiene in preventing nosocomial spread of pathogens and thus to develop more-sophisticated approaches for improving its efficacy.
Source: Journal Watch Infectious Diseases
Hospitalization rates and mortality rose during outbreaks in nursing homes.
Gastroenteritis outbreaks, 86% of which are caused by norovirus, are common in nursing homes. Norovirus infection is thought to be associated with substantial morbidity and mortality in nursing home residents, but the exact risk is undefined.
In this retrospective cohort study, researchers used linked databases of infection outbreaks and Medicare nursing homes to assess the incidences of hospitalizations and deaths during norovirus outbreaks in 308 nursing homes in Oregon, Wisconsin, and Pennsylvania. Four hundred seven outbreaks were reported during 2009 and 2010, with a median of 26 cases per outbreak. In analyses adjusted for seasonal differences, risk for hospitalization was 9% higher and risk for death was 11% higher during outbreaks than at other times.
Comment: These results put some hard numbers to the trends that are observed clinically: Risks for hospitalization and death rise during norovirus outbreaks in nursing homes. The authors estimate that about 100 excess hospitalizations and 45 excess deaths occurred in these homes during the study period, which translates to 500 to 600 excess deaths in nursing home residents nationwide during 2 years. Norovirus vaccine development (now under way) and more aggressive infection control strategies are warranted.
Source: Journal Watch General Medicine