Most facility's are doing total house surveillance. This means that they monitor all infections, in all residents, at all times. In a large facility (>150 beds), this can be time consuming and inaccurate. Poorly collected data results in misleading infection rates, including infection rates that are artifically low. Therefore, in many health care settings, especially the acute care setting, infection control activities are focued on one type of infection for a specific period of time. This is sometimes refered to as priority directed, site-specific surveillance.

How do you decide what type of infection to select for a focus surveillance system? Most infection control professionals will agree that infection surveillance should focus on infections that occur in high numbers, those that cost the most money or infections in which there is the high morbidity or mortality. You can decide which of these best fits your facility, based on the total house surveillance infection data you have been collecting.

Here is an example. If the most common infection is urinary tract infections (UTI), then the facility would set a goal to decrease UTI's by 25% (an arbitrary figure) over a six month period. This would be done by having the staff (nurses and nursing assistants) review the implement a UTI prevention program. While other infections are not ignored, the time formerly spent on collecting infection on all infections is now used to identify high risk resdients for UTI and preventing these infections.

In order for this type of surveillance system to work, the infection contol nurse must be familiar with the most recent literature and scientific study on the subject. Old habits need to be evaluated for effectiveness. For example, monthly urine catheter changes have not been found to decrease infection rates. Therefore regularly scheduled catheter or catheter bag changes should be avoided. This is also true for irrigation of the urinary catheter.

One draw back to this system is missed clusters of infection and outbreaks. When focus surveillance is used, maintaining communication with the staff is vital. This may include regular meetings with the staff at the change of shift or during staff meetings. Another method is for the infection control nurse to review the 24 hour log or change of condition report on a regular basis, in order to find unusual occurences.

The decision to use focus surveillance should be made with input from the infection control committee. The infection control nurse should prepare articles and lead a discussion on the benefits of changing. Remember to include the cost benefits to the facility as part of your presentation. For example, the cost to diagnose and treat a UTI is about $600. This means for each UTI you prevent, there is a cost savings of $600 in supplies, equipment, staff time and medications. There are cost estimates for other nosocomial infections found infection control literature.

BCG Vaccine and TB skin testing

Many foreign counties still use BCG as part of their TB programs, especially for infants. There is no reliable method of distinguishing tuberculin reactions caused by BCG from those caused by natural infection. A reaction to a Mantoux skin test in a person with a history of BCG vaccination is mose likely to be due to infection with Mycobacterium tuberculoisis if:

• the induration is large (>20 mm)
• the person was vaccianted a long time ago (>15 years)
• the person is a recent contact of a person with infectious TB
• there is a family history of TB
• the person comes from an area of the world were TB is common
• chest x-ray findings show evidence of pervious TB

If the resident or staff member has any of the preceding risk factors, a postive TB reaction (>10 mm) indicates infection with M. tuberculosis. Such persons should be evaluated for isoniazid (INH) preventive therapy after active disease has been ruled out.

References

Core Cirriculum on Tuberculosis, 3rd Edition, Centers for Disease Control and Prevention (CDC)
Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Facilities, 1994, Centers for Disease Control and Prevention (CDC)