Home healthcare is the most rapidly growing segment of the healthcare delivery system; about as many persons in the United States receive healthcare in the home as in acute care settings (1). More than 20,000 agencies deliver home care to 7.6 million individuals, generating about $40 billion in expenditures (2). Medicare is the largest payer of home health services (3). The most commonly used services are skilled nursing care, personal care, and physical therapy.

Home healthcare specialists provide many services traditionally given in the hospital or in a long-term care facility (LTCF). The number and types of patients who receive professional care in the home setting are increasing; major categories of home care services include infusion therapy, respiratory therapy, dialysis, diabetic monitoring, wound care, other skilled nursing care, physical therapy, nutritional therapy, occupational therapy, social services, and hospice care. Also included in these general categories are patients requiring special nursing support by virtue of medical needs (e.g., enteral nutrition) or disease complexity (e.g., acquired immunodeficiency syndrome). In total, about 950,000 persons are employed in the home healthcare industry, mostly home care aides and registered nurses (2,3). Other professionals including respiratory therapists, physical therapists, social service workers, speech therapists, pharmacists, and durable medical equipment suppliers are also involved in providing home healthcare.

Patients cared for at home have conditions that predispose to infectious diseases such as advanced age, multiple underlying comorbidities, and immunosuppressive conditions (2,3 and 4,5,6,7,8 and 9). Many infections acquired in the home are related to devices or breaks in local defenses (Table 99-1). Invasive devices were noted in up to one third of patients in the home (4,5,9), most notably urethral or suprapubic catheters (12-21%), nasogastric tubes (11%), intravenous (IV) catheters (6-17%), gastrostomy tubes (7%), and tracheostomies (2%). Some infections in the home setting are hospital-acquired (attributable to a prior hospital stay), most commonly urinary tract infection (UTI) and skin/wound infection (10). Although comparative data are not available, home healthcare patients are presumably less immunosuppressed than typical hospital or LTCF patients but more at risk for infection than other community-dwelling individuals.

Home healthcare patients may have a variety of infectious diseases that require infection control in the home. Limited data suggest that the prevalence of infection in home healthcare patients is 16% to 20% (4,9). One prevalence survey found an overall infection rate in the home of 16%, with 8% of these infections being home care acquired, 16% hospital acquired, 41% community acquired, and 35% unknown (9). The most common infections involved the urinary tract (27%), respiratory tract (24%), skin and soft tissue (24%), surgical wounds (12%), and bloodstream (2%). Others (11) have noted a relatively low rate of device-associated infection in the home (0.22 central line-associated bloodstream infections [BSIs] per 1,000 device days, and 1.24 UTIs per 1,000 device days). The definitions of infection in the home care setting are discussed below in “Surveillance.”

The occurrence of an infection in a patient in an acute care hospital or LTCF does not imply that the infection was caused by the facility, or necessarily preventable. Infections that occur in home healthcare patients are much more difficult to ascribe to the home health agency, which has contact with the patient usually only a few minutes per day compared with 24 hours for the hospital or LTCF. Exposure to microorganisms from family members, visitors, or the environment are usually beyond the control of the home health agency, as are factors such as home sanitation, compliance with basic hygiene, and exposure to contagious persons (12). In the case of intravascular catheters, multiple providers may have access to the device (13). The incidence, origin, risk factors, and preventability of infections in the home healthcare setting still remain largely to be defined.

Most infections in home infusion therapy are related to vascular access devices. The measured incidence rate of central line-associated bacteremia varies widely in the literature, from 7 to 58 bacteremias per 10,000 catheter days (14,15,16,17 and 18). Noninfectious complications of venous access in the home environment include thrombosis, bleeding, and air embolism (19).

Infections related to indwelling vascular access devices can present as sepsis or fever without localizing signs or symptoms. Alternately, one may see signs of exit-site infection (erythema, tenderness, or purulent discharge at the catheter exit site) or a tunnel infection (erythema, tenderness, and induration along the subcutaneous tract). Catheter-related sepsis and tunnel infections often require catheter removal (14). The most common microorganisms associated with these infections are coagulasenegative staphylococci, Staphylococcus aureus, aerobic gram-negative bacilli (such as Klebsiella pneumoniae and Pseudomonas aeruginosa), and Candida species. In one report, gram-negative microorganisms were responsible for a greater proportion of central line-related bacteremias in pediatric oncology patients receiving home care than in those in the hospital; the mean time between catheter insertion and bacteremia was 133 days (17).

Risk factors for BSIs in patients receiving home infusion therapy include bone marrow transplantation, parenteral nutrition, and use of multilumen catheters (20). The importance of aseptic technique is suggested by the association of lower education and younger age with patient BSI (21). Proper infection control technique is likely an important component of preventing home infusion-related infectious complications (22), although little research has been done in the home setting. One investigator found that routine replacement of peripheral catheters every 3 to 4 days was not associated with a lower rate of complications (23).

One special area of home infusion therapy is home parenteral nutrition (HPN). Most infections in HPN are related to the indwelling vascular catheter (24). Catheter-related bacteremia in HPN patients occurs at a rate of approximately 20 infections per 10,000 HPN days (16,18). The leading causative microorganisms are coagulase-negative staphylococci, K. pneumoniae, Escherichia coli, S. aureus, and Candida species.

Infusate-related bacteremia from contaminated parenteral nutrition fluids is relatively uncommon but remains a concern. A variety of microorganisms have been shown to proliferate in parenteral nutrition solutions, particularly gram-negative bacteria and Candida species (25).

Infection control recommendations for home infusion therapy pertain mainly to the prevention of vascular access-associated infections. Guidelines for preventing catheter-related infections in the hospital have been published (22). The guidelines address frequency of catheter and administration set change, aseptic technique during catheter insertion, and length of hang time for lipid-containing solutions. The home care agency is responsible for ensuring sterility of solutions prepared for IV infusion. Both the patient and the home healthcare provider need to be familiar with the signs and symptoms of infection, the side effects of infusion therapy, and the maintenance and care of vascular access devices. See Chapters 18 for more information on the infection control aspects of long-term vascular access.

There are no controlled studies of the risk of infection or of infection control methods for respiratory patients in the home environment. Recommendations (28,29) are based on extrapolations from current hospital practices (see Chapter 22). Areas of concern are listed in Table 99-2.

For patients receiving mechanical ventilation in the home, cleaning of the ventilatory circuits is important. Several circuits should be provided, and the circuits (including tubing, manifold, and humidifier) not in use should be cleaned and dried before being stored. Adequate precleaning of equipment is an important part of the disinfection process.

Room humidifiers that produce a fine spray of water droplets are frequently used in the home and are often contaminated with bacteria. These humidifiers are difficult to clean and pose significant risk to immunocompromised patients. Drying between uses decreases bacterial contamination. Humidifiers that work by simple evaporation are safer than those that produce a fine mist spray.

Guidelines for prevention of healthcare-associated pneumonia (29) have relevance for home care, including immunization recommendations (pneumococcal vaccine, influenza vaccine), suctioning, ventilator care, aspiration prevention after enteral feeding, and humidifier care. The American Association of Respiratory Care provides clinical practice guidelines for home suctioning, home ventilation, postural drainage, and ventilator circuit changes (28), as well as a discussion of frequency of ventilator tubing change and infection control aspects of humidification. The home suctioning guideline discusses cleaning and reuse of suction catheters (30).

One of the most serious problems associated with peritoneal dialysis is infection involving either the catheter exit site through the skin or the peritoneal cavity itself. The former infection, analogous to indwelling central IV access device infections, may involve either the exit site or the tunnel. The latter generally presents as peritonitis (31). The incidence of infectious complications related to continuous ambulatory peritoneal dialysis (CAPD) is about 1.1 to 1.3 episodes per patient year (32). Recurrent peritonitis is a leading cause of CAPD failure.

Most bacteria causing CAPD-related peritonitis are gram-positive bacteria (specifically, coagulase-negative staphylococci and S. aureus), reflecting the important role of skin flora in catheter-related peritonitis (31,32). Polymicrobial infections and the presence of gram-negative bacteria suggest a bowel perforation by the catheter. Nasal carriage of S. aureus may be a risk factor for catheter exitsite infections by this microorganism (33).

A key to minimizing the risk of peritonitis due to CAPD is appropriate care of the exit site and surrounding skin. Initial care after catheter placement has been described and consists of cleaning the exit site and surrounding skin with an antiseptic agent, drying the skin, covering the exit site with a sterile gauze dressing, and securing with surgical tape. The catheter should be protected from mechanical stress. After the exit site has healed, routine care includes frequent examination of the exit site and tunnel for signs of inflammation as well as cleaning of the exit site (34,35 and 36). The potential for contamination of the peritoneal dialysis system exists when the system is opened to connect or disconnect bags of fluid. Hand washing and aseptic technique are important. Infections in peritoneal dialysis are discussed in greater depth in Chapter 64.

A guideline for preventing infection transmission in chronic hemodialysis patients discusses cleaning and disinfection of equipment (37). Hemodialysis and related complications are discussed in Chapter 63. Patients should be educated in basic hygienic techniques and the signs of access-site infection and sepsis.