Alter MJ, Gallager M, Morris TT, et al. Acute non-A-E hepatitis in the United States and the role of hepatitis G virus infection. N Engl J Med 1997; 336:741-6.
Although the association of hepatitis G virus (HGV) with disease remains unclear, there is no question that HGV is a unique virus that can be transmitted by blood, the authors report.
In addition to transmission by transfusion or experimental inoculation, there have been reports of presumed bloodborne transmission of HGV from infected women to their newborns and possibly among patients on hemodialysis. The authors could not draw conclusions about risk factors for acquiring HGV infection. However, HGV infection appeared to be acquired at younger ages than other known types of viral hepatitis. Of the patients with HGV infection alone, only one reported injection-drug use and none had evidence of prior exposure to HBV. In addition, the high prevalence of HGV infection among patients with hepatitis A or B who had no history of drug use raises the possibility that other routes of transmission for HGV may be important, they report.
Persistent infection with HGV appears to be quite prevalent in the general population, with almost 2% of blood donors and 14% to 52% of patients with other types of viral hepatitis being positive for HGV RNA.
The authors selected patients from a surveillance study of acute viral hepatitis in four U.S. counties who had acute disease during 1985 to 1986 or 1991 to 1995. Serum samples were tested for HGV RNA by polymerase chain reaction. The results indicated HGV RNA was detected in four of 45 patients with a diagnosis of non-a-E hepatitis (9%); 23 of 116 patients with hepatitis C (20%); 25 of 100 patients with hepatitis A (25%); and 32 of 100 patients with hepatitis B (32%).
The clinical characteristics of the acute illness were similar for patients with HGV alone and those with hepatitis A, B, or C with or without HGV infection. During a follow-up period of one to nine years, chronic hepatitis did not develop in any of the patients with HGV alone, but 75% were persistently positive for HGV RNA, as were 87% of those with both hepatitis C and HGV infection. The rates of chronic hepatitis were similar in patients with hepatitis C alone (60%) and those with both hepatitis C and HGV infection (61%).
Hadley S. Fungal infections in liver transplant recipients. Infect Med 1997; 14:311-318.
Despite advances in surgical techniques and immunosuppressive regimens, invasive fungal infections remain an important infectious complication after liver transplant, the author reports. Patients who are more ill at the time of the transplant procedure or who have a more complicated operation are more likely to develop an invasive fungal infection. Efforts to reduce infection through antifungal prophylaxis are being investigated, but no single strategy has emerged as superior. Diagnosis is based primarily on clinical signs and a high index of suspicion, because blood cultures are often negative.
Once established, fungal infections require aggressive treatment with removal of intravascular devices, surgical debridement or drainage, and institution of antifungal therapy. Nephrotoxicity is the major complication of antifungal therapy and will predictably occur if renal function and immunosuppressive drug levels are not carefully monitored. A thoughtful, multidisciplinary approach is often necessary for the successful prevention and treatment of invasive fungal infections in the liver transplant recipient.
Invasive fungal infections occur in approximately 15% of patients who undergo orthotopic liver transplantation. Methods to detect early signs of infection include routine fungal surveillance cultures of oral cavity, stool or rectum, skin, urine, and wound. The merits of microbiologic surveillance are disputed, but the author noted that retrospective studies showed clinical colonization to be an independent predictor of invasive fungal infection in liver transplant recipients. Colonization at baseline (within three days of transplantation) correlated with early invasive infection.
Beezhold DW, Slaughter S, Hayden MK, et al. Skin colonization with vancomycin-resistant enterococci among hospitalized patients with bacteremia. Clin Infect Dis 1997; 24:704-706.
The authors detected a surprising level of skin colonization with VRE on hospitalized patients, which suggests both increased risk of cross-transmission and catheter-related sepsis.
The study involved 14 case patients with VRE bacteremia and 30 controls who had bacteremia due to other pathogens. The authors detected rectal colonization with VRE in all patients who had bacteremia due to VRE and in 37% of patients with bacteremia due to other microorganisms.
"This finding supports the widely held notion that the gastrointestinal tract is the most common site of colonization with VRE," they state. "It was more surprising that we detected skin colonization by VRE in 12 (86%) of 14 patients with vancomycin-resistant enterococcal bacteremia and in 23% of patients with bacteremia due to other microorganisms."
Skin colonization by VRE was associated with prior diarrhea or fecal incontinence, suggesting that skin colonization results from self-soiling by patients. An additional risk factor for skin colonization in the study was prior therapy with vancomycin, underscoring the need for prudent use of antibiotics as part of VRE control measures.
"Skin colonization with VRE has several important epidemiological and clinical implications," the authors conclude. "First, the high prevalence of this condition may facilitate transmission of VRE from patient to patient and may help to explain the rapid dissemination of VRE in hospitals over the past several years. Second, the frequent spontaneous resolution of VRE bacteremia (nine [64%] of 14 cases in our study) suggests that some of the positive blood cultures may result from contamination of specimens via colonized skin."
Kotilainen HR, Keroack MA. Cost analysis and clinical impact of weekly ventilator circuit changes in patients in intensive care unit. Am J Infect Control 1997; 25:117-120.
Weekly circuit changes in patients undergoing ventilation therapy in the intensive care unit are cost-effective and do not contribute to increased rates of nosocomial pneumonia, the authors report.
"Switching to weekly ventilator tubing changes is accompanied by considerable cost savings," they conclude. "At our institution, the practice now has been extended to our neonatal ICU, with an anticipated doubling in annual cost savings. Whether a time limit to the safe usage of respiratory circuits exists remains to be defined by future studies."
The introduction of heated circuits and sealed, single-use humidifiers has prompted investigators to question the traditional recommendations for frequently changing ventilator circuits. Thus, the authors studied the clinical and cost impact of extending the circuit-change interval from 72 hours to seven days in two intensive care units.
After the institution of weekly circuit changes, daily surveillance of intubated patients was performed. The rate of ventilator-associated pneumonia for the 72-hour circuit change group was 9.1%, or 1.29 per 100 ventilator days. After the institution of weekly changes, pneumonia occurred in 9 of 146 patients 6.2%, or 0.74 per 100 ventilator days. Weekly changes reduced the number of circuits used from a predicted 469 to 214. Estimating $26.46 per circuit change, annualized cost savings were $20,246.
"Our data support the finding that ventilatory tubing changes may be extended beyond 72 hours without increasing the risk of nosocomial pneumonia," they note. "Indeed, the data suggest that change intervals beyond one week merit study. Sampling of the tubing revealed no colonization with documented or potential respiratory pathogens, demonstrating the effectiveness of the heated wire system."