Preventing transmission of bloodborne viruses from infected healthcare workers to patients: Summary of a new Canadian Guideline.

BACKGROUND: Although it is well documented that bloodborne viruses (BBVs), including human immunodeficiency virus (HIV), hepatitis C virus (HCV) and hepatitis B virus (HBV) have been transmitted from patients to healthcare workers (HCWs), there has also been reported transmission from HCWs to patients during the provision of health care. With remarkable progress in infection prevention, diagnosis tools, treatment regimens and major improvements in guideline development methodology, there was a need to develop an evidence-based guideline to replace the 1998 Canadian consensus document for managing HCWs infected with BBVs. PURPOSE: This article summarizes the Canadian Guideline on the Prevention of Transmission of Bloodborne Viruses from Infected Healthcare Workers in Healthcare Settings. METHODS: A Guideline Development Task Group was established and key questions developed to inform the guideline content. Systematic reviews were conducted to evaluate the risk of HCW-to-patient transmission of HIV, HCV and HBV. Environmental scans were used to provide information on Expert Review Panels, disclosure of a HCW's serologic status and lookback investigations. Federal, provincial and territorial partners and key stakeholder organizations were consulted on the Guideline. RESULTS: The risk of HCW-to-patient BBV transmission was found to be negligible, except during exposure-prone procedures, where there is a risk that injury to the HCW may result in exposure of a patient's open tissues to the HCW's blood. Risk of ensuing transmission and the rate of transmission varied by BBV, and were lowest with HIV and highest with HBV. The Guideline provides key content, including recommendations regarding criteria to determine if a procedure is an exposure-prone procedure, management of HCWs infected with a BBV, including considerations for the HCW's fitness for practice, Expert Review Panels, HCW disclosure obligations and right to privacy and lookback investigations. CONCLUSION: This new Guideline provides a pan-Canadian approach for managing HCWs infected with a BBV, with recommendations related to preventing HCW-to-patient transmission of BBVs during the provision of care.

Lyme disease: clinical diagnosis and treatment.

BACKGROUND: Lyme disease is an emerging zoonotic infection in Canada. As the Ixodes tick expands its range, more Canadians will be exposed to Borrelia burgdorferi, the bacterium that causes Lyme disease. OBJECTIVE: To review the clinical diagnosis and treatment of Lyme disease for front-line clinicians. METHODS: A literature search using PubMed and restricted to articles published in English between 1977 and 2014. RESULTS: Individuals in Lyme-endemic areas are at greatest risk, but not all tick bites transmit Lyme disease. The diagnosis is predominantly clinical. Patients with Lyme disease may present with early disease that is characterized by a "bull's eye rash", fever and myalgias or with early disseminated disease that can manifest with arthralgias, cardiac conduction abnormalities or neurologic symptoms. Late Lyme disease in North America typically manifests with oligoarticular arthritis but can present with a subacute encephalopathy. Antibiotic treatment is effective against Lyme disease and works best when given early in the infection. Prophylaxis with doxycyline may be indicated in certain circumstances. While a minority of patients may have persistent symptoms, evidence does not demonstrate that prolonged courses of antibiotics improve outcome. CONCLUSION: Clinicians need to be aware of the signs and symptoms of Lyme disease. Knowing the regions where Borrelia infection is endemic in North America is important for recognizing patients at risk and informing the need for treatment.

Oseltamivir pharmacokinetics in morbid obesity (OPTIMO trial).

BACKGROUND: Detailed pharmacokinetics to guide oseltamivir (Tamiflu®) dosing in morbidly obese patients is lacking. METHODS: The OPTIMO trial was a single-centre, non-randomized, open-label pharmacokinetic study of single-dose and steady-state oral oseltamivir phosphate and its carboxylate metabolite in healthy, morbidly obese [body mass index (BMI) >  40)] and healthy, non-obese (BMI  <  30) subjects. RESULTS: In the morbidly obese versus control subjects, respectively, the single-dose median oseltamivir oral clearance (CL/F) [840 (range 720-1640) L/h versus 580 (470-1800) L/h] was higher, the area under the curve from time zero to infinity (AUC(0-∞)) [89 (46-104) ng·h/mL versus 132 (42-160) ng·h/mL] was lower and the volume of distribution (V/F) [2320 (900-8210) L versus 1670 (700-7290) L] was unchanged. In the morbidly obese versus control subjects, respectively, the single-dose median oseltamivir carboxylate CL/F [22 (17-40) L/h versus 23 (12-33) L/h], AUC(0-∞) [3100 (1700-4100) ng·h/mL versus 3000 (2100-5900) ng·h/mL] and V/F [200 (130-370) L versus 260 (150-430) L] were similar. Similar results for oseltamivir and oseltamivir carboxylate CL/F, AUC0₋12 and V/F values were observed in the multiple-dose study. CONCLUSIONS: With single and multiple dosing, the systemic exposure to oseltamivir is decreased but that of oseltamivir carboxylate is largely unchanged. Based on these pharmacokinetic data, an oseltamivir dose adjustment for body weight would not be needed in morbidly obese individuals.

Seroprevalence of HIV infection in childbearing women in Nova Scotia.

OBJECTIVE: To determine the prevalence of HIV-1 infection in childbearing women in Nova Scotia. DESIGN: An anonymous, unlinked seroprevalence study using "leftover" cord bloods. The study was done in 2 stages: I-Halifax Co. women delivering between February 1, 1992 and December 31, 1993; II-non-Halifax Co. women delivering between November 15, 1993 and December 15, 1994. RESULTS: Of 9,115 deliveries during stage I and 5,515 during stage II, specimens were tested from 8,864 (97.2%) and 5,219 (95%) respectively. Halifax Co. women were older, more often married and more often reported a STD than the non-Halifax Co. participants with 20% under age 20 reporting a history of STD. There was one EIA and WB positive result among Halifax Co. women (seroprevalence 1/10,000; 95% CI 0.03-6.29) and one EIA positive, WB indeterminant result among non-Halifax Co. women (seroprevalence 0/10,000; 95% CI 0-5.7). CONCLUSION: There is a low prevalence of HIV infection among Nova Scotia childbearing women. However, a substantial number, especially those < age 20, reported a history of STD.

Subcutaneous dirofilariasis in Nova Scotia.

A case of dirofilariasis in a 78-year-old woman from Nova Scotia is described along with the histological findings and the basis of identification of the parasite. The patient developed a subcutaneous nodule, which was excised. Dirofilaria ursi and ursi-like nematodes are a rare cause of subcutaneous nodules. This is the first time dirofilariasis has been diagnosed in an adult in Atlantic Canada.

Preventing pneumococcal bacteremia in patients at risk. Results of a matched case-control study.

BACKGROUND: Three randomized controlled trials of the effectiveness of pneumococcal vaccine in elderly and chronically ill adults in the United States have failed to show significant protective efficacy during 44,213 person-years of follow-up. Case-control studies have greater statistical power to detect significant prevention of rare diseases such as pneumococcal bacteremia, but they also have a greater susceptibility to bias, necessitating consistent results from multiple studies. Three case-control studies at two different universities have shown prevention of systemic infection, but another study found no benefit. METHODS: Patients with pneumococcal bacteremia who were at least 2 years old and had chronic illness indicating the need for pneumococcal vaccine, or who were at least 65 years old were compared with matched control subjects for frequency of prior vaccination. Matching variables included date of admission, age, sex, race, type and duration of chronic illness serving as the major vaccine indication, number of vaccine indications and number of medical hospitalizations since licensure of the pneumococcal vaccine in 1978, and type of primary medical care. RESULTS: Pneumococcal vaccination was documented in the records of six (7%) of 85 cases and 26 (17%) of 152 control subjects, suggesting 81% efficacy in conditional logistical regression analysis (95% confidence interval, 34% to 94%, P = .008). CONCLUSIONS: Four case-control studies at three universities have now demonstrated significant protective efficacy of pneumococcal vaccine for preventing pneumococcal bacteremia. The development of antibiotic-resistant Streptococcus pneumoniae indicates an urgent need for an increased rate of vaccination among high-risk patients and for the development of more immunogenic conjugate vaccines that may enhance efficacy among elderly and immunocompromised patients as well as infants.

Encephalomyeloradiculopathy of infectious or parainfectious etiology--a new entity?

Between 19 March 1990 and 24 December 1992, six persons in Nova Scotia presented with a unique neurological illness. A prodrome of fever and headache was followed by neurogenic bladder, transverse myelitis, and encephalopathy in association with mononuclear pleocytosis of the CSF and nerve-conduction study findings consistent with polyradiculopathy. The spinal cords of three of the patients appeared abnormal on myelograms or magnetic resonance imaging studies. No microbial agent was isolated or demonstrated serologically. All of the patients were treated with antimicrobial agents and corticosteroids. Three recovered completely, but neurogenic bladder persisted in the remaining three. We suggest that this group of patients manifested an encephalomyeloradiculopathy that is likely a new clinical entity of infectious or parainfectious etiology.

Confidants' feedback and traumatic life events.

One hundred six undergraduate (83 women and 23 men) completed surveys concerning their most traumatic life event, the feedback they received following their disclosure of the event to others, and how they felt after the disclosure. Results indicated that the better they felt after disclosure, the less disturbed they were by thoughts of the event at the time of the study. In addition, the more personal the trauma was, the worse they felt after their disclosure, and the more disturbed they were about the trauma. However, no significant relation existed between the positivity (e.g., supportiveness) of their confidant's feedback and their present degree of disturbance. Implications for understanding the complex relation between confiding traumatic events and resolving feelings surrounding those events were discussed.

Postdischarge surgical site infection surveillance.

OBJECTIVE: To evaluate three methods for conducting post-discharge surgical site infection (SSI) surveillance. DESIGN: Patients undergoing in-patient and day-patient surgery were prospectively randomized to one of three surveillance methods: group 1, patient questionnaire (mailed back); group 2, surgeon follow-up card; or group 3, patient questionnaire (telephoned by an infection control practitioner [ICP]). There were 200 in-patients and 200 day-patients randomized to each group. Evaluation of SSI was conducted 30 days postoperatively. SETTING: A 760-bed tertiary care teaching hospital. RESULTS: Questionnaires were sent home with 350 patients. Fifteen in-patients and 35 day-patients were excluded; 15 in-patients and 17 day-patients returned questionnaires early (fewer than three weeks postoperation), leaving 54 of 185 in-patients (29.2%) and 25 of 165 day-patients (15.2%) with timely returns. Seven (three in-patients and four day-patients) reported symptoms of SSI. Surgeons received cards for 400 patients; cards were returned for 118 of 203 in-patients (58.1%) and 142 of 197 day-patients (72.1%). Twelve (seven in-patients and five day-patients) were reported to have developed SSI. ICPS telephoned 332 patients; 187 of 196 in-patients (95.4%) and 107 of 126 day-patients (84.9%) were reached in six or fewer attempts. Four in-patients and 74 day-patients were lost due to cancellation of surgery or no surgical incision. Fourteen (10 in-patients and four day-patients) reported symptoms of SSI. For group 1 patients, ICPS spent 17 h distributing questionnaires and instructing staff; for group 2, ICPs spent no time distributing material; and for group 3, ICPS spent at least 8 h completing data forms, 16.5 h on the telephone and 33 h conducting demographic data retrieval from the hospital computer. CONCLUSIONS: In this setting, surgeon follow-up cards were the most efficient and reliable method for conducting postdischarge SSI surveillance. They provided a good rate of return and were time efficient, and wound evaluation was done by trained professionals using standard criteria for diagnosis of postoperative SSI.

An outbreak of Candida parapsilosis prosthetic valve endocarditis following cardiac surgery.

Five of 34 (15%) patients who received prosthetic cardiac valves between May and August 1982 at the Victoria General Hospital in Halifax, Nova Scotia, developed Candida parapsilosis prosthetic valve endocarditis. The clustering of these cases pointed to a common source outbreak. In a retrospective cohort study, no significant differences were found between infected and uninfected patients in terms of pre-, intra-, and postoperative risk factors. Environmental investigations suggested intraoperative contamination through the cardiac bypass equipment as the source of infection but a causal relationship could not be established. The outcome for the cases was uniformly fatal, emphasizing the need for prevention of such serious nosocomial infections.

Methicillin-resistant Staphylococcus aureus as a cause of community-acquired pneumonia--a critical review.

Methicillin-resistant Staphylococcus aureus (MRSA) has been recognized as a nosocomial pathogen in Europe and North America for 3 decades. More recently it has emerged as a problem in long-term care facilities. It is less frequently considered a pathogen in nonfacility, community-acquired infections, where it is most often seen in intravenous drug users. There are no studies in the literature specifically describing the clinical features of MRSA pneumonia. Presumably its presentation and outcome are similar to that of pneumonia caused by susceptible strains. Staphylococcus aureus pneumonia is more often nosocomial- or nursing home-acquired, has a variable association with influenza, has clinical and laboratory features similar to other types of community-acquired pneumonia and carries a relatively high mortality of 20% to 84%. MRSA should be considered resistant to all classes of beta-lactam (beta) antibiotics. In addition, these isolates are frequently resistant to a number of other antibiotics, with vancomycin and only antibiotic to have consistently shown activity against MRSA. Therefore, vancomycin remains the treatment of choice for infections caused by MRSA, although treatment failures have been reported. The use of alternative antibiotics should be based on results of susceptibility testing of the strain isolated from the patient.

Mycobacterium avium-intracellulare endocarditis causing rupture: replacement and repair with aortic homograft.

Aortic valve endocarditis with extension to the tricuspid annulus and ventricular septum in an intravenous drug abuser - with Mycobacterium avium-intracellulare identified as the offending organism - forms the basis of this report. The aortic root and ventricular septal defect were successfully repaired using an aortic cryopreserved homograft. This case is of particular interest because M avium-intracellulare has not been recognized as a cause of endocarditis. The incidence of atypical organisms as a cause of endocarditis may increase in the future because of the rise of drug abuse and the acquired immune deficiency syndrome in North America.