Rebecca Wurtz

Antimicrobial Dosing in Obese Patients

Although the dose of some drugs is commonly adjusted for weight, weight-related dosage adjustments are rarely made for most antimicrobials. We reviewed the English-language literature on antimicrobial pharmacokinetics and dosing in obesity. Although there are many potential pharmacokinetic consequences of obesity, the actual effect on the pharmacokinetics and clinical efficacy of most antimicrobials is unknown. Since approximately 30% of adipose is water, an empirical approach is use of the Devine formula to calculate ideal body weight (IBW), to which is added a dosing weight correction factor (DWCF) of 0.3 times the difference between actual body weight (ABW) and IBW (IBW + 0.3 x [ABW-IBW]) to arrive at a weight on which to base dosage of hydrophilic antibiotics. No studies confirm this approach for beta-lactam drugs. Clinical studies suggest a DWCF of approximately 0.40 for aminoglycosides and 0.45 for quinolones. Final dosage adjustments for antimicrobials with a narrow toxic-therapeutic window should be based on serum concentrations.

Nosocomial infections in a burn intensive care unit

Although many studies have reviewed burn wound infections (BWIs) in burn patients, few have prospectively surveyed other nosocomial infections. Seriously burned patients are clearly at increased risk for infection due to the nature of the burn injury itself, immunocompromising effects of burn injury, prolonged hospital stays, and invasive diagnostic and therapeutic procedures. Over 6 months, we prospectively reviewed all patients admitted to our burn intensive care unit (BICU) for nosocomial infections. We used standard CDC definitions of nosocomial infections (NIs). Because we had previously documented a high incidence of nosocomial pneumonias in these patients, we were particularly interested in determining risk factors for nosocomial pneumonia. The total census during the study period was 57. There were 40 discharges and deaths. Surveillance demonstrated 36 nosocomial infections in 26 patients, for a total of 90 nosocomial infections per 100 discharges and deaths, or 32.3 NIs/1000 patient days. Infections included 22 pneumonias, 10 urinary tract infections, two bacteraemias, one BWI and one episode of cellulitis. Intubation was strongly associated with nosocomial infection, particularly with pneumonia, BWI and bacteraemia. Sixty per cent of all patients were intubated at some time during their BICU stay, but 88 per cent of those who developed a nosocomial infection were intubated (P < 0.001). Inhalation injury was less significant than intubation in the development of nosocomial infection. All patients who developed pneumonia or a BWI were intubated.(ABSTRACT TRUNCATED AT 250 WORDS)

Handwashing machines, handwashing compliance, and potential for cross-contamination

Although handwashing is considered an important factor in the prevention of nosocomial infections, the optimal technique has not been determined and compliance is often difficult to obtain. Handwashing compliance is particularly important in intensive care areas of the hospital. In an effort to improve HW compliance, the surgical intensive care unit in our hospital purchased three handwashing machines. Four months after installation of the handwashing machines, an outbreak of methicillin-resistant Staphylococcus aureus occurred in the intensive care unit. As part of evaluating the outbreak, we cultured the handwashing machines, including the portholes and the paper towel dispenser. Cultures were positive for methicillin-resistant Staphylococcus epidermidis, Achromobacter species, and Streptococcus viridans. The design of the handwashing machines made contamination of sleeves and already-washed hands possible. An observational study revealed that handwashing compliance was poor but improved from 22% to 38% when the handwashing machines were in use. Nurses preferred handwashing at the sink and physicians preferred the handwashing machine. Handwashing machines may increase handwashing compliance because of their novelty, but they may also result in novel problems.

Osteomyelitis of the Pubis Following Suspension of the Neck of the Bladder with Use of Bone Anchors. A Report of Four Cases

We report on four patients who had a retropubic abscess (three with osteomyelitis) with involvement of the adjacent soft tissues following a procedure to correct stress urinary incontinence with use of pelvic bone screws to serve as anchors for sutures that were placed to support the bladder neck. The ages of the patients ranged from seventy-one to eighty years old. None of the patients had a known previous urinary tract infection. Two of the procedures were performed at our institution, and two were performed at different outside institutions. The patients were seen because of suprapubic pain, swelling, and erythema between four and twenty-four weeks after the procedure. Two had received courses of orally administered antibiotics because of wound drainage within a week to ten days after the original procedure. Computerized tomography scans of the pelvis showed soft-tissue swelling behind the symphysis pubis and erosion of the adjacent bone. The abscess was drained in all patients, and infected bone was excised, with removal of a total of two to three centimeters of bone, in three patients. In all patients, the sinus tract was excised, extensive soft-tissue debridement was performed, and the suspension sutures and bone anchors were removed. In one patient, debridement was necessary on two occasions. Cultures were positive for Pseudomonas aeruginosa and Staphylococcus aureus in one patient, Pseudomonas aeruginosa and coagulase-negative Staphylococcus in one patient, Staphylococcus aureus in one patient, and Citrobacter species and a gram-positive coccus in one patient. Each of the four patients was managed intravenously with antibiotics, with the dosage determined according to her age and renal function, for six weeks. Suspension of the bladder with use of pelvic screws as suture anchors may increase the risk of osteomyelitis because the screw-suture combination passes through the vaginal lumen before it is anchored into bone. CASE 1. …

Malassezia furfur Fungemia in a Patient without the Usual Risk Factors

Excerpt Malassezia furfuris a lipophilic yeast that causes the superficial skin mycosis, tinea versicolor. Only recently hasM. furfurbeen recognized as a cause of deep-tissue infections. Twenty-fiv...

Positive tuberculin skin test reactions among house staff at a public hospital in the era of resurgent tuberculosis

BACKGROUND The number and significance of tuberculin skin test reactions were compared with self-reported baseline values among house staff working in a public hospital. High-risk medical specialties, locations, and infection control practices were examined. METHODS House staff interviews, tuberculin skin test applications, review of employee health service records, and environmental monitoring of high-risk areas were performed. RESULTS Among house staff self-reported as having negative tuberculin skin test status, 46.2% (95% CI 27.0% to 65.4%) of internal medicine house staff, compared with 4.8% (95% CI 4.3% to 13.9%) of house staff from other areas (p < 0.005), had positive results on a repeat tuberculin skin testing before graduation. These differences were not entirely explained by the use of surgical masks, year of training, or previous vaccination with bacille Calmette-Guérin. Most skin test reactions (69%) occurred among house staff who had not been vaccinated with bacille Calmette-Guérin. Increased skin reactivity probably represented excess conversions from unprotected exposure. Tuberculosis transmission was facilitated by delays in diagnosis, inadequate isolation facilities, and suboptimal ventilation. House staff did not comply with recommended tuberculosis surveillance because of time constraints, fear, and misunderstandings about tuberculin skin test interpretations in light of previous bacille Calmette-Guérin vaccination. CONCLUSIONS House staff in high-exposure settings with suboptimal environmental controls are at increased risk for tuberculosis infection. Participation in surveillance programs can be increased by enlisting the participation and advocacy of respected medical colleagues, screening house staff differentially according to exposure and job classifications, and more accurately interpreting subsequent test results from baseline two-step testing.

La Crosse Encephalitis Presenting Like Herpes Simplex Encephalitis in an Immunocompromised Adult

The diagnosis of the precise cause of viral encephalitis can be difficult, hampered by the nonspecific presentation, the number of etiologic viruses, and limited culture and serologic diagnostic methods. Because herpes simplex encephalitis (HSE) can be neurologically devastating and is treatable, timely diagnosis is important. We report an immunocompromised adult with encephalitis clinically consistent with HSE who had serology consistent with recent La Crosse encephalitis (LAC).

Psychiatric diseases presenting as infectious diseases

Although many psychiatric diseases have somatic manifestations, some focus on fears or delusions of infection. When a patient with a psychiatric basis for an apparent infection presents to an infectious disease physician, the physician may find the problem confusing, amusing, and ultimately frustrating until the psychiatric basis for disease is recognized. Some of these psychiatric disorders can be treated and controlled with medication and psychotherapy, although patients may resist psychiatric referral. This article reviews examples of psychiatric disorders in patients who present to the infectious disease physician, including factitious infection, malingering, obsessive compulsive disorder, phobias, veneroneuroses, somatization disorders, and delusional infection. The role that physicians play in amplifying these disorders is reviewed. Strategies for referral to psychiatric services are also discussed. Patients with a psychiatric disease are seen in infectious disease practices more commonly than physicians realize.

Perceptions of Options Available for Victims of Physical Intimate Partner Violence in Northern India

We used qualitative methodologies to understand perceptions regarding options available for victims of physical intimate partner violence (IPV) in northern India. We interviewed male and female community members along with IPV experts. Interviews were transcribed, coded, and analyzed using grounded theory. Participants emphasized that a victim of physical IPV should bear the violence, modify her husbands’ behaviors, or seek help from her natal family. Accessing external resources such as the police or nongovernmental organizations was viewed as both socially inappropriate and infeasible. These results have widespread implications and lay the foundation for the development of IPV prevention initiatives in India.

Parents as a vector for nosocomial infection in the neonatal intensive care unit.

To the Editor: The frequency of multiple births is increasing. Multiple gestations are more likely to result in premature birth and problems associated with prematurity. This may result in newborn siblings being admitted to the neonatal intensive care unit (NICU) simultaneously. We report two situations where the parent appeared to transfer or be the source of an organism that infected multiple siblings. Case 1. Siblings Al, A2, and A3 were born by cesarean section at 25 weeks gestation, after the mother developed premature rupture of members for baby Al. Placenta Al showed evidence of chorioamnionitis, but cultures were negative. Each infant weighed less than 1,000 g. Different nurses cared for each infant in three different rooms of our five-room NICU. Resident and attending physicians were the same for all three infants; however, the physicians could not recall moving directly from one sibling to another. Baby A2 developed sepsis and died on day 14 of life. Pseudomonas aeruginosa, an unusual isolate in our NICU, was grown from premortem blood, postmortem blood, and sputum specimens. The mother held the infant after its death. Infant Al developed necrotizing enterocolitis on day 19 of life and had positive endotracheal cultures for P aeruginosa on the same day. Subsequently, stool cultures were intermittently positive for P aeruginosa. In association with necrotizing enterocolitis, the infant developed enterocutaneous fistulae that intermittently drained stool. Infant A3 had multiple problems due to prematurity but had stabilized before suddenly deteriorating on day 46. This infant died 24 hours later and had postmortem cultures of lung, liver, and spleen positive for P aeruginosa. Genomic DNA was analyzed per protocol on a GenePath contourclamped homogeneous-field apparatus (Bio-Rad, Hercules, CA). Fingerprinting analysis was performed using the GelDoclOOO and Molecular Analyst restriction fragment-length polymorphism software (BioRad, Hercules, CA). The pulsed-field gel electrophoresis fingerprint for all three Pseudomonas isolates was identical. Case 2. Siblings Bl, B2, and B3 were born by cesarean section at 29 weeks. On day 29 of life, baby Bl developed Staphylococcus aureus bacteremia and expired. On day 52 of life, baby B2 developed S aureus conjunctivitis that was treated topically. S aureus is an uncommon isolate in our NICU. The father of these infants had a chronic open wound with prior cultures positive for S aureus. He visited the children several times a week. Pulsed-field gel electrophoresis typing of the isolates from babies Bl and B2 and the fathers wound were identical.