Mario C. Raviglione

Infections associated with hickman catheters in patients with acquired immunodeficiency syndrome

PURPOSEnHickman catheters are frequently used as convenient long-term venous access in patients with acquired immunodeficiency syndrome (AIDS). These patients seem to be at increased risk for bacterial infections of intravenous devices. The aim of our study was to determine the frequency of Hickman catheter infection in patients with AIDS as compared with that in other patients.nnnPATIENTS AND METHODSnWe analyzed the records of 69 patients who underwent 71 consecutive Hickman catheter placements during a one-year study period.nnnRESULTSnForty-six Hickman catheters were inserted in 44 patients with AIDS, and 25 Hickman catheters were placed in 25 other patients. There were 18 infections: 16 occurred in patients with AIDS, and two developed in the control group (p less than 0.05). The 16 infections in AIDS were as follows: five exit site, five septicemias, two tunnel, one septic phlebitis, and three probable Hickman catheter-related. Staphylococcus aureus was responsible for 14 cases (87%); Staphylococcus epidermidis was responsible for four cases (25%). Mean onset of infection was 32 days, but seven patients were diagnosed in the first eight days after Hickman catheter insertion. Fever occurred in all patients with early infection, leukopenia was present only in three; infusion of parenteral nutrition did not increase the risk. Two early infections were fatal. The rate of Hickman catheter infection in patients with AIDS was 0.47 per 100 catheter days, as compared with 0.09 in the control group.nnnCONCLUSIONnOur findings underscore the need for using Hickman catheters only when absolutely indicated in patients with AIDS, since the risk of serious infectious complications appears to be high.

Ciprofloxacin-resistant methicillin-resistant Staphylococcus aureus in an acute-care hospital.

Use of ciprofloxacin as an alternative to vancomycin for treatment of methicillin-resistant Staphylococcus aureus infection has been paralleled by the emergence of resistant strains. This phenomenon has also been noticed in our hospital. To confirm our observation, methicillin and ciprofloxacin susceptibilities were tested by disk diffusion and broth microdilution techniques. We studied 83 methicillin-resistant Staphylococcus aureus isolates obtained from various sources over a 4-month period. Ciprofloxacin resistance (MIC, greater than 2 micrograms/ml) was detected in 69 isolates (83%). Prior use of ciprofloxacin was reported for 24 of 69 patients with ciprofloxacin-resistant strains and 0 of 14 patients with ciprofloxacin-susceptible strains. The day of detection during the hospital stay and the location of the source patient were not significantly different between resistant and susceptible strains. Bacteriophage typing showed a higher occurrence of nontypeable strains among ciprofloxacin-resistant strains (54%). Review of our microbiology register showed a progressive increase in the rate of resistance to ciprofloxacin during the first year of use, with initial rates being about 10% and recent rates being higher than 80%. On the other hand, methicillin-susceptible S. aureus remained uniformly susceptible to ciprofloxacin (98.4%). We conclude that prior use of ciprofloxacin is an important factor for the selection of ciprofloxacin-resistant strains and that ciprofloxacin has limited usefulness against methicillin-resistant S. aureus.

HighStaphylococcus aureus nasal carriage rate in patients with acquired immunodeficiency syndrome or AIDS-related complex

Staphylococcus aureus has been reported to cause a high number of infections and septicemias, often related to intravenous catheters, in patients with acquired immunodeficiency syndrome (AIDS). Our objective was to assess the frequency of S. aureus nasal carriage among patients with AIDS or AIDS-related complex (ARC). The nasal carriage rate of S. aureus was determined within 24 hours of admission in 64 consecutively hospitalized patients with AIDS or ARC. Intravenous drug abusers were excluded. A control group of 64 patients with other diseases was also tested. Of 64 patients with AIDS or ARC, 35 (55%) were nasal carriers of S. aureus, compared with 18 (28%) of 64 control patients. Recent hospitalization did not influence carriage rate, nor did the recent use of antibiotics or zidovudine. The significant S. aureus carriage rate in patients with AIDS or ARC may contribute to the high incidence of intravenous catheter-related S. aureus infections in this population.

Clinical Features and Management of Severe Dermatological Reactions to Drugs

SummaryCutaneous adverse drug reactions are a frequent occurrence and have been reported in more than 2% of hospitalised patients. Among the most commonly involved drugs are sulphonamides, penicillins, anticonvulsants and non-steroidal anti-inflammatory drugs.Two groups of mechanisms are involved in the pathogenesis of drug reactions: immunological, with all 4 types of hypersensitivity reactions described; and non-immunological, accounting for at least 75% of all drug reactions.Besides minor skin reactions like urticaria, maculopapular rash, fixed eruptions or erythema nodosum, which are generally self-limited, severe life-threatening manifestations also occur. Erythema multiforme is secondary to drugs in half the cases; the minor form is characterised by typical target and iris lesions and is usually benign. However, a much more severe condition, erythema multiforme major or Stevens-Johnson syndrome, is associated with mucosal, ocular and visceral involvement, and carries a mortality of 5 to 15% if untreated. Toxic epidermal necrolysis, which could represent an even more dramatic form of the same disease, is characterised by severe widespread erythema, blisters and loss of skin in sheets, with denudation of more than 10% of the body surface area. This entity is frequently due to drugs. Mortality is 25 to 70%, and 90% of the survivors will have sequelae.Exfoliative dermatitis is an erythematous scaling disease often produced by drugs and carrying significant mortality. Photodermatitis may at times present with severe eczematous features.For clinical and epidemiological reasons it is important to try to identify the culprit drug following an approach based on previous experience with the drug, timing of events, patient reaction to dechallenge, patient reaction to rechallenge (if feasible), alternative aetiological candidates, and drug concentration or evidence of overdose.Management of severe skin reactions to drugs should require admission to a burn unit, where patients should be placed in warmed air-fluidised beds, receive excellent nursing care, analgesics and tranquillisers. Peeling necrotic epidermis should be removed and denuded dermis covered with biological grafts or synthetic dressings. Fluid balance must be adequately maintained; nutritional support and careful monitoring of early signs of skin infections is mandatory to ensure immediate antimicrobial treatment. Ocular care must be excellent to avoid serious sight-threatening sequelae. Steroids are presently not recommended. With these therapeutic modalities, morbidity and mortality can be markedly decreased.

Group G streptococcal meningitis and sepsis in a patient with AIDS a method to biotype group G streptococcus

Lancefield group G streptococcus is now recognized as a pathogen and has been reported to cause severe infections, including meningitis. We describe the first case of meningitis caused by this organism in a patient with acquired immunodeficiency syndrome (AIDS) and the direct transmission of the pathogen to a technologist accidentally exposed to the cerebrospinal fluid. To prove the identity of the two strains, we have tested them employing the Vitek system. We have also tested 13 other strains of group G streptococci obtained from different sources. Our results yielded 14 different biotypes with the 15 strains tested. The only identical ones were the two suspect strains from the index case and the technologist. We conclude that the biotyping system employed in our study appears to be a useful epidemiological tool for marking group G streptococci.