Morton N. Swartz

Acute bacterial meningitis in adults. A review of 493 episodes.

BACKGROUND AND METHODS To characterize acute bacterial meningitis in adults, we reviewed the charts of all persons 16 years of age or older in whom acute bacterial meningitis was diagnosed at Massachusetts General Hospital from 1962 through 1988. We included patients who were admitted after initial treatment at other hospitals. RESULTS During the 27-year period, 445 adults were treated for 493 episodes of acute bacterial meningitis, of which 197 (40 percent) were nosocomial. Gram-negative bacilli (other than Haemophilus influenzae) caused 33 percent of the nosocomial episodes but only 3 percent of the community-acquired episodes. In the 296 episodes of community-acquired meningitis, the most common pathogens were Streptococcus pneumoniae (37 percent), Neisseria meningitidis (13 percent), and Listeria monocytogenes (10 percent); these organisms accounted for only 8 percent of the nosocomial episodes. Only 19 of the 493 episodes of meningitis (4 percent) were due to H. influenzae. Nine percent of all patients had recurrent meningitis; many had a cerebrospinal fluid leak. Seizures occurred in 23 percent of patients with community-acquired meningitis, and 28 percent had focal central nervous system findings. Risk factors for death among those with single episodes of community-acquired meningitis included older age (> or = 60 years), obtunded mental state on admission, and seizures within the first 24 hours. Among those with single episodes, the in-hospital mortality rate was 25 percent for community-acquired and 35 percent for nosocomial meningitis. The overall case fatality rate was 25 percent and did not vary significantly over the 27 years. CONCLUSIONS In our large urban hospital, a major proportion of cases of acute bacterial meningitis in adults were nosocomial. Recurrent episodes of meningitis were frequent. The overall mortality rate remained high.

Osteomyelitis: A Review of Clinical Features, Therapeutic Considerations and Unusual Aspects

Osteomyelitis Associated with Vascular Insufficiency The special problems connected with the presentation, clinical course, prognosis and treatment of osteomyelitis associated with vascular insuffi...

Spinal epidural abscess.

In an editorial describing his clinical experience of spinal epidural abscess, Heusner (1948) reminds us that “… the decisive factor in the outcome of most cases is the celerity with which the first physician suspects the probable nature of the ailment and summons expert aid”. On pathological grounds he recognized three presentations: (1) an acute metastatic presentation which evolves over hours to days and where the epidural abscess cavity contains frankly purulent material; (2) a subacute presentation evolving over days to weeks where the epidural abscess cavity comprises granulation tissue without significant quantities of necrotic material; (3) a chronic presentation, most often associated with osteomyelitis. The last accounted for only 10% of his series and involved a broader differential diagnosis. In more recent series (Hlavin et al. 1990; Nussbaum et al. 1992; Darouiche et al. 1992; Corboy and Price 1993) this classification has been less distinct with the acute variety predominating.Thirty-nine patients with spinal epidural abscess were evaluated at the Massachusetts General Hospital between 1947 and 1974. Twenty had acute symptoms, and purulent epidural collections were present; 19 had prolonged courses, and epidural granulation tissue was observed at operation. Staphylococcus aureus was the most common etiologic agent (57 per cent), followed by streptococci (18 per cent) and gram-negative bacilli (13 per cent). The source of infection was osteomyelitis in 38 per cent of cases and bacteremia in 26 per cent. In 16 per cent epidural abscess was due to postoperative infection. The progression from spinal ache to root pain to weakness followed by paralysis continues to be characteristic of spinal epidural abscess. Although the disease is uncommon, the complications are so serious that prompt diagnosis and treatment are of paramount importance. The combination of back pain with fewer and local tenderness is an indication for cerebrospinal-fluid examination and, depending on the results, immediate performance of myelography.

Pasteurella multocida infections. Report of 34 cases and review of the literature.

Pasteurella multocida, a small, gram-negative coccobacillus , is part of the normal oral flora of many animals, including the dog and cat. P. multocida is the etiologic agent in a variety of infectious disease syndromes. We have reported 34 cases of infection caused by P. multocida and have reviewed the English literature. P. multocida infections may be divided into three broad groups: 1. Infections resulting from animal bites and scratches : The most common infections caused by P. multocida are local wound infections following animal bites or scratches . Cats are the source of infection in 60 to 80% of cases and dogs in the great majority of the remainder. Local infections are characterized by the rapid appearance of erythema, warmth, tenderness, and frequently purulent drainage. The most common local complications are abscess formation and tenosynovitis. Serious local complications include septic arthritis proximal to bites or scratches , osteomyelitis resulting from direct inoculation or extension of cellulitis, and the combination of septic arthritis and osteomyelitis, most commonly involving a finger or hand after a cat bite. 2. Isolation of P. multocida from the respiratory tract: The isolation of P. multocida from the respiratory tract must be interpreted differently than its isolation from other systemic sites. Most commonly P. multocida found in the respiratory tract is a commensal organism in patients with underlying pulmonary disease, but serious respiratory tract infections including pneumonia, empyema, and lung abscesses may develop. Most patients with respiratory tract colonization or infection have a history of animal exposure. 3. Other systemic infections: P. multocida is recognized as a pathogen in a variety of systemic infections including bacteremia, meningitis, brain abscess, spontaneous bacterial peritonitis, and intra-abdominal abscess. P. multocida often acts as an opportunistic pathogen with a predilection for causing bacteremia in patients with liver dysfunction, septic arthritis in damaged joints, meningitis in the very young or elderly, and pulmonary colonization or invasion in patients with underlying respiratory tract abnormalities.(ABSTRACT TRUNCATED AT 400 WORDS)

Septic thrombosis of the dural venous sinuses.

From 1940 to 1984, 19 cases of septic dural-sinus thrombosis have been diagnosed at the Massachusetts General Hospital, and some 136 cases have been reported from other institutions. Septic thrombosis most frequently involves the cavernous sinuses (96 cases). Facial or sphenoid air sinus infection often precede cavernous-sinus disease. In addition to the classical signs of proptosis, chemosis, and oculomotor paralysis, isolated sixth-nerve palsy and hypo- or hyperesthesia of the fifth nerve may be found. The major pathogens associated with cavernous-sinus infection include Staphylococcus aureus, other gram-positive organisms, and anaerobes. Septic lateral-sinus thrombosis (64 cases) is almost exclusively a complication of otitis media and/or mastoid infection. Organisms causing this infection include Proteus species, Escherichia coli, S. aureus, and anaerobes. Septic thrombosis of the superior sagittal sinus (23 cases) most frequently accompanies bacterial meningitis or air sinus infection. Causative organisms include Streptococcus pneumoniae, S. aureus, other streptococci, and Klebsiella species. Because septic dural-sinus thrombosis is rare, this disease is frequently misdiagnosed. Evaluation should include lumbar puncture, air sinus films, and computed tomographic scan with contrast. Other helpful diagnostic tests may include carotid angiography, and dynamic brain scan. Orbital venography is the most definitive study in cases of chronic cavernous-sinus thrombosis. Therapy should include intravenous antibiotics and early surgical drainage of purulent exudate in the air sinuses or mastoid regions. Retrospective analysis suggests that treatment with heparin may reduce mortality in carefully selected cases of septic cavernous-sinus thrombosis. Anticoagulation is not recommended in other forms of septic dural-sinus thrombosis. Mortality in the antibiotic-era remains high, particularly in patients with septic thrombosis of the cavernous (30%) and superior sagittal (78%) sinuses.

Prosthetic Valve Endocarditis Analysis of 38 Cases

In 38 cases of prosthetic valve endocarditis, 19 were early cases (onset ≦ 60 days after insertion of prosthesis) and 19, late cases (onset ≧ 60 days). Nine late cases had onsets 12 to 53 months after surgery. The sources or predisposing factors in late cases included dental disease or manipulation; genitourinary tract procedures; and skin, urinary, or wound infections. In contrast, most early cases were secondary to complications of operation. Streptococci were the most common organisms causing late endocarditis, whereas staphylococci were most common among early cases. Four of the six patients who survived early onset were treated with antibiotics alone; the others, with antibiotics plus reoperation. In contrast, seven of the 11 late cases that survived were treated with antibiotics alone; the other four, with antibiotics plus reoperation. The lower mortality (42% vs 68%) in the late group probably reflects the less virulent infecting organisms and the better clinical condition of the hosts. Regardless of whether prosthetic valve endocarditis occurs early or late, intensive and prolonged administration of appropriate antibiotics together with aggressive surgical reintervention in selected situations appears necessary for cure. Any patient who has a prosthetic valve and undergoes any procedure likely to produce bacteremia should receive antibiotic prophylaxis in an attempt to prevent late endocarditis.

Genitourinary tuberculosis: Clinical features in a general hospital population

Abstract Seventy-eight patients with genitourinary tuberculosis were evaluated during a 12 year period. Active tuberculosis was confined to the genitourinary tract in all but 10 patients. Aside from five cases of miliary tuberculosis, most genitourinary infections developed from the breakdown of granulomes acquired earlier during transient dissemination from a primary pulmonary infection. Patients with genitourinary tuberculosis exhibited features of local organ dysfunction rather than systemic symptoms of infection; fever, weight loss and anorexia were uncommon. Seventy-one per cent of the patients with active tuberculosis of kidneys, ureters and bladder presented because of urinary tract symptoms. Twenty per cent were asymptomatic and were detected because of abnormal urinary sediments. The diagnosis of genitourinary tuberculosis should be suspected on the basis of an abnormal urinalysis (hematuria and/or pyuria) with negative routine cultures, and a positive tuberculin skin test. Intravenous pyelograms disclosed abnormalities in most patients but were rarely diagnostic. Serial intravenous pyelograms disclosed increasing ureteral obstruction during chemotherapy in three patients. Multiple drug chemotherapy is the mainstay of treatment, but reconstructive surgery remains important. Male genital tuberculosis may result from direct spread from infected urine or from hematogenous seeding. Our nine patients presented with a mass lesion in the epididymis, testicle or prostate. Female genital tuberculosis results from hematogenous seeding, with fallopian tube involvement most common. Infertility, pelvic pain or abnormal vaginal bleeding were the initial symptoms. Endometrial curettage is important for the diagnosis of tuberculosis endometritis, and tuberculosis salpingitis often requires laparotomy for diagnosis.

Hepatic abscess: Changes in clinical, bacteriologic and therapeutic aspects

Abstract Clinical, bacteriologic and therapeutic aspects of 53 patients with hepatic abscess seen from 1961 to 1973 are reviewed. Of these abscesses, 50 were pyogenic and 3 amebic in etiology. The mortality was 63 per cent; the greatest number of cases (38) and the greatest mortality (79 per cent) occurred in patients over 50 years of age. Thirty-five patients had macroscopic abscesses; in the remaining 18 the abscesses were microscopic in size. The most common causes of pyogenic macroscopic abscess were biliary tract infection (11 cases), direct extension from contiguous sites of infection (8 cases) and nonpenetrating trauma (5 cases). The causes of microscopic abscesses were biliary tract infection (9 cases), systemic bacteremia (8 cases) and pylephlebitis (1 case). Although the diagnosis was often obscure with nonspecific clinical and laboratory findings, the hepatic scintiscan and abdominal angiography were positive in all cases in which the abscesses were greater than 1 cm in diameter. Bacteria of bowel origin (particularly Escherichia coli, other Enterobacteriaceae and anaerobes) were the common etiologic agents. Staphylococcus aureus was implicated predominantly in children with bacteremia. Prolonged antibiotic administration and aggressive surgical drainage are the cornerstones of effective therapy.

Human diseases caused by foodborne pathogens of animal origin.

Many lines of evidence link antimicrobial-resistant human infections to foodborne pathogens of animal origin. Types of evidence reviewed include: (1) direct epidemiologic studies; (2) temporal evidence; (3) additional circumstantial evidence; (4) trends in antimicrobial resistance among Salmonella isolates; and (5) trends in antimicrobial resistance among other pathogens, such as Campylobacter jejuni. Commensal microorganisms in animals and humans may contribute to antimicrobial resistance among pathogens that cause disease among humans. For instance, enterococci of food-animal origin, particularly strains that are vancomycin resistant, have been linked to strains found in the human gastrointestinal tract. The latent period between the introduction of a given antimicrobial and emergence of resistance varies considerably, but once the prevalence in a population reaches a certain level, control becomes extremely difficult.

Genetic and biochemical characterization of norfloxacin resistance in Escherichia coli.

In Escherichia coli the frequency of spontaneous single-step mutation to high levels of resistance to the newer 4-quinolone agent norfloxacin was confirmed to be over 300-fold lower than that to the older agent nalidixic acid. Serial passage on incremental concentrations of drug was necessary to produce mutants highly resistant to norfloxacin. Genetic analysis of one such highly resistant strain identified two mutations conferring drug resistance. One mutation, nfxA, mapped around 48 min on the E. coli genetic map and was shown to be an allele of gyrA by studies demonstrating an increased drug resistance of DNA gyrase reconstituted with the gyrase A subunit isolated from the mutant strain. These findings also identified the DNA gyrase A subunit as a target of norfloxacin. The second mutation, nfxB, mapped between 20 and 22 min was associated with additional resistances to tetracycline, chloramphenicol, and cefoxitin and with decreases in outer membrane porin protein OmpF. The nfxA and nfxB mutations together accounted for most, but not all, of the norfloxacin resistance phenotype of this strain. Images