Human infection with herpes zoster: etiology, pathophysiology, diagnosis, clinical course, and treatment.

Herpes zoster is a cutaneous vesicular eruption resulting from recrudescence of the chickenpox virus. It is mainly a disease of adults, with a predisposition for the elderly or immunocompromised. Although usually localized, the disease can disseminate to visceral organs. Diagnosis is often made based on the characteristic pattern of the lesion and clinical features. Tzanck smear, viral isolation, seroconversion, antibody titers, and monoclonal antibodies may further aid or confirm the diagnosis. Clinical features of herpes zoster may follow a progression through 3 stages, prodromal, acute, and chronic. The prodromal and acute phases seldom require more than symptomatic management. The chronic pain syndrome, postherpetic neuralgia (PHN), demands a more aggressive approach. Pharmacologic intervention, neuroaugmentation, and/or surgery may prevent or alleviate PHN, but universal response to any of these therapeutic approaches is unlikely. Tricyclic antidepressants remain the first choice in treating this pain syndrome. A trial of antiviral therapy may be warranted in patients with disseminated disease or in immunocompromised patients with localized disease. Of the antiviral agents, acyclovir is considered the drug of choice by most clinicians.

Fatal Legionnaires' disease coincident with initiation of immunosuppressive therapy.

A fatal relapse of legionnaires' disease occurred coincidental with the initiation of chemotherapy in a patient who had received previous parenteral erythromycin gluceptate therapy for 30 days. Sputum examinations utilizing the direct fluorescent antibody test for Legionella pneumophila suggested persistence of infection during the course of antibiotic therapy. This case suggests that administration of immunosuppressive agents should be delayed in patients whose sputum is positive on direct fluorescent antibody testing, regardless of previous antibiotic therapy.

Urinary tract infections with antibiotic resistant organisms in catheterized nursing home patients.

Long-term use of indwelling urinary catheters in nursing home (NH) patients is a potential cause of significantly morbidity. We retrospectively studied 10 NH patients with chronic indwelling urinary catheters. Sixty-four percent of all 84 antibiotic courses prescribed were for bacteriuria alone without clinical infection. Seventy percent of 63 antibiotic courses were followed by bacteriuria with organisms resistant to the antibiotic administered. Bacteria isolated from NH patients often displayed greater resistance to specific antibiotics than those isolated from hospitalized patients. Four of the 20 urinary tract infections were associated with bacteremia. Three episodes of bacteremia were with highly-resistant organisms and one was fatal. Use of urinary catheters and inappropriate use of antibiotics in NH patients results in urinary tract colonization and infection with resistant bacteria and is an important cause of morbidity and mortality.

Actinomycetoma in the United States.

Actinomycetoma (Madura foot) caused by Actinomadura madurae occurred in an Indiana factory worker. Previous cases of culture-proven actinomycetoma from the United States and reports of drug therapy were reviewed. Treatment with sulfonamides, streptomycin, dapsone, and other antimicrobial agents has been effective. Trimethoprim-sulfamethoxazole (TMP-SMZ) therapy was effective in our case, but sulfadiazine was not. In vitro, SMZ was 16 times more active against the infecting strain of A. madurae than was sulfadiazine, and TMP was inactive, suggesting that our patient's satisfactory treatment might have been due to SMZ alone. Prolonged therapy is usually necessary. Relatively simple immunologic procedures and antimicrobiol susceptibility tests have been useful in the diagnosis and management of actinomycetoma. With appropriate antimicrobial therapy, surgical excision or amputation usually can be avoided. Recommendations for the medical management of actinomycetoma are summarized.

Leukocyte and 67Ga-citrate dynamics in experimental subcutaneous Streptococcus faecalis infections.

The dynamics of white blood cell (WBC) and 67Ga-citrate accumulation were studied in rabbits with subcutaneous polyethylene chambers. Uninfected chamber fluid (CF) contained less than 1,000 WBCs/mm3, most of which were mononuclear. After 67Ga injection, radioactivity increased slowly in uninfected fluid, peaked between 24 and 48 hours, and then gradually decreased. 67Ga scans showed no uptake in excess of background levels around the uninfected chambers. After injection of Streptococcus faecalis directly into the chambers, bacterial concentrations initially decreased, increased by 4-24 hours, and then decreased slightly. WBCs began to increase 4 hours after infection due to influx of polymorphonuclear leukocytes. 67Ga localized in infected chambers before the increase in WBCs. Use of the subcutaneous chamber model could help elucidate the mechanism(s) of 67Ga accumulation at sites of inflammation.

Incidence of positive serologic tests for treponemal infection in healthy rabbits.

Sera from 167 apparently normal rabbits were screened by the Venereal Disease Research Laboratory (VDRL) slide test and by the fluorescent treponemal antibody-absorption (FTA-Abs) and microhemagglutination assay for Treponema pallidum antibodies (MHA-TP) test. Three sera (1.8%) were reactive in all three tests, a fact suggesting possible inapparent infection with Treponema paraluis-cuniculi. One hundred forty-four sera (86.2%) were nonreactive in all tests. The VDRL slide test was reactive with 22 sera (13.2%). In 19 of these, treponemal tests were nonreactive; thus the rabbits probably were not infected with pathogenic treponemes. One hundred sixty-three sera (97.6%) were nonreactive in both treponemal tests, and three sera (1.8%) were reactive in both. One serum was reactive in the FTA-Abs test and nonreactive in the MHA-TP test. The lower incidence of reactivity with treponemal tests suggests that the FTA-Abs and MHA-TP tests are more useful than the VDRL slide test for screening rabbits intended for experimental studies of syphilis.

Quantitative microhaemagglutination assay for Treponema pallidum antibodies in experimental syphilis.

The quantitative microhaemagglutination assay for Treponema pallidum antibodies (MHA-TP) was studies in 52 untreated and treated rabbits with experimental syphilis. Rabbits with incubating experimental syphilis were cured or inadequately treated with penicillin G and some cured rabbits were later reinfected. MHA-TP conversion occurred within 45 days in untreated rabbits. Titres reached peak levels about four months after inoculation and remained relatively high for up to two years. The quantitative MHA-TP test differentiated between rabbits cured of experimental incubating syphilis and those untreated and inadequately treated. MHA-TP titres decreased after treatment given six or 12 months after inoculation but reversion did not occur. MHA-TP conversion or significant increases in titre occurred as soon as seven days after reinfection and preceded corresponding changes in a quantitative non-treponemal test. The MHA-TP is useful as a screening test for treponemal antibodies in rabbits. The quantitative MHA-TP in humans after treatment for syphilis and reinfection deserves further study.

Ampicillin therapy of experimental enterococcal endocarditis.

In rabbits with experimental enterococcal endocarditis, subcutaneously implanted perforated polyethylene chambers were used for ampicillin administration by intra-chamber injection. A total of 21 days of intra-chamber ampicillin therapy sterilized vegetations of 14 out of 14 rabbits with experimental enterococcal endocarditis. In rabbits treated for less than 21 days, the duration of therapy and quantitative vegetation cultures were inversely related. Peak serum minimal bactericidal titers were greater than or equal to 1:8 in 94% of the determinations. Trough serum minimal bactericidal titers were less than or equal to 1:2. The mean trough serum ampicillin concentration (2.6 micrograms/ml) was greater than the minimal bactericidal concentration of ampicillin for the infecting enterococcus and less than the mean trough chamber fluid ampicillin concentration (3.7 micrograms/ml). Relatively prolonged therapy with intrachamber injections seemed to be well tolerated. Combination drug therapy of enterococcal endocarditis may not always be required. The maintenance of serum minimal bactericidal titers greater than or equal to 1:8 throughout the therapy of endocarditis, as is often recommended, may be unnecessary.

Serum and subcutaneous chamber fluid dynamics of penicillins after single large parenteral doses.

Serum and subcutaneous chamber fluid (CF) dynamics of penicillin G, ampicillin, and amoxicillin were studied in rabbits after single large parenteral doses comparable to doses used in treating gonorrhea and endocarditis. The effects of parenteral probenecid and of injection of an antibiotic directly into a subcutaneous chamber ("intrachamber" injection) also were studied. Peak serum antibiotic concentrations exceeded peak CF concentrations and occurred sooner. Antimicrobial activity persisted longer in CF than in serum. Percent penetration [100 x (CF peak/serum peak)] of CF was least after intramuscular ampicillin and amoxicillin, was greatest after intrachamber ampicillin and intramuscular aqueous procaine penicillin G, and was related to duration of antibiotic concentration gradients from serum to CF. Intramuscular aqueous crystalline penicillin G resulted in higher serum and CF penicillin G concentrations than intramuscular aqueous procaine penicillin G, which prolonged the duration of penicillin G in serum and CF. Amoxicillin diffused into CF more readily than ampicillin. Probenecid resulted in higher early serum and CF antibiotic concentrations, but had little or no effect on duration of antibiotic activity. Intrachamber ampicillin resulted in more prolonged serum and CF ampicillin activity than intramuscular ampicillin, but much lower peak serum concentrations. The data suggest a possible means by which probenecid improves the efficacy of gonorrhea therapy with aqueous procaine penicillin G. Intrachamber administration of penicillins could be useful in treating experimental infections requiring prolonged therapy.

Aspergillus fumigatus epidural abscess in a renal transplant recipient.

An epidural abscess caused by Aspergillus fumigatus occurred in a recipient of a cadaveric, renal allograft. The patient had persistent back pain and a peripheral neuropathy that involved the lower extremities. Signs of spinal cord compression evolved. No definite portal of entry was found. Diagnosis was made by histologic examination and culture of a biopsy specimen. Therapy, consisting of aggressive surgical debridement, intravenous amphotericin B, and oral flucytosine was unsuccessful in eradicating the organism. At postmortem examination, Aspergillus was identified at the abscess site. To our knowledge, aspergillosis presenting as an epidural abscess in the immunosuppressed, renal transplant recipient has not previously been reported and should be considered in the differential diagnosis of back pain and peripheral neuropathy in such a patient.

Treponema pallidum infection in subcutaneous polyethylene chambers in rabbits.

Male New Zealand white rabbits with subcutaneous polyethylene chambers in place for at least 3 months were inoculated by one of the following three methods: (i) "intra-chamber" (IC) inoculation with "normal" chamber fluid: (ii) intratesticular inoculation with Treponema pallidum; or (iii) IC inoculation with T. pallidum. Rabbits given dexamethasone only, oxisuran only, both drugs, or no drug were observed serially after inoculation. T. pallidum survived and temporarily multiplied to significant numbers within subucutaneous chambers after IC inoculation in rabbits given dexamethasone. In rabbits not treated with dexamethasone, T. pallidum counts in chamber fluid decreased rapidly and remained at low levels for 30 days after IC inoculation. Oxisuran appeared to have little or no effect on T. pallidum multiplication. All rabbits studied had a nonreactive serum and chamber fluid serological test for syphilis before inoculation. All rabbits inoculated with T. pallidum eventually developed reactive serum and chamber fluid serological tests. The IC route of inoculation was associated with a delay in the development of serum serological reactivity and with earlier chamber fluid reactivity as compared with the intratesticular route of inoculation. An immediate but transent influx of polymorphonuclear leukocytes was associated with IC inoculation of T. pallidum. Chamber fluid total protein content declined very slightly in all groups of rabbits during the month after inoculations. Successful cultivation of T. pallidum in an in vivo setting suggests that this animal model may be useful in further studies of the biology of the organism of the pathogenesis, immunology, and treatment of syphilis.

Tobramycin: in vitro and clinical evaluation in 30 patients.

Clinical evaluation of intramuscular tobramycin was accomplished in 30 patients with respiratory, soft tissue, urinary tract, bone or septicemic infections due to gram negative bacilli. Median sensitivity to tobramycin of Pseudomonas aeruginosa isolates (19 strains) was 0.62 mug/ml and range 0.31-2.5 mug/ml; less activity was observed for Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae and Enterobacter species isolates but median minimum inhibitory concentrations were less than or equal to 2.5 mug/ml. Therapy resulted in clinical and bacteriologic cures in 16 patients (53 per cent) including 13 of 16 (181 per cent) with urinary tract infections; 9 of the 14 patients who did not obtain bacteriologic cure had satisfactory clinical responses. Tobramycin was effective for selected gram negative bacillary infections and particularly for P. aeruginosa.

Fluid and penicillin G dynamics in polyethylene chambers implanted subcutaneously in rabbits.

Chemical and cellular characteristics of fluid within subcutaneously implanted polyethylene chambers in rabbits were studied over a 3-month period. The fluid attained a relatively stable protein and cellular composition which was consistent with a mononuclear exudate. After a single dose of intramuscular penicillin G, the antibacterial activity of chamber fluid was found to be dynamic and similar to the serum antibacterial activity. This animal model may be useful for in vivo studies of the interaction of microorganisms with antimicrobial agents.