Frank J. Bia

The Practice of Travel Medicine: Guidelines by the Infectious Diseases Society of America

David R. Hill, Charles D. Ericsson, Richard D. Pearson, Jay S. Keystone, David O. Freedman, Phyllis E. Kozarsky, Herbert L. DuPont, Frank J. Bia, Philip R. Fischer, and Edward T. Ryan National Travel Health Network and Centre and Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, England; Department of Medicine, University of Toronto, and Center for Travel and Tropical Medicine, Toronto General Hospital, Toronto, Ontario, Canada; Department of Internal Medicine, Clinical Infectious Diseases, University of Texas Medical School at Houston, Department of Internal Medicine, St. Luke’s Hospital, and Center for Infectious Diseases, University of Texas at Houston School of Public Health, and Department of Medicine, Baylor College of Medicine, Houston, Texas; Departments of Medicine and Pathology, Division of Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, Virginia; Departments of Medicine and Epidemiology, Division of Geographic Medicine, University of Alabama at Birmingham, Birmingham; Department of Medicine, Infectious Diseases, Emory University School of Medicine, and 16 Division of Global Migration and Quarantine, Centers for Disease Control and Prevention, Atlanta, Georgia; Department of Medicine and Laboratory Medicine, Yale Medical School, New Haven, Connecticut; Department of Pediatrics, Division of General Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine, and Mayo Eugenio Litta Children’s Hospital, Mayo Clinic, Rochester, Minnesota; and Department of Medicine, Division of Infectious Diseases, Harvard Medical School, Harvard School of Public Health, and Tropical and Geographic Medicine Center, Massachusetts General Hospital, Boston, Massachusetts

Persistent and Relapsing Babesiosis in Immunocompromised Patients

BACKGROUND Human babesiosis is a tickborne malaria-like illness that generally resolves without complication after administration of atovaquone and azithromycin or clindamycin and quinine. Although patients experiencing babesiosis that is unresponsive to standard antimicrobial therapy have been described, the pathogenesis, clinical course, and optimal treatment regimen of such cases remain uncertain. METHODS We compared the immunologic status, clinical course, and treatment of 14 case patients who experienced morbidity or death after persistence of Babesia microti infection, despite repeated courses of antibabesial treatment, with those of 46 control subjects whose infection resolved after a single course of standard therapy. This retrospective case-control study was performed in southern New England, New York, and Wisconsin. RESULTS All case patients were immunosuppressed at the time of acute babesiosis, compared with <10% of the control subjects. Most case patients experienced B cell lymphoma and were asplenic or had received rituximab before babesial illness. The case patients were more likely than control subjects to experience complications, and 3 died. Resolution of persistent infection occurred in 11 patients after 2-10 courses of therapy, including administration of a final antimicrobial regimen for at least 2 weeks after babesia were no longer seen on blood smear. CONCLUSIONS Immunocompromised people who are infected by B. microti are at risk of persistent relapsing illness. Such patients generally require antibabesial treatment for >or=6 weeks to achieve cure, including 2 weeks after parasites are no longer detected on blood smear.

Parasitic Infections of the Central Nervous System

The authors give a comprehensive review of the epidemiology, clinical presentations, diagnosis and current therapy of parasitic infections with CNS manifestations in both the normal and immunocompromised host. These include toxoplasmosis, malaria, amebiasis, neurocystcersosis, hydatid disease, and trichinosis. Additional sections cover disseminated strongyloidiasis, eosinophilic meningitis, visceral and ocular larva migrans, schistosomiasis, and cerebral paragonimiasis. Emphasis is on the neurologic complications of these diseases and their presentations in populations at increased risk for acquiring or reactivating these infections.

THE COMPROMISED TRAVELER

Compromised travelers represent a diverse and challenging group of individuals. They include HIV-infected patients who are at risk for potentially adverse reactions to immunizations, and new exposures to enteric water-borne opportunistic pathogens associated with chronic infections. Such travelers may encounter unfamiliar opportunistic fungi and classical tropical infections, such as leishmaniasis, whose pathogenesis can be enhanced by the presence of prior HIV infection. Other immunocompromised groups include those who are functionally or anatomically asplenic, and patients who are iatrogenically immunosuppressed from medications utilized for solid organ transplantation, chemotherapy, or treatment of malignancies. This population of travelers also includes those with diabetes mellitus who may require adjustments in their dosing, administration, and possibly even the types of insulin used on their trips. These patients are also at greater risk for acquisition of tuberculosis, severe community-acquired pneumonia, urinary tract infections, and pyomyositis. Older travelers present both the infectious disease and travel medicine specialist with issues such events, malignancy-related infections, myocardial infarction, and other forms of cardiopulmonary compromise, which the authors address in this article.

Ultrastructural development of guinea pig cytomegalovirus in cultured guinea pig embryo cells.

The ultrastructural development of guinea pig cytomegalovirus (GPCMV) in guinea pig embryo cells was studied using electron microscopy. Tubular structures were found in nuclei of virus infected cells, followed by the appearance of intranuclear inclusions containing virus nucleocapsids. While some nucleocapsids were enveloped at the inner nuclear membrane, others were released into the cytoplasm where they were associated with, or within, dense matrix which was subsequently enveloped by cytoplasmic membranes to form enveloped dense virions. Dense bodies without virus capsids were formed in the cytoplasm and enveloped in a similar manner. An involvement of the nuclear pores in the release of unenveloped virus capsids from the nucleus to the cytoplasm was postulated. Evidence that the enveloped dense virions and dense bodies shared common envelope antigen(s) was obtained by immunoelectron microscopy. The similarities and differences in the ultrastructural development of GPCMV and other cytomegaloviruses are discussed.

Rapidly Progressive Glomerulonephritis during Antituberculous Therapy

Within 3 weeks of beginning continuous daily isoniazid and rifampin therapy for pulmonary tuberculosis, a patient developed acute renal failure. Renal biopsy demonstrated lesions characteristic of rapidly progressive glomerulonephritis with minor interstitial changes. Prior reports have emphasized the tubular and interstitial lesions associated with intermittent or discontinuous rifampin therapy for tuberculosis. This report documents the occurrence of severe glomerular pathology associated with continuous, daily antituberculous therapy. The spectrum of renal lesions occurring during antituberculous therapy, particularly in association with rifampin, may be wider than previously suspected.

Propionibacterium acnes causes postoperative brain abscesses unassociated with foreign bodies: case reports.

Propionibacterium acnes was isolated in pure culture from brain abscesses that occurred in two patients after intracranial surgery. Although such infections are usually associated with cerebrospinal fluid shunts and other foreign bodies, these cases clearly demonstrate the pathogenicity of this anaerobic diphtheroid in the absence of such. Progression of P. acnes infection in the central nervous system can be insidious. To treat such infections adequately, therapy cannot rely upon some standard antimicrobial agents. Metronidazole, which is useful against most anaerobic organisms, is not effective against P. acnes.

Departments of medicine and international health

There is an emerging role in international health for departments of medicine that care to accept the challenge. Supervised medical rotations in the developing world and the care of culturally distinct immigrant populations provide unique opportunities to expand the scope of medical education while emphasizing a sensitive and humanistic approach to health care. The restraints imposed by diminished laboratory support and limited availability of drugs can foster reliance on diagnostic skills and the essential elements of therapy. Medical schools may elect to become involved in international health, but they must do so without becoming exploitative. Rotations of students, residents, and faculty in both directions should lead to productive interaction at both the clinical and research levels, for all participants.

Ultrastructural development and persistence of guinea pig cytomegalovirus in duct cells of guinea pig submaxillary gland

SummarySalivary glands from Hartley guinea pigs were experimentally infected with guinea pig cytomegalovirus (GPCMV) and examined by light and electron microscopy at different time intervals. Characteristic intranuclear and intracytoplasmic viral inclusions were observed in duct cells of infected animals. Viral inclusion counts and infectivity titers in the salivary gland reached maximum levels by 3 to 4 weeks after infection; infectivity persisted, though at reduced levels, for at least 30 weeks. Electron microscopic examination of viral inclusions revealed several developmental events including nucleocapsid assembly, envelopment of nucleocapsids at the inner nuclear membrane and their enclosure by a thin vacuolar membrane. While contained within cytoplasmic vacuoles, enveloped virions acquired surface spikes. Cytoplasmic vacuoles containing virions subsequently coalesced and discharged mature virions at the cell surface into the lumen of the salivary gland duct. The data indicate that the ultrastructural development of GPCMV in the guinea pig salivary gland shows many similarities to that of human cytomegalovirus in humans. The salivary gland may provide a primary locus for virus shedding and horizontal transmission of cytomegalovirus.

Nontuberculous mycobacterial peritonitis in peritoneal dialysis patients.

While nontuberculous mycobacterial peritonitis is uncommon among peritoneal dialysis (PD) patients, these infections have serious consequences. They present a significant diagnostic and therapeutic challenge for clinicians. Diagnosis can be delayed due to the slow growth rate of some mycobacterial species. These organisms can also be overlooked when adequate culture media are not used in the microbiological evaluation process. The choice of antimicrobial therapy depends upon isolation and speciation of the infecting Mycobacterium species, and prompt catheter removal is essential. Because serious intra‐abdominal complications may follow infection, identifying patient risk factors for nontuberculous mycobacterial peritonitis and initiating prompt diagnosis and treatment are essential. We report three cases of peritonitis associated with Mycobacterium chelonae and Mycobacterium gordonae, each with a unique presentation, and discuss the appropriate diagnosis and treatment strategies for the management of PD‐associated mycobacterial infections.