Institute of Medical Virology and Epidemiology of Viral Diseases
Department of Hand and Plastic Surgery, Burn Center, BG Trauma Center, University Hospital of Tübingen, Tübingen, Germany
Department of Pathology, Vrije Universiteit Medical Center, Amsterdam, The Netherlands
To date, only seroepidemiological data are available on the role of human cytomegalovirus (HCMV) in patients with severe burns. We present the first longitudinal analysis of disseminated HCMV infection with a demonstration of self-limited productive viral replication identified in both the blood and lung of a burn patient.
An otherwise-healthy, 40-year-old female presented to our burn center after having suffered a 65% total body-surface-area self-immolation burn. She sustained full-thickness burns to her neck, both her arms, her chest, her abdomen, and her back as well as partial-thickness burns to both upper and lower extremities. On postburn day 2, a tracheostomy was performed. Subsequently, a fascial excision of all of the full-thickness-burned area was performed, and the area was covered with glycerol-preserved allogeneic skin (Euroskin; Beverwijk, The Netherlands). After removal of the cadaver skin, meshed split-thickness autologous skin was transplanted to both the arms and the neck. On hospital day 23, after the removal of the cadaver skin from the patient's chest and abdomen and the debrided areas on both legs, these areas were grafted with cultured epithelial autografts (Epicel; Genzyme Tissue Repair, Cambridge, MA) simultaneously overlaid on acellular allogeneic dermis (AlloDerm; LifeCell Corp., Branchburg, NJ). The back was grafted with split-thickness autologous micrografts (1:6; Meek) simultaneously overlaid on Alloderm. All areas of the skin transplants healed uneventfully, with the exception of the back. The transplanted area on the back developed a heavy bacterial colonization with pus and partial graft loss 10 days after transplantation (postburn day 56). Wound swabs revealed Staphylococcus epidermidis and Staphylococcus aureus, while blood cultures stayed negative for bacterial pathogens. As a result of wound care and intravenous antibiotics, wound healing without sequelae was observed within 2 days. During the course of the intensive care unit stay, the patient suffered from multiple septic episodes (3) with body temperatures of >38°C or <36°C, tachycardia of >90 beats/min, tachypnea or a need for mechanical ventilation, and leukocytosis of >12 x 103 cells/mm3 or <4 x 103 cells/mm3 (3). Daily chest X rays excluded any radiological evidence of interstitial pneumonia. Within the first 3 weeks after the burn, the patient received 32 units of packed red blood cells. The patient was weaned from the ventilator on hospitalization day 77 and discharged from the intensive care unit 4.5 months after the injury.
Longitudinal human cytomegalovirus (HCMV) screening was performed using serology, virus culturing, and nucleic acid amplification techniques from day 0 to day 120 after the burn (Fig. 1). Serology was done by anti-HCMV immunoglobulin G (IgG)/IgM enzyme-linked immunosorbent assay (DiaSorin, Düsseldorf, Germany). Virus culturing was performed by conventional tube cell culturing of bronchoalveolar lavage (BAL) fluids, throat swabs, urine samples, and skin biopsy specimens. Nested PCR with leukocytes, plasma, BAL fluids, throat swabs, and skin biopsy specimens was performed using primer sequences from the HCMV immediate-early region exon 4 (8). Quantitative HCMV DNA was detected with a COBAS AMPLICOR CMV MONITOR test (Roche Diagnostics), and qualitative HCMV late pp67 mRNA was screened by nucleic acid sequence-based amplification (Organon Teknika, Boxtel, The Netherlands) (5) from blood and BAL fluids.
The initial serostatus of the patient was unknown. On day 0, HCMV DNA was not detectable in serum. Fluctuating HCMV IgG levels resulted from the transfusion of multiple blood products. HCMV IgM seroconversion was initially observed on postburn day 25, when the patient was septic (3). The patient suffered from disseminated HCMV infection with viral leukocyte and plasma DNAemia. The peak level of the viral load was noted on postburn day 39 and was greater than 10,000 copies of HCMV DNA/ml plasma. Viral replication in blood was productive from day 21 to day 45 after the burn, as confirmed by the simultaneous detection of late viral RNA (Fig. 1). Low viral DNA levels were detectable in plasma for an additional week. The retrospectively analyzed course of the plasma viral DNA load described a unimodal kinetics (Fig. 1). Antiviral treatment was not performed. Despite the lack of radiological signs of interstitial pneumonia, both viral DNA and late viral RNA were detectable simultaneously in BAL fluids. Additionally, viral isolates from BAL fluids and viral DNA from throat swabs were also obtained during this time. Interestingly, productive viral replication in the lung seemed to persist for nearly 1 month longer than observed in the blood. Therefore, viral RNA and infectious virus could be isolated from BAL fluids as late as postburn day 71 (Fig. 1).
Very little data are available on the role of HCMV as an etiological factor for disease in the thermally injured patient. With the exception of one study (2), most of these reports are anecdotal or based on seroepidemiological studies (1, 4, 10, 11, 17, 18). In human burn patients, HCMV may potentially be transmitted by skin allografts, as shown by the manifestation of HCMV infection in initially seronegative burn patients grafted with cadaver allografts for temporary wound closure (12). The prevalence of herpesvirus infections (HCMV and herpes simplex virus type 1) in patients with severe burn injuries was estimated to be 52% (10). A significant correlation between herpesvirus infections and bacterial sepsis was found (10), but HCMV or herpes simplex virus type 1 infections did not contribute significantly to the morbidity and mortality of burn patients (1, 10, 11). In contrast, more-detailed data on the immune response of thermally injured mice against murine cytomegalovirus infection have recently become available, showing evidence of a significant contribution of murine cytomegalovirus infection to morbidity and mortality (13-15).
To our knowledge, this is the first case of a productive HCMV infection with documented viral DNAemia and RNAemia in a patient with severe burns. The involvement of the lung could be demonstrated convincingly by the detection of viral DNA, viral RNA, and infectious virus from BAL fluids.
This report demonstrates that HCMV infections in burn patients may well have been underdiagnosed in the past. The self-limited dynamics of viral DNAemia and viral RNAemia may explain several of the former clinical observations and suggest the minor importance of HCMV infection relative to overall mortality. However, the presence of highly productive HCMV replication in the blood and lung of a severely injured burn patient in the context of several septic episodes and prolonged mechanical ventilation warrants further investigation of these findings in a clinical trial, as HCMV reactivation in nonimmunosuppressed critically ill patients with acute sepsis has a high prevalence (9). More-detailed data are necessary to characterize the influence of septic episodes on the dynamics of HCMV replication (6, 7, 16).
Bale, J. F., Jr., G. P. Kealey, R. M. Massanari, and R. G. Strauss. 1990. The epidemiology of cytomegalovirus infection among patients with burns. Infect. Control Hosp. Epidemiol. 11:17-22.
Bale, J. F., Jr., G. P. Kealey, C. L. Ebelhack, C. E. Platz, and J. A. Goeken. 1992. Cytomegalovirus infection in a cyclosporine-treated burn patient: case report. J. Trauma 32:263-267.
Bone, R. C., R. A. Balk, F. B. Cerra, R. P. Dellinger, A. M. Fein, W. A. Knaus, R. M. Schein, W. J. Sibbald, and The ACCP/SCCM Consensus Conference Committee of the American College of Chest Physicians/Society of Critical Care Medicine. 1992. Definitions for sepsis and organ failure and guidelines for the use of innovative therapies for sepsis. Chest 101:1644-1655.
Deepe, G. S., Jr., B. G. MacMillan, and C. C. Linnemann, Jr. 1982. Unexplained fever in burn patients due to cytomegalovirus infection. JAMA 248:2299-2301.
Grejer, A. E., E. A. M. Verschuuren, M. C. Harmsen, C. A. J. Dekkers, H. M. A. Adriaanse, T. H. The, and J. M. Middeldorp. 2001. Direct quantification of human cytomegalovirus immediate-early and late mRNA levels in blood of lung transplant recipients by competitive nucleic acid sequence-based amplification. J. Clin. Microbiol. 39:251-259.
Grimsehl, K., R. A. Seaton, and M. R. Checketts. 1999. Fulminant cytomegalovirus colitis complicating Staphylococcus aureus septicaemia and multiorgan failure in a previously immunocompetent patient. J. R. Soc. Med. 92:80-81.
Hamilton, J. R., J. C. Overall, Jr., and L. A. Glasgow. 1976. Synergistic effect on mortality in mice with murine cytomegalovirus and Pseudomonas aeruginosa, Staphylococcus aureus, or Candida albicans infections. Infect. Immun. 14:982-989.
Hamprecht, K., M. Steinmal, H. Einsele, and G. Jahn. 1998. Discordant detection of human cytomegalovirus DNA from peripheral blood mononuclear cells, granulocytes and plasma: correlation to viremia and HCMV infection. J. Clin. Virol. 11:125-136.
Heininger, A., G. Jahn, C. Engel, T. Notheisen, K. Unertl, and K. Hamprecht. 2001. Human cytomegalovirus infections in nonimmunosuppressed critically ill patients. Crit. Care Med. 29:541-547.
Kagan, R. J., S. Naraqi, T. Matsuda, and O. M. Jonasson. 1985. Herpes simplex virus and cytomegalovirus infections in burned patients. J. Trauma 25:40-45.
Kealey, G. P., J. F. Bale, R. G. Strauss, and R. M. Massanari. 1987. Cytomegalovirus infection in burn patients. J. Burn Care Rehabil. 8:543-545.
Kealey, G. P., J. Aguiar, R. W. Lewis II, M. D. Rosenquist, R. G. Strauss, and J. F. Bale, Jr. 1996. Cadaver skin allografts and transmission of human cytomegalovirus to burn patients. J. Am. Coll. Surg. 182:201-205.
Kobayashi, H., M. Kobayashi, R. L. McCauley, D. N. Herndon, R. B. Pollard, and F. Suzuki. 1999. Cadaveric skin allograft-associated cytomegalovirus transmission in a mouse model of thermal injury. Clin. Immunol. 92:181-187.
Kobayashi, H., M. Kobayashi, D. N. Herndon, R. B. Pollard, and F. Suzuki. 2001. Susceptibility of thermally injured mice to cytomegalovirus infection. Burns 27:675-680.
Kobayashi, H., M. Kobayashi, H. Takahashi, D. N. Herndon, R. B. Pollard, and F. Suzuki. 2003. Soluble IL-4 receptor improves the skin-graft-associated cytomegalovirus infection in thermally injured mice. Burns 29:315-321.
Mutimer, D., D. Mirza, J. Shaw, K. O'Donnell, and E. Elias. 1997. Enhanced (cytomegalovirus) viral replication associated with septic bacterial complications in liver transplant recipients. Transplantation 63:1411-1415.
Ng, J. W., and A. Y. Chan. 1987. Severe hemorrhage from cytomegalovirus rectal ulcers in a burned adult. Am. J. Gastroenterol. 82:695-698.
Seeman, J., and R. Konigova. 1976. Cytomegalovirus infection in severely burned patients. Acta Chir. Plast. 18:142-151.