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CHAPTER 80: Viral Hemorrhagic Fevers 733

opioid preparations, which are commonly used for analgesia in critically • Thwaites CL, Yen LM, Loan HT, et al. Magnesium sulphate for
ill patients, also help treat autonomic dysfunction. Additionally, atro- treatment of severe tetanus: a randomised controlled trial. Lancet.
pine, clonidine, and an epidural with bupivacaine and sufentanil have October 21, 2006;368(9545):1436-1443.
also been used successfully. 39-41 • Trujillo MH, Castillo A, Espana J, Manzo A, Zerpa R. Impact of
■ OTHER CONSIDERATIONS intensive care management on the prognosis of tetanus. Analysis

General critical care supportive measures should be implemented in of 641 cases. Chest. July 1987;92(1):63-65.
patients with tetanus. These include establishing intravenous access and
insertion of a urinary catheter to monitor urine production and prevent
urinary retention. Stress ulcer and venothromboembolic prophylaxis REFERENCES
are indicated in critically ill tetanus patients. Enteral feeding should be Complete references available online at www.mhprofessional.com/hall
provided assuming a normal basal metabolic rate. 42

PROGNOSIS
CHAPTER Viral Hemorrhagic Fevers
In the developing world mortality due to tetanus exceeds 50%, with
most deaths due to acute respiratory failure and mortality is often Jean-Luc Benoit
higher in the elderly. 10,11,14,43 In areas with modern intensive care man- 80
agement, mortality ranges from 10% to 15%. 10,44 The leading causes of
death in this setting are cardiovascular collapse and pneumonia. The
general quality of critical care support is likely a key determinant of
prognosis. In a recent study tracking mortality from severe tetanus in KEY POINTS
Brazil over two decades, mortality fell from 36.5% in the early time • More than 20 RNA viruses within four families (Flaviviridae,
frame to 18.0% in the later period, likely related to general advances in
ICU management. 45 Arenaviridae, Filoviridae, and Bunyaviridae) cause viral hemor-
rhagic fevers (VHFs).
Predicting the severity of tetanus can be based on several factors.
An incubation period of <5 days and onset of symptoms in less than • The prevalent VHFs are dengue HF, yellow fever (YF), Lassa fever
48 hours are both indicators of poor prognosis. Extremes of age, lack of (LF), Rift Valley fever (RVF), and hemorrhagic fever with renal
previous immunity, infections of the uterus, head and neck involvement, syndrome (HFRS).
and early autonomic instability are also associated with more severe • Emerging VHFs include Chapare, Lujo, Alkhurma, severe fever
disease. There has also been a higher mortality associated with intra- with thrombocytopenia syndrome (SFTS), and novel hantaviruses.
muscular quinine injection and intravenous heroin use. 1,17,30 • Hantaviruses cause HFRS in the Old World and hantavirus cardio-
Finally, it is important to remember that recovery from tetanus pulmonary syndrome (HCPS) in the New World. HCPS manifests as
does not guarantee natural immunity. Patients should begin their low-pressure pulmonary edema, pleural effusions, and cardiogenic
11
primary immunization series prior to leaving the hospital; indeed, shock, but not VHF.
since passive immunization with HTIG does not interfere with suc- • Mosquitoes are the vector of dengue, YF, and RVF.
cessful active immunization, the series can begin even before the
patient leaves the ICU. • Ticks are the vector of Crimean-Congo HF (CCHF), Omsk HF
(OHF), Kyasanur forest disease (KFD), Alkhurma HF, and SFTS.
• Arenaviruses and hantaviruses are rodent-borne zoonoses.
KEY REFERENCES • Exposure to domestic animals is a major mode of infection in RVF
and CCHF.
• Ahmadsyah I, Salim A. Treatment of tetanus: an open study to
compare the efficacy of procaine penicillin and metronidazole. Br • RVF causes simultaneous epizootics in animals and large epidem-
Med J (Clin Res Ed). September 7, 1985 291(6496):648-650. ics in humans.
• Apte NM, Karnad DR. Short report: the spatula test: a simple • Dengue and Seoul hantavirus are urban infections. YF is endemic
bedside test to diagnose tetanus. Am J Trop Med Hyg. October in jungles and African savannas, but also causes urban epidemics.
1995;53(4):386-387. The other VHFs are rural infections because of the distribution of
ticks and rodent or bat reservoirs.
• Bleck TP. Tetanus: pathophysiology, management, and prophy- • Nosocomial infections are a feature of CCHF, filoviruses, arena-
laxis. Dis Mon. September 1991;37(9):545-603. viruses, Andes hantavirus, and SFTS bunyavirus. This risk is high
• Brook I. Current concepts in the management of Clostridium tet- when standard precautions for blood-borne pathogens are not
ani infection. Expert Rev Anti Infect Ther. June 2008;6(3):327-336. followed. Attempting viral isolation requires high biosafety level
• Buchanan N, Smit L, Cane RD, De Andrade M. Sympathetic over- precautions (BSL 3 or 4 for most VHF pathogens).
activity in tetanus: fatality associated with propranolol. Br Med J. • The incubation period usually is shorter than 2 weeks, but longer with
July 22 1978;2(6132):254-255. hantaviruses. The onset of illness usually is sudden, but insidious
• Farrar JJ, Yen LM, Cook T, et al. Tetanus. J Neurol Neurosurg with arenaviruses.
Psychiatry. September 2000;69(3):292-301. • Clues to dengue fever are urban acquisition, break-bone fever,
• Gergen PJ, McQuillan GM, Kiely M, Ezzati-Rice TM, Sutter rash, hemoconcentration, and thrombocytopenia. Danger signs
RW, Virella G. A population-based serologic survey of immu- for dengue HF include abdominal pain, persistent vomiting, effu-
nity to tetanus in the United States. N Engl J Med. March 23, sions, mucosal bleed, lethargy, restlessness, liver enlargement,
1995;332(12):761-766. hemoconcentration, and severe thrombocytopenia.
• Gibson K, Bonaventure Uwineza J, Kiviri W, Parlow J. Tetanus • YF vaccine–associated viscerotropic disease (YEL-AVD) is
in developing countries: a case series and review. Can J Anaesth. encountered only rarely in recipients who are older or have abnor-
April 2009;56(4):307-315. mal thymus function.

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