eMedicine Specialties > Infectious Diseases > CNS Infections

Venezuelan Encephalitis: Treatment & Medication

Author: Iris Reyes, MD, Advisory Dean; Director of Quality Improvement, Associate Professor, Department of Emergency Medicine, University of Pennsylvania
Coauthor(s): Sarah M Perman, MD, Resident, Department of Emergency Medicine, University of Pennsylvania Health Systems; William H Shoff, MD, DTM&H, Director, PENN Travel Medicine, Associate Professor, Department of Emergency Medicine, Hospital of the University of Pennsylvania; Suzanne Moore Shepherd, MD, MS, DTM&H, FACEP, FAAEM, Associate Professor, Department of Emergency Medicine, Hospital of the University of Pennsylvania; Director of Education and Research, PENN Travel Medicine
Contributor Information and Disclosures

Updated: Oct 10, 2008

Treatment

Medical Care

Patients with non-neurologic Venezuelan equine encephalitis (VEE) virus infection generally require only supportive care, including fluid management for dehydration and electrolyte derangement caused by fever and vomiting.

  • Patients with neurologic manifestations of Venezuelan equine encephalitis require prompt supportive care to reduce the risk of mortality.
    • Appropriate measures include standard anticonvulsant therapy as treatment for seizures; fluid management for dehydration and electrolyte imbalance produced by fever, vomiting, decreased oral intake, and inappropriate ADH secretion; and proper airway and respiratory management in those progressing to coma.
    • When possible, neurosurgical evaluation and treatment of secondary bacterial infection significantly improve the prognosis. Monitoring for increased intracranial pressure is beneficial.
  • Prevention and treatment of secondary bacterial infection significantly improve the patient's prognosis.
  • Trials are currently underway to develop a vaccine for Venezuelan equine encephalitis. V3526, a compound currently under investigation, is similar to TC-83, a previously studied compound. However, V3526 has improved immunogenicity. Studies have shown that the V3526 vaccine has been safe and efficacious in the treatment of horses. Vaccination with V3526 results in a lack of detectable viremia. However, further research is needed to determine whether this vaccine will safely confer immunity in humans.3

Consultations

Neurosurgical evaluation and monitoring for increased intracranial pressure, when possible, is beneficial.

Medication

No specific treatment for Venezuelan equine encephalitis (VEE) infections exists.

Anticonvulsants

These agents are used to prevent seizure recurrence and to terminate clinical and electrical seizure activity.


Phenytoin (Dilantin)

Used for seizures. May act in motor cortex, where it may inhibit spread of seizure activity. Activity of brainstem centers responsible for tonic phase of grand mal seizures may also be inhibited. Dose should be individualized. Administer larger dose before retiring if dose cannot be divided equally.

Adult

Loading: 15-20 mg/kg PO/IV once or divided doses, followed by 100-150 mg per dose at 30-min intervals
Initial: 100 mg (125 mg susp) IV/PO tid
Maintenance: 300-400 mg/d PO/IV divided tid or qd/bid if using ER; increase to 600 mg/d (625 mg/d susp) may be necessary; not to exceed 1500 mg/d
Rate of infusion must not exceed 50 mg/min to avoid hypotension and arrhythmia

Pediatric

Loading: 15-20 mg/kg PO/IV once or divided doses
Initial: 5 mg/kg/d PO/IV divided bid/tid
Maintenance: 4-8 mg/kg PO/IV divided bid/tid
<6 years: Not established
>6 years: May require minimum adult dose (300 mg/d); not to exceed 300 mg/d

Amiodarone, benzodiazepines, chloramphenicol, cimetidine, fluconazole, isoniazid, metronidazole, miconazole, phenylbutazone, succinimides, sulfonamides, omeprazole, phenacemide, disulfiram, ethanol (acute ingestion), trimethoprim, and valproic acid may increase phenytoin toxicity; phenytoin effects may decrease when taken concurrently with barbiturates, diazoxide, ethanol (chronic ingestion), rifampin, antacids, charcoal, carbamazepine, theophylline, and sucralfate; phenytoin may decrease effects of acetaminophen, corticosteroids, dicumarol, disopyramide, doxycycline, estrogens, haloperidol, amiodarone, carbamazepine, cardiac glycosides, quinidine, theophylline, methadone, metyrapone, mexiletine, oral contraceptives, and valproic acid

Documented hypersensitivity; hypotension; second- and third-degree AV block

Pregnancy

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Perform blood counts and urinalyses when therapy is begun and at monthly intervals for several months thereafter to monitor for blood dyscrasias; discontinue use if a skin rash appears and do not resume use if rash is exfoliative, bullous, or purpuric; rapid IV infusion may result in death from cardiac arrest, marked by QRS widening; caution in acute intermittent porphyria and diabetes (may elevate blood sugars); discontinue use if hepatic dysfunction occurs


Carbamazepine (Tegretol)

Used for seizures. Indicated for complex partial seizures and trigeminal neuralgia. May block posttetanic potentiation by reducing summation of temporal stimulation. Following a therapeutic response, may reduce dose to minimum effective level or discontinue treatment at least once q3mo.

Adult

200 mg PO bid (100 mg PO qid susp); increase at weekly intervals by no more than 200 mg/d tid/qid (bid with ER) until best response obtained; not to exceed 1600 mg/d

Pediatric

<6 years: 10-20 mg/kg/d PO bid/tid (qid susp), increase weekly to achieve optimal clinical response tid/qid; not to exceed 100 mg/d
6-12 years: 100 mg PO bid (50 mg qid susp), increase gradually every wk by adding 100 mg/d PO divided tid/qid (bid with ER) until best response is obtained; not to exceed 1000 mg/d
>12 years: Administer as in adults; not to exceed 1000 mg/d in children aged 12-15 y or 1200 mg/d if >15 y

Serum levels may increase significantly within 30 d of danazol coadministration (avoid whenever possible); do not coadminister with MAOIs; cimetidine may increase toxicity, especially if taken in first 4 wk of therapy; carbamazepine may decrease primidone and phenobarbital levels (their coadministration may increase carbamazepine levels)

Documented hypersensitivity; history of bone marrow depression; administration of MAOIs within last 14 d

Pregnancy

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Do not use to relieve minor aches or pains; caution with increased intraocular pressure; obtain CBCs and serum iron baseline levels prior to treatment, during first 2 mo, and yearly or every other year thereafter; can cause drowsiness, dizziness, and blurred vision; caution while driving or performing other tasks requiring alertness

More on Venezuelan Encephalitis

Overview: Venezuelan Encephalitis
Differential Diagnoses & Workup: Venezuelan Encephalitis
Treatment & Medication: Venezuelan Encephalitis
Follow-up: Venezuelan Encephalitis
References
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References

  1. Figueiredo LT. Emergent arboviruses in Brazil. Rev Soc Bras Med Trop. Mar-Apr 2007;40(2):224-9. [Medline].

  2. Jackson AC, Rossiter JP. Apoptotic cell death is an important cause of neuronal injury in experimental Venezuelan equine encephalitis virus infection of mice. Acta Neuropathol. Apr 1997;93(4):349-53. [Medline].

  3. Fine DL, Roberts BA, Teehee ML, et al. Venezuelan equine encephalitis virus vaccine candidate (V3526) safety, immunogenicity and efficacy in horses. Vaccine. Feb 26 2007;25(10):1868-76. [Medline].

  4. Chin J. IA Venezuelan equine encephalomyelitis virus disease. In: Chin J, ed. Control of Communicable Diseases Manual. 17th ed. Washington, DC: American Public Health Association; 2000:45-48.

  5. Gruppo RA, Brown D, Wilkes MM, et al. Comparative effectiveness of full-length and B-domain deleted factor VIII for prophylaxis--a meta-analysis. Haemophilia. May 2003;9(3):251-60. [Medline].

  6. Han MH, Zunt JR. Bioterrorism and the nervous system. Curr Neurol Neurosci Rep. Nov 2003;3(6):476-82. [Medline].

  7. Ludwig GV, Kondig JP, Smith JF. A putative receptor for Venezuelan equine encephalitis virus from mosquito cells. J Virol. Aug 1996;70(8):5592-9. [Medline].

  8. Markoff L. Alphaviruses. In: Mandell GL, Bennett JE, Dolin R, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. Philadelphia, Pa: Churchill Livingstone; 2000:1703-08.

  9. Phillpotts RJ, O'brien L, Appleton RE, et al. Intranasal immunisation with defective adenovirus serotype 5 expressing the Venezuelan equine encephalitis virus E2 glycoprotein protects against airborne challenge with virulent virus. Vaccine. Feb 18 2005;23(13):1615-23. [Medline].

  10. Rivas F, Diaz LA, Cardenas VM, et al. Epidemic Venezuelan equine encephalitis in La Guajira, Colombia, 1995. J Infect Dis. Apr 1997;175(4):828-32. [Medline].

  11. Turell MJ. Vector competence of three Venezuelan mosquitoes (Diptera: Culicidae) for an epizootic IC strain of Venezuelan equine encephalitis virus. J Med Entomol. Jul 1999;36(4):407-9. [Medline].

  12. Watts DM, Callahan J, Rossi C, et al. Venezuelan equine encephalitis febrile cases among humans in the Peruvian Amazon River region. Am J Trop Med Hyg. Jan 1998;58(1):35-40. [Medline].

  13. Watts DM, Lavera V, Callahan J, et al. Venezuelan equine encephalitis and Oropouche virus infections among Peruvian army troops in the Amazon region of Peru. Am J Trop Med Hyg. Jun 1997;56(6):661-7. [Medline].

  14. Watts DM, Oberste MS. Venezuelan equine encephalitis. Hunter's Tropical Medicine and Emerging Diseases. In: Strickland GT, ed. Hunter's Tropical Medicine and Emerging Infectious Diseases. 8th ed. Philadelphia, Pa: WB Saunders; 2000:263-4.

  15. Weaver SC. Recurrent emergence of Venezuelan equine encephalomyelitis. In: Scheld WM, Amstrong D, Hughes JM, eds. Emerging Infections 1. Washington, DC: ASM Press; 1998:27-42.

  16. Weaver SC, Ferro C, Barrera R, et al. Venezuelan equine encephalitis. Annu Rev Entomol. 2004;49:141-74. [Medline].

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Further Reading

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Keywords

Venezuelan equine encephalitis, Venezuelan encephalitis, VEE, Venezuelan equine encephalitis virus, encephalomyelitis, peste loca

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Contributor Information and Disclosures

Author

Iris Reyes, MD, Advisory Dean; Director of Quality Improvement, Associate Professor, Department of Emergency Medicine, University of Pennsylvania
Iris Reyes, MD is a member of the following medical societies: American College of Emergency Physicians
Disclosure: Nothing to disclose.

Coauthor(s)

Sarah M Perman, MD, Resident, Department of Emergency Medicine, University of Pennsylvania Health Systems
Sarah M Perman, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Emergency Physicians, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

William H Shoff, MD, DTM&H, Director, PENN Travel Medicine, Associate Professor, Department of Emergency Medicine, Hospital of the University of Pennsylvania
William H Shoff, MD, DTM&H is a member of the following medical societies: American College of Physicians, American Society of Tropical Medicine and Hygiene, International Society of Travel Medicine, Society for Academic Emergency Medicine, and Wilderness Medical Society
Disclosure: Glaxo Smith Kline Consulting fee Consulting; Glaxo Smith Kline Honoraria Speaking and teaching

Suzanne Moore Shepherd, MD, MS, DTM&H, FACEP, FAAEM, Associate Professor, Department of Emergency Medicine, Hospital of the University of Pennsylvania; Director of Education and Research, PENN Travel Medicine
Suzanne Moore Shepherd, MD, MS, DTM&H, FACEP, FAAEM is a member of the following medical societies: Alpha Omega Alpha, American Academy of Emergency Medicine, American Society of Tropical Medicine and Hygiene, International Society of Travel Medicine, Society for Academic Emergency Medicine, and Wilderness Medical Society
Disclosure: Nothing to disclose.

Medical Editor

Martin J Wood, MD †, Former Consulting Staff, Department of Infection and Tropical Medicine, Birmingham Heartlands Hospital, UK
Martin J Wood, MD † is a member of the following medical societies: Alliance for the Prudent Use of Antibiotics, American Society for Microbiology, Infectious Diseases Society of America, International Society for Infectious Diseases, and Royal College of Physicians
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

John L Brusch, MD, FACP, Assistant Professor of Medicine, Harvard Medical School; Consulting Staff, Department of Medicine and Infectious Disease Service, Cambridge Health Alliance
John L Brusch, MD, FACP is a member of the following medical societies: American College of Physicians and Infectious Diseases Society of America
Disclosure: Nothing to disclose.

CME Editor

Eleftherios Mylonakis, MD, Clinical and Research Fellow, Department of Internal Medicine, Division of Infectious Diseases, Massachusetts General Hospital
Eleftherios Mylonakis, MD is a member of the following medical societies: American Association for the Advancement of Science, American College of Physicians, American Society for Microbiology, and Infectious Diseases Society of America
Disclosure: Nothing to disclose.

Chief Editor

Burke A Cunha, MD, Professor of Medicine, State University of New York School of Medicine at Stony Brook; Chief, Infectious Disease Division, Winthrop-University Hospital
Burke A Cunha, MD is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, and Infectious Diseases Society of America
Disclosure: Nothing to disclose.

 
 
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