eMedicine Specialties > Infectious Diseases > Viral Infections
Arenaviruses: Follow-up
Updated: May 15, 2009
Follow-up
Deterrence/Prevention
- Rodent control
- Unlike plague, in which a rodent die-off can cause an increased risk of a human outbreak, the rodents carrying arenaviruses do not become ill or shed the virus in their urine.
- Aggressive rodent control (eg, trapping, rodent poisons) and avoidance of high-density rodent areas are the most important preventative maneuvers.
- Procedures to avoid rodent droppings and exposure include properly disposing of trash and clutter, moving woodpiles away from residences, properly airing out cabins and buildings prior to reoccupation, and avoiding creating dust when cleaning buildings with signs of rodent infestation.
- Arenavirus vaccination
- No commercially available vaccines are available to prevent Arenavirus infection.
- In one study with Lassa virus, a recombinant vaccinia virus that expressed Lassa virus glycoprotein was found to be efficacious in primates.
- More recently, clinical trials have begun on an attenuated Junin virus vaccine, and the vaccine has shown immunogenicity. This vaccine also may be protective against Machupo virus because of cross-antigenicity.
- Anecdotal information suggests that antigenically similar but nonpathogenic arenaviruses may be protective against Lassa fever in monkeys.
Complications
- LCM virus infection
- CNS complications beyond aseptic meningitis include encephalitis and may involve cranial nerve palsies and/or damage to the autonomic nervous system. Hypoglycorrhachia can be found.
- Non-CNS complications include orchitis, myocarditis, and small-joint arthritis. These develop, if at all, late in the illness, during the recurrence of fever.
- Intrauterine infection with LCM virus has been described. Infection may manifest as hydrocephalus and/or chorioretinitis with persistent spastic pareses and death within several years.
- Lassa fever
- Deafness, which can be unilateral or bilateral, is observed in as many as 30% of patients. Recovery of hearing occurs in approximately 50% of patients, but the deafness can be permanent.
- Maternal and fetal losses during Lassa fever infection are substantial. Maternal mortality rates can approach 30% and may be reduced with abortion. Fetal loss rates are close to 90% and are not affected by the trimester of infection.
- Renal or hepatic failure is not observed.
- South American hemorrhagic fevers
- In addition to severe hemorrhagic or CNS complications, convalescence in survivors can be quite prolonged, with weight loss, hair loss, and autonomic instability.
- As with Lassa fever, South American hemorrhagic fevers have substantial effects on the developing fetus.
Prognosis
- LCM virus infection: Survival with recovery from LCM virus infection is the rule.
- Lassa fever
- Hemorrhagic features are mild and rarely of prognostic significance.
- Risk factors for increased mortality are facial and/or neck edema, elevated aminotransferases, and increased viremia. With these in combination, the mortality rate can be higher than 80%.
- South American hemorrhagic fevers
- Mortality rates can be higher than 30%.
- Risk factors for mortality include a pronounced bleeding diathesis, severe neurologic deterioration, and shock.
Miscellaneous
Medicolegal Pitfalls
- Recognition of a case of Lassa fever or any of the South American Arenavirus infections is crucial from both infection control and epidemiologic standpoints. Suspected cases should be reported immediately to local public health authorities.
Special Concerns
- Management of contacts of imported cases of Lassa fever: Initially, imported cases of Lassa fever were treated with supportive care under conditions of total isolation. More recently, simple barrier nursing techniques have been found to be effective in preventing transmission to health care personnel. Guidelines have been developed to establish a level of risk for Lassa fever based on the degree of exposure to an index case. Similar criteria can be used for risk of exposure to South American hemorrhagic fever viruses.
- High-risk: These activities include unprotected contact with index case body fluids or excreta (eg, mouth-to-mouth kissing; sharing food, liquids, or eating utensils; sexual intercourse7 ; needle sticks). High-risk exposures usually precipitate ribavirin prophylaxis; closely monitor the contact for fever and/or illness and measure for seroconversion beginning on day 0 and on day 15.
- Medium-risk: Activities that are medium-risk include unprotected contact with surfaces that probably were contaminated or possible unprotected contact with index case body fluid or excreta (eg, drawing blood or handling lab slides containing unfixed specimen, handling bed sheets or bed pans, or perceived skin or mucosal contact with the aerosolized respiratory secretions from an index case). Medium-risk exposures trigger public health officials to monitor exposure for 21 days after the last exposure. If a fever of 38.3°C or higher occurs, intravenous ribavirin should be given and diagnostic studies of Lassa virus obtained. If the fever is low grade, other criteria, such as aminotransferase levels, should be used to determine action.
- Low-risk: These exposures include unprotected contact with the index case with little chance of exposure to body fluids/excreta (eg, examining index case without gloves or being within several feet of the case when a cough or sneeze occurs). Patients with low-risk exposures should be monitored for 21 days after the last exposure. If fever is higher than 38.3°C and aminotransferases are elevated, based on clinical judgment, further action (including hospitalization with or without ribavirin) may be indicated.
- No risk: Such exposure includes proximity of the index case without direct contact to potentially contaminated objects (eg, brief visit to patient's room without contact or handling blood or secretions with gloves).
More on Arenaviruses |
| Overview: Arenaviruses |
| Differential Diagnoses & Workup: Arenaviruses |
| Treatment & Medication: Arenaviruses |
 Follow-up: Arenaviruses |
| References |
| Further Reading |
| « Previous Page |
References
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Whitby LR, Lee AM, Kunz S, Oldstone MB, Boger DL. Characterization of lassa virus cell entry inhibitors: Determination of the active enantiomer by asymmetric synthesis. Bioorg Med Chem Lett. May 3 2009;[Medline].
Fichet-Calvet E, Rogers DJ. Risk maps of lassa Fever in west Africa. PLoS Negl Trop Dis. 2009;3(3):e388. [Medline].
Cosset FL, Marianneau P, Verney G, Gallais F, Tordo N, Pécheur EI, et al. Characterization of Lassa virus cell entry and neutralization with Lassa virus pseudoparticles. J Virol. Apr 2009;83(7):3228-37. [Medline].
Bateman C. Arenavirus deaths--emergency air services tighten up. S Afr Med J. Dec 2008;98(12):910, 912, 914. [Medline].
Furuta Y, Takahashi K, Shiraki K, Sakamoto K, Smee DF, Barnard DL, et al. T-705 (favipiravir) and related compounds: Novel broad-spectrum inhibitors of RNA viral infections. Antiviral Res. Jun 2009;82(3):95-102. [Medline].
Banerjee C, Allen LJ, Salazar-Bravo J. Models for an arenavirus infection in a rodent population: consequences of horizontal, vertical and sexual transmission. Math Biosci Eng. Oct 2008;5(4):617-45. [Medline].
Biggar RJ, Woodall JP, Walter PD, Haughie GE. Lymphocytic choriomeningitis outbreak associated with pet hamsters. Fifty-seven cases from New York State. JAMA. May 5 1975;232(5):494-500. [Medline].
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Centers for Disease Control and Prevention. Arenavirus infection--Connecticut, 1994. MMWR Morb Mortal Wkly Rep. Sep 2 1994;43(34):635-6. [Medline].
Centers for Disease Control and Prevention. Fatal illnesses associated with a new world arenavirus--California, 1999-2000. MMWR Morb Mortal Wkly Rep. Aug 11 2000;49(31):709-11. [Medline].
Cummins D, McCormick JB, Bennett D, et al. Acute sensorineural deafness in Lassa fever. JAMA. Oct 24-31 1990;264(16):2093-6. [Medline].
Fischer SA, Graham MB, Kuehnert MJ. Transmission of lymphocytic choriomeningitis virus by organ transplantation. N Engl J Med. 2006;354:2208-11.
Hinman AR, Fraser DW, Douglas RG, et al. Outbreak of lymphocytic choriomeningitis virus infections in medical center personnel. Am J Epidemiol. Feb 1975;101(2):103-10. [Medline].
Holmes GP, McCormick JB, Trock SC. Lassa fever in the United States. Investigation of a case and new guidelines for management. N Engl J Med. Oct 18 1990;323(16):1120-3. [Medline].
Jay MT, Glaser C, Fulhorst CF. The arenaviruses. J Am Vet Med Assoc. 2005;227:904-15.
Kiley MP, Lange JV, Johnson KM. Protection of rhesus monkeys from Lassa virus by immunisation with closely related Arenavirus. Lancet. Oct 6 1979;2(8145):738. [Medline].
Kunz S, de la Torre JC. Novel antiviral strategies to combat human Arenavirus infections. Curr Mol Med. 2005;5:735-51.
Lan S, McLay Schelde L, Wang J, Kumar N, Ly H, Liang Y. Development of infectious clones for virulent and avirulent Pichinde viruses - a model virus to study arenavirus-induced hemorrhagic fevers. J Virol. Apr 22 2009;[Medline].
Maiztegui JI. Clinical and epidemiological patterns of Argentine haemorrhagic fever. Bull World Health Organ. 1975;52(4-6):567-75. [Medline].
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Stinebaugh BJ, Schloeder FX, Johnson KM, et al. Bolivian hemorrhagic fever. A report of four cases. Am J Med. Feb 1966;40(2):217-30. [Medline].
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Further Reading
Clinical guidelines
Guidelines for environmental infection control in health-care facilities. Recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee.
Centers for Disease Control and Prevention - Federal Government Agency [U.S.]. 2003 Jun 6. 42 pages. NGC:003059
Guideline for isolation precautions: preventing transmission of infectious agents in healthcare settings 2007. Standard precautions.
Centers for Disease Control and Prevention - Federal Government Agency [U.S.]. 1996 Jan (revised 2007 Jun). 17 pages. NGC:005766
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Keywords
arenaviruses, lymphocytic choriomeningitis virus, Lassa fever virus, Machupo virus, Junin virus, Guanarito virus, viral hemorrhagic fever
