Arenaviral hemorrhagic fevers, new world

CASES/YEAR
0 (US); 150 (Global)
CATEGORY
Zoonoses
AGENT TYPE
Viruses
OTHER NAMES
Junin hemorrhagic fever (Argentina); Machupo hemorrhagic fever (Bolivia); Guanarito hemorrhagic fever (Venezuela); Sabia hemorrhagic fever (Brazil); Chapare hemorrhagic fever (Bolivia);
ACUITY
Acute-Severe
INCUBATION
Usually 6-14 days; Range of 5 to 21 days; [CCDM, p. 49]
INITIAL SYMPTOMS
Flu-like illness with headache, fever, conjunctival injection, GI symptoms, flushing of the face and trunk, and petechiae of skin and soft palate; bleeding in severe infections; [CCDM]
PRECAUTIONS
Person-to-person is uncommon--has been documented for Machupo virus in healthcare workers and family; Also transmission by scalpel accidents and in laboratory; [CCDM, p. 49]
COMMENTS
FINDINGS:
About 20-30% of Junin infections are severe, and patients in the second week have epistaxis, hematemesis, melena, hematuria, gingival bleeding, and neurological symptoms (confusion, tremors, convulsions, cranial nerve palsies, and coma). Other findings are bradycardia, shock, leukopenia, thrombocytopenia, and proteinuria. [CCDM, p. 47] Other symptoms are dizziness, hyperesthesias, epigastric pain, back pain, lethargy, and in complicated cases hemorrhagic diathesis and/or delirium, coma, and convulsions. Weakness is prominent during the prolonged recovery. [ID, p. 2136-7] Acute renal failure is uncommon, but may occur as a consequence of shock and acute tubular necrosis. [Guerrant, p. 456] Most prominent findings (+++) are bleeding and neurological. Heart may be affected (++). Atypical (+) are effects on the lungs and skin (rash). Not typically noted (0) are jaundice, eye effects, and kidney disease. [Cecil, 2217t] Pulmonary edema and infiltrates from vascular leaks may occur. [PPID 7th Ed., p. 2299]

EPIDEMIOLOGY
The case fatality rate ranges from 15%-30% in untreated cases. The viruses are carried by wild rodents and transmitted by rodent feces or saliva. Field workers are at increased risk if exposed to dispersed rodent feces, e.g., by harvesting machines. Also at risk are laboratory workers and workers exposed to aerosols from farming or grain processing. [CCDM, p. 49]
DIAGNOSTIC
Viral culture; PCR; Antigen detection; IgM capture and IgG detection by ELISA; Biosafety level-4 required for culture and neutralizing antibody tests; [CCDM, p. 47-8]
SCOPE
Carried by wild rodents in South America; About 100-4000 cases per year reported from the endemic areas of the Argentine pampas; [CCDM]
SIGNS & SYMPTOMS
  • >fatigue, weakness
  • >fever
  • >myalgia
  • >relative bradycardia
  • E epistaxis
  • E stomatitis
  • G abdominal pain
  • G blood in stool
  • G constipation
  • G diarrhea
  • G hematemesis
  • G liver function test, abnormal
  • G nausea, vomiting
  • H leukopenia
  • H lymphadenopathy
  • H thrombocytopenia
  • N confusion, delirium
  • N headache
  • N lethargy
  • N paresthesia
  • N seizure
  • O conjunctivitis, acute
  • R hemoptysis
  • S petechiae and ecchymoses
  • S skin blister or vesicles
  • U hematuria
  • X lung infiltrates
  • *acute renal failure
  • *bleeding tendency
  • *cranial neuropathy
  • *myocarditis
  • *pulmonary edema
  • *shock
  • *stupor, coma
  • *weight loss
ANTIMICROBIC

Yes

VACCINE

Yes

ENTRY
Inhalation, Needle (Includes Drug Abuse), Scalpel or Transfusion, Skin or Mucous Membranes (Includes Conjunctiva)
SOURCE
Person-to-Person, Animal Excreta
RESERVOIR
Rodents
RISK FACTORS
  • Care for patients (bloodborne pathogen)
  • Care for patients (droplet/airborne)
  • Handle infected rodents (not bite)
  • Handle needles or surgical instruments
  • Raise dust of excreta from rodents
  • Travel to endemic area
  • Victim--air release of infectious agents
  • Work in a medical or research lab
TREATMENT
Convalescent serum given within 8 days of onset reduced the case fatality rate in Argentine disease to less than 1%. [CCDM, p. 49] "Passive antibody treatment for Junin/Argentine HF is effective, and an effective vaccine exists." [Harrisons, p. 570]
DRUG LINK
REFERENCES FOR CASES/YEAR
1.
2. (Global) Infections occur in rural settings; Annual incidence = 10-100 (Junin), 10 (Machupo), 10-100 (Guanarito) and unknown (Sabia); Case fatality rate is about 20%; [ID, p. 2133-4] <200 cases per year for Junin, Machupo, and Guanarito; Unknown for Chapare and Sabia; [Cecil, p. 2214t]