Andes virus (ANDV)

Andes virus (ANDV)

• is a type of hantavirus, within the order Bunyavirales
  
  
• ANDVinfection in humans was first described in 1995 in Argentina, and was identified in Chile later in the same year
  • is a cause of hantavirus cardiopulmonary syndrome (HCP) in South America, which is a potentially fatal, acute medical complication of specific hantavirus infections
• wild rodents of the family Cricetidae are the natural animal reservoir of ANDV, particularly the long-tailed pygmy rice rat (Oligoryzomys longicaudatus). Humans can acquire ANDV infection by contact with infected rodents or their excreta in South America, principally in Argentina and Chile, and rarely through contact with an infected person
  
  
• are several ANDV hantavirus strains associated with HCPS. Officially classified strains include Castelo dos Sonhos virus, Lechiguanas virus and Orán virus, whilst Araucária virus, Araraquara virus, Bermejo virus, Buenos Aires virus, Juquitiba virus, Paranoa virus and Plata virus are unclassified strains

In Argentina

• cases of ANDV HCPS mostly occur across 4 endemic regions: North (Salta, Jujuy), Centro (Buenos Aires, Santa Fe, and Entre Ríos), Northeast (Misiones) and Patagonia (Neuquén, Río Negro, and Chubut)

In Chile

• ANDV infections occur mainly in southern Chile and ANDV infection is endemic in the Región de Los Lagos

Seasonal Variation in Morbidity

• cases peak in spring and summer, when the number of infected rodents tends to be high and people engage in more outdoor activities, particularly in rural and semi-rural areas. Some years may be associated with an increased risk of exposure, according to factors such as favourable climatic conditions and increases in rodent populations

Patient assessment

• ANDV infection is classed as an airborne high consequence infectious disease (HCID) in England and clinical assessment should be performed by specialist hospital staff, with adherence to strict infection prevention and control precautions (see below) to prevent secondary transmission
  
  
• currently no agreed case criteria for ANDV infection. Consider ANDV infection in a patient with a relevant travel and exposure history who presents with a compatible illness, particularly severe acute respiratory illness, and the onset of illness was within 8 weeks of a potential exposure
  
  
• visitors to rural areas of Argentina and Chile (for example mountain trekkers and campers) may be at increased risk of ANDV infection, including those who do not report a history of known exposure to rodents and their excreta. ANDV infection is a rare disease and other travel associated and common infections should also be considered in the differential diagnosis
  
  
• any suspected cases in England should be discussed initially with local infection specialists and then with the Imported Fever Service (IFS) (24 hour telephone service: 0844 778 8990). The IFS can advise on whether laboratory testing is indicated. The IFS is also available to clinicians in Scotland, Wales and Northern Ireland. Any suspected cases should be notified immediately to the local Health Protection Team.

Laboratory diagnosis

• in the UK, the Rare and Imported Pathogens Laboratory (RIPL) at Public Health England (PHE) Porton Down is the designated diagnostic laboratory. RIPL offers RT-PCR and IgG serological assays for the detection of hantaviruses
  
  
• any suspected case should be discussed with local infection specialists and with the IFS , as above. The IFS can advise on whether laboratory testing is indicated, and if so, will provide advice about the samples types required. IFS will also advise on sample collection precautions and transport requirements

Notes:

• other hantaviruses found in North and South America can cause HCPS, for example Sin Nombre virus in the US and Laguna Negra virus in Paraguay and Bolivia. However, ANDV is the only hantavirus for which human-to-human transmission has been described. Limited human-to-human transmission within families and within healthcare settings has been reported for previous outbreaks in Chile and Argentina
  
  
• rare cases of travel associated ANDV infection have also been reported, including infections in travellers returning to the US and Europe from Argentina and Chile, respectively
  • see risk map for HCPS caused by ANDV in southern Argentina

Reference:

• Public Health England (May 2021). Andes hantavirus: epidemiology, outbreaks and guidance