Health Professionals

Clinical Updates

7 September 2012

Hantavirus pulmonary syndrome: park visitors California, USA - update

This updates the Clinical Update of 29 August 2012

As of 7 September 2012, a total of eight cases of hantavirus pulmonary syndrome (HPS) have been reported in American tourists who stayed in Yosemite National Park on separate occasions since 10 June 2012 [1]. Three tourists have died and the five remaining individuals are either improving or recovering. Seven of the cases are known to have stayed in “Signature Tent Cabins” in the Boystown area of Curry Village in Yosemite National Park. One case stayed in multiple High Sierra Camps in the eastern, more remote part of Yosemite, a different area to Curry Village; this individual only had mild symptoms and is recovering.

Following recommendations from the California Department of Public Health, Yosemite National Park has closed tents in the Boystown area of Curry Village indefinitely. The National Park Service has contacted guests who stayed in the Boystown area between 10 June and late August to alert them to the HPS concern and advise them to seek medical attention if they are unwell [1].

Local Health Protection Agency (HPA) Units are contacting approximately 100 United Kingdom tourists who booked to stay at the park. The tourists are being supplied with health information and advice on HPS [2]. Any members of the public who have recently visited Yosemite and are concerned can find more information on the HPA website: FAQ Hantavirus Pulmonary Syndrome outbreak in Yosemite National Park, 2012.


Hantaviruses are a group of viruses, with different geographical distributions and specific rodent hosts, belonging to the family Bunyaviridae.

Humans can become infected when they inhale virus particles from rodent excreta (urine, faeces or saliva). Rodent infestation in and around the home remains the primary risk for hantavirus exposure, however risk factors for rodent exposure may be linked to occupational or leisure activities.

Hantavirus Pulmonary Syndrome (HPS) is a severe, sometimes fatal, respiratory disease in humans caused by infection with a hantavirus.

Advice for travellers

The risk of hantavirus in most travellers is generally considered to be low [3]. However, those who may be in close proximity with rodents, such as travellers undertaking activities in rural areas, e.g. camping or hiking should take the following precautions:

  • Wash hands thoroughly before eating.
  • Avoid direct contact with rodents or their excreta.
  • Inside areas frequented by rodents should be moistened and cleaned with disinfectant and then vacuumed whilst wearing a mask and gloves.
  • Take measures to avoid attracting rodents, such as keeping food covered and not storing firewood inside.

Yosemite National Park has produced information on recommended precautionary measures for visitors to the park.

There is no vaccine to protect against hantavirus infection.

Information on other specific health risks for travellers can be found on the NaTHNaC Country Information Pages.


1. Yosemite National Park Service.  Hantavirus in Yosemite [Accessed 7 September 2012]. Available at:

2. Health Protection Agency. HPA statement on outbreak of hantavirus pulmonary syndrome in the US. 3 September 2012. [Accessed 7 September 2012]. Available at:



3. Health Protection Agency. Hantaviruses. [Accessed 7 September 2012]. Available at: