For Immediate Release:

August 15, 2006

LOS ANGELES - In late July, a fatal case of hantavirus pulmonary syndrome occurred in a Los Angeles County resident who had been camping for weeks prior to onset of illness in Mono County, California, a location previously known to carry hantavirus.

Late last week, the Los Angeles County Department of Public Health confirmed another case of hantavirus pulmonary syndrome, in a youth living in the Antelope Valley. He complained of fever, headache, shortness of breath, and cough in late July. He was hospitalized when his condition worsened, and he died of acute respiratory distress syndrome on August 6. A test performed by the California Viral and Rickettsial Disease Laboratory confirmed the illness to be due to hantavirus. An investigation is underway to determine the source of his exposure.

Hantavirus pulmonary syndrome (HPS) is a disease transmitted by infected rodents through urine, droppings, or saliva. Humans can contract the disease when they breathe in aerosolized virus through activities such as dusting or sweeping areas contaminated with rodent excrement. Hantavirus infections can be asymptomatic, cause a mild hantaviral illness or HPS. Supportive medical care is necessary since there is no specific treatment for the disease. HPS was first recognized in 1993 and has since been identified throughout the United States. The virus strain most common in the western US is called Sin Nombre virus. The virus is not transmissible from person to person.

Public Health's Environmental Health Division will be testing deer mice in areas frequented by the youth for evidence of hantavirus. Evidence of hantavirus in deer mice has been detected by Environmental Health previously in some parts of the Antelope Valley. Deer mice commonly are found in natural grasslands, chaparral habitats and sparsely vegetated desert areas. The only other two confirmed hantavirus cases recorded in Los Angeles County since the disease recognition in 1993, acquired disease in other parts of the state or outside California.

In California, the only rodent to transmit hantavirus is the deer mouse, Peromyscus maniculatus. Control of deer mice in and around homes and cabins remains the primary strategy for preventing hantavirus infection. The common house mouse or other rodents do not carry this disease. A list of frequently asked questions and answers is attached.

About Public Health

Public Health is committed to protecting and improving the health of the nearly 10 million residents of Los Angeles County. Through a variety of programs, community partnerships and services, Public Health oversees environmental health, disease control and community and family health and comprises more than 3,800 employees with an annual budget exceeding $700 million. *********************************************************

Hantavirus - Frequently Asked Questions

What is hantavirus pulmonary syndrome (HPS)?

Hantavirus pulmonary syndrome (HPS) is a deadly disease transmitted by infected rodents through urine, droppings, or saliva. Humans can contract the disease when they breathe in aerosolized virus.

Who is at risk of contracting HPS?

Anyone who comes into contact with rodents that carry hantavirus is at risk of HPS. Rodent infestation in and around the home remains the primary risk for hantavirus exposure. Even healthy individuals are at risk for HPS infection if exposed to the virus.

Which rodents are known to be carriers of hantavirus that cause HPS in humans?

In the United States, deer mice, cotton and rice rats (in the Southeast), and the white-footed mouse (in the Northeast), are the only known rodent carriers of hantaviruses causing HPS.

How is HPS transmitted?

Hantavirus is transmitted by infected rodents through urine, droppings, or saliva. Individuals become infected with HPS after breathing fresh aerosolized urine, droppings, saliva, or nesting materials. Transmission can also occur when these materials are directly introduced into broken skin, the nose or the mouth. If a rodent with the virus bites someone, the virus may be spread to that person, but this type of transmission is rare.

Can you contract HPS from another person?

HPS in the United States cannot be transmitted from one person to another. You cannot get the virus from touching or kissing a person who has HPS or from a health care worker who has treated someone with the disease. In addition, you cannot contract the virus from a blood transfusion in which you receive blood from a person who survived HPS.

Can you contract HPS from other animals?

Hantaviruses that cause HPS in the United States are only known to be transmitted by certain species of rodents. HPS in the United States is not known to be transmitted by farm animals, dogs, or cats or from rodents purchased from a pet store.

How long can hantavirus remain infectious in the environment?

The length of time hantaviruses can remain infectious in the environment is variable and depends on environmental conditions, such as temperature and humidity, whether the virus is indoors or outdoors or exposed to the sun, and even on the rodents diet (which would affect the chemistry of its urine). Viability for 2 or 3 days has been shown at normal room temperature. Exposure to sunlight will decrease the time of viability, and freezing temperatures will actually increase the time that the virus remains viable. Since the survival of infectious virus is measured in terms of hours or days, only active infestations of infected rodents result in conditions that are likely to lead to human hantavirus infection.

How do I prevent HPS?

SEAL UP, TRAP UP, CLEAN UP: Seal up rodent entry holes or gaps with steel wool, lath metal, or caulk. Trap rats and mice by using an appropriate snap trap. Clean up rodent food sources and nesting sites and take precautions when cleaning rodent-infested areas.

What are the recommendations for cleaning a rodent- infested area?