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8:30 AMStuff the Bus Volunteer Day
Published on May 11, 2018. Last modified on May 14, 2018
Signs & Symptoms
Due to the small number of HPS cases, the “incubation time” is not positively known. However, on the basis of limited information, it appears that symptoms may develop between 1 and 8 weeks after exposure to fresh urine, droppings, or saliva of infected rodents. Early Symptoms include fatigue, fever and muscle aches, especially in the large muscle groups—thighs, hips, back, and sometimes shoulders. These symptoms are universal. There may also be headaches, dizziness, chills, and abdominal problems, such as nausea, vomiting, diarrhea, and abdominal pain. About half of all HPS patients experience these symptoms. Four to 10 days after the initial phase of illness, the late symptoms of HPS appear. These include coughing and shortness of breath, with the sensation of, as one survivor put it, a “…tight band around my chest and a pillow over my face” as the lungs fill with fluid. HPS can be fatal. It has a mortality rate of 38%.
Infected rodents shed hantavirus in their urine, droppings, and saliva. Most HPS patients become infected by breathing air contaminated with dried rodent urine or droppings, such as when cleaning out a rodent-infested space. This most commonly occurs in small, confined spaces where there is little air circulation. Rarely, individuals can also be infected by: 1) consuming food contaminated with rodent urine or droppings; 2) touching surfaces where rodents have been, and then putting their hand in their mouth; 3) being bitten by an infected rodent.
Rodents and Hantavirus
Hantaviruses are maintained in nature in wild rodents. In California, only deer mice carry and shed hantavirus. Other rodents such as squirrels, chipmunks, and house mice are rarely, if ever, infected and do not pose a risk of HPS to humans. The hantavirus strain present in deer mice is Sin Nombre (SNV).
The Deer Mouse (Peromyscus maniculatus) is a deceptively cute animal, with big eyes and ears. Its head and body measure approximately 2-3 inches (5cm – 7.5cm) in length, and the tail adds another 2 – 3 inches. In color, the deer mouse ranges from grey to reddish brown, depending on age. The underbelly is always white and the tail has clearly defined white sides. The deer mouse is found throughout North America, preferring woodlands, but also appearing in desert areas.