Nicole M. Bouvier1,2 and Anice C. Lowen2,*
Guinea pigs have been used to study transmission of the influenza virus and the effectiveness of vaccines. The guinea pig most commonly used for influenza virus research is the outbred Hartley strain. Though they (and all guinea pigs) are naturally susceptible, "The main drawback of the guinea pig model for influenza research is the lack of disease signs exhibited by infected animals."
The virus is:
- Often administered intranasally
- Viral growth predominantly in the upper respiratory tract
- By day 8, infection may be cleared
- Growth in lungs is more moderate and shorter lived with no virus 5 days post infection
The study below also demonstrates the lack of visible signs of illness:
Influenza Virus Transmission Is Dependent on Relative Humidity and Temperature
Influenza virus–infected guinea pigs did not display detectable signs of disease (e.g., weight loss, fever, sneezing, coughing) during the experiments described in this article. Nasal swabs showed the presence of the disease.
The researchers discovered that influenza is more easily spread in cool/cold dry spaces. If temperatures are high and/or humidity is high (80%+), influenza does not seem to spread. This may help explain the seasonal nature of influenza.