Mimivirus is associated with community and hospital-acquired pneumonia. In a recent study, antibodies against Mimivirus were found in patients with community-acquired pneumonia more frequently than in control patients. The antibodies were detected with microimmunofluorescence assays and seroconversion calculations. Patients with community-acquired pneumonia and serologic evidence of Mimivirus were more frequently re-hospitalized after discharge probably due to the lack of antimicrobial agents against viruses. The study therefore suggests that Mimivirus is a good candidate as an etiologic agent of pneumonia acquired in institutions. Furthermore, Mimivirus DNA was found in bronchoalveolar lavage suggesting it may reach the respiratory tract and thus be spread via a respiratory route. Not enough studies have been conducted yet to determine the epidemiology of Mimivirus infection, but the relationship between viral infection and human disease is worth exploring since the causes of many pneumonia cases are still unknown.
Figure. As observed by scanning electronic microscopy,
Mimivirus antigen (A) is recognized by antibodies in our microimmunofluorescence
assay using conventional fluorescence microscope
(B) and confocal microscope (C). Mature particles within
amebas are also recognized by antibodies seen with transmission
electronic microscopy immunogold technique (D) Mimivirus particle
size 400 nm).
Picture: La Scola et al (2005)