Chlamydophila psitacci is a bacterium that causes Psittacosis , commonly known as parrot fever, ornithosis or avian chlamydiosis It is aa bacterial infection that causes severe pneumonia in humans. The bacteria is transmitted from birds to humans by inhalation, contact or ingestion from pet birds or poultry.
The bacteria can be dormant in birds for a long time before they get activated. Activation can be due to stress. Psittacosis, has flu-like symptoms and can develop into septicaemia and infect the cells of organs and GI tract while being passed on to eggs of birds. contact with infected birds in the form of respiratory tract secretions, feces, mouth to beak contact or even in handling the infected birds’ feathers. Human beings that deal with birds and poultry are more susceptible to infection.
All forms of this bacteria are transmissable to humans and can cause severe to fatal pneumonia. The bacterium can survive outside the host without being active for a long time as an elementary body, till they find a suitable host. Since the elementary body is resistant it can survive outside the host without being destroyed. Once in the host the bacterium can remain dormant or can become active upon stress and then be transmitted to an uninfected bird. Since the bacterium in the elementary body form can remain dormant it can go undetected for a long time in the host also thus making Psittacosis hard to diagnose.
Once the elementary body reaches the lungs of the host it is engulfed into the cellular apparatus by a means called phagocytosis. While in the cell of the host the bacterium is encased in a sac called the endosome wherein it transforms into its active state also called the reticulate body and starts to replicate.
The bacterium generally infects the lungs and once in the cells it replicates rapidly using the host’s cellular apparatus’. Once replication is complete the bacteria are released in the dormant form or as an elementary body, killing the host cell in the process, and then infect another cell of the same host or remain dormant till they find another uninfected host. Between these two forms the elementary body and the reticulate body the difference is that the elementary body can infect but cannot replicate whereas the reticulate body can replicate but cannot cause new infection in the host.
The bacterium is lethal and causes severe respiratory disorders in humans. It can be treated with tetracyline.
