Psittacosis: an underdiagnosed disease?

Birds are that part of the living species that have the wonderful possibility of flying (at least most of them), and we can enjoy watching them, not only for their maneuvers in the air but also for the striking color of their plumage. We can also see that in some houses they have in captivity some birds such as parrots, parakeets, macaws, among others.

This can be a very nice thing to see, however, in doing so we are exposing ourselves to a disease that may be underdiagnosed and actual prevalence could be higher than reported due to lack of proper diagnosis and reporting, I am referring to psittacosis.

This disease may actually have a higher prevalence than what is recorded, but largely because it is underreported it seems to have no impact at the societal level, however, it could be the cause of many consultations without even knowing it yet. If you want to know more about it, I invite you to read on, what I have to tell you will surely interest you.

Zoonoses are diseases that have the possibility of being transmitted from animals to humans, such is the case of this disease that I want to talk about today.

Psittacosis is an infectious disease that is transmitted to humans from contact with infected birds, especially parrots and parakeets. We may also know it as parrot disease or Chlamydia psittaci disease.

I do not usually talk about the life cycle of the bacteria, but in this case I want to do so, because it is there where you can clearly see each part of the process and thus be able to act at specific times to prevent the spread of the disease:

Generally speaking, the life cycle of Chlamydia psittaci, (the causative agent of psittacosis), develops in two forms: elementary form and reticular form.

Let's look at how this happens:

• The first is Ingestion: The elemental form is acquired by ingesting the bacteria present in the fecal matter or saliva of an infected bird.

• Transformation: Once in the intestinal tract, the elemental forms are transformed into reticular forms.

• Dispersal: The reticular forms disseminate through the circulatory system and reach tissues and organs where they can cause infection.

• Adhesion: Reticular forms adhere to host cells and penetrate into their interior.

• Replication: Within the host cells, the reticular forms multiply and cause damage to the cells.

• Release: Mature reticular forms leave the host cells and spread to other tissues and organs.

• Cyst formation: Reticular forms enclose themselves in cysts to protect themselves from host defenses.

• Transmission: Infected birds excrete the bacteria in their saliva, fecal matter and feathers, allowing transmission to other birds and humans.

The life cycle of Chlamydia psittaci is complex and its ability to cause infection depends on environmental and host factors, such as the immune response and virulence of the strain.

Symptoms of psittacosis include:

• Fever: It is one of the most common symptoms of psittacosis and can be of high or moderate intensity. As with any other infectious disease.

• Headache: It is a frequent symptom of psittacosis and can be very severe.

• Cough: Cough is a common symptom of psittacosis and can be dry or productive. This particular sign is confluent with many diseases.

• Muscle pain: There may be muscle pain and fatigue associated with psittacosis.

• Abdominal pain: There may be abdominal pain and nausea associated with psittacosis. This can be mistaken for gastrointestinal illness, and by taking an antibiotic for what is believed to be the cause, the Chlamydia psittaci is eventually eliminated.

• Chills: Chills and night sweats are common symptoms of psittacosis. This symptomatology can also be found in other diseases such as malaria, for example.

• Shortness of breath: There may be shortness of breath and shortness of breath associated with psittacosis.

It is important to consider that these symptoms can appear at any time after exposure to an infected bird, but usually appear between 2 and 14 days later.

Pixabay/ Author: ExergenCorporation

The treatment of psittacosis generally consists of the use of antibiotics. Considering the importance of maintaining an adequate use of these drugs and avoiding the increase of bacterial resistance to them, it is necessary that they are indicated by physicians.

The following are some of the antibiotics that are usually indicated for the treatment of this disease:

Doxycycline: It is a broad-spectrum antibiotic.

Erythromycin: This is another antibiotic used to treat psittacosis, especially in patients who cannot take doxycycline.

Clarithromycin: It is a second-line antibiotic used in some cases of psittacosis.

Logically, and I will not tire of repeating it, the treatment must be supervised by a physician and must be followed carefully to ensure cure of the infection. The duration of treatment depends on the severity of the infection and can last from several days to several weeks.

In addition to antibiotics, it is important to follow good hygienic practice measures to prevent transmission of the infection to other people and birds. This includes disinfection of contact areas with infected birds, frequent hand washing and avoidance of close contact with sick birds.

Pixabay/ Author: akirEVarga

Psittacosis is a zoonotic disease that can be found all over the world. The prevalence of this disease varies by region and depends on factors such as bird population density, the presence of exotic birds and bird management practices, especially the latter. At least based on the epidemiological data available.

In some regions, psittacosis is common in poultry farms and poultry hatcheries, while in other regions it is found mainly in wild birds.

In general, psittacosis is more common in regions with a high concentration of birds, especially in areas where domestic and wild birds frequently mix. In developed countries, the prevalence of the disease is usually low due to effective control and prevention measures.

But I particularly think that we could be in the presence of a fairly common disease, based on the symptomatology that I have talked about, however, not properly diagnosed. Fortunately treatment is given in some cases that can also work to eliminate the Chlamydia psittaci bacteria, and so there are no complications.

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This is just a thought I wanted to share about it, and there may not actually be any such infections. For now, I'm done with this post. Thank you very much for reading this post, if you have anything to add you can do so in the comments and we can all benefit.

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• Links consulted

• Persistent Chlamydiae: from Cell Culture to a Paradigm for
  Chlamydial Pathogenesis

• The chlamydial developmental cycle

• ompendium of Measures To Control Chlamydia psittaci Infection Among Humans (Psittacosis) and Pet Birds (Avian Chlamydiosis), 1998

• Avian Chlamydiosis