Todayโs path rounds are on ๐ ๐๐๐ฏ๐๐ซ!
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐ ๐๐๐ฏ๐๐ซ is a bacterial disease that is considered highly ๐ฉ๐๐ญ๐ก๐จ๐ ๐๐ง๐ข๐ (easily causes disease). In fact, it is so infectious that it has been listed as a potential biological warfare agent! Just one bacterium is enough to cause serious disease in humans.
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
We most commonly associate this disease with sheep and goats!
๐๐ก๐๐ญ ๐๐๐ฎ๐ฌ๐๐ฌ ๐ข๐ญ?
The bacteria is spread between animals via normal bodily secretions, as well as the ๐ฉ๐ฅ๐๐๐๐ง๐ญ๐ and ๐๐ฆ๐ง๐ข๐จ๐ญ๐ข๐ ๐๐ฅ๐ฎ๐ข๐ (fluid the fetus sits in). The animal will inhale or ingest the bacteria, allowing it to enter the body. Typically, the bacteria likes to make a home for itself in the mammary gland, placenta or uterus of these animals. This is why the reproductive tissues are such an important source of infection! In fact, contact with sheep and goats giving birth is actually the main way this disease is spread to humans. The bacteria will persist in the reproductive tissues of these animals indefinitely, meaning they are a constant source of bacterial contamination.
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ ๐ฉ๐ซ๐จ๐๐ฅ๐๐ฆ?
Initial infection of a pregnant sheep or goat can cause ๐๐๐จ๐ซ๐ญ๐ข๐จ๐ง, as the bacteria will cause a ๐ฉ๐ฅ๐๐๐๐ง๐ญ๐ข๐ญ๐ข๐ฌ (infection of the placenta). This characteristically has the appearance of a thick, leathery placenta with the ๐๐จ๐ญ๐ฒ๐ฅ๐๐๐จ๐ง๐ฌ (the part that connects to the fetus) being unaffected.
In humans, Q fever causes fever, muscle aches, nausea, vomiting and diarrhea. In some cases, individuals may become ๐๐ก๐ซ๐จ๐ง๐ข๐๐๐ฅ๐ฅ๐ฒ ๐ข๐ง๐๐๐๐ญ๐๐ (long-term infection), which can cause ๐๐ง๐๐จ๐๐๐ซ๐๐ข๐ญ๐ข๐ฌ. Endocarditis is inflammation or infection of a heart valve, and in this case is caused by the bacteria setting up shop within the heart! If not treated, this can cause serious heart disease and even death.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐๐ ๐ง๐จ๐ฌ๐๐?
Diagnosis in sheep and goats is usually made by ๐ข๐ฆ๐ฆ๐ฎ๐ง๐จ๐ก๐ข๐ฌ๐ญ๐จ๐๐ก๐๐ฆ๐ข๐ฌ๐ญ๐ซ๐ฒ, where a dyed antibody against the bacteria is introduced on the slide. This highlights the bacteria under the microscope! In humans, ๐ฌ๐๐ซ๐จ๐ฅ๐จ๐ ๐ฒ to identify antibodies against the bacteria in the personโs blood is often used.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐? ๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ฉ๐ซ๐๐ฏ๐๐ง๐ญ๐๐?
Treatment is often not an option for infected animals, due to the significant risk this pathogen poses to humans. Additionally, treatment attempts have been largely unsuccessful. In people, treatment involves antibiotic therapy. In chronic cases, these antibiotics may need to be taken for several months.
๐๐ก๐จ๐ญ๐จ๐ฌ
1-2) Thickened placentas with the cotyledons (the big red dots) being unaffected.
3) An immunohistochemistry of a human heart valve showing the bacteria highlighted in brown!
4) What the bacteria actually looks like! These bacteria are ๐จ๐๐ฅ๐ข๐ ๐๐ญ๐ ๐ข๐ง๐ญ๐ซ๐๐๐๐ฅ๐ฅ๐ฎ๐ฅ๐๐ซ pathogens, meaning they can only survive within a cell. In this case, you can see the ๐ฏ๐๐๐ฎ๐จ๐ฅ๐ (essentially a bag) that they are living in!
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Maxie, G. Jubb, Kennedy and Palmerโs Pathology of Domestic Animals, Volume 3. Sixth Edition.
Q Fever. Centers for Disease Control and Prevention.
Photos 1-2 ยฉ Noahโs Arkive contributor King licensed under CC BY-SA 4.0.
Photos 3-4 ยฉ Centers for Disease Control and Prevention and the National Institutes of Health.
