Introduction
Crimean–Congo hemorrhagic fever (CCHF) is an endemic disease in the
Northern Anatolia Region of Turkey that is characterized by fever and
hemorrhage and can have a severe and potentially life-threatening course1. The CCHF virus is generally transmitted to humans
through tick bites or contact with infected ticks or the bodily fluids
of infected animals. The main targets of CCHF are mononuclear
phagocytes, endothelial cells, and hepatocytes 2.
Signs and symptoms occur as a result of the effect of the virus on
target organs. Sudden-onset fever, headache, malaise, anorexia,
widespread body pain, and nausea are the most common symptoms3.
The pathogenesis of CCHF is not fully understood, though macrophage
activation and hemophagocytosis are known to be the basis of the
pathological process. After entering the body, the virus proliferates in
local lymph nodes and tissues, then spreads via the lymph and monocytes
to other parts of the body, especially the spleen, liver, lymph ganglia,
lungs, adrenal glands, and endothelium 4. Secondary
infection of parenchymal cells occurs by macrophage migration.
Macrophage and endothelial cell activation induces inflammatory and
vasoactive processes, resulting in systemic inflammatory response
syndrome (SIRS) 5. Coagulation system activation and
extensive fibrin accumulation in the vascular beds lead to disseminated
intravascular coagulation (DIC) and multiple organ failure (MOF)2.
Blood gas analysis is important for evaluating prognosis in SIRS and
MOF. Studies have shown that low pH, high lactate, and low
carboxyhemoglobin levels in venous blood gas analysis are important
markers of clinical course and prognosis 6. In
particular, lactate level is a serum marker frequently used in clinical
practice. High serum lactate is an indicator of tissue hypoperfusion.
Lactate is produced by many tissues of the human body and at high levels
in muscle tissue. Under normal circumstances, lactate is rapidly
eliminated by the liver and partly by the kidneys 7.
Procalcitonin level is believed to increase mostly in bacterial
infections and sepsis as part of the systemic inflammatory response
against infection. It is generally not expected to increase in response
to viral infections. However, it has been suggested that a major
increase in cytokine levels may lead to procalcitonin elevation8.
The aim of our study was to evaluate the relationship between
procalcitonin level and venous blood gas parameters and the clinical
course and prognosis of CCHF.