Tularemia
Tularemia may be defined as a zoonotic disease that is widely distributed all over the world. It is caused by Francisella tularensis, “small, aerobic, catalase-positive, pleomorphic, gram-negative coccobacilli” of animals and, in rare circumstances, of humans (Penn, 2015, p. 2591). Although Francisella tularensis requires cysteine or cysteine for growth, it will not grow on gram-negative selective media or most routine solid media (Penn, 2015). For the identification of this pathogen in specialized laboratories, direct fluorescent antibody and polymerase chain reaction tests are traditionally used (Penn, 2015). As a facultative intracellular pathogen, Francisella tularensis survives within the host organism’s macrophages due to phagosome lysosome fusion and may suppress or avoid cellular and humoral defenses (Penn, 2015). Humans are infected intradermally or when a particular dose of Francisella tularensis was inhaled. Several main patterns of the disease include pneumonic, typhoidal, glandular, oculoglandular, ulceroglandular, and pharyngeal tularemia (Penn, 2015). In general, the major symptoms of the infection are headache, chills, fever, fatigue, and anorexia. Other distinct signs of tularemia may include vomiting, myalgias, cough, sore throat, chest discomfort, diarrhea, and abdominal pain.
The treatment of tularemia is generally determined by the severity of the disease. The general treatment of mild and moderate tularemia implies the use of antibiotics, such as streptomycin and gentamicin, while the most serious forms of the disease require surgical treatment (Penn, 2015). Intramuscular injections frequently require the delivery of health care in medical settings as certain negative reactions and symptoms increase may occur. In general, antibiotics have “exhibited achievable minimal inhibitory concentrations” against Francisella tularensis (Penn, 2015, p. 2600). Even though vaccination for tularemia does not exist, effective preventative measures include the avoidance of exposure to the organism and antibiotic prophylaxis (Penn, 2015). At the same time, the isolation of patients with tularemia is not necessary, as the person-to-person spread was not recorded.
Hantavirus
Hantavirus belongs to the virus family Bunyaviridae and the mechanism of its activity implies the replication in the host cells’ cytoplasm (Muranyi, et al., 2005). It generally has a spherical shape, and its genome consists of large, medium, and small segments (Jiang, et al., 2017). Hantavirus infects humans’ endothelial cells and induces severe vascular endothelial dysfunction in small vessels and capillaries (Jiang, et al., 2017). Humans become infected “through the inhalation of aerosols contaminated with the virus concealed in the excreta, saliva, and urine of infected animals” (Jiang, et al., 2017, p. 32). In laboratory settings, thrombocytopenia related to hantavirus may be detectable through an ELISA-based detection, immunochromatographic assays, or reverse transcriptase–PCR (Muranyi, et al., 2005). Several diseases may be caused by hantavirus – hemorrhagic fever with renal syndrome, nephropathy epidemic, and hantavirus cardiopulmonary syndrome (Jiang, et al., 2017). In general, distinct symptoms include sudden fever, abdominal discomfort, myalgia, diarrhea, headache, vomiting, coughing, or eye inflammation.
In the present day, there is an absence of antiviral drugs that may apply to the treatment of hantavirus infections. The therapy is restricted to particular supportive procedures to control life-threatening symptoms (Muranyi, et al., 2005). Patients with hantavirus are supervised in emergency departments of intensive care for monitoring and health care until the beginning of the convalescent phase (Muranyi, et al., 2005). The preventative measures include the prevention of contact with murid rodents and vaccination against hantavirus for the development of antibodies.
References
Jiang, H., Zheng, X., Wang, L., Du, H., Wang, P., & Bai, X. (2017). Hantavirus infection: A global zoonotic challenge. Virologica Sinica, 32(1), 32-43.
Muranyi, W., Bahr, U., Zeier, M, & Woude, F. J. (2005). Hantavirus infection. Journal of the American Society of Nephrology, 16(12), 3669-3679.
Penn, R. L. (2015). 229 – Francisella tularensis (Tularemia). Mandell, Douglas, and Bennett’s principles and practice of infectious diseases, 2590-2602.