Zoonotic encephalitis is most often transmitted hematologically as an arboviral infection with an arthropod vector and animal host. Often the vector is a mosquito or tick and the animal host is a small animal or bird. The one exception is rabies, which follows peripheral nerve tracts after inoculation from an infected animal's bite. Additionally, encephalitis may be seen in the nonviral zoonotic infections of Bartonella henselae, Brucella canis, borreliosis, Coxiella burnetii, Ehrlichia sp., listeriosis, leptospirosis, Lyme disease, RMSF, psittacosis, and toxoplasmosis.1 ,29,30 The presentation is one of a prodromal illness with malaise, myalgia, fever and, occasionally, parotiditis. This prodromal phase advances to a sudden decline in mental status associated with headache and fever. Prompt recognition and therapy of encephalitis is important, given the high morbidity and mortality rates. However, it is significant to recognize that there are no pathognomonic signs and symptoms that distinguish the exact etiology of encephalitis. The CSF is often abnormal, showing a slightly elevated opening pressure, normal to slightly elevated protein concentration, normal glucose levels, and predominance of lymphocytes. The patient has an abnormal electroencephalogram with diffuse bilateral slowing interrupted by occasional spike activity. CSF viral cultures are frequently sterile, and the infectious agent is rarely isolated from the CSF. 31,3 and 33 ELISA of serum can be used to detect most arboviral infections causing encephalitis. Treatment is supportive and directed toward decreasing the intracranial pressure.
Zoonotic meningitis has an equally varied range of pathogens. Brucellosis, listeriosis, plague, salmonellosis, tularemia, leptospirosis, Lyme disease, ehrlichiosis, Q fever, RMSF, and psittacosis can all be etiologic agents. CSF is almost always abnormal as in zoonotic encephalitis but with a greater concentration of lymphocytes. Treatment is directed toward the specific organism cultured from the CSF. However, empiric antibiotic coverage should be administered immediately in any presumptive case of meningitis in an effort to reduce mortality and morbidity.
Was this article helpful?
The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.