A viral organism was isolated from a painful blister on the lip of a teenage girl. The agent was found to double-stranded, linear DNA and was enveloped. The patient had a similar sore approximately 2 months ago. Which of the following is the most likely causative organism?
Herpes simplex is an enveloped, linear DNA virus that is a very common infectious agent; most adults will have anti-Herpes simplex antibodies in their serum, although many may not have ever had any clinical signs of disease. The hallmark of this disease is painful skin vesicles often called "cold" sores, or "fever" blisters to denote the precipitating event that preceded the appearance of the lesions. The virus has a propensity to become latent in the host, finding safe refuge in nervous tissue. Activation of the infection occurs following mild trauma (e.g., a visit to the dentist), hormonal changes (e.g., menses), and immunosuppression (e.g., following organ transplantation). Other, more serious, manifestations of disease include encephalitis, pneumonia, and hepatitis; these are paicularly likely to be seen in immunodeficient patients such as those with AIDS. Adenoviruses are naked, linear, double-stranded DNA viruses that cause acute, usually self-limiting, influenza-like illnesses occurring in winter. The symptoms include pharyngitis, fever, cough, and general malaise. Epidemic pharyngoconjunctivitis and pneumonia can occur in closed populations such as military installations. Coxsackie viruses are naked, single-stranded, polycistronic viruses with an RNA genome. They are divided into groups A and B based on their virulence in suckling mice. Coxsackie A group causes generalized myositis and flaccid paralysis, which is rapidly fatal to infant mice, whereas group B produces less severe lesions of the hea, pancreas, and central nervous system. In man, Coxsackie A causes herpangina and hand-foot-and-mouth disease, while Coxsackie B is seen in patients with pleurodynia, myocarditis, and pericarditis. Both groups cause upper respiratory infections, febrile rashes, and meningitis. Herpes zoster, the varicella virus, is an enveloped, double-stranded DNA virus that is a very common infectious agent in children. Chickenpox is a mild, self-limiting illness in children that is evidenced as a fever followed by a macular rash that progresses to papules, then vesicles of the skin and mucous membranes. Shingles is a recurrence of a previously latent varicella infection in which the virus has taken refuge in sensory ganglia of spinal or cranial nerves. Various factors that decrease the immune status of the patient contribute to the exacerbation of the infection. Severe dermatomal pain occurs with a vesicular eruption, fever, and malaise. Ref: Brooks G.F. (2013). Chapter 33. Herpesviruses. In G.F. Brooks (Ed), Jawetz, Melnick, & Adelberg's Medical Microbiology, 26e.
Adenovirus
Coxsackie virus
Herpes simplex type 1 virus
Herpes zoster virus