Clostridium difficile ( C. difficile ) is a Gram-positive, sporeforming bacterium usually spread by the fecal-oral route. It is non-invasive and produces toxins A and B that cause disease, ranging from asymptomatic carriage, to mild diarrhea, to colitis, or pseudomembranous colitis. CDI is defined as the acute onset of diarrhea with documented toxigenic C. difficile or its toxin and no other documented cause for diarrhea.
Dengue virus infection produces a broad spectrum of symptoms, many of which are non-specific. Thus, a diagnosis based only on clinical symptoms is unreliable. Early laboratory confirmation of clinical diagnosis may be valuable because some patients progress over a short period from mild to severe disease and sometimes to death. Early intervention may be life-saving.
Zika virus is spread to people through mosquito bites. The most common symptoms of Zika virus disease are fever, rash, joint pain, and conjunctivitis (red eyes). The illness is usually mild with symptoms lasting from several days to a week. Severe disease requiring hospitalization is uncommon.
Early recognition is critical for infection control. Healthcare providers should be alert for and evaluate any patients suspected of having EVD.
Health care-associated pneumonia has been categorized as a discrete entity, with the goal of identifying patients with pneumonia that develops outside the hospital yet is caused by pathogens usually associated with hospital-acquired pneumonia or even ventilator-associated pneumonia, including methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant (MDR) gram-negative pathogens.
Primary infection with varicella–zoster virus (VZV) results in chickenpox, characterized by viremia with a diffuse rash and seeding of multiple sensory ganglia, where the virus establishes lifelong latency. Herpes zoster is caused by reactivation of latent VZV in cranial-nerve or dorsal-root ganglia, with spread of the virus along the sensory nerve to the dermatome.
Chronic HBV infection is a necroinflammatory disease of the liver caused by persistent infection with HBV, and can be categorized as hepatitis B e antigen (HBeAg) positive or negative. Inactive hepatitis B surface antigen (HBsAg) carriers have HBV infection of the liver without significant, ongoing necroinflammatory disease. HBV infection is resolved when there is no further virologic, biochemical, or histologic evidence of active viral infection or disease.
Acute bacterial sinusitis in children is diagnosed on the basis of the history, with the use of the criteria. Imaging studies (plain-film radiography, computed tomography [CT], magnetic resonance imaging [MRI], and ultrasonography) show signs of sinus inflammation but are not recommended in patients with uncomplicated infection, given the low specificity of these studies.
Cierny and Mader classified osteomyelitis based on the affected portion of the bone, the physiologic status of the host and the local environment. This classification lends itself to the treatment and prognosis of osteomyelitis; stage 1 (medullary osteomyelitis) can usually be treated with antibiotics alone, while stages 2, 3 and 4 (superficial, localized and diffuse osteomyelitis) usually require aggressive debridement, antimicrobial therapy and subsequent orthopedic reconstruction.