Tags: Sinusitis

Cryptosporidium, Cyclospora, & Isospora Species & Microsporidia

Within the last decade, the AIDS epidemic has heightened awareness of several gastrointestinal spore-forming protozoan pathogens. The genera Cryptosporidium, Isospora, and Cyclospora are members of the subclass Coccidia and phylum Apicomplexa; the microsporidia are a group of organisms belonging to the phylum Microspora. The spectrum of disease caused by these protozoans goes beyond gastrointestinal manifestations, and the significance of these protozoan infections is becoming increasingly appreciated in both immunocompromised and immunocompetent hosts. CRYPTOSPORIDIUM Essentials of Diagnosis • Key signs and symptoms include dehydration with watery diarrhea of variable quantity. • Waterborne transmission is the most common mode of oocyst transmission. • Patients at risk for person-to-person transmission include household contacts, sexual …

Continue Reading...

Cryptosporidium: Clinical Syndromes

Enteric cryptosporidiosis is the most common clinical presentation in patient populations. In addition, immunocompromised patients may present with cholecystitis or respiratory infections attributed to C parvum (Box 1). Asymptomatic infection has also been reported. 1. ENTERIC CRYPTOSPORIDIOSIS Clinical Findings A. Signs and Symptoms. An average of 5-7 days passes from oocyst ingestion to symptom onset. Symptoms are similar in both immunocompetent and immunocompromised patients but are prolonged and considerably more severe in compromised patients. Patients complain of watery diarrhea in variable quantities of = 25 L/day leading to significant dehydration. Abdominal cramps, malaise, low-grade fever, and anorexia are frequently reported. Nausea, vomiting, myalgia, headache, and weight loss may also occur. Symptoms …

Continue Reading...

Aspergillus, Pseudallescheria, & Agents of Mucormycosis

ASPERGILLUS INFECTION Essentials of Diagnosis • Filamentous fungus with septate hyphae 3-6 um in diameter. • Branching of hyphal elements typically at 45° angle. • Specific IgG antibodies generally of no use diagnostically since most patients are immunosuppressed and will not generate antibody response. • Pulmonary lesions, localized or cavitary in susceptible host. General Considerations A. Epidemiology. Aspergillus spp. are found worldwide and grow in a variety of conditions. They commonly grow in soil and moist locations and are among the most common molds encountered on spoiled food and decaying vegetation, in compost piles, and in stored hay and grain. Aspergillus spp. often grow in houseplant soil, and such soil may …

Continue Reading...

Mucormycosis: Clinical Syndromes

1. RHINOCEREBRAL MUCORMYCOSIS Rhinocerebral mucormycosis occurs most commonly in patients with uncontrolled diabetes, especially after an episode of diabetic ketoacidosis. It may also occur in leukemic patients who have had prolonged neutropenia and therapy with broad-spectrum antibiotics and occasionally in organ transplant recipients. Clinical Findings A. Signs and Symptoms. The earliest symptoms in rhinocerebral mucormycosis are facial pain, headache, and nasal stuffiness. As the disease progresses, orbital pain and facial anesthesia may be noted. Double vision or loss of vision may develop after invasion of the orbit by the rapidly spreading infection. Mental status changes herald the penetration into the brain with ensuing cavernous sinus thrombosis, carotid artery thrombosis, and cerebral …

Continue Reading...

Pseudallescheria Boydii Infection

Essentials of Diagnosis • Filamentous fungus that is morphologically similar to Aspergillus spp. • Most serious infections occur in immunosuppressed patients. • Recovery from culture must be distinguished from colonization or contamination. General Considerations P boydii is a mold that is capable of causing infection in immunosuppressed patients and less frequently in immunocompetent patients. Overall, infection with P boydii is rare. A. Epidemiology. Although a relatively common environmental mold, P boydii is a rare cause of human disease. It can be easily recovered from soil, water, and manure. Both community and nosocomial acquisition have been documented. In most instances, its recovery from culture specimens will reflect colonization or contamination; however, it …

Continue Reading...

Aspergillus Sinusitis

Aspergillus spp. are capable of causing a variety of infections involving the paranasal sinuses (Table 2). Although uncommon, Aspergillus sinusitis is related to the immune status and immunologic response of the host. A. Signs and Symptoms. In the severely immunosuppressed or neutropenic patient, Aspergillus sinusitis or rhinosinusitis may occur. Symptoms include headache, toothache, nasal congestion, purulent nasal discharge, and sinus or eye pain. Fever is commonly encountered. The nasal mucosa may exhibit hyperemia or necrosis that may extend into the mouth. Ptosis and loss of extraocular eye movement are prominent signs, indicating extensive invasion into the orbit. Sudden onset of blindness may occur. In patients with normal immune status and a …

Continue Reading...

Chlamydia

General Considerations Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae are among the most prevalent microbial pathogens in humans worldwide. C trachomatis is responsible for a variety of sexually transmitted disease (STD) syndromes in both sexes. In addition, certain serotypes of C trachomatis are responsible for trachoma, the most common infectious cause of blindness in humans. C psittaci is a zoonotic pathogen associated with atypical pneumonia. C pneumoniae infects approximately one-half of the world’s human population and is a cause of upper and lower respiratory tract disease. It has also been associated with atherosclerotic cardiovascular disease. A. Epidemiology. In the United States, genital infections by C trachomatis serovars D through K occur …

Continue Reading...

Mycoplasma & Ureaplasma

Mycoplasma and Ureaplasma species (mycoplasmas) are ubiquitous in nature and are commonly found in plants, animals, and humans. These bacteria contain the smallest amount of double-stranded DNA that is capable of producing a free-living microorganism; they measure between 0.15 and 0.3 um in diameter and = 2 um in length. They are believed to have evolved from a putative common ancestor of the gram-positive bacteria by a process of genome reduction and adoption of a dependent, parasitic life style. Mycoplasma and Ureaplasma spp. lack a cell wall. Therefore, they cannot be visualized with the Gram stain and are not susceptible to antibiotics that act on cell wall synthesis (eg, penicillins and …

Continue Reading...

Actinomyces

Essentials of Diagnosis • “Sulfur granules” in specimens and sinus tract drainage: hard, irregularly shaped, yellow particles measuring from 1 to 5 mm in size • Gram-positive branching filaments arranged in ray-like projections under the microscope • Colonies with characteristic “molar tooth” appearance • Production of extensive fibrosis with “woody” induration • No specific antibody or antigen detection tests General Considerations A. Epidemiology. The Actinomyces species are facultative anaerobes that commonly inhabit the oral cavity, the gastrointestinal tract, and the female genital tract, where they exist as commensals. Diversity within this genus is broad, which has led to taxonomic revision and reclassification of some species as members of the Arcanobacterium genus, …

Continue Reading...

Nocardia

Essentials of Diagnosis • Gram-positive, variably acid-fast, branching filaments with aerial hyphae. • Colonies have characteristic chalky-white or cotton ball appearance. • Suspect when chronic pulmonary disease is accompanied by CNS or skin lesions. • No specific antibody or antigen detection tests. General Considerations A. Epidemiology. Nocardia spp. are strictly aerobic, ubiquitous soil-dwelling organisms that are largely responsible for the decomposition of organic plant material. Infection usually occurs via inhalation of these organisms in airborne dust particles, leading to pulmonary disease. However, infection can also be acquired via direct percutaneous inoculation by thorns, animal scratches, bites, surgical wounds, and intravenous catheters. Dissemination commonly occurs to the central nervous system (CNS), skin, …

Continue Reading...
CLOSE
CLOSE