Tags: Trimethoprim

Toxoplasma Gondii

Toxoplasma gondii infection, or toxoplasmosis, is a zoonosis (the definitive hosts are members of the cat family). The two most common routes of infection in humans are by oral ingestion of the parasite and by transplacental (congenital) transmission to the fetus. Ingestion of undercooked or raw meat that contains cysts or of water or food contaminated with oocysts results in acute infection.

Toxoplasma Gondii: Treatment

Immunocompetent adults and children with toxoplasmic lymphadenitis do not require treatment unless symptoms are severe or persistent. Infections acquired by laboratory accident or transfusion of blood products are potentially more severe, and these patients should always be treated. The combination of pyrimethamine, sulfadiazine, and folinic acid for 4-6 weeks is the most commonly used and recommended drug regimen (Box 2).

Pneumocystis Carinii

In 1983, P carinii pneumonia (PCP) was described as the AIDS-defining illness in = 60% of the first 1000 patients diagnosed with AIDS in the United States. Subsequently, the advent of prophylactic measures has reduced the incidence of PCP presenting as the initial diagnosis for AIDS to < 50% of cases. In addition, the hospitalization rate is also declining for patients with AIDS who also have PCP. This decline has presumably been caused by successful use of prophylaxis against the organism.

Extrapulmonary P Carinii Infections

Extrapulmonary P carinii infections occur in < 3% of patients and must be diagnosed with histopathologic samples. Primary prophylaxis for PCP with pentamidine may confer a higher risk for extrapulmonary infection. Symptoms of extrapulmonary involvement are nonspecific, usually consisting of fevers, chills, and sweats.

Fusarium, Penicillium, Paracoccidioides, & Agents of Chromomycosis

Fusarium spp. is an emerging fungal pathogen. Although long recognized as a cause of local infection involving nails, traumatized skin, or the cornea (eg, in contact lens wearers), deep or disseminated infection was not described until the mid 1970s. Despite its worldwide distribution and its frequent recovery from soil and vegetative material, infection is quite rare. Only ~ 100 cases involving invasive disease in immunosuppressed patients have been described in the medical literature.

Paracoccidioidomycosis

Paracoccidioidomycosis is caused by Paracoccidioides brasiliensis. Also known as South American blastomycosis, it is the most prevalent systemic mycosis found in Central and South America and is the most common endemic mycosis in this area. Paracoccidioidomycosis is acquired only in Central and South America and ranges from Mexico to Argentina.

Fever & Bacteremia/Trench Fever/Endocarditis

Patients complain of fever, myalgias, malaise, headache, bone pain — particularly of the legs, and a transient macular rash. Usually the illness continues for 4-6 weeks.

Nocardia

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.

Brucella, Francisella, Pasteurella, Yersinia, & Hacek

Brucellosis (also called undulant fever, Mediterranean fever, Malta fever) is an infection that causes abortion in domestic animals. It is caused by one of six species of Brucella coccobacilli. It may occasionally be transmitted to humans, in whom the disease could be acute or chronic with ongoing fever and constitutional symptoms without localized findings.