Immunocompromised Information and Courses from MediaLab, Inc.

This is a higher power view of this same smear demonstrating a neutrophil that is filled with Toxopasma gondii tachyzoites (blue arrow).There are a few free organisms in this image well, indicated by the red arrows. Again, the typical morphology for toxoplasmsa organisms is lavender cytoplasm with a red granular cluster in the center of each parasite.This patient was negative for Toxoplasma gondii prior to a transplant but had received 15 units of blood products due to cytopenias.It is believed that a donor for one of the transfused units had been exposed to Toxoplasma gondii either through cats or contaminated food and had transient circulating Toxoplasma gondii in his or her blood when the donation was made. In this case, the recipient was profoundly immunocompromised, which lead to rapidly developing systemic disease.

Rocourt J. Jacquet C. Reilly A.: Epidemiology of human listeriosis and seafoods. International Journal of Food Microbiology. 62:197-209, 2000 While rarely diagnosed prior to 1960, more than 10,000 cases of listeriosis were recorded in the medical literature between 1960 and 1982, and thousands more have been reported annually world-wide. This widespread increase in reporting is most likely due to demographic trends and changes in food production, processing and storage, especially the extended cold food chain and the ability of Listeria monocytogenes to grow at low temperatures L. monocytogenes is a bacterium responsible for opportunistic infections, preferentially affecting individuals whose immune system is perturbed, including pregnant women, newborns, people over 65 years, immunocompromised patients, such as cancer victims, transplant recipients, people on hemodialysis and AIDS patients. Thus, the increasing lifespan and medical progress allowing immunodeficient individuals to survive, partially explains the increasing incidence of listeriosis. Moreover, L. monocytogenes is ubiquitous and can grow at temperatures as low as 0 degrees C. At this temperature growth is very slow. The expansion of the agro-food industry, the widespread use of systems of cold storage and changes in consumers demands have led to a large increase in the pool of Listeria that can cause food-borne infections.

The mucicarmine staining procedure is very specific in its detection of mucins of epithelial origin and is used to identify adenocarcinomas. It is particularly useful in detecting adenocarcinomas originating in the gastrointestinal tract. This procedure can also successfully stain and detect the capsule of a fungal organism known as Cryptococcus neoformans . This fungus is usually identified in the lungs and in nervous tissues. C. neoformans is more likely to infect immunocompromised patients than persons with active immune systems.

Enterococci are largely commensal organisms that are opportunistic pathogens. Underlying disease, an immunocompromised state, age, lengthy hospital stays or long term care, invasive treatments, and/or prior antimicrobial therapy are factors that are associated with significant infections with these species. As noted previously, Enterococci are intrinsically resistant to many antibiotics. Intrinsic resistance affects not only beta lactams (including a broad range of cepahlosporins) and aminoglycosides, but also clindamycin and trimethoprim/sulfamethoxazole. The standard recommended therapy for systemic infections is a combination of either penicillin or vancomycin and an aminoglycoside (gentamicin or streptomycin). The goal of combination therapy is to achieve a synergistic bacteriocidal effect between the cell wall agent and the aminoglycoside.In recent decades, increasing resistance to other antibiotics through acquired resistance mechanisms has become a growing therapeutic and infection control problem. Of key concern are high level resistance (HLR) to aminoglycosides and increasing resistance to glycopeptides such as vancomycin.

The Influenza A 2009 H1N1 virus spreads from person to person in a similar way to the seasonal flu in previous years.The primary route of influenza virus transmission and infection are by respiratory droplets and aerosols. Transmission may also occur via contaminated hands (person-to-person) and surfaces. Infected individuals can shed the virus and spread Influenza A 2009 H1N1 to others anywhere from 1 day prior to getting sick up until 5-7 days after symptoms arise. This range of viral shedding can be even longer in children and in some individuals who are immunocompromised.

Transfusion-associated graft versus host disease (TA-GVHD) is a rare but highly lethal adverse reaction. The disease has a 90% mortality rate. It is caused by the transfusion of donor lymphocytes to a recipient who is immunocompromised. The donor lymphocytes engraft and escalate an immune response against the host's tissues including organs such as the lungs, skin, intestines, and liver. The recipient is unable to destroy the foreign lymphocytes and the cells proliferate and respond to incompatible antigens in the host. Certain recipients have increased risk for developing TA-GVHD. They are: Neonates less than 4 months of age Fetuses Recipients with a congenital or acquired immunodeficiency Recipients of donor units from a blood relative