Despite the postulated role of the immune system in the control of the infection by Paracoccidioides brasiliensis, only a few studies have addressed this point in patients.

In patients with chronic paracoccidioidomycosis (n ‫؍‬ 10), levels of tumor necrosis factor alpha, interleukin-10, and interleukin-2 in serum, measured by enzyme-linked immunosorbent assay (in picograms per milliliter, as mean ؎ standard error of the mean), were higher than in normal controls (n ‫؍‬ 8): 186 ؎ 40 versus 40 ؎ 7 (P < 0.05), 203 ؎ 95 versus 20 ؎ 8 (P ‫؍‬ 0.001), and 96.3 ؎ 78.57 versus 1.19 ؎ 1.19 (P ‫؍‬ 0.045), respectively. Gamma interferon and interleukin-4 levels were similar in patients and controls.

Strongyloides stercoralis is a prevalent cause of severe infection and death in many areas of the world where fecal contamination of soil or water is common. The nematode is endemic in tropical and subtropical regions of the world, including northeastern Argentina, where infection rates may exceed 30% of the population. Strongyloides infections are often light and associated with few or no signs and symptoms, particularly during initial migration through the body. However, certain persons are at risk of severe, clinically significant disease developing. The manifestations of hyperinfection syndrome are divided, based on the system of origin, into intestinal and extraintestinal disease mainly involving the respiratory tract. Unfortunately, S stercoralis hyperinfection is seldom diagnosed until late in the course of the disease, which contributes to a high death rate. In patients with the hyperinfection syndrome and massive Strongyloides infection, adult respiratory distress syndrome with pulmonary insufficiency that requires intubation and mechanical ventilation may also develop. We report a case of S stercoralis hyperinfection in an HIV-infected patient, which resulted in death.

An episode of fungal peritonitis was produced by Bipolaris spicifera in a 3-year-old girl with chronic renal failure secondary to uremic-hemolytic syndrome and who was under treatment with continuous ambulatory peritoneal dialysis (CAPD). Previously, an episode of purulent peritonitis caused by Pseudomonas spp. had been treated successfully with combined antibacterial therapy for 10 days. Microscopic and macroscopic examinations of the freshly collected purulent dialysate were negative for fungal structures and bacteria. The fungus grew from the dialysate plated on Sabouraud dextrose agar and was also macroscopically recognized as a colony attached to the inner wall of the Tenckhoff catheter. Specific cultures of dialysate for common bacteria and mycobacteria were negative. The patient was successfully treated with early catheter removal and empirical administration of 200 mg/day oral fluconazole for 2 weeks. Subsequently, a new catheter was placed and the patient continued well on CAPD. Post-treatment control cultures of dialysate for fungi, bacteria and mycobacteria were negative and the cell count returned to normal.

Serological assays for T. cruzi infection may be negative in severely immunocompromised patients. Direct parasitological techniques should be performed in the diagnosis of patients for whom there is a suspicion of T. cruzi reactivation. HIV patients with a lower CD4 count are at higher risk of reactivation.

SUMMARYWe report the observation of acid-fast Cyclospora cayetanensis oocysts in a sputum sample. The patient, a 60 year-old, HIV negative man, was successfully treated for pulmonary tuberculosis during 1997. On February 1998, he was admitted to our center due to loss of weight, cough with purulent expectoration, dysphonia and a radiological picture of pulmonary fibrosis.Bacilloscopic study of sputum (negative for acid-fast bacilli) stained with Ziehl-Neelsen technique showed large (8-10 µm) spherical, acid-fast Cyclospora cayetanensis oocysts. No other pathogens were isolated on cultures from this sample or from laryngeal biopsy. Serial parasitologic studies showed C. cayetanensis and also eggs of Trichuris trichiura, Ascaris lumbricoides and Hymenolepis nana and of Entamoeba coli cysts.The patient lives in the outskirts of Buenos Aires in a brick-made house with potable water and works as builder of sewers. He travelled in several occasions to the rural area of province of Tucumán which has poor sanitary conditions. C. cayetanensis is an emergent agent of diarrhea and as far as we know this is the first time the parasite is observed in respiratory samples.

SUMMARYWe have compared the searching of the presence of "honeycomb" structures by direct microscopy on wet mount preparations with the direct immunofluorescence (DIF) for the diagnosis of Pneumocystis carinii pneumonia (PCP) in 115 bronchoalveolar (BAL) fluids. The samples belonged to 115 AIDS patients; 87 with presumptive diagnosis of PCP and 28 with presumptive diagnosis other than PCP.The obtained results were coincident in 114 out of 115 studied samples (27 were positive and 87 negative) with both techniques. A higher percentage of positive results (32.18%) among patients with presumptive diagnosis of PCP with respect to those with presumptive diagnosis other than PCP (3.57%) was observed. One BAL fluid was positive only with DIF, showed scarce and isolated P. carinii elements and absence of typical "honeycomb" structures.The searching for "honeycomb" structures by direct microscopy on wet mount preparations could be considered as a cheap and rapid alternative for diagnosis of PCP when other techniques are not available or as screening test for DIF. This method showed a sensitivity close to DIF when it was applied to BAL fluids of AIDS patients with poor clinical condition and it was performed by an experienced microscopist.

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