Azithromycin versus Sulfadiazine and Pyrimethamine for non-vision-threatening toxoplasmic retinochoroiditis: a pilot study.

BACKGROUND: The purpose of this pilot study is to compare the efficacy and tolerance of azithromycin alone as opposed to standard treatment with sulfadiazine and pyrimethamine for active, non-vision-threatening toxoplasmic retinochoroiditis. MATERIAL/METHODS: We conducted a prospective, randomized, institutional clinical study comparing azithromycin to sulfadiazine and pyrimethamine for active, non-vision-threatening toxoplasmic retinochoroiditis. Nineteen out of 75 patients fulfilled inclusion criteria and were randomized into 2 treatment regimens. Nine patients were treated with sulfadiazine and pyrimethamine and 10 patients with azithromycin at a dose of 500 mg qd. Main outcome measures assessed were time to sharpening of lesion borders, time to lesion scarring, time to disease inactivity, and treatment tolerance. RESULTS: Azithromycin monotherapy achieved lesion scarring and disease inactivity in all but 1 patient. Although no statistically significant difference was found between the 2 patient groups as regards main outcome measures for treatment efficacy, all median times to endpoints (days) were longer for the azithromycin group - time to sharpening of lesion borders on clinical evaluation (25.5 vs. 24) and masked evaluation of photographs (30.5 vs. 24), time to lesion scarring on clinical evaluation (73 vs. 47) and masked evaluation of photographs (71.5 vs. 36) and time to disease inactivity (73 vs. 49). Treatment tolerance was significantly better for the azithromycin group (p=0.0005). CONCLUSIONS: Azithromycin monotherapy at a dose of 500 mg per day was shown to be effective and well-tolerated for the treatment of active, non-vision-threatening toxoplasmic retinochoroiditis. Duration of treatment was clinically longer for the azithromycin group.

Identification of an atypical strain of toxoplasma gondii as the cause of a waterborne outbreak of toxoplasmosis in Santa Isabel do Ivai, Brazil.

Multilocus DNA sequencing has identified a nonarchetypal strain of Toxoplasma gondii as the causal agent of a waterborne outbreak in Brazil in 2001. The strain, isolated from a water supply epidemiologically linked to the outbreak, was virulent to mice, and it has previously been identified as BrI. Using a serologic assay that detects strain-specific antibodies, we found that 13 (65%) of 20 individuals who were immunoglobulin (Ig) M positive during the outbreak possessed the same serotype as mice infected with the purported epidemic strain. The remaining 7 individuals, plus additional IgM-negative, IgG-positive individuals, possessed 1 of 4 novel serotypes, the most common of which matched the serotype of mice infected with strains isolated from chickens foraging near the outbreak site. The latter strains likely reflect the genetic diversity of T. gondii circulating in highly endemic regions of Brazil. The serotyping assay proved a useful tool for identification of specific individuals infected with the outbreak agent.

Characteristics of untreated AIDS-related cytomegalovirus retinitis. I. Findings before the era of highly active antiretroviral therapy (1988 to 1994).

PURPOSE: To identify factors related to variations in the appearance of untreated AIDS-related cytomegalovirus (CMV) retinitis in severely immunodeficient individuals before the availability of highly active antiretroviral therapy (HAART) and to draw inferences regarding early events in the natural history of CMV retinitis based on clinical findings. DESIGN: Retrospective, observational case series. METHODS: We evaluated a series of 100 adult patients with AIDS and newly diagnosed CMV retinitis before the HAART era who were not being treated with specific anti-CMV therapy. Demographic factors, ophthalmic findings, and the influence of drug therapy (zidovudine, acyclovir) on lesion characteristics were evaluated. Lesion border opacity was scored using a four-point scale of severity. RESULTS: Lesions could be categorized by type (fulminant/edematous or indolent/granular) in only 66% of eyes. Severe lesion border opacity (4+) was related to presence of zone 1 lesions (P = .032) and greater extent of disease (P = .004). Acyclovir use was associated with less severe opacity (P = .029) and less zone 1 involvement (P = .016). Early lesions were adjacent to vessels in 73% of eyes; the fovea was involved in 13% of eyes. CONCLUSIONS: Lesion location and drug use that affects virus activity may influence the severity of lesion border opacity, a measure that may be more useful than lesion type in future clinical studies of CMV retinitis. In contrast to earlier concepts, CMV retinitis does not seem to be a fovea-sparing disease. Findings in this study can serve as a reference for investigations into possible changes in CMV retinitis since the introduction of HAART.

Characteristics of untreated AIDS-related cytomegalovirus retinitis. II. Findings in the era of highly active antiretroviral therapy (1997 to 2000).

PURPOSE: To describe host characteristics (use of highly active antiretroviral therapy [HAART]; CD4+ T-lymphocyte count; HIV ribonucleic acid [RNA] blood level) of people who were diagnosed with AIDS-related cytomegalovirus (CMV) retinitis after HAART became available and to investigate effects of HAART on ophthalmic findings. DESIGN: Retrospective, observational case series. METHODS: We collected demographic, medical, laboratory, and ophthalmic data for all patients with AIDS and newly diagnosed, untreated CMV retinitis from January 1997 through December 2000 at 10 sites in Los Angeles and Orange Counties, California. RESULTS: The proportions of Hispanic and African-American patients were equivalent to or greater than their prevalences in the AIDS and general populations of Los Angeles County. Most patients (n = 80; 63.5%) were known to be receiving HAART at the time of CMV retinitis diagnosis; only 22 patients (17.5%) were HAART-naïve. Median CD4+ T-lymphocyte count was 15 cells/microl and median HIV RNA blood level was 103,000 copies/ml for all patients, but in 10 patients, CMV retinitis developed despite good immunologic and virologic responses to HAART. When compared with HAART-naïve patients, HAART-failure patients with CMV retinitis had more asymptomatic disease (P = .073), better visual acuity in the better eye (P = .003), more bilateral disease (P = .007), less zone 1 involvement (P = .042), and lower lesion border opacity scores (P = .054). CONCLUSIONS: Most patients with AIDS and newly diagnosed CMV retinitis in an urban setting are HAART-experienced. HAART may influence characteristics of new CMV retinitis lesions at presentation, despite laboratory evidence of treatment failure, possibly because of residual CMV-specific immunity.

Severe interference between retinal angiography and automated four-color flow cytometry analysis of blood mononuclear cells.

BACKGROUND: Retinal angiography has become a widely used diagnostic tool. It requires the intravenous administration of the fluorescent dyes fluorescein and indocyanin green. We recently received blood taken 8 h after retinal angiography, without our knowing it. We describe the failure of an automated flow cytometry system in the enumeration of lymphocyte subpopulations in this sample. METHODS: Cell enumeration was achieved by the use of the lyse-no wash MultiTEST procedure (Becton-Dickinson) together with the FACSCalibur cytometer. Absolute cell counts were obtained using TruCount beads. Data were analyzed automatically by the MultiSET and manually with the CellQuest softwares. RESULTS: The dot plots obtained with this sample looked quite abnormal. All monuclear cells stained brightly in the FITC channel irrespective of anti-CD3-FITC conjugate binding. This resulted in a major undercompensation for the increased spillover of the fluorescein emission into the PE-channel. PE-labeled cell and TruCount bead events coalesced. The MultiSET software failed to draw proper gatings and proved useless. Alternative manual gatings could partially rescue the analysis. CONCLUSIONS: Clinicians and cytometrists should be aware that, because of dye entry or binding, blood mononuclear cells collected shortly after retinal angiography are not suitable even for common cytometry applications.