Microscopic detection of parasites has been the reference standard for malaria diagnosis for decades. However, difficulty in maintaining required technical skills and infrastructure has spurred the development of several nonmicroscopic malaria rapid diagnostic devices based on the detection of malaria parasite antigen in whole blood. The ParaSight F test is one such device. It detects the presence of Plasmodium falciparum-specific histidine-rich protein 2 by using an antigen-capture immunochromatographic strip format. The present study was conducted at outpatient malaria clinics in Iquitos, Peru, and Maesod, Thailand. Duplicate, blinded, expert microscopy was employed as the reference standard for evaluating device performance. Of 2,988 eligible patients, microscopy showed that 547 (18%) had P. falciparum, 658 (22%) had P. vivax, 2 (0.07%) had P. malariae, and 1,750 (59%) were negative for Plasmodium. Mixed infections (P. falciparum and P. vivax) were identified in 31 patients (1%). The overall sensitivity of ParaSight F for P. falciparum was 95%. When stratified by magnitude of parasitemia (no. of asexual parasites per microliter of whole blood), sensitivities were 83% (>0 to 500 parasites/l), 87% (501 to 1,000/l), 98% (1,001 to 5,000/l), and 98% (>5,000/l). Device specificity was 86%.

The ParaSight F test was developed as a pioneer industry effort in the large-scale, process-controlled production of a device for the rapid diagnosis of malaria. This device performed well in field settings but was limited to the detection of a single malaria species, Plasmodium falciparum. The ParaSight F؉V assay advanced upon the ParaSight F test format by incorporating a monoclonal antibody directed against a proprietary Plasmodium vivax-specific antigen, in addition to the antibody directed against P. falciparum histidine-rich protein 2, which was used in the ParaSight F assay. The modified assay was developed to add the capability to detect P. falciparum and P. vivax in a single-test-strip format. The present study evaluated three distinct ParaSight F؉V prototypes with samples from symptomatic patients in regions of Thailand and Peru where malaria is endemic. Over a 2-year enrollment period (1998 and 1999), a total of 4,894 patients consented to participation in the study. Compared with the results for duplicate microscopic examinations of Giemsastained blood smears as the reference diagnostic standard, each successive prototype showed substantial improvement in performance. The final ParaSight F؉V prototype, evaluated in 1999, had an overall sensitivity for detection of asexual P. falciparum parasites of 98%. The sensitivity of the device was 100% for P. falciparum densities of >500 parasites/l, with a sensitivity of 83% for parasite densities of <500/l. The specificity for the exclusion of P. falciparum was 93%. For P. vivax, the overall sensitivity was 87% for the final 1999 prototype. The sensitivities calculated for different levels of P. vivax parasitemia were 99% for parasite densities of >5,000/l, 92% for parasite densities of 1,001 to 5,000/l, 94% for parasite densities of 501 to 1,000/l, and 55% for parasite densities of 1 to 500/l. The specificity for the exclusion of P. vivax was 87%. The areas under the receiver operating characteristic curves for the diagnostic performance of the assay for the detection of P. falciparum and P. vivax were 0.8907 and 0.8522, respectively. These findings indicate that assays for rapid diagnosis have the potential to enhance diagnostic capabilities in those instances in which skilled microscopy is not readily available.The limitations associated with diagnostic microscopy are well documented. These limitations have fostered the development of nonmicroscopic alternatives for the diagnosis of malaria (1,3,6,11,20,21,23,26,36). Devices for the rapid diagnosis of malaria (MRDDs [malaria rapid diagnostic devices]) emerged in the past decade to meet the need for a reliable diagnostic adjunct to microscopy in the clinical setting (40). Timely, accurate diagnosis has the potential to greatly facilitate the provision of appropriate therapeutic interventions, and as the MRDD technology matures, these devices will have a pivotal role in malaria control initiatives.The leading MRDD technology is the immunochromatographic strip (ICS) format, into which antigen-capture immunoas...

Infected aneurysms caused by Listeria monocytogenes are rare. Worldwide, 16 cases have been reported, none in the iliac system. The authors report the case of an 80-year-old man being followed for small aortic and right common iliac artery (RCIA) aneurysms who presented with progressive gastrointestinal symptoms. Serial computed tomography demonstrated a 200% increase in RCIA diameter with development of infection over 1 month. Right axillobifemoral bypass and aneurysm resection were performed. The authors believe this case represents the first description of bacteremic seeding of an iliac degenerative aneurysm by Listeria monocytogenes. The natural history and aggressive course of vascular infection with this organism are documented.

This report presents a case of visceral leishmaniasis in a soldier returning from Operation Enduring Freedom. During the United States' last major military conflict, Operation Desert Storm, the diagnosis of multiple cases of visceral leishmaniasis led to policy changes, including a temporary ban on troop blood donation. This case demonstrates the applicability of recently developed Leishmania polymerase chain reaction and serological assays when conventional methods of diagnosis, such as tissue microscopy and culture, fail.