Use of a Latent Class Analysis in the Diagnosis of Chronic Chagas Disease in the Washington Metropolitan Area.

Background: The diversity of individuals at risk for Trypanosoma cruzi infection in the United States poses challenges for diagnosis. We evaluated the diagnostic accuracy of Food and Drug Administration (FDA)-cleared tests in the Washington Metropolitan area (WMA).

Methods: In total, 1514 individuals were evaluated (1078 from Mexico, Central and northern South America [TcI-predominant areas], and 436 from southern South America [TcII/V/VI-predominant areas]).

The Immunoglobulin M-Shed Acute Phase Antigen (SAPA)-test for the Early Diagnosis of Congenital Chagas Disease in the Time of the Elimination Goal of Mother-to-Child Transmission.

Background: Diagnosis of congenital Chagas disease (CChD) in most endemic areas is based on low-sensitive microscopy at birth and 9-month immunoglobulin G (IgG), which has poor adherence. We aim to evaluate the accuracy of the Immunoglobulin M (IgM)-Shed Acute Phase Antigen (SAPA) test in the diagnosis of CChD at birth.

Methods: Two cohort studies (training and validation cohorts) were conducted in 3 hospitals in the department of Santa Cruz, Bolivia.

Use of magnetic particles in the purification of IgM antibodies against Taenia solium.

The use of L protein coupled magnetic particles for the concentration and purification of immunoglobulin M (mIgM) monoclonal antibodies against Taenia solium was evaluated. Three concentration methods and different elution times were evaluated and the ratio of particles to the ratio of mIgM was optimized. It is demonstrated that: 1) with the use of magnetic particles, a previous concentration of mIgM is not required, which reduces the manipulation of the antibodies and improves the recovery, 2) the use of a binding buffer can be omitted, since the pH of most cell culture supernatants are neutral, and 3) longer elution times (~ 45 minutes) are needed to increase recovery to a level greater than 80%.

Chagas Disease in Southern Coastal Ecuador: Coinfections with Arboviruses and a Comparison of Serological Assays for Chagas Disease Diagnosis.

Occurrence of Chagas disease and arbovirus coinfections is unknown, despite the vast co-endemic areas throughout the Americas. This study examined the proportion of individuals positive for and coinfections with dengue, chikungunya, and Zika viruses in Machala, Ecuador (January 2014-December 2015). Chagas seropositivity was evaluated with five commercially available assays.

Nanoparticle-Based Histidine-Rich Protein-2 Assay for the Detection of the Malaria Parasite Plasmodium falciparum.

A nanoparticle-based assay for detection and quantification of Plasmodium falciparum histidine-rich protein 2 (HRP2) in urine and serum is reported. The assay uses magnetic beads conjugated with anti-HRP2 antibody for protein capture and concentration, and antibody-conjugated quantum dots for optical detection. Western blot analysis demonstrated that magnetic beads allow the concentration of HRP2 protein in urine by 20-fold.

Domestic Pig (Sus scrofa) as an Animal Model for Experimental Trypanosoma cruzi Infection.

Pigs were infected with a Bolivian strain of Trypanosoma cruzi (genotype I) and evaluated up to 150 days postinoculation (dpi) to determine the use of pigs as an animal model of Chagas disease. Parasitemia was observed in the infected pigs during the acute phase (15-40 dpi). Anti-T.

Use of a Chagas Urine Nanoparticle Test (Chunap) to Correlate with Parasitemia Levels in T. cruzi/HIV Co-infected Patients.

Background: Early diagnosis of reactivated Chagas disease in HIV patients could be lifesaving. In Latin America, the diagnosis is made by microscopical detection of the T. cruzi parasite in the blood; a diagnostic test that lacks sensitivity.

Use of a novel chagas urine nanoparticle test (chunap) for diagnosis of congenital chagas disease.

Background: Detection of congenital T. cruzi transmission is considered one of the pillars of control programs of Chagas disease. Congenital transmission accounts for 25% of new infections with an estimated 15,000 infected infants per year.

Detection of soluble antigen and DNA of Trypanosoma cruzi in urine is independent of renal injury in the guinea pig model.

The diagnosis of Chagas disease in humans is generally limited to the detection of specific antibodies. Detection of T. cruzi antigens in urine has been reported previously, but is not used in the diagnosis.

Cell death and serum markers of collagen metabolism during cardiac remodeling in Cavia porcellus experimentally infected with Trypanosoma cruzi.

We studied cell death by apoptosis and necrosis in cardiac remodeling produced by Trypanosoma cruzi infection. In addition, we evaluated collagen I, III, IV (CI, CIII and CIV) deposition in cardiac tissue, and their relationship with serum levels of procollagen type I carboxy-terminal propeptide (PICP) and procollagen type III amino-terminal propeptide (PIIINP). Eight infected and two uninfected guinea pigs were necropsied at seven time points up to one year post-infection.

Cavia porcellus as a model for experimental infection by Trypanosoma cruzi.

The guinea pig (Cavia porcellus) is a natural reservoir for Trypanosoma cruzi but has seldom been used as an experimental infection model. We developed a guinea pig infection model for acute and chronic Chagas disease. Seventy-two guinea pigs were inoculated intradermally with 10(4) trypomastigotes of T.