# Novel nanoparticular diagnostics for cerebral toxoplasmosis and Chagas in HIV patients living in Latin America

> **NIH NIH R01** · JOHNS HOPKINS UNIVERSITY · 2021 · $648,345

## Abstract

PROJECT SUMMARY
Among the most devastating opportunistic diseases associated with human immunodeficiency virus (HIV) are
those that affect the central nervous system (CNS). Their nonspecific presentation makes diagnosis difficult even
in the best-resourced settings, and in Low and Middle Income Countries (LMICs), a definitive diagnosis can be
all but impossible. In this context, CNS infections such as toxoplasmic encephalitis (TE) and CNS Chagas
disease are often treated empirically, which can be fatal when physicians' best guesses are incorrect.
Toxoplasma gondii seroprevalence is estimated to be highest in Latin America, but diagnosis in HIV-positive
patients is difficult without expensive technologies that are unavailable in resource-poor countries. Similarly,
Chagas disease, caused by Trypanosoma cruzi, is a serious opportunistic infection in people living with
HIV/AIDS, and is also difficult to diagnose. Finally, tuberculosis meningitis (TBM) is difficult to diagnose and
frequently fatal because of the delay in diagnosis. 33% of Peruvians and Bolivians are at risk for the development
of TB, when patients are HIV positive they are at risk of TBM. Much of South America, including our study site
in Bolivia, is highly endemic for both T. cruzi and T. gondii as well as other common CNS opportunistic
pathogens. We propose the development and pilot testing of a novel diagnostic assays and their use in clinical
diagnosis of TE and CNS Chagas disease through the following aims:
Specific Aim 1: Development of parallel lateral flow assays for TE, TBM, and CNS Chagas. In addition to
our already developed dot blot assays for Chagas and TB, we have preliminary data that demonstrates
nanoparticles' ability to capture and detect multiple T. gondii antigens. (3-5) With further development, we will
be able to transition these individual immunoassays into a simultaneous lateral flow test.
Specific Aim 2. To determine the sensitivity and specificity of the nanoparticle diagnostic assays for TE,
TBM and CNS Chagas disease in a well-characterized cohort of HIV-infected patients with acute
neurological syndromes. We expect that the proportion of neurological syndromes due to toxoplasmosis, TBM,
and cryptococcal meningitis will be similar to those in other South American HIV populations. We anticipate,
however, that CNS Chagas disease will also cause a substantial proportion of neurological disease in the
Bolivian population, which may have been underdiagnosed.
This project will help define the clinical spectrum of HIV-associated neurological disease in Latin America and
use innovative diagnostic techniques to distinguish between CNS Chagas disease, TBM, TE, and other CNS
infections. Where multiple pathogens are endemic and are rapidly fatal, more rapid, sensitive, and specific tests
could accelerate the initiation of specific and potentially life-saving therapy.

## Key facts

- **NIH application ID:** 10207356
- **Project number:** 5R01AI136722-04
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** ROBERT H GILMAN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $648,345
- **Award type:** 5
- **Project period:** 2018-06-18 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10207356

## Citation

> US National Institutes of Health, RePORTER application 10207356, Novel nanoparticular diagnostics for cerebral toxoplasmosis and Chagas in HIV patients living in Latin America (5R01AI136722-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10207356. Licensed CC0.

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