# A Point-of-Care Test for Rapid Diagnosis of Valley Fever

> **NIH NIH R43** · CACTUS BIO, LLC · 2023 · $243,118

## Abstract

A Point-Of-Care Test for Rapid Diagnosis of Valley Fever
PROJECT SUMMARY
Coccidioidomycosis (Valley Fever) is a respiratory disease caused by inhalation of spores from the desert soil-
dwelling fungus, Coccidioides spp. In endemic areas, up to 30% of community acquired pneumonia (CAP) is
caused by Coccidioides spp.1 Valley Fever mimics other viral and bacterial respiratory infections and is
challenging to diagnose. Nearly three million tests for Valley Fever are done in clinical laboratories each year
in humans. Typically, a tube of blood is sent to a clinical laboratory to test for antibodies against a Coccidioidal
fungal antigen preparation using Enzyme ImmunoAssay (EIA), ImmunoDiffusion (ID) and/or complement
fixation (CF) tests. The time from blood draw to assay result may be 48 hours to 2 weeks. This SBIR proposal
focuses on a rapid antibody test that can be performed in 10 minutes while the patient is present.
Based on clues in previous publications2,3, our preliminary data demonstrate that CTS1, a chitinase, is the
primary sero-reactive immunodominant Coccidioidal antigen. Therefore, we developed a rapid test that
employs recombinant CTS1 (rCTS1) to detect Coccidioidal-specific IgG or IgM, independent of species being
tested (e.g. human or canine). Excluding the large veterinary market, the primary human market for this test is
Urgent Care Clinics, Emergency Departments and many primary care practices.
First Innovation: Although rapid antibody tests using lateral flow technology are not new, a 10-minute rapid
test for VF that provides sufficient sensitivity and specificity and detects either IgM or IgG antibodies against
the fungus would dramatically advance clinical care for human (and canine) patients. One example is in the
urgent care clinic where a patient with a community acquired pneumonia caused by Coccidioides spp. could
receive an accurate diagnosis using our rapid test during their visit with a simple finger-stick drop of blood.
Without the availability of a rapid, sensitive and specific test, an urgent care physician is unlikely to order a VF
test because the result comes back to the physician up to 4 days after the patient has been discharged.
Instead, patients usually receive a prescription for an antibiotic for pneumonia–which is an inappropriate
treatment for coccidioidomycosis–and leave urgent care with an incorrect/incomplete diagnosis, potentially lost
to follow up. The innovation of our rapid 10-minute test is that it provides a clinically actionable answer in 10
minutes with a single drop of blood instead of 2-4 days using current testing methods.
Second Innovation: Growth of Coccidioides spp. requires a certified BSL3 laboratory, highly trained personnel
and special facilities which are expensive and time-consuming; this BSL3 effort cannot be overstated. Our
innovative hypothesis is that rCTS1 can serve as the primary antigen target for antibodies in patients with
coccidioidomycosis. We will test the performance of our...

## Key facts

- **NIH application ID:** 10759985
- **Project number:** 1R43AI179331-01
- **Recipient organization:** CACTUS BIO, LLC
- **Principal Investigator:** Francisca Grill
- **Activity code:** R43 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $243,118
- **Award type:** 1
- **Project period:** 2023-07-24 → 2026-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10759985

## Citation

> US National Institutes of Health, RePORTER application 10759985, A Point-of-Care Test for Rapid Diagnosis of Valley Fever (1R43AI179331-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10759985. Licensed CC0.

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