“Once somebody manages to make it in the door at our place, that’s a major accomplishment,” Dr. Grande said. For many patients, navigating a complex pathway to treatment, entailing multiple return visits over a period of weeks or months, can prove insurmountable. “It’s just a big barrier.”

Automated molecular tests could compress this process. From a small sample of blood or saliva, the tests amplify any trace of viral genetic material in a process akin to the older laboratory-based method of polymerase chain reaction (or P.C.R.), but have been miniaturized to run on small machines. The technologies have been around for years but gained greater visibility during the pandemic, when the F.D.A. allowed many test developers to leapfrog what is traditionally a lengthy approval process.

Companies that have developed coronavirus tests of this ilk have seen enormous growth. Cue Health, which is the official test provider of the N.B.A. and has sold more than 120,000 testing platforms, reported that annual revenue grew 25-fold to more than $600 million during the pandemic. Ayub Khattak, the company’s co-founder, said the streamlined regulatory process was transformative: “It just broke open the door.”

A similar molecular test for hepatitis C could allow clinicians to deliver a diagnosis immediately and perhaps start many patients on medications the same day, an approach known as “test and treat.” Patients may then be less likely to transmit the disease to others, and more likely to complete treatment and be cured.

One of the most promising hepatitis C tests was created by Cepheid, a diagnostic company based in California. With a palm-size cartridge preloaded with chemical reagents, the test runs on the company’s proprietary GeneXpert machine and can confirm the presence of a suspected pathogen in less than an hour. Because of its simplicity and size — the whole unit is the size of a desktop printer — it can be deployed at remote sites and can be operated by staff members with minimal medical training.

Research on how a rapid diagnosis affects patients’ hepatitis C treatment is limited. In a pair of pilot studies where the technology was taken to a syringe exchange and a prison, more than two-thirds of diagnosed patients began treatment, perhaps double the share of those who started therapy under typical conditions. Both studies received funding from drugmakers and in-kind support from Cepheid.

Jason Grebely, one of the investigators leading the study and a professor at the Kirby Institute, a medical research organization in Sydney, Australia, said the technology “is probably the next game-changer” in the field of treatment for hepatitis C. Dr. Grebely previously received research funding from Cepheid and various pharmaceutical companies.