This microbiologist endured a four-year court battle over COVID-19 tests

When the COVID-19 pandemic began sweeping across the world in February 2020, Linda Guamán, a microbiologist at the University UTE in Quito, was ready to serve her country. Ecuador announced its first case on 29 February, and the disease spread quickly. Guayaquil, the nation’s largest city, was hit particularly hard. Hospitals, funeral homes and mortuaries were overwhelmed, with bodies reportedly being abandoned in the streets. Guamán, whose research focused on synthetic biology and metabolic engineering, knew that the country would not have enough testing capacity — and she wanted to help.

“It was clear to me that I should use all the knowledge that I had gained. I joke about this, but I was kind of happy in the sense that this is what I’d been reading about for my whole career. This is what I’d trained for,” she says.

However, within months, that excitement turned to anguish as she became embroiled in a political controversy over the purchase of COVID-19 tests. In an ordeal that lasted several years, she would be arrested, face a trial with the possibility of a prison sentence of up to 13 years and be forced to wear an ankle tag to monitor her movements.

Guamán recounts how she received a call in April 2020 from Ximena Abarca, a public-health scientist and former vice-minister of health, inviting her to work on Quito’s COVID-19 testing strategy. The city had purchased around 100,000 rapid point-of-care tests from a company overseas, and even before Guamán accepted Abarca’s offer, there were stories in the press about the tests being overpriced. “My mum said, ‘You’re going to get into trouble if you take this job.’ But to me it seemed pretty clear. I didn’t participate in the purchase of the tests — I’m just going to work as hard as I can,” Guamán recalls.

In January 2021, the police contacted her. And in March, she was accused of misappropriating public funds, alongside Abarca, Jorge Yunda — a physician, and Quito’s mayor at the time — and 11 others, mainly scientists and health workers. At first, Guamán did not realize the gravity of the situation.

“I just thought, this is absurd. It makes no sense and it’s all going to end really soon,” she says.

The investigation focused on why the Municipality of Quito chose to use loop-mediated isothermal amplification (LAMP) tests rather than the more widespread polymerase chain reaction (PCR) tests. LAMP tests are similar to PCR tests but are faster and simpler to use, because they don’t require repeated cycles of heating and cooling. Michael Mina, an epidemiologist and immunologist who was based at the Harvard T.H. Chan School of Public Health in Boston, Massachusetts, at the time and gave evidence through a video link at the trial, tells Nature he felt it was his duty as a scientist to explain how testing for the virus worked.

“At the time, there was tremendous confusion about the science of testing,” he says. “Linda was not confused,” he adds. She saw LAMP as “a very powerful and inexpensive approach to COVID-19 testing” that her country could use at a time when PCR reagents were in short supply across the globe. “LAMP was an alternative to PCR that was exceptionally high quality, and available,” Mina says.

Testing alternatives

Mina, who went on to help lead the US government’s Home Test to Treat Program, points to an erroneous view at the time that PCR was the only test that could be relied on. He says that LAMP, and then antigen tests, each had their own applications in different circumstances. “In some ways, PCR turned out to be one of the most limited technologies for the needs of the pandemic,” he adds. “It was too sensitive to reliably use as an indicator of whether someone was infectious and required isolation. It was also technically challenging for many labs, and reagents were expensive and scarce. LAMP was a great alternative.”

Guamán maintains that prosecutors built a case against her and her co-defendants using a report she had commissioned, which was published as a paper¹ in January 2021. It showed that the LAMP tests had a sensitivity of 61.9%, and prosecutors reasoned that they were therefore substandard (a point eventually rejected by the court, she says).

Prosecutors alleged that Guamán and her fellow defendants had misused public funds. Ecuador has long been characterized by political instability, which Guamán suddenly found herself caught up in. Yunda described the allegations at the time as “political persecution”.

The first court case, which took place in September 2021, was paused after the defence lawyers argued that one of the judges was biased.

During this hiatus, restrictions were placed on the defendants’ movements: they had to report to a police station twice a week, could not buy or sell any property and had to wear an ankle tag.

For Guamán, this was one of the most humiliating aspects of the ordeal. She says police would contact her through the tag and if they rang she would have to lift up her ankle to speak into it. It needed to be charged frequently, and she would have to sit down while it was plugged into the wall. She became pregnant during this period, and had to apply to the court to have the tag removed while she gave birth in 2023. Within days of her son being born, police came to refit it.

Guamán’s university organized a public statement in her and Abarca’s defence, which was signed by 60 academics from across Ecuador. In it, they expressed “solidarity and support” for Guamán as a fellow scientist and said that they were concerned by an “attempt to implicate” her in a “possible act of embezzlement”. They added: “We reject this emphatically, given her impeccable career, which has earned her recognition both within and outside the country.”

In November 2021, the Committee of Concerned Scientists, an international non-profit organization based in New York City, wrote to Ecuador’s president, Guillermo Lasso. The letter acknowledged that doubts had been raised about the LAMP tests, but voiced concerns “that scientific research has been used to settle a political score with the former administration of Quito that authorized the testing”. The political climate in Ecuador is febrile.

The letter said of Guamán’s ordeal: “Such weaponization of science has no place in health services.”

Public recognition

In 2023, Guamán was shortlisted for the John Maddox Prize, an award for individuals who stand up for science and evidence, but she could not travel to London for the award ceremony. The citation praised “her bravery in enduring political intimidation for her conduct as a scientist in public office” and said she had been “caught up in a backlash against the city mayor”. During her ordeal, Guamán says, she was ostracized by some colleagues and stopped being invited to conferences. Others supported her in private but were too fearful to speak out publicly.

While waiting for the trial to resume, she carried on working and was made director of the Centre of Biomedical Research (CENBIO) at UTE. Her work now focuses on biodiscovery, looking both in the laboratory and in the jungles of Ecuador for molecules that have anti-cancer, anti-inflammatory or anti-microbial properties. She refused the job offer at first, because she wanted to concentrate on the looming legal proceedings, but her boss said it would give her something else to think about. The increased salary was also helpful — Guamán was paying legal fees and had hired a public-relations firm to address the intense media interest in the case.

The trial began again in February 2025 and lasted for 30 days. Guamán, who had been studying law in preparation, says she approached the court case as if she were teaching the “most important class of her life”.

“I had so many resources from my lab. I had whiteboard pens, I had ping-pong balls to show what a viral load is. I had a teddy bear and I took out the stuffing to show what DNA is. I had a PCR test and I was showing the jury how the PCR test worked.” She says that as she was describing the differences between the tests, at one point the judge asked if she had explained all of this to the prosecutors. When she replied that she had, “he said, ‘why are you here?’”

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