Cancer patient tests positive for coronavirus for 471 days

Researchers at Yale, North Carolina and Sydney universities identified a patient infected with the new coronavirus for 471 days. The 60-year-old man, being treated for lymphocytic leukemia and cancer of the lymphatic system, tested positive for Covid for the first time in November 2020 and until March of this year the Sars-CoV-2 virus was still detected in his body.

The survey was shared on the medRxiv platform. The study has not yet been analyzed by other scientists in the field and approved for publication. It characterizes a single case and did not evaluate the performance of the patient’s immune system, who presented mild symptoms during the first days of infection and then remained asymptomatic.

The work points out that, during prolonged infection, mutations of the virus in the patient’s body led to the emergence of three different and coexisting strains.

The publication also indicates a rate of 35 replacements of parts of genetic material per year, approximately twice as high as the estimate of the global average. Because of this index, scientists signal that chronic and untreated infections of Sars-CoV-2 can accelerate the evolution of the virus and, ultimately, favor the emergence of more transmissible variants.

“Our study provides evidence that chronic infections by Sars-CoV-2 may be a source for the emergence of genetically diverse variants capable of causing future outbreaks of Covid-19”, say the researchers.

Previous studies have pointed to chronic infections by the new coronavirus in patients with compromised immunity, such as people with cancer, autoimmune diseases and advanced HIV, and the research seeks to contribute to a better understanding of this phenomenon.

To monitor the patient’s infection, the group of 26 scientists analyzed 30 samples collected by the RT-PCR method from 79^O infection day. They then did the genetic sequencing and identified three strains of the virus.

The first was the most found in nasal swabs between days 79 and 247 of infection, but from day 281 onwards the dominance varied between it and two other virus genotypes, indicating the coexistence of three strains.

The researchers evaluated the differences between each and found a high rate of virus modification, a level not reported in cases of acute infection.

They recommend active monitoring of immunocompromised individuals to identify potential chronic infections early and reinforce the need for vaccines. They also underscore the importance of continuous investment in research and development of vaccines capable of protecting against future variants.

For the researchers, these strategies could stop the accelerated evolution of Sars-CoV-2 seen in chronically infected individuals, stopping the emergence of more transmissible variants and, ultimately, preventing deaths and greater economic impact.