A number of viral infections, including flu, Covid-19 and shingles, are linked to an increased risk of heart disease and stroke, a new study affirmed.

The risk of a heart attack triples within the first few weeks after a Covid-19 infection, the study suggested, and quadruples in the month after a flu infection. The study, published Wednesday in the Journal of the American Heart Association, was a large review and analysis of existing research.

“It endorses a general idea that we’ve been thinking about and talking about for the past several years — that infections are generally not benign,” said Dr. Ziyad Al-Aly, a senior clinical epidemiologist at Washington University in St. Louis, who was not involved in the study.

“It may start as a respiratory virus, but that’s really the tip of the iceberg, and it has downstream ramifications in multiple organ systems, specifically in this case in the cardiovascular space,” Dr. Al-Aly said.