After Areli Torres caught the coronavirus, the fever and headache disappeared in a joker few days, but she says it took seven months for Mexican doctors to correctly diagnose the debilitating long-term effects.

Her case illustrates the huge challenge that the country's already overwhelmed health system faces helping people with "long Covid" -- the symptoms that sometimes linger long after the infection.

Torres, a 31-year-old engineer, fell ill with the coronavirus last June but the worst of her initial symptoms lasted only four days.
She tested positive three times up to August but decided to try to return to her normal life.
A month after she was infected, however, parts of her body began to go numb.

Now, it is one of her legs that gives her the most discomfort.
"Everything's uncertain. Everything's been an ordeal. I've seen four doctors," Torres said.
The first doctor, from the Mexican Institute of Social Security (IMSS), concluded that it was anxiety and prescribed antidepressants.
Two private doctors, including a neurologist, agreed with that diagnosis.
Torres tried therapy, yoga and exercise but still "half her body was numb," she said.

- 'Be patient' -

It was in February that another doctor identified the problem as inflammation of the nervous system as a result of the coronavirus.
Among other things she was advised to "be patient," although by then she had already had to postpone her wedding.
At least 1.6 million people have survived Covid-19 and around 184,000 have died from it in Mexico, a country of 126 million, according to official figures.
Limited testing means that in reality, both figures are likely to be significantly higher.
There is no data on the number who are have suffered long-term effects.
In October, a senior health ministry official said that less than five percent of those who became seriously ill needed respiratory rehabilitation.

But doctors are increasingly taking the view that people who initially experience mild symptoms are also at risk of suffering from long Covid.