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Tuberculosis makes a dangerous return to Paris
A study released by the French public health authorities says there has been an overall increase in the number of cases of tuberculosis since 2016, particularly in the north Parisian region of Seine-Saint-Denis.
But there has been an increase in the number of cases since 2015, with numbers rising from 14.6 per 100,000 inhabitants to 15.8 per 100,000 in 2017.
Such a jump suggests a reversal of trends, with the city of Paris reporting the most important increase, with 16.8 per 100,000 inhabitants in 2017.
Does this mean the disease, often associated with the first half of the 20th century and earlier, is making a comeback?
“I wouldn’t say we should be worried,” smiles Giulia Manina, who heads a research group studying microbial individuality and infection with a focus on tuberculosis at the Pasteur Institute in Paris.
But she adds that awareness is key and while Paris has a higher incidence due to “globalisation, migration fluxes . . . it is not the only reason for the re-emergence of tuberculosis”.
Understanding the disease
Although considered a disease of the past, tuberculosis has never left us. The mainly pulmonary (or lung) disease can spread to other organs such as the brain or the bones.
And because it is typically in the lungs, “it can spread easily” explains Manina.
If a person has an active infection, as opposed to one that is still dormant, he or she can infect a lot of other people. “For instance, it is estimated that one person can infect up to ten others with a cough” adds the scientist, explaining the infectiousness of the disease, especially in high-density areas.
While tuberculosis is a bacterial infection, it is not necessary the case that it develops into a full-fledged infection.
Many infections can be cured or the person can remain without symptoms, Manina adds.
But having an acute infection does not mean it can or will be cured. “It is pretty aggressive. You have shivering, fever. . . .loss of weight, you cough blood, so it’s a very aggressive infection. And it is very difficult to treat.”
Generally there are two strains of the disease: one which is drug-sensitive, while the other is drug-resistant.
The treatments currently in place are exactly the same as those in use 40 years ago. “The therapy that was introduced 40 years ago is still the gold standard, the best therapy we have,” stresses Manina.
If you have a bronchial infection for example, you often take antibiotics for one or two weeks, and then all is well.
But for tuberculosis, “you have to take up to four drugs for six months. So you can imagine that people have side effects, feel sick, so it’s very complicated to end this therapy”.
For drug-resistant tuberculosis, which is becoming increasingly a problem worldwide, “you have to take antibiotics for up to one, two years,” explains the Pasteur Institute scientist.
As indicated by the latest public health statistics, the overall rate of incidence of tuberculosis in the Paris region has increased.
But France as a whole is considered a low-incidence country.
“Basically for a low-incidence country, we mean 10 cases per 100,000 individuals,” explains Manina.
In such countries, the infection is mainly located in large cosmopolitan areas.
This study shows that the rate begins to increase around the peak of migration to Europe in 2016.
The study suggests that the majority of those suffering from tuberculosis are persons born abroad and recently arrived in France.
However, that’s not the only explanation for the return of the disease.
“One problems is drug-resistance and then there are vulnerable groups that are more prone to tuberculosis,” explains Manina.
“The fact that the population is aging, if you have type 2 diabetes, or HIV … these are all factors that can facilitate the resurgence of acute tuberculosis.”
Of course, those who suffer from drug- or alcohol-abuse are also more vulnerable because their immune system is often weakend.
We’ve seen major advances since the 20th century to defeat diseases such as measles and polio.
There has been a parallel global commitment to fight tuberculosis.
Given that tuberculosis is a bacterial infection, could we not witness its complete eradication?
“Since we don’t have a vaccine that works efficiently at the moment, it’s complicated to eradicate,” says Manina.
Added to that is the fact that it is estimated that one in three or four persons have “latent tuberculosis”, meaning they have the infection, but without any symptoms, and are therefore undetectable.
“Despite it being an extremely ancient disease, we still have a lot of lack of knowledge. So a lot has to be discovered,” stresses the scientist.
But research at the international level is on-going, and some advances are being made.
Ideally, maintaining a healthy lifestyle limits one’s risk of contracting the disease, as is the case with any air-borne illness.
Manina adds that hygiene is always important, as are such measures as avoiding excessive alcohol and smoking.