On the State Day of Awareness, Mobilization and Fight against Leprosy, celebrated on August 5, researchers from the Oswaldo Cruz Foundation (Fiocruz) highlight that the disease is curable, and a new study confirms the effectiveness of the treatment. Based on the follow-up of 713 patients seen over 20 years, the research shows that the return of the infection after the completion of therapy in 12 months is extremely rare, affecting only one in every thousand people treated per year. The largest and longest survey on the subject, the study was carried out at the Ambulatório Souza Araújo, maintained by the Leprosy Laboratory of the Instituto Oswaldo Cruz (IOC/Fiocruz), which acts as a national reference service for the disease with the Ministry of Health.

“This result emphasizes that multidrug therapy [treatment based on a combination of antibiotics] for 12 months is enough to cure multibacillary leprosy”, says the researcher from the Center for Technological Development in Health (CDTS/Fiocruz) and collaborator of the Ambulatório Souza Araújo, Ximena Illarramendi, author of the research.

“The return of the disease after treatment weakens all efforts to control leprosy, so the analysis of relapses is the most important way of evaluating the effectiveness of the therapy”, adds Anna Maria Sales, researcher at Ambulatório Souza Araújo, also study author.

The article was published in the international open access scientific journal 'Plos Neglected Tropical Diseases'. Study data is available in the repository Ark, from Fiocroz.

Despite the good news, experts warn: in the midst of the Covid-19 pandemic, leprosy diagnoses dropped by about 40% in Rio de Janeiro. In 2020, only 637 cases of the disease were registered in the state, against 1.133 in 2019, according to data from the Information System of Notifiable Diseases of the Ministry of Health (Sinan/MS). The drop is attributed to the population's fear of looking for health units and the overload of care and surveillance services. Therefore, more than ever, awareness and mobilization to fight the disease are fundamental.

Among the symptoms that alert to the possibility of leprosy are spots on the skin, with loss of sensitivity to cold, heat or pain, lumps on the body, numbness and tingling. “Anyone who has these symptoms should look for the health center closest to their residence. If you know of a family member or friend with any of these problems, you should advise them, say that leprosy is curable and it is important to be treated”, emphasizes Ximena.

“Early diagnosis of leprosy brings many benefits. It prevents the development of more severe and disseminated skin lesions and the onset or worsening of physical disabilities. It also breaks the chain of transmission of the disease”, highlights Anna.

Like the population, health professionals need to be aware of the early diagnosis of leprosy, which is often confused with other skin diseases. That's what happened to a 24-year-old man from Itaguaí. With reddish spots and lumps on the skin, the administrative assistant went to a health center, a public hospital and a private clinic before obtaining a diagnosis of leprosy at the Evandro Chagas National Institute of Infectology (INI/Fiocruz), in November 2020.

Watch the video "Leprosy clinic: permanent commitment to quality" 

“The first doctors told me it was an allergy. I went to the appointment thinking I might have skin cancer. The infectologist and dermatologist at INI told me it was leprosy. I had heard about the disease, but the possibility had never crossed my mind”, says the young man.

Referred to the Souza Araújo Ambulatory, he started multidrug therapy. With inflammation in a nerve in the arm, causing numbness on the side of the hand and loss of strength, he was also taken to Hospital Pedro Ernesto, where he underwent treatment for neuritis.

“The treatment is going well and my hand is improving. I think it's very important to be informed. Sometimes we think that a skin problem is no big deal and can be a serious thing. With the technology we have today, it is possible to treat diseases,” she points out.

caused by Mycobacterium leprae, leprosy can affect the skin, mucous membranes and nerves. If not treated in time, the disease can leave sequelae, such as deformities, loss of hand movements and difficulty walking. Therapy is also important to interrupt the transmission of the disease, because, soon after the beginning of treatment, patients stop eliminating bacteria in nasal secretions, speech droplets, coughing, sneezing (Click here to learn more about the disease).

risk of reinfection

So-called relapses occur when patients who have completed treatment for leprosy have new lesions or worsening of old lesions, with an increase in the amount of bacteria in the body. “The return of lesions can occur due to latent bacteria, which have remained in the body. However, it is most likely due to reinfection, since the patients are susceptible people, who live in areas with transmission of the disease, since leprosy control has not yet been achieved”, explains Ximena.

In recent years, the World Health Organization (WHO) has reported an increase in relapses, which rose from 2,8 in 2016 to 3,8 in 2019. The data include cases recorded after different treatment regimens, covering both treated patients with a multibacillary regimen (indicated for people who have many lesions and a large number of bacteria in the body) and with a paucibacillary regimen (recommended for people who have few lesions and a low number of bacteria in the body).

For the researchers, the increase in records may be the result of failures in older therapeutic regimens, such as monotherapy, which applied only one antibiotic. It can also be attributed to errors in diagnosis, with patients with many lesions and high bacillary burden receiving a paucibacillary regimen. Finally, considering the risk of reinfection, it is natural that the number of relapses increases over time, as the number of patients followed up increases.

Fixed-dose multibacillary multidrug therapy in 12 months has been indicated since 1998. The therapeutic regimen is based on supervised monthly administration of three antibiotics plus daily self-administered doses of two of them. The adoption of this regimen meant an advance over the previous regimen, which lasted 24 months, as the shorter therapy time improves adherence to treatment.

Confirming the effectiveness of the current regimen is considered an important step towards advancing studies on the possibility of reducing therapy time. “In randomized clinical trials, good results of 6-month therapy for multibacillary infections have already been observed. It is a change that would simplify the treatment and would allow the unification of the therapeutic regimens for all cases of leprosy”, ponders the doctor, noting that, since July of this year, people with indication of paucibacillary regimen started to be treated with the same antibiotics indicated for multibacillary infections, maintaining the duration of 6 months.