Projects

qPCR in household contact monitoring

  • Grant: LRI Regular Grant
  • Research priorities: Diagnostic tests
  • Country: Brazil
  • Project no.: 703.15.45
  • Budget: € 60,269
  • Duration: August 2015 - July 2018
  • Status: Completed

Full project title:
Evaluation of the qPCR in household contact monitoring

Project coordination
Laboratório de Hanseníase Fundação Oswaldo Cruz/ FIOCRUZ (Brazil)

Partners
Fundação Afredo da Mata (Brazil)
Universidade Federal de Juiz de Fora (Brazil)
Ludwig-Maximilians University (Germany)

Aim: There are no diagnostic tests that could predict whether or not a “contact” will develop the disease. This project investigated the possible use of M.leprae DNA detection as a early detection method in over 1600 household contacts of leprosy patients. 

Final project summary
Leprosy is a disease caused by a bacterium and proper diagnosis can completely cure patients, but clinical signs of the disease are sometimes difficult to detect. The bacteria infect skin and nerves and late diagnosis are generally associated with permanent nerve injuries. It is well known that the group of individuals at greatest risk are the family members and household contacts that live in close proximity to patients.

Since there is a lack of diagnostic tests that could predict whether or not a “contact” will develop the disease, the aim of this research project was to provide a better way of diagnosis. In the past few years, novel technologies to amplify the causative agent, Mycobacterium leprae, of leprosy DNA are available and these tests are becoming more accurate, faster and cheaper. This project has investigated the use of quantitative PCR and PGL-I serology in monitoring household contacts right after the diagnosis of the index case and followed them for at least three years.

The researchers were able to perform examination of a group of more than 2,000 people who were at risk to develop leprosy because they lived in the household of a patient with active disease. Approximately 1,600 individuals were tested for the presence of the bacterial DNA and 955 followed-up. The results so far indicate that qPCR from ear lobes slit skin smear is not recommended to estimate risk of leprosy, but qPCR is very helpful increasing the precision of diagnosis of household contacts when they present suspected lesions, since skin biopsies were performed for confirmation and qPCR was complementary to histopathological analysis.

Impact

Quantitative polymerase chain reaction in paucibacillary leprosy diagnosis: A follow-up study. Barbieri RR, Manta F, Moreira SJ M, et al. PLoS neglected tropical diseases. 2019; 13 (3) : e0007147