Unexpectedly high leprosy seroprevalence detected using a random surveillance strategy in midwestern Brazil: A comparison of ELISA and a rapid diagnostic test.
BACKGROUND:Leprosy diagnosis is mainly based on clinical evaluation, although this approach is difficult, especially for untrained physicians. We conducted a temporary campaign to detect previously unknown leprosy cases in midwestern Brazil and to compare the performance of different serological tes...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2017-02-01
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| Series: | PLoS Neglected Tropical Diseases |
| Online Access: | http://europepmc.org/articles/PMC5358972?pdf=render |
| _version_ | 1819151331395371008 |
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| author | Marco Andrey C Frade Natália A de Paula Ciro M Gomes Sebastian Vernal Fred Bernardes Filho Helena B Lugão Marilda M M de Abreu Patrícia Botini Malcolm S Duthie John S Spencer Rosa Castália F R Soares Norma T Foss |
| author_facet | Marco Andrey C Frade Natália A de Paula Ciro M Gomes Sebastian Vernal Fred Bernardes Filho Helena B Lugão Marilda M M de Abreu Patrícia Botini Malcolm S Duthie John S Spencer Rosa Castália F R Soares Norma T Foss |
| author_sort | Marco Andrey C Frade |
| collection | DOAJ |
| description | BACKGROUND:Leprosy diagnosis is mainly based on clinical evaluation, although this approach is difficult, especially for untrained physicians. We conducted a temporary campaign to detect previously unknown leprosy cases in midwestern Brazil and to compare the performance of different serological tests. METHODS:A mobile clinic was stationed at the main bus terminal in Brasília, Brazil. Volunteers were quizzed and given a clinical exam to allow categorization as either patients, known contacts of patients or non-contacts, and blood was collected to determine anti-PGL-I and anti-LID-1 antibody titers by ELISA and by the NDO-LID rapid test. New cases of leprosy and the impact of performing this broad random surveillance strategy were evaluated. Accuracy values and concordance between the test results were evaluated among all groups. RESULTS:Four hundred thirty-four individuals were evaluated, and 44 (10.1%) were diagnosed with leprosy. Borderline forms were the most frequent presentation. Both tests presented higher positivity in those individuals with multibacillary disease. Serological tests demonstrated specificities arround 70% for anti-PGL-1 and anti-LID ELISA; and arround 40% for NDO-LID. Sensitivities ranged from 48 to 62%. A substantial agreement between NDO-LID and ELISA with concomitant positive results was found within leprosy patients (Kappa index = 0.79 CI95% 0.36-1.22). CONCLUSIONS:The unexpectedly high leprosy prevalence in this population indicates ongoing community-based exposure to Mycobacterium leprae antigens and high rates of subclinical infection. All tests showed low specificity and sensitivity values and therefore cannot be considered for use as stand-alone diagnostics. Rather, considering their positivity among MB patients and non-patients, these tests can be considered effective tools for screening and identifying individuals at high risk who might benefit from regular monitoring. |
| first_indexed | 2024-12-22T14:31:42Z |
| format | Article |
| id | doaj.art-e36720b0d1734cb6a5e0d7c98d9102c3 |
| institution | Directory Open Access Journal |
| issn | 1935-2727 1935-2735 |
| language | English |
| last_indexed | 2024-12-22T14:31:42Z |
| publishDate | 2017-02-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Neglected Tropical Diseases |
| spelling | doaj.art-e36720b0d1734cb6a5e0d7c98d9102c32022-12-21T18:22:44ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352017-02-01112e000537510.1371/journal.pntd.0005375Unexpectedly high leprosy seroprevalence detected using a random surveillance strategy in midwestern Brazil: A comparison of ELISA and a rapid diagnostic test.Marco Andrey C FradeNatália A de PaulaCiro M GomesSebastian VernalFred Bernardes FilhoHelena B LugãoMarilda M M de AbreuPatrícia BotiniMalcolm S DuthieJohn S SpencerRosa Castália F R SoaresNorma T FossBACKGROUND:Leprosy diagnosis is mainly based on clinical evaluation, although this approach is difficult, especially for untrained physicians. We conducted a temporary campaign to detect previously unknown leprosy cases in midwestern Brazil and to compare the performance of different serological tests. METHODS:A mobile clinic was stationed at the main bus terminal in Brasília, Brazil. Volunteers were quizzed and given a clinical exam to allow categorization as either patients, known contacts of patients or non-contacts, and blood was collected to determine anti-PGL-I and anti-LID-1 antibody titers by ELISA and by the NDO-LID rapid test. New cases of leprosy and the impact of performing this broad random surveillance strategy were evaluated. Accuracy values and concordance between the test results were evaluated among all groups. RESULTS:Four hundred thirty-four individuals were evaluated, and 44 (10.1%) were diagnosed with leprosy. Borderline forms were the most frequent presentation. Both tests presented higher positivity in those individuals with multibacillary disease. Serological tests demonstrated specificities arround 70% for anti-PGL-1 and anti-LID ELISA; and arround 40% for NDO-LID. Sensitivities ranged from 48 to 62%. A substantial agreement between NDO-LID and ELISA with concomitant positive results was found within leprosy patients (Kappa index = 0.79 CI95% 0.36-1.22). CONCLUSIONS:The unexpectedly high leprosy prevalence in this population indicates ongoing community-based exposure to Mycobacterium leprae antigens and high rates of subclinical infection. All tests showed low specificity and sensitivity values and therefore cannot be considered for use as stand-alone diagnostics. Rather, considering their positivity among MB patients and non-patients, these tests can be considered effective tools for screening and identifying individuals at high risk who might benefit from regular monitoring.http://europepmc.org/articles/PMC5358972?pdf=render |
| spellingShingle | Marco Andrey C Frade Natália A de Paula Ciro M Gomes Sebastian Vernal Fred Bernardes Filho Helena B Lugão Marilda M M de Abreu Patrícia Botini Malcolm S Duthie John S Spencer Rosa Castália F R Soares Norma T Foss Unexpectedly high leprosy seroprevalence detected using a random surveillance strategy in midwestern Brazil: A comparison of ELISA and a rapid diagnostic test. PLoS Neglected Tropical Diseases |
| title | Unexpectedly high leprosy seroprevalence detected using a random surveillance strategy in midwestern Brazil: A comparison of ELISA and a rapid diagnostic test. |
| title_full | Unexpectedly high leprosy seroprevalence detected using a random surveillance strategy in midwestern Brazil: A comparison of ELISA and a rapid diagnostic test. |
| title_fullStr | Unexpectedly high leprosy seroprevalence detected using a random surveillance strategy in midwestern Brazil: A comparison of ELISA and a rapid diagnostic test. |
| title_full_unstemmed | Unexpectedly high leprosy seroprevalence detected using a random surveillance strategy in midwestern Brazil: A comparison of ELISA and a rapid diagnostic test. |
| title_short | Unexpectedly high leprosy seroprevalence detected using a random surveillance strategy in midwestern Brazil: A comparison of ELISA and a rapid diagnostic test. |
| title_sort | unexpectedly high leprosy seroprevalence detected using a random surveillance strategy in midwestern brazil a comparison of elisa and a rapid diagnostic test |
| url | http://europepmc.org/articles/PMC5358972?pdf=render |
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