Clustering of leprosy beyond the household level in a highly endemic setting on the Comoros, an observational study
Abstract Background The island of Anjouan (Comoros) is highly endemic for leprosy with an annual incidence of 5–10/10,000. In May/June, 2015 single-dose Rifampicin post-exposure prophylaxis (SDR-PEP) was administered to 269 close contacts of 70 leprosy-patients in four villages as a pilot programmat...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2019-06-01
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| Series: | BMC Infectious Diseases |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s12879-019-4116-y |
| _version_ | 1818873080602165248 |
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| author | Nimer Ortuno-Gutierrez Abdallah Baco Sofie Braet Assoumani Younoussa Aboubacar Mzembaba Zahara Salim Mohamed Amidy Saverio Grillone Bouke C. de Jong Jan Hendrik Richardus Epco Hasker |
| author_facet | Nimer Ortuno-Gutierrez Abdallah Baco Sofie Braet Assoumani Younoussa Aboubacar Mzembaba Zahara Salim Mohamed Amidy Saverio Grillone Bouke C. de Jong Jan Hendrik Richardus Epco Hasker |
| author_sort | Nimer Ortuno-Gutierrez |
| collection | DOAJ |
| description | Abstract Background The island of Anjouan (Comoros) is highly endemic for leprosy with an annual incidence of 5–10/10,000. In May/June, 2015 single-dose Rifampicin post-exposure prophylaxis (SDR-PEP) was administered to 269 close contacts of 70 leprosy-patients in four villages as a pilot programmatic intervention. Two years later we revisited the villages for follow-up investigations. The main aim of our study was to quantify spatial associations between reported leprosy cases before and after PEP implementation. A secondary aim was to assess the effect of this single round of SDR-PEP at the individual level. Methods We conducted door-to-door leprosy screening in all four villages in August/September, 2017. We screened all consenting individuals for leprosy and recorded geographic coordinates of their household. We also recorded whether they had received SDR-PEP and whether they had been diagnosed with leprosy, before or after the 2015 intervention. We fitted a Poisson model with leprosy as outcome and distance to the nearest pre-intervention case and SDR-PEP as predictors. Results During the survey we found 114 new cases among 5760 contacts screened (2.0% prevalence), in addition to the 39 cases detected in the two preceding years. We found statistically significant associations of incident leprosy with physical distance to index cases ranging from 2.4 (95% confidence interval (95% CI) 1.5–3.6) for household contacts to 1.8 (95% CI 1.3–2.5) for those living at 1–25 m, compared to individuals living at ≥75 m. The effect of SDR-PEP appeared protective but did not reach statistical significance due to the low numbers, with an incidence rate ratio (IRR) of 0.6 (95% CI 0.3–1.2) overall, and 0.5 (95% CI 0.2–1.3) when considering only household contacts. Conclusions This pilot demonstrated an increased risk of leprosy in contacts beyond the household, therefore a wider circle should be considered for chemoprophylaxis. Baseline surveys and extended contact definitions are essential for improving SDR-PEP effectiveness. |
| first_indexed | 2024-12-19T12:49:01Z |
| format | Article |
| id | doaj.art-79b5512393244821a1cbf2ccfcd04ba5 |
| institution | Directory Open Access Journal |
| issn | 1471-2334 |
| language | English |
| last_indexed | 2024-12-19T12:49:01Z |
| publishDate | 2019-06-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Infectious Diseases |
| spelling | doaj.art-79b5512393244821a1cbf2ccfcd04ba52022-12-21T20:20:37ZengBMCBMC Infectious Diseases1471-23342019-06-011911710.1186/s12879-019-4116-yClustering of leprosy beyond the household level in a highly endemic setting on the Comoros, an observational studyNimer Ortuno-Gutierrez0Abdallah Baco1Sofie Braet2Assoumani Younoussa3Aboubacar Mzembaba4Zahara Salim5Mohamed Amidy6Saverio Grillone7Bouke C. de Jong8Jan Hendrik Richardus9Epco Hasker10Projects Department, Damien FoundationNational Tuberculosis and Leprosy control ProgramInstitute of Tropical MedicineNational Tuberculosis and Leprosy control ProgramNational Tuberculosis and Leprosy control ProgramNational Tuberculosis and Leprosy control ProgramNational Tuberculosis and Leprosy control ProgramNational Tuberculosis and Leprosy control ProgramInstitute of Tropical MedicineErasmus MC, University Medical Center RotterdamInstitute of Tropical MedicineAbstract Background The island of Anjouan (Comoros) is highly endemic for leprosy with an annual incidence of 5–10/10,000. In May/June, 2015 single-dose Rifampicin post-exposure prophylaxis (SDR-PEP) was administered to 269 close contacts of 70 leprosy-patients in four villages as a pilot programmatic intervention. Two years later we revisited the villages for follow-up investigations. The main aim of our study was to quantify spatial associations between reported leprosy cases before and after PEP implementation. A secondary aim was to assess the effect of this single round of SDR-PEP at the individual level. Methods We conducted door-to-door leprosy screening in all four villages in August/September, 2017. We screened all consenting individuals for leprosy and recorded geographic coordinates of their household. We also recorded whether they had received SDR-PEP and whether they had been diagnosed with leprosy, before or after the 2015 intervention. We fitted a Poisson model with leprosy as outcome and distance to the nearest pre-intervention case and SDR-PEP as predictors. Results During the survey we found 114 new cases among 5760 contacts screened (2.0% prevalence), in addition to the 39 cases detected in the two preceding years. We found statistically significant associations of incident leprosy with physical distance to index cases ranging from 2.4 (95% confidence interval (95% CI) 1.5–3.6) for household contacts to 1.8 (95% CI 1.3–2.5) for those living at 1–25 m, compared to individuals living at ≥75 m. The effect of SDR-PEP appeared protective but did not reach statistical significance due to the low numbers, with an incidence rate ratio (IRR) of 0.6 (95% CI 0.3–1.2) overall, and 0.5 (95% CI 0.2–1.3) when considering only household contacts. Conclusions This pilot demonstrated an increased risk of leprosy in contacts beyond the household, therefore a wider circle should be considered for chemoprophylaxis. Baseline surveys and extended contact definitions are essential for improving SDR-PEP effectiveness.http://link.springer.com/article/10.1186/s12879-019-4116-yMappingClusteringLeprosyPost-exposure prophylaxisTransmissionSingle dose rifampicin |
| spellingShingle | Nimer Ortuno-Gutierrez Abdallah Baco Sofie Braet Assoumani Younoussa Aboubacar Mzembaba Zahara Salim Mohamed Amidy Saverio Grillone Bouke C. de Jong Jan Hendrik Richardus Epco Hasker Clustering of leprosy beyond the household level in a highly endemic setting on the Comoros, an observational study BMC Infectious Diseases Mapping Clustering Leprosy Post-exposure prophylaxis Transmission Single dose rifampicin |
| title | Clustering of leprosy beyond the household level in a highly endemic setting on the Comoros, an observational study |
| title_full | Clustering of leprosy beyond the household level in a highly endemic setting on the Comoros, an observational study |
| title_fullStr | Clustering of leprosy beyond the household level in a highly endemic setting on the Comoros, an observational study |
| title_full_unstemmed | Clustering of leprosy beyond the household level in a highly endemic setting on the Comoros, an observational study |
| title_short | Clustering of leprosy beyond the household level in a highly endemic setting on the Comoros, an observational study |
| title_sort | clustering of leprosy beyond the household level in a highly endemic setting on the comoros an observational study |
| topic | Mapping Clustering Leprosy Post-exposure prophylaxis Transmission Single dose rifampicin |
| url | http://link.springer.com/article/10.1186/s12879-019-4116-y |
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