Sensitivity of diagnostic methods for Mansonella ozzardi microfilariae detection in the Brazilian Amazon Region
Mem. Inst. Oswaldo Cruz
;
113(3): 173-177, Mar. 2018. tab, graf
Article
Dans Anglais
| LILACS
| ID: biblio-894902
ABSTRACT
BACKGROUND The human filarial worm Mansonella ozzardi is highly endemic in the large tributaries of the Amazon River. This infection is still highly neglected and can be falsely negative when microfilariae levels are low. OBJECTIVES This study investigated the frequency of individuals with M. ozzardi in riverine communities in Coari municipality, Brazilian Amazon. METHODS Different diagnostic methods including polymerase chain reaction (PCR), blood polycarbonate membrane filtration (PCMF), Knott's method (Knott), digital thick blood smears (DTBS) and venous thick blood smears (VTBS) were used to compare sensitivity and specificity among the methods. Data were analysed using PCMF and Bayesian latent class models (BLCM) as the gold standard. We used BLCM to calculate the prevalence of mansonelliasis based on the results of five diagnostic methods. FINDINGS The prevalence of mansonelliasis was 35.4% by PCMF and 30.1% by BLCM. PCR and Knott methods both possessed high sensitivity. Sensitivity relative to PCMF was 98.5% [95% confidence interval (CI) 92.0 - 99.7] for PCR and 83.5% (95% CI 72.9 - 90.5) for Knott. Sensitivity derived by BLCM was 100% (95% CI 93.7 - 100) for PCMF, 100% (95% CI 93.7 - 100) for PCR and 98.3% (95% CI 90.6 - 99.9) for Knott. The odds ratio of being diagnosed as microfilaremic increased with age but did not differ between genders. Microfilariae loads were higher in subjects aged 30 - 45 and 45 - 60 years. MAIN CONCLUSIONS PCMF and PCR were the best methods to assess the prevalence of mansonelliasis in our samples. As such, using these methods could lead to higher prevalence of mansonelliasis in this region than the most commonly used method (i.e., thick blood smears).
Texte intégral:
Disponible
Indice:
LILAS (Amériques)
Sujet Principal:
Ciment carboxylate
/
Mansonella
/
Mansonellose
Type d'étude:
Etude diagnostique
/
Étude pronostique
/
Facteurs de risque
Limites du sujet:
Humains
Pays comme sujet:
Amérique du Sud
/
Brésil
langue:
Anglais
Texte intégral:
Mem. Inst. Oswaldo Cruz
Thème du journal:
Médecine tropicale
/
Parasitologie
Année:
2018
Type:
Article
Pays d'affiliation:
Brésil
Institution/Pays d'affiliation:
Fundação Oswaldo Cruz-Fiocruz/BR
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