Author:
Macfarlane Cara L.,Quek Shannon,Pionnier Nicolas,Turner Joseph D.,Wanji Samuel,Wagstaff Simon C.,Taylor Mark J.
Abstract
AbstractSkin snip evaluation for onchocerciasis has insufficient sensitivity when skin microfilarial (mf) densities are low, such as following ivermectin treatment. Mf density is suitable for assessing microfilaricidal efficacy but only serves as an indirect indicator of macrofilaricidal activity. We assessed circulating nucleic acids from Onchocerca volvulus as an alternative to skin snips. We screened a plasma sample set of infected individuals followed up at four, 12 and 21 months after microfilaricidal (ivermectin, n = four), macrofilaricidal (doxycycline, n = nine), or combination treatment (n = five). Two parasite-derived miRNAs, cel-miR-71-5p and bma-lin-4, and O-150 repeat DNA were assessed. Highly abundant DNA repeat families identified in the O. volvulus genome were also evaluated. miRNAs were detected in two of 72 plasma samples (2.8%) and two of 47 samples (4.3%) with microfilaridermia using RT-qPCR. O-150 DNA was detected in eight (44.4%) baseline samples by qPCR and the number of positives declined post-treatment. One doxycycline-treated individual remained O-150 positive. However, only 11 (23.4%) samples with microfilaridermia were qPCR-positive. Analysis by qPCR showed novel DNA repeat families were comparatively less abundant than the O-150 repeat. Circulating parasite-derived nucleic acids are therefore insufficient as diagnostic tools or as biomarkers of treatment efficacy for O. volvulus.
Publisher
Springer Science and Business Media LLC
Reference50 articles.
1. Hotez, P. J. & Kamath, A. Neglected tropical diseases in sub-saharan Africa: review of their prevalence, distribution, and disease burden. Plos Negl. Trop. Dis. 3, e412 (2009).
2. World Health Organization. African Programme for Onchocerciasis Control - report of the sixth meeting of National Task Forces, October 2009. Wkly. Epidemiol. Rec. 85, 23–28 (2010).
3. Basanez, M. G. et al. Effect of single-dose ivermectin on Onchocerca volvulus: a systematic review and meta-analysis. Lancet Infect. Dis. 8, 310–322 (2008).
4. World Health Organization Guidelines for stopping mass drug administration and verifying elimination of human onchocerciasis: criteria and procedures. Available at https://www.who.int/onchocerciasis/resources/9789241510011/en/ (2016).
5. Albers, A. et al. Real-time PCR detection of the HhaI tandem DNA repeat in pre-and post-patent Brugia malayi infections: a study in Indonesian transmigrants. Parasit. Vectors. 7, 146 (2014).
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