[Myases from here and elsewhere†: pseudo-furonculosis and Ignatzschineria larvae bacteremia]. / Myiases d'ici et d'ailleurs†: pseudo-furonculose et bactériémie à Ignatzschineria larvae.

Myiasis is an infestation by maggots. In humans, it predominates in regions with low socio-economic development. We report on two cases of myiasis acquired during a tropical travel and in Switzerland, respectively. The first one presented as a furunculous-like disease due to the invasion of subcutaneous tissues by Cordylobia sp. larvae. The second corresponded to a chronic wound infestation that resulted in a rarely reported bacteremia due to Ignatzschineria larvae, a commensal bacteria of maggots' digestive tract. Surgery was necessary in both cases, mainly for psychological reasons in the first case. Both the entomologist and molecular biology were instrumental for treatment decisions.

La myiase est une infestation par des larves de mouches. Chez l'homme, elle prédomine dans les régions à faible niveau socio-économique. Nous rapportons ici deux cas de myiase, l'un acquis lors d'un voyage sous les tropiques et l'autre autochtone : une myiase furonculaire due à la pénétration d'une larve de diptère dans la peau, en l'occurrence Cordylobia sp. ; et une myiase de plaie survenue par ponte de mouches dans des tissus nécrotiques, avec une exceptionnelle bactériémie secondaire, due à une bactérie commensale du tractus digestif de ces larves, Ignatzschineria larvae. Dans les deux situations, la chirurgie a été nécessaire, pour une indication surtout d'ordre psychologique dans la première. Dans les deux cas, l'apport de l'entomologiste et de la biologie moléculaire a été déterminant dans la décision thérapeutique.

Added diagnostic value of 16S rRNA gene pan-mycobacterial PCR for nontuberculous mycobacterial infections: a 10-year retrospective study.

The diagnosis of mycobacterial infections has been dramatically improved by the introduction of molecular methods aimed to reduce the time to diagnosis as compared with culture. The broad range pan-mycobacterial PCR can detect all the mycobacterial species directly from clinical specimens. We aimed to evaluate its usefulness and its clinical added value for the diagnosis of nontuberculous mycobacterial (NTM) infections. We performed a retrospective study (2003-2013) including 952 samples taken from 639 patients with clinical suspicion of NTM infection. The performance of smear microscopy, PCR and culture was established using clinical data to investigate discrepant results. We also compared the time to microbial diagnosis between the direct PCR and culture. The sensitivity, specificity, positive and negative predictive values of the PCR were 61.6% (53.5-69.1), 99.1% (98.2-99.6), 92.8% (85.8-96.5) and 93.4% (91.6-94.9), respectively, when considering all specimens. When considering smear-positive specimens and smear-negative specimens, the sensitivity was 81.6% and 40%, respectively. The sensitivity for pulmonary and extra-pulmonary smear-positive specimens was 85.2% versus 72.7%. The median time to identification at species level was 35 days (SD, 17.67) for culture and 6 days (SD, 2.67) for the PCR (when positive), which represents a 29-day shorter time to results (p < 0.0001). The 16S rRNA gene pan-mycobacterial PCR displays a substantial benefit in terms of time to diagnose NTM infections when compared with culture. Despite an excellent specificity, its sensitivity is yet limited in particular for smear-negative specimens, which might be improved by relying onto real-time PCRs.