Molecular Identification of Zoonotic Tissue-Invasive Tapeworm Larvae Other than Taenia solium in Suspected Human Cysticercosis Cases.

Rarely, zoonotic Taenia species other than Taenia solium cause human cysticercosis. The larval stages are morphologically often indistinguishable. We therefore investigated 12 samples of suspected human cysticercosis cases at the molecular level and surprisingly identified one Taenia crassiceps and one Taenia serialis (coenurosis) infection, which were caused by tapeworm larvae normally infecting rodents and sheep via eggs released from foxes and dogs.

Detection of tropical fungi in formalin-fixed, paraffin-embedded tissue: still an indication for microscopy in times of sequence-based diagnosis?

INTRODUCTION: The aim of the study was the evaluation of panfungal PCR protocols with subsequent sequence analysis for the diagnostic identification of invasive mycoses in formalin-fixed, paraffin-embedded tissue samples with rare tropical mycoses. MATERIALS AND METHODS: Five different previously described panfungal PCR/sequencing protocols targeting 18S and 28S ribosomal RNA gene fragments as well as internal transcribed spacer 1 and 2 fragments were evaluated with a collection of 17 formalin-fixed, paraffin-embedded tissue samples of patients with rare and/or tropical invasive mycoses, comprising chromoblastomycosis, coccidioidomycosis, cryptococcosis, histoplasmosis, mucormycosis, mycetoma/maduromycosis, and rhinosporidiosis, in a proof-of-principle analysis. RESULTS: The primers of the panfungal PCRs readily and predominantly reacted with contaminating environmental fungi that had deposited on the paraffin blocks. Altogether three sequence results of histoplasmosis and mycetoma samples that matched the histological assessment were associated with sample age <10 years and virtually without PCR inhibition. CONCLUSIONS: The high risk of amplifying environmental contaminants severely reduces the usefulness of the assessed panfungal PCR/sequencing protocols for the identification of rare and/or tropical mycoses in stored formalin-fixed, paraffin-embedded tissues. Histological assessment remains valuable for such indications if cultural differentiation is impossible from inactivated sample material.

Molecular Diagnosis of Abdominal Armillifer grandis Pentastomiasis in the Democratic Republic of Congo.

Pentastomiasis is an emerging snake-borne parasitic zoonosis in the tropics. We describe a molecular and morphological study to diagnose a cluster of asymptomatic abdominal human infections caused by Armillifer grandis. The findings may indicate a silent epidemic in a rural area where severe symptomatic ocular cases with the same parasite species have recently surfaced. Molecular diagnostics are of increasing importance when patient material from remote areas cannot be thoroughly examined locally for logistic reasons.

Case report: Molecular diagnosis of subcutaneous Spirometra erinaceieuropaei sparganosis in a Japanese immigrant.

We report a case of subcutaneous sparganosis in a 68-year-old female Japanese immigrant in Germany. The patient complained of a painless erythema caudal of the umbilicus with a palpable subcutaneous cherry-sized lump. Polymerase chain reaction on formalin-fixed parasite tissue identified Spirometra erinaceieuropaei as the causative agent; the proliferative form of sparganosis, which is caused by the branching and disseminating Sparganum proliferum, could, thus, be excluded. From the excised sparganum, an immunofluorescence test was established and revealed an antibody response directed against the parasite's tegument. Histological key features of the plerocercoid that facilitate diagnosis with different stains are presented.