Where have all the diagnostic morphological parasitologists gone?

Advances in laboratory techniques have revolutionized parasitology diagnostics over the past several decades. Widespread implementation of rapid antigen detection tests has greatly expanded access to tests for global parasitic threats such as malaria, while next-generation amplification and sequencing methods allow for sensitive and specific detection of human and animal parasites in complex specimen matrices. Recently, the introduction of multiplex panels for human gastrointestinal infections has enhanced the identification of common intestinal protozoa in feces along with bacterial and viral pathogens. Despite the benefits provided by novel diagnostics, increased reliance on nonmicroscopy-based methods has contributed to the progressive, widespread loss of morphology expertise for parasite identification. Loss of microscopy and morphology skills has the potential to negatively impact patient care, public health, and epidemiology. Molecular- and antigen-based diagnostics are not available for all parasites and may not be suitable for all specimen types and clinical settings. Furthermore, inadequate morphology experience may lead to missed and inaccurate diagnoses and erroneous descriptions of new human parasitic diseases. This commentary highlights the need to maintain expert microscopy and morphological parasitology diagnostic skills within the medical and scientific community. We proposed that light microscopy remains an important part of training and practice in the diagnosis of parasitic diseases and that efforts should be made to train the next generation of morphological parasitologists before the requisite knowledge, skills, and capacity for this complex and important mode of diagnosis are lost. In summary, the widespread, progressive loss of morphology expertise for parasite identification negatively impacts patient care, public health, and epidemiology. © 2022 American Society for Microbiology

Dirofilaria repens Nematode Infection with Microfilaremia in Traveler Returning to Belgium from Senegal

We report human infection with a Dirofilaria repens nematode likely acquired in Senegal. An adult worm was extracted from the right conjunctiva of the case-patient, and blood microfilariae were detected, which led to an initial misdiagnosis of loiasis. We also observed the complete life cycle of a D. repens nematode in this patient

Unexpected Infection with Armillifer Parasites

Visceral pentastomiasis is usually found incidentally during surgery. We describe a case of visceral pentastomiasis discovered during inguinoscrotal hernia surgery for a man from Benin, Africa. Because surgical removal of nymphs is needed for symptomatic patients only, this patient’s asymptomatic pentastomiasis was not treated and he recovered from surgery uneventfully

Incidence of Zika virus infection in a prospective cohort of Belgian travellers to the Americas in 2016

BACKGROUND: The incidence rate of Zika virus (ZIKV) infection in travellers from non-endemic areas to the Americas during the ZIKV outbreak in 2016 is unknown. METHODS: Belgian adults who planned to travel to South America, Central America, and the Caribbean were recruited prospectively to study the incidence and characteristics of ZIKV. Demographic data and sera were collected at baseline. Participants were trained to collect capillary blood on filter paper (BFP). When ill during travel, the participants completed a questionnaire and they sampled BFP for post-hoc analysis. All symptomatic participants were screened for ZIKV using ZIKV-specific RT-PCR on serum or urine, or BFP, and antibody detection assays (ELISA). Follow-up sera of asymptomatic travellers, obtained at least 20 days post travel, were tested by ZIKV ELISA only. All positive ELISA results were subject to confirmation by virus neutralization testing (VNT). RESULTS: Forty-nine participants completed follow-up: 38 women and 11 men, with a median age of 32 years (range 19-64 years). Travel destinations were countries in South America (n=20), Central America (n=24), and the Caribbean (n=5). The total travel duration was 67.8 person-months. Illness was reported by 24 participants (49.0%). ZIKV infection was confirmed in nine cases, by RT-PCR (n=5) and by VNT (n=4). Only one of nine ZIKV cases (11.1%) was asymptomatic. The ZIKV incidence rate was 17.0% (95% confidence interval 7.8-32.2%) per month of travel. CONCLUSIONS: The ZIKV incidence rate in adult travellers from non-endemic countries to the epidemic territories during the 2016 outbreak was high. Asymptomatic ZIKV infection was rare in this population.status: publishe

Bench Aids for the diagnosis of intestinal parasites Second edition

This second edition of Bench aids for the diagnosis of intestinal parasites is intended both as a practical tool for the diagnosis of intestinal parasitic infections for laboratory and field workers and as a teaching aid for students and trainees. The plates are arranged on two sides: the recto with microphotographs for the identification of eggs, larvae, trophozoites, cysts and oocysts occurring in faeces, and the verso dedicated to the different copromicroscopical methods (procedures) and main staining techniques used in parasitology. Special attention has been devoted to all graphical and pictorial contents. The decision to include the outline of an Ascaris lumbricoides egg in its relative size next to each parasitic structure fulfils the intention of visualizing the actual dimensions that the eye needs to be looking for when examining the specimens with a microscope. For each image, the size of the parasite and a short description are provided to assist in the microscopical identification. Two summary plates, one for helminths and the other for protozoa, are also included to provide a visual overview of the different presentations of parasitic elements. The bench aids have been produced in a weatherproof plastic-sealed format that is robust and easy to use at the bench. They are recommended for use by all health workers engaged in the routine diagnosis of intestinal parasitic infections