High performance of a novel point-of-care blood test for Toxoplasma infection in women from diverse regions of Morocco

ABSTRACT

Point-of-care (POC) testing for Toxoplasma infection has the potential to revolutionize diagnosis and management of toxoplasmosis, especially in high-risk populations in areas with significant environmental contamination and poor health infrastructure precluding appropriate follow-up and preventing access to medical care. Toxoplasmosis is a significant public health challenge in Morocco, with a relatively heavy burden of infection and, to this point, minimal investment nationally to address this infection. Herein, we analyse the performance of a novel, low-cost rapid test using fingerstick-derived whole blood from 632 women (82 of whom were pregnant) from slums, educational centres, and from nomad groups across different geographical regions (i.e. oceanic, mountainous) of Morocco. The POC test was highly sensitive and specific from all settings. In the first group of 283 women, sera were tested by Platelia ELISA IgG and IgM along with fingerstick whole blood test. Then a matrix study with 349 women was performed in which fingerstick – POC test results and serum obtained by venipuncture contemporaneously were compared. These results show high POC test performance (Sensitivity: 96.4% [IC95 90.6–98.9%]; Specificity: 99.6% [IC95 97.3–99.9%]) and high prevalence of Toxoplasma infection among women living in rural and mountainous areas, and in urban areas with lower educational levels. The high performance of POC test confirms that it can reduce the need for venipuncture and clinical infrastructure in a low-resource setting. It can be used to efficiently perform seroprevalence determinations in large group settings across a range of demographics, and potentially expands healthcare access, thereby preventing human suffering.

KEYWORDS:

• Congenital toxoplasmosis
• POC
• screening
• LDBIO test
• diagnostics

Disclosure statement

Dr. Raphael Piarroux and Dr. Denis Limonne work at LDBIO. All authors have not reported any conflicts of interest.

Aknowledgement and Funding

We gratefully acknowledge LDBIO diagnostics for supporting this work and completing blindly the western blot validation tests. LDBIO had no role in data collection, exploitation and interpretation of the results. We are also grateful to Boubker Maazoz and IDMAJ Neighborhoods Association for their help and support in organizing the contact with women from marginalized neighborhoods in Casablanca. We express our sincere gratitude to Dr. Kamal Bouisk and Maria Mazouri for their help in organizing the ongoing study at ISPITS. This work was carried out under National funding from the Moroccan Ministry of Higher Education & Scientific Research (Contrat Fincome nº435/2016) to (K. El Bissati). K. E. is a recipient of the Fulbright US Scholar Award, Investigators of medical sciences and public health. This work was also supported by the Toxoplasmosis Research Institute (TRI) at the University of Chicago and the Thrasher Foundation (to R. McLeod). We also wish to acknowledge the contributions of Dahbi, the Mann-Cornwell, Drago, Morel, Taub, Tirado, Mussilami, Samuel, Rodriguez, Rosenthal, Benhamou, Rooney, Pritzker, Kehoe, and Engel families, physicians and nurses in sites, and participants in parallel studies in the United States and in the NCCCTS.