Assessment of COVID-19 Molecular Testing Capacity in Jordan: A Cross-Sectional Study at the Country Level

Optimized strategy for real-time qPCR detection of Onchocerca volvulus DNA in pooled Simulium sp. blackfly vectors

BACKGROUND

Onchocerca volvulus is a filarial parasite that is a major cause of dermatitis and blindness in endemic regions primarily in sub-Saharan Africa. Widespread efforts to control the disease caused by O. volvulus infection (onchocerciasis) began in 1974 and in recent years, following successful elimination of transmission in much of the Americas, the focus of efforts in Africa has moved from control to the more challenging goal of elimination of transmission in all endemic countries. Mass drug administration (MDA) with ivermectin has reached more than 150 million people and elimination of transmission has been confirmed in four South American countries, with at least two African countries having now stopped MDA as they approach verification of elimination. It is essential that accurate data for active transmission are used to assist in making the critical decision to stop MDA, since missing low levels of transmission and infection can lead to continued spread or recrudescence of the disease.

METHODOLOGY/PRINCIPAL FINDINGS

Current World Health Organization guidelines for MDA stopping decisions and post-treatment surveillance include screening pools of the Simulium blackfly vector for the presence of O. volvulus larvae using a PCR-ELISA-based molecular technique. In this study, we address the potential of an updated, practical, standardized molecular diagnostic tool with increased sensitivity and species-specificity by comparing several candidate qPCR assays. When paired with heat-stable reagents, a qPCR assay with a mitochondrial DNA target (OvND5) was found to be more sensitive and species-specific than an O150 qPCR, which targets a non-protein coding repetitive DNA sequence. The OvND5 assay detected 19/20 pools of 100 blackfly heads spiked with a single L3, compared to 16/20 for the O150 qPCR assay.

CONCLUSIONS/SIGNIFICANCE

Given the improved sensitivity, species-specificity and resistance to PCR inhibitors, we identified OvND5 as the optimal target for field sample detection. All reagents for this assay can be shipped at room temperature with no loss of activity. The qPCR protocol we propose is also simpler, faster, and more cost-effective than the current end-point molecular assays.

Risk as catalyst for positive change: lessons learnt from public health readiness for cholera in Jordan

This case study highlights how a looming health crisis was leveraged as drivers for positive change for the health sector, in line with the health security agenda. In Jordan, several authorities are mandated by law to manage health emergencies. Following the declaration of outbreaks of cholera in Iraq, Lebanon and Syria, health authorities in Jordan called for a series of emergency meetings during September 2022 to discuss implications around travel and trade as well as shared waters. WHO was part of the consultations and provided guidance on the application of the International Health Regulations 2005. As the risk for cholera importation persisted, the Ministry of Health assumed its leadership role for the overall health sector response while the Jordanian Center for Disease Control assumed a coordinating function. Roles and responsibilities were enshrined in the National Cholera Preparedness and Response Plan. In consideration of the vulnerability of refugee camps and settlements towards Cholera, the existing Jordan humanitarian coordination platforms such as the Health Sector Working Group were used to share information and to coordinate activities. A whole-of-government risk assessment during December 2022 was complemented by a field visit at Zaatari refugee camp. This helped assess the risk and readiness for a cholera outbreak in Jordan and informed priority activities, such as the establishment of a national risk communication and community engagement working group as well as training on case management.

Evaluation of pooling strategy of SARS-CoV-2 RT-PCR in limited resources setting in Egypt at low prevalence

Sample pooling testing for SARS-COV-2 can be an effective tool in COVID-19 screening when resources are limited, yet it is important to assess the performance before implementation as pooling has its limitations. Our objective was to assess the efficacy of pooling samples for coronavirus 2019 (COVID-19) compared to an individual analysis by using commercial platforms for nucleic acid testing. A total of 2200 nasopharyngeal swabs for SARS-COV-2 were tested individually and in pools of 4, 8, and 10. The cycle threshold (Ct) values of the positive pooled samples were compared to their corresponding individual positive samples. In pool size 10 samples, an estimated increase of 3-Ct was obtained, which led to false negative results in low viral load positive samples. Pooling SARS COV-2 samples is an effective strategy of screening to increase laboratories' capacity and reduce costs without affecting diagnostic performance. A pool size of 8 is recommended.