What is this study about?

This study evaluates the use of a multiplex molecular diagnostic test – the QIAstat-Dx Viral Vesicular Panel – to identify the causes of vesicular and rash illnesses in patients who were suspected of having mpox but tested negative. By analysing these mpox-negative cases, the study aimed to determine what other viral infections were responsible for the rash presentations seen during increased mpox surveillance in South Africa.

Why does this matter?

This matters because only a very small proportion of suspected mpox cases were confirmed as mpox, yet all required urgent public health response. Misclassification can strain laboratory services, delay correct patient management, and divert public health resources. Identifying alternative causes – such as varicella-zoster virus or herpesviruses – helps ensure patients receive appropriate care and that public health actions are proportionate to the actual threat.

How did this study come about?

With the global emergence of mpox in 2022, cases of mpox have also been reported in South Africa. The  National Institute for Communicable Diseases (NICD) receives samples from patients with mpox-like rashes, most of which have tested negative. This raised important questions about what was causing these illnesses. The study was initiated to explore these unanswered diagnoses using a syndromic diagnostic approach that could detect multiple rash-causing viruses simultaneously.

What was your role in the study?

As the medical scientist leading mpox laboratory investigations at the NICD, I was in a position to conceptualise the study, develop the methodology, direct the investigations, and interpret the findings.

Why should people read this series?

This report highlights how emerging-disease preparedness intersects with routine infectious diseases. It provides real-world evidence of the value of syndromic diagnostics in outbreak settings and demonstrates how common infections can masquerade as high-consequence diseases. The findings are especially relevant for clinicians, laboratorians, and public health decision-makers working in resource-constrained or high-burden settings.

What impact do you hope this study will have on public health policy and healthcare access?

We trust that the report may encourage uptake of the modern multiplex diagnostic approach in public health laboratories. Improved diagnostics can reduce unnecessary alarm, guide appropriate patient management, and strengthen surveillance systems. Ultimately, this could lead to more efficient use of resources, better outbreak response, and improved equity in access to accurate diagnostics across the healthcare system.

Dr Naazneen Moolla is a Senior Medical Scientist at the Special Viral Pathogens Laboratory of the Centre for Emerging Zoonotic and Parasitic Diseases at the NICD. 

For a more in-depth look into this captivating article, download the full article below.