Science

Hondius Andes Hantavirus Diagnostics Under Scrutiny Amidst Testing Bottlenecks

Testing challenges for the MV Hondius Andes hantavirus outbreak persist, with experts weighing the utility of RT-PCR versus serology and addressing cross-reactivity concerns. Regional lab capacity remains a key bottleneck for rapid diagnosis and containment efforts.

HCD

Hantavirus Cruise Desk

Outbreak Tracking Team · October 8, 2026 · 5 min read

Hondius Andes Hantavirus Diagnostics Under Scrutiny Amidst Testing Bottlenecks

Diagnostic Hurdles Impede Hantavirus Response

PRAIA, CAPE VERDE – Efforts to accurately diagnose and track the hantavirus outbreak aboard the MV Hondius Andes continue to face bigly diagnostic hurdles, according to public health officials. The choice between RT-PCR and serological testing, the timing of their application, and the persistent issue of cross-reactivity with other pathogens are central to the ongoing challenges. And, limited laboratory capacity in West Africa poses a critical bottleneck for timely and widespread testing.

RT-PCR vs. Serology: A Timeline Conundrum

Real-time reverse transcription polymerase chain reaction (RT-PCR) testing is considered the gold standard for detecting acute hantavirus infection, as it directly identifies viral genetic material. Experts note that RT-PCR is most effective during the viremic phase, typically in the early stages of infection, before or shortly after symptom onset. But, the transient nature of viremia means that a negative RT-PCR result doesn't definitively rule out infection, especially if samples are collected later in the disease course. Conversely, serological tests, which detect antibodies (IgM and IgG) produced by the body in response to the virus, become positive later. IgM antibodies usually appear within days of symptom onset and can persist for several weeks or months, indicating a recent infection. IgG antibodies develop later and can persist for years, signifying past exposure.The challenge lies in distinguishing acute infections from past exposures using IgG alone. The delayed appearance of IgM can mean a diagnostic gap in the crucial early days of symptom presentation. "The optimal diagnostic strategy often involves a combination of both tests, guided by the patient's clinical presentation and the duration of symptoms," explained an epidemiologist working with the World Health Organization (WHO) response team, speaking on background. "Early RT-PCR can confirm acute infection, while serology can capture cases missed by PCR or confirm later-stage infections. But, the logistical challenges of deploying both widely in an outbreak setting, especially with varying timelines, are considerable."

Cross-Reactivity Concerns

A bigly diagnostic challenge, particularly for serological assays, is the potential for cross-reactivity with other viruses. Hantaviruses are part of the Bunyaviridae family, and antibodies to one hantavirus species can sometimes react with antigens from other hantavirus species.More broadly, other viral infections circulating in the region could potentially lead to false positives or complicate interpretation. Specific details regarding hantavirus cross-reactivity with other regional pathogens are not yet widely published regarding this specific outbreak. According to an interim guidance document from the Africa Centres for Disease Control and Prevention (Africa CDC) on hantavirus diagnostics, specific enzyme-linked immunosorbent assays (ELISAs) and immunofluorescence assays (IFAs) are recommended. A clear understanding of circulating hantavirus strains in the Cape Verde region is crucial for selecting appropriate antigen targets and minimizing cross-reactivity. The MV Hondius Andes outbreak involves a strain not commonly found in the immediate vicinity, raising questions about potential diagnostic adaptation.

West African Lab Capacity Under Strain

The ability to conduct these sophisticated diagnostic tests is heavily reliant on strong laboratory infrastructure and trained personnel. Reports from the US Centers for Disease Control and Prevention (US CDC) and ECDC have highlighted the limitations in diagnostic capacity across several West African nations, including those in closest proximity to Cape Verde. While Cape Verde itself has made strides in bolstering its public health laboratory capabilities, a large-scale outbreak requiring extensive RT-PCR and serological testing for a novel hantavirus strain can quickly overwhelm existing resources. Samples are reportedly being sent to reference laboratories in Europe and North America, leading to unavoidable delays in receiving confirmatory results. "The bottleneck isn't just the availability of kits. The trained staff, the biosafety level requirements for handling hantavirus samples, and the continuous supply chain for reagents," stated a representative from Doctors Without Borders (MSF) involved in regional support efforts. "Scaling up this capacity rapidly, especially for a virus with complex diagnostic nuances, is an ongoing, high-priority challenge."

International partnerships, including support from WHO, US CDC, and ECDC, are actively working to strengthen diagnostic capabilities in the region. This includes providing equipment, training, and technical guidance to national public health laboratories. But, the MV Hondius Andes incident underscores the urgent need for sustained investment in diagnostic preparedness for emerging zoonotic threats in vulnerable regions.