Africa CDC warns that current Mpox lab diagnostics and tests are unreliable due to high false negatives

Medical News: The Africa Centre for Disease Control and Prevention (Africa CDC) has raised a significant alarm regarding the reliability of current laboratory diagnostics for Mpox. In a letter addressed to the Health Ministers of African Union (AU) member states, the agency emphasized that a negative lab test for Mpox does not guarantee the absence of the virus in a sample. This warning comes at a critical time, as Mpox cases are on the rise across the continent, with new countries reporting their first confirmed cases.


Africa CDC warns that current Mpox lab diagnostics and tests are unreliable due
to high rates of false negatives

The Inaccuracy of Current Mpox Testing
In its communication, the Africa CDC cautioned that relying solely on laboratory results to diagnose Mpox can be misleading. Dr. Jean Kaseya, Director-General of Africa CDC, highlighted that despite a negative lab test, the Mpox virus could still be present in the body. “Relying solely on laboratory test results for diagnosing Mpox is not advisable. False negatives are possible,” Dr. Kaseya stated, underscoring the need for a more comprehensive approach to Mpox diagnosis.
 
This conclusion was reached after extensive consultations with top epidemiologists and laboratory experts from Africa, as well as international bodies like the US CDC, China CDC, Europe CDC, and the World Health Organization (WHO). The consensus is clear: negative lab results should not be taken as definitive proof of the absence of Mpox, especially when there is strong clinical and epidemiological evidence pointing to an outbreak.
 
Factors Contributing to False Negatives
Dr. Kaseya outlined six key factors that can lead to a false negative Mpox lab test result:
 
-Timing of Sample Collection: The timing of sample collection plays a critical role in the accuracy of Mpox testing. If the sample is taken too early or too late in the infection cycle, the viral load might be too low to be detected.
 
-Type of Sample Collected: The type of sample, such as lesion swabs, blood, or other bodily fluids, can significantly affect test outcomes. Lesion swabs are generally more reliable, but other sample types may not contain enough viral material for detection.
 
-Quality of the Sample: Poor sample collection techniques, including improper handling, storage, or contamination, can result in inadequate samples, leading to false negatives.
 
-Test Sensitivity and Specificity: Some Mpox tests may have lower sensitivity, meaning they might not detect very low levels of the virus, resulting in a false negative if the viral load is below the test's detection threshold.
 
-Viral Variability: Different strains or mutations of the Mpox virus might not be easily detected by certain tests, especially if the tests were designed for a specific strain.
 
-Host Immune Response: In some cases, an individual's immune system might clear the virus or suppress its replication to levels undetectable by laboratory tests, even though the disease is present.
 
Thailand Medical News has taken the liberty of adding some resources from peer reviewed medical journals and government health agencies so that readers who are interested can know more about current lab Mpox diagnostic methods:
 
https://www.mdpi.com/2076-2607/11/5/1186
 
https://link.springer.com/article/10.1007/s00705-023-05848-w
 
https://www.cell.com/iscience/fulltext/S2589-0042(23)00836-2
 
https://www.health.gov.au/sites/default/files/2023-07/monkeypox-laboratory-case-definition.pdf
 
https://www.cdc.gov/poxvirus/mpox/lab-personnel/lab-procedures.html
 
A Holistic Approach to Mpox Diagnosis
Given the potential for false negatives, the Africa CDC advocates for a holistic approach to Mpox diagnosis. This comprehensive method should integrate laboratory testing with clinical assessment and epidemiological data to ensure accurate diagnosis and effective management of the disease.
 
Key components of this approach include:
-Clinical Presentation: Evaluating the patient’s signs and symptoms, such as fever, rash, swollen lymph nodes, and lesions.
 
-Epidemiological Context: Understanding the patient’s exposure history, including contact with known cases or travel to areas with reported Mpox outbreaks.
 
-History and Risk Factors: Reviewing the patient’s medical history, particularly recent exposure to animals or contaminated materials.
 
-Laboratory Testing: While crucial, lab tests should be interpreted alongside clinical and epidemiological data. A negative test should not be the sole determinant in ruling out Mpox.
 
-Follow-up and Monitoring: Continuous monitoring of the patient’s symptoms and possibly repeating tests to confirm a diagnosis.
 
-Differential Diagnosis: Considering and ruling out other conditions with similar symptoms, such as chickenpox, measles, or bacterial skin infections.
 
The Growing Threat of Mpox in Africa
The urgency of these warnings is underscored by the rising number of Mpox cases across the continent. As of August 2024, 13 AU member states have reported a total of 21,466 Mpox cases, including 3,350 confirmed and 18,116 suspected cases. These cases have resulted in 591 deaths, leading to a case fatality rate (CFR) of 2.9%.
 
These figures are only the tip of the iceberg as many health experts are warning that the actual infection and death rates could be as high as 10 to 12-fold as many are not being tested and many in rural areas, deaths are not being reported. The issue of lack of testing in many geolocations in Africa coupled with even the revealed issue of false negatives from lab tests is compounding the problems of the spread and transmission of the disease.
 
The spread of Mpox is particularly concerning in Africa that is lacking the relevant funding and resources and where the prevalence of immunocompromised populations, especially individuals living with HIV, exacerbates the severity of the disease. Dr. Kaseya highlighted the alarming situation, stating, “The case fatality rate of Mpox is unacceptably high, and the risk of further spread, particularly to countries with fragile healthcare systems, is a major concern.”
 
Regional Cooperation and Vaccine Access
The Africa CDC has called for increased regional cooperation and a unified response to combat the Mpox outbreak. The agency warned that without coordinated efforts, the disease could spread beyond Africa’s borders, posing a global health threat.

One of the most pressing issues identified by the Africa CDC is the limited access to reliable diagnostics and vaccines across many African countries. While vaccines for Mpox are available, their access remains restricted, and their clinical efficacy is still under scrutiny. The Africa CDC stressed the importance of developing a strategic plan to deploy vaccines where they will have the greatest impact, particularly in high-risk populations.
 
The Need for a Coordinated Response
To address the challenges posed by Mpox, the Africa CDC has urged AU member states to enhance their collaboration and share resources and information. This coordinated response is essential to mount an effective defense against the ongoing crisis. The agency also recommended integrating Mpox testing with other essential health screenings, particularly for HIV and sexually transmitted infections (STIs), given the strong link between these conditions and the severity of Mpox infections.
 
In conclusion, the Africa CDC’s warning serves as a stark reminder of the complexities involved in diagnosing and managing Mpox. As the outbreak continues to spread, the agency’s call for a holistic approach to diagnosis and a coordinated regional response is more critical than ever.
 
For the latest Mpox News, keep on logging to Thailand Medical News.
 
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