The Africa CDC told African health ministers that laboratory tests alone cannot sufficiently detect Mpox cases
With the continued spread of Mpox across the continent, the African Center for Disease Control (Africa CDC) has written to all African health ministers, calling for coordinated efforts to tackle the infection and improved testing methods.
In a letter dated 23 August and signed by the Africa CDC Director-General, Jean Kaseya, the public health body said the disease was spreading rapidly, and cases have almost tripled within a short period.
This is unlike what was obtainable in 2022 when Mpox was first declared a Public Health Emergency of International Concern (PHEIC).
Mr Kaseya said that the case fatality rate of the disease is high at about 3 per cent and has been linked to HIV which makes it more concerning.
"Several countries without previous cases have recently reported imported cases of their first Mpox cases for 2024. Given this trend, there is a high risk that it could spread beyond Africa as well," the letter read.
Mr Kaseya noted that Mpox was declared a public health emergency by the agency on 13 August, after assessing the danger that the onslaught was posing to the continent.
He said the declaration was made after "Africa CDC called for a meeting of an independent high-level technical body called Emergency Consultative Group (ECG)."
The ECG made up of a group of 20 high-level science and health experts reviewed the epidemiological situation in the continent and made recommendations.
The epidemiological situation
Between 1 January and 23 August there were 21,466 reported Mpox cases across 13 African Union member states.
Of these, 3,350 were confirmed cases, while 18,116 were suspected. The outbreak also resulted in 591 deaths, leading to a case fatality rate (CFR) of 2.9 per cent.
Mr Kaseya said the affected countries include Burundi, Cameroon, the Central African Republic, Congo, Cote d'Ivoire, the Democratic Republic of Congo, Gabon, Liberia, Kenya, Nigeria, Rwanda, South Africa, and Uganda.
He also noted that Gabon has confirmed its first case of the disease while Sierra Leone and Malawi have begun testing suspected cases.
"Even as I wrote this letter, Gabon has confirmed its first case, while Sierra Leone and Malawi are now testing their suspected cases," the letter added.
Currently, Nigeria has recorded 40 confirmed cases and 830 suspected cases of the zoonotic disease. However, it has yet to record any death cases.
Lab tests not reliable
However, the DG told African health ministers that laboratory tests alone cannot sufficiently detect Mpox cases and should not be relied on as the sole method to identify confirmed cases.
"I would like to draw Your Excellencies' attention to the fact that a negative test result in the laboratory does not mean there is no Mpox epidemic," he said.
"Some of you are reaching out to us, especially in the context where lab is negative for Mpox.
"To better advise you, Africa CDC have also consulted our African best epidemiologist and lab experts but also international experts and appropriate bodies like the US CDC, China CDC, Europe CDC and WHO."
He said the recommendation provided was that countries must restrain from relying solely on laboratory test results for diagnosing Mpox.
Instead, he said, there is a need for a holistic approach that integrates laboratory testing with clinical assessment and epidemiological data.
According to him, this is essential for accurately diagnosing and managing Mpox.
Mr Kaseya told the ministers that diagnosis and management of Mpox should involve a comprehensive approach that considers multiple factors.
He said, one of these factors is clinical presentation, which involves monitoring signs and symptoms of Mpox, such as fever, rash, swollen lymph nodes, and lesions.
He also recommended a thorough clinical examination especially when laboratory results are inconclusive or negative.
"Epidemiological Context - Understanding the patient's exposure history, such as contact with known cases or travel to areas with ongoing Mpox outbreaks, is crucial.
"This context can provide strong evidence for a probable case, even in the absence of positive lab results," he advised.
Testing for confirmed cases
Mr Kaseya suggested that health ministers review the patient's medical history, including any recent exposure to animals or contaminated materials can offer additional clues for diagnosis.
"While important, lab tests should be interpreted in conjunction with clinical and epidemiological data. False negatives are possible, and a negative test does
not entirely rule out Mpox, especially if there is strong clinical suspicion," he said.
Sign up for free AllAfrica Newsletters
Get the latest in African news delivered straight to your inbox
The Africa CDC DG added that for all Mpox cases, countries must perform HIV and STI tests.
He urged for continuous monitoring of the patient's symptoms and possibly repeating tests can help in making a definitive diagnosis.
He said health providers should also be conscious of the timing, quality and type of samples collected.
According to him, the accuracy of Mpox testing depends significantly on when the sample is collected.
He said If the sample is taken too early or too late in the course of the infection, the viral load might be too low to be detected.
"The type of sample collected (e.g., from a lesion, blood, or other bodily fluids) can affect the test results. Lesion swabs are typically the most reliable,
but if a different type of sample is used, it may not contain enough viral material for detection," he said.
Also, he disclosed that different strains or mutations of the Mpox virus might not be as easily detected by certain tests.
"Some tests were designed for a specific strain," he said.
He further noted that in some cases, an individual's immune system might clear the virus or suppress its replication such that it becomes undetectable by laboratory tests.
