Until recently, measles cases in Limpopo had been confined to the greater Sekhukhune district around Groblersdal, but now three new cases have been reported in Giyani, in the Mopani district, bringing to 15 the number of cases in the province, reports Daily Maverick.
While patients in the Greater Sekhukhune District range from babies to 24-years-old, those infected in the Mopani district are only children, aged two to five-years-old.
The Sekhukhune cases involved three children who were fully vaccinated, seven who had unknown measles vaccination histories, and two children who had not been vaccinated against measles.
Of the new cases, none was hospitalised.
Dr Nishi Prabdial-Sing from the National Institute for Communicable Diseases said their investigations had established a link between two cases only, and that none was school related or events related..
She said about one in 50 vaccinated people might develop a mild fever and a rash similar to the measles rash and two cases of this rare side effect have been documented in Limpopo recently.
“Other rare reasons why people who have been vaccinated develop measles include interference with maternal antibodies or loss of vaccine potency. Children who are vaccinated at six months still have residual antibodies against measles from their mothers. These may interfere with the vaccine, and prevent it from eliciting a robust antibody response. Usually, this problem is overcome by providing two opportunities for the measles vaccine in childhood, as with the second measles dose given at 12 months.
“Another less common reason is that after the 10-dose measles vial has been reconstituted, it needs to be maintained at minus -50℃. Once the vial is reconstituted, the vaccine will degrade at higher temperatures. At -27℃, the vaccine loses 50% potency every hour. This means that when out of the fridge, it should be kept on ice.
“Sometimes in busy clinics, this procedure may not strictly be adhered to so children who receive the vaccine might effectively receive a slightly lower dose of active vaccine, and although still protective, it might be less so. Training at clinics and healthcare facilities regarding vaccine dosage and stability is continual,” she added.
Daily Maverick article – Measles outbreak spreads to another district in Limpopo (Open access)
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