Macao Special Administrative Region (SAR) inspectors found that the four affected batches, which were made between April and November last year, were contaminated with 10 times the permitted level of the fungus Rhizopus microsporus.
While ordering Europharm to halt production and recall all batches of the drug, Dr Lam said the contamination was due to improper storage during Europharm’s production operations.
He explained that the bureau's analysis had revealed that granules of the drug’s active pharmaceutical ingredient (API) were routinely held at 25 degrees Celsius for anything from five to 14 days prior to tablet formation and adding that, in such non-sterile conditions, fungus can grow.
Dr Lam told Reuters that the delay was entirely unnecessary and that it only served to form a “culture medium” that enabled fungal growth.
According to the South China Morning Post, Purinol is regularly used by 40,000 plus people in the region as a treatment for uric acid crystal build up or gout. However, it is also used to prevent hyperuricemia in patients being treated for cancer.
The people whose deaths have been linked to the drug, who include a six year old according to an AFP report, were all being treated for leukaemia at Hong Kong’s Queen Mary Hospital.
Tests revealed that the five, who were all receiving immunosuppressive therapy, were all suffering intestinal mucormycosis a relatively rare infection where fungi are able to evade the body’s defences and colonise the lower gut.
According to local media reports Europharma has temporarily halted all production at its Hong Kong facility, where it makes 41 drugs, until health authorities complete a full investigation of operational practices.