For the first time in the UK, it has been reported that the Plasmodium falciparum species of malaria has been found to be resistant to the main drug used to fight it. Reported in the journal Antimicrobial Agents and Chemotherapy, four patients were treated at the London School of Hygiene and Tropical Medicine, in what could be a worrying development.
All of the four patients had just returned from Africa. There were initially treated with the combination drug artemether-lumefantrine, before being discharged and sent home after a week. Within six weeks the patients were then all readmitted, each displaying recurrent symptoms and elevated levels of the malaria parasite in their blood. They were then all treated with an alternative drug, which cured them. Importantly, all four cases occurred within months of each other, leading the doctors to suspect that this could be the start of a larger pattern.
What is surprising, and potentially worrying, is that these four cases that have suddenly appeared are some of the earliest reports of malaria being resistant to this widely-used treatment. The doctors are concerned that it may be the tip of the iceberg and suggest that tests should be carried out in Africa to see if the resistance is more prevalent than thought, and what steps need to be taken to further limit it.
“Artemether-lumefantrine is the recommended treatment for non-life threatening cases of falciparum malaria in the UK,” explained Dr Colin Sutherland, who led the study looking into the four cases. “This strategy is considered to be working well, however, our findings suggest that it might need reviewing – fortunately, there are other effective drugs available."
He pointed out, however: "All the patients were identified by self-referral, which suggests more cases of treatment failure in the UK may have occurred.”
The researchers stress that people should not panic just yet, but that medical professionals should be aware that things may get worse, and that there should be an urgent review into the drug use and levels of resistance across the continent. “Frontline doctors should be alert to the possibility of artemisinin-based drugs failing, and assist with the collection of detailed information about specific travel destinations,”
“Frontline doctors should be alert to the possibility of artemisinin-based drugs failing, and assist with the collection of detailed information about specific travel destinations,” Dr Sutherland added. “These cases act as a warning for Africa.”
Malaria in other parts of the world, notably Southeast Asia, are already showing signs of developing resistance to drugs commonly used to fight it. Attention should now be focused on how the parasite managed to clear the artemether-lumefantrine, particularly as mutations were found in genes of the parasite identified in these patients that had previously been implicated in drug resistance in Africa, and could be flagged as a potential first sign that it is able to fight the medicine.