It can take just one mosquito bite for someone to become infected with malaria and with drug-resistant malaria present in parts of south-east Asia, it could pose serious risks for South Africa.
While there are no cases of drug-resistant malaria in South Africa, it still remains a great concern, according to Dr Jaishree Raman from the National Institute for Communicable Diseases (NICD).
Dr Raman, who is a medical scientist working in the parasitology reference laboratory at the NICD, has a keen interest in anti-malarial drug resistance.
How a mosquito bite can kill
In light of World Malaria Day on April 25, She explained to Health24 how malaria is caused. When an infected malaria mosquito bites an uninfected human to take a blood meal, malaria parasites, called sporozoites, are transferred from the mosquito salivary glands into the human blood stream.
These parasites rapidly travel to the liver (within 30 minutes) where they undergo a peroid of division and maturation.
Once mature, the parasites, now known as merozoites are released into the blood stream, where they invade red blood cells. Inside a red blood cell, merozoites undergo further division, using all the nutrients within the red blood cells.
"At regular intervals, the infected red blood cells burst open, freeing the young merozoites to invade other uninfected red blood cells. This process of merozoites being released from infected red blood cells and invading unaffected red blood cells can continue indefinitely and is associated with the onset of malaria signs and symptoms as cellular debris and parasite by-products are released into the blood stream," said Dr Raman.
Symptoms of malaria include chills, sweats, feelings of weakness, lethargy and dizziness, muscular, body and abdominal pains, headaches, nausea and diarrhoea.
She pointed out that the NICD conducts routine surveillance for anti-malarial drug resistance to the artemisinin combination therapies (ACTs) used in South Africa.
"Fortunately, artemisinin resistant parasites have not yet been detected in Africa. Therefore the artemisinin-based combination, artemether-lumefantrine (sold as Co-artem ) recommended for the treatment of uncomplicated malaria in South Africa, is still extremely effective, provided the correct dose is taken together with milk," Dr Raman told Health24.
"To ensure South Africa does not experience an artemisinin resistant malaria epidemic, the routine surveillance for molecular markers thought to be associated with artemisinin resistance is conducted by the NICD," she said.
"It is hoped that this surveillance will facilitate a timely drug policy in the event artemisinin resistance is detected."
Dr Raman said the south-east Asian region is the historical epi-centre of the emergence of anti-malarial drug resistant parasites.
"The development of artemisinin-resistant parasites in south-east Asia is of great concern to us."
She said genetic studies have shown that anti-malarial drug resistant parasites have spread outwards from south-east Asia through the Indian sub-continent into Africa causing high levels of malaria related morbidity and mortality in the recent past.
"Despite concerted artemisinin resistance containment efforts, recent data appears to indicate artemisinin resistant parasites have been detected along the Myanmar-Indian border."
Anti-malarial drug resistant devastation
It will be catastrophic if anti-malarial drug resistant parasites emerge in Africa, warned Dr Raman.
"Should these resistant parasites spread into Africa or artemisinin resistant parasites develop independently in Africa, control and elimination efforts will be placed at risk with millions of lives threatened."
Sylvester Jobic, head of environmental science for Bayer in Sub-Saharan Africa, concurred with Dr Raman. "The consequences of resistance can be devastating. For instance, when chloroquine resistance spread across Africa in the 1980s, there was a dramatic rise in malaria-related deaths."
He said monitoring the efficacy of antimalarial medicines is a key component of malaria control.
"As long as good surveillance and monitoring remains in place, such as ensuring the correct use of the correct choice of insecticides, accompanied by malaria medication and bed nets (that is, all round protection by 3 sources), malaria should be able to be controlled."
However, Jobic noted that protecting the efficacy of ACTs as the current first-line treatment for malaria is among the top global public health priorities.
The spread of drug-resistant parasites
Dr Raman explained that a number of different factors contribute to the development of drug-resistant parasites.
"In south-east Asia the emergence of artemisinin resistant malaria parasites has been linked to the high artemisinin drug pressure associated with the wide-spread use of counterfeit/sub-optimal artemisinin based anti-malarials, long term sustained use of artemisinins drugs as mono-therapies, most malaria patients being symptomatic and seeking treatment as well as malaria patients frequently not completing their malaria treatment."
Read: How malaria is treated
As malaria is a totally preventable and treatable disease, no one should be dying of this disease in this day and age, said Dr Raman. She also shared some tips for people to help protect themselves from malaria. If travelling to a high malaria risk area one should:
- Take appropriate malaria chemoprophylactic treatment
- Sleep under a bed net and in a room with window/door screens where possible
- Use personal protection measure to prevent mosquito like wearing long sleeved shirts and long trousers particularly if out-doors during dusk and dawn.
- Using mosquito repellent, anti mosquito coils or sprays
A victim of success
Dr Raman noted that while South Africa has reduced both malaria distribution and incidence, in many ways the malaria control programme in the country is a victim of its own success.
"The reduction in malaria incidence has been so impressive that South Africa embarked on a malaria elimination agenda in 2012. Unfortunately this impressive reduction in malaria incidence has had a negative impact on the resources made available for essential control/elimination activities and much needed operational research."
If not rectified urgently, she cautioned, this severe under-resourcing threatens to undermine the impressive gains the country has made against malaria.
Watch this video outlining the global threat of antimalarial drug resistance:
Image: Malaria drugs by Shutterstock