In fact, on that continent every minute a child dies from malaria. However, WHO stresses that, since 2000, the malaria mortality rate in children has been reduced by approximately 58 per cent in Africa.
Malaria is a disease caused by parasites of the genus Plasmodium, which are transmitted to people through the bite of the Anopheles mosquito. There are five species of parasites that cause malaria in humans. Among them, the deadliest is Plasmodium falciparum.
PARTIAL IMMUNITY AND TREATMENTS
Malaria is an acute febrile illness. Symptoms usually appear 10 to 15 days after the mosquito bite. The WHO warns of the difficulty, sometimes, to recognize the malarial origin of the first symptoms, such as fever, headache, chills and vomiting.
“Children in endemic areas with severe disease often manifest one or more of the following: severe anaemia, respiratory distress related to metabolic acidosis, or cerebral malaria. In adults, multi-organ involvement is also frequent,” says the WHO.
He adds that in malaria-endemic areas, people can acquire partial immunity, allowing asymptomatic infections to occur.
WHO also stresses that early diagnosis and treatment of malaria attenuates the disease, prevents death and helps reduce transmission.
“The best available therapeutic option, especially in the case of Plasmodium falciparum malaria, is artemisinin-based combination therapy,” he says.
“Artemisinin is a derivative of a Chinese plant of proven efficacy. Easy to use (orally or injectable), it acts quickly and eliminates the parasite in the blood more quickly than other available molecules,” explain the specialists of Doctors Without Borders.
“There is talk of combination therapies because artemisinin is administered in combination with other molecules that are still effective, usually amodiaquine or mefloquine. This combination is used to prolong and reinforce the effect of the treatment and delay the emergence of resistance,” they detail.
Drug resistance has been a major problem in the fight against malaria. In the 1970s and 1980s, Plasmodium falciparum developed resistance to previous generations of antimalarial drugs such as chloroquine and sulfadoxine-pyrimethamine, undermining efforts to control the disease.
In recent years, resistance of the parasite to artemisinin has been detected in five countries: Cambodia, Myanmar, Lao People’s Democratic Republic, Thailand and Vietnam.
Currently, among the main problems related to antimalarial drugs are low-quality and falsified medicines.
FAKE OR LOW-QUALITY DRUGS
“Low-quality drugs can cause avoidable effects including morbidity, mortality, increased resistance to antimalarial drugs and loss of confidence in health systems, especially in low- and middle-income countries,” said Paul Newton, Director of Pharmacological Quality. of the Worldwide Antimalarial Resistance Network (WWARN) and Andrea Stewart, Director of Advocacy and Communications of WWARN.
Both specialists detail that the administration of falsified drugs, which do not contain antimalarial, does not in itself cause resistance, since the parasites are not exposed to any drugs in the blood. However, patients can continue to seek other drugs if they remain ill until symptoms improve.
If they are then taking substandard quality antimalarials, which usually contain less than the prescribed amount of antimalarial, the perfect environment can be created for resistant parasites to remain in the bloodstream and continue to infect other patients.
The parasite that causes malaria, once it reaches the human body through the mosquito bite, multiplies in the liver and later infects red blood cells.
According to Professor Manuel Elkin Patarroyo, who created the first synthetic vaccine against malaria more than a quarter of a century ago, this parasite “can reproduce about fifty times every forty-eight hours. Thus, if there is only one red blood cell out of every thousand infected, in two days there could already be fifty out of every thousand and in four days the figure would be about 2,500.”
What for the Colombian researcher Patarroyo represents “an impossible number to handle”. In this way, he comments that “one red blood cell out of every thousand infected by the malaria parasite would be as if in a demonstration of a thousand people there was a terrorist. That’s the analogy because the terrorist can destroy what’s around.”
Indeed, vaccine research is a promising chapter in the fight against this disease. At the moment, there is no licensed vaccine against malaria. However, work with the RTS,S/ASO1 vaccine is well advanced.
The efficacy of this vaccine is currently being evaluated in several African countries. WHO may recommend its use based on the results of such clinical trials.
In fact, WHO is expected to make a recommendation on whether the vaccine should be included among the means of malaria control by the end of 2015.
Pedro Alonso, principal investigator of this project, insists on the need to consider vaccines along with the rest of the measures that already exist to combat the disease.
“This first generation of malaria vaccines, with efficacy of around 50%, alone is not the solution to the problem. Its use, therefore, must be considered in the context of the other control tools we have: insecticide-impregnated mosquito nets, drugs for treatment, new rapid diagnostic tests or indoor fumigations,” he says.
Similarly, WHO says that large-scale use of available tools and strategies recommended by WHO, strong country commitment and coordinated efforts will increase the number of countries making progress towards malaria elimination.