As the nations marked the World Malaria Day yesterday, the danger of this disease came to the fore once again. This is not surprising as about 3.2 billion people, almost half of the world’s populations, are at risk of malaria. Indeed, young children, pregnant women and travellers are vulnerable to the disease.
Malaria is a life-threatening disease caused by parasites transmitted to people through the bites of infected female mosquitoes.
With a theme, “Ready to beat Malaria,” this year’s World Malaria Day underscores the collective energy and commitment of the global malaria community in uniting around the common goal of a world free of malaria.
It highlights the remarkable progress achieved in tackling one of humanity’s oldest diseases, while also calling out worrying trends as captured in the 2017 World malaria report, which stated: “The global response to malaria is at a crossroads. After an unprecedented period of success in malaria control, progress has stalled.”
The report said the current pace at fighting malaria was “insufficient to achieve the 2020 milestones of the WHO Global Technical Strategy for Malaria 2016–2030 – specifically, targets calling for a 40 per cent reduction in malaria case incidence and death rates.”
Painting a gloomy picture, the report gave a damning verdict: “Countries with ongoing transmission are increasingly falling into one of two categories: those moving towards elimination and those with a high burden of the disease that have reported significant increases in malaria cases.”
It said without urgent action, “the major gains in the fight against malaria are under threat.”
Therefore, on the last World Malaria Day, WHO continued to call for “greater investment and expanded coverage of proved tools that prevent, diagnose and treat malaria.”
X-raying the scourge of malaria, Chief Consultant, Family Physician/Director of Training, EKO Hospitals, Dr. BC Chukwukelu, said there are four parasite species that cause malaria in humans: P.falciparum, P.malariae, P.ovale and P.vivax. He said two of these species, P. falciparum and P.vivax, pose the greatest threat.
“Environmental condition helps to determine the intensity of malaria transmission in a region. For example, optimal temperature for parasite development in mosquito is 20-30°C. Sporogony ceases below 16°C. Temperature also affects mosquito development. It takes seven days to develop from egg to adult at 31°C. It takes 20 days to develop from egg to adult at 20°C,” he said.
The malaria problem in Nigeria
Nigeria has 25 per cent of the world’s disease burden for malaria and reports more deaths from the disease than any other country in the world. In Nigeria, malaria is responsible for the death of an estimated 3, 000, 000 children per year and contributes to over 4,000 maternal deaths annually. It is also the number one cause of absenteeism in Nigeria, resulting in loss in productivity at work and school.
Reports revealed that 97 per cent of Nigerians are at risk of malaria, with an estimated 50 per cent of adults suffering at least one episode of the disease a year. Malaria counts for 60 per cent of outpatient visit and 30 per cent of hospitalisation, it was gathered.
Also, Nigeria is one of the exporters of malaria to other countries as 45 per cent of reported malaria cases in London between 2000 and 2012 occurred due to travel from the country. This is why most major international airlines spray planes with insecticide before departure from Nigeria.
Malaria transmission is possible if the weather conditions are right to support the growth and infection of Anopheles mosquitoes and if a reservoir of malaria parasites is available. Malaria parasite reservoir can become available in non-malaria regions when travellers or immigrants arrive with malaria infection.
Elaborating on this, Dr. Chukwukelu said: “Malaria poses a public health problem, which is increasing by the day and used to be found all over the world, with the exception of a few temperate areas. It occurs in areas with conducive atmosphere for the growth of the anopheles mosquito; adequate rainfall, poor sanitation.”
Following mosquito bite, there is about seven-30 days period before symptoms appear (incubation period). The incubation period for P. vivax is usually 10 to 17 days, but can be much longer (about one year and rarely, as long as 30 years). P. falciparum usually has a short incubation period (10 to 14 days). Other species of Plasmodium that cause malaria have incubation periods similar to P. vivax.
Experts say malaria is an acute febrile illness. In a non-immune individual, symptoms appear seven days or more (usually 10 to 15 days) after the infective mosquito bite. The first symptoms are fever, headache, chills and vomiting. If not treated within 24 hours, P. falciparum malaria can progress to severe illness, often leading to death.
Children with severe malaria frequently develop one or more of the following symptoms: severe anaemia, respiratory distress in relation to metabolic acidosis, or cerebral malaria. In adults, multi-organ involvement is also frequent.
Most malaria cases and deaths occur in sub-Saharan Africa. However, Asia, Latin America, and, to a lesser extent, the Middle East, are also at risk.
However, some population groups are at considerably higher risk of contracting malaria, and developing severe disease than others. These include infants, children under 5 years of age, pregnant women and patients with HIV/AIDS, as well as non-immune migrants, mobile populations and travellers.
Chukwukelu further states that there were 300 million cases of malaria in the world annually, 90 per cent of which is in sub-Saharan Africa.
Experts suggest vector control as the main way to prevent and reduce malaria transmission. If coverage of vector control interventions within a specific area is high enough, then a measure of protection will be conferred across the community, they said.
Also, WHO recommends protection for all people at risk of malaria with effective malaria vector control: use of insecticide-treated mosquito nets and indoor residual spraying of insecticide.
Besides these, early diagnosis and treatment of malaria reduce disease and prevent deaths. These also contribute in reducing malaria transmission. WHO recommends that all cases of suspected malaria be confirmed using parasite-based diagnostic testing (either microscopy or rapid diagnostic test) before administering treatment. Results of parasitological confirmation can be available in 30 minutes or less. Treatment, solely on the basis of symptoms, should only be considered when a parasitological diagnosis is not possible”
However, research shows that resistance to antimalarial medicines is a recurring problem. Resistance of P. falciparum to previous generations of medicines, such as Chloroquine and Sulfadoxine-pyrimethamine (SP) became widespread in the 1970s and 1980s, undermining malaria control efforts and reversing gains in child survival. WHO recommends the routine monitoring of antimalarial drug resistance, and supports countries to strengthen their efforts in this important area of work.
According to Dr. Godwin Ntadom of National Malaria Elimination Programme (NMEP), Nigeria has made important strides towards the elimination of malaria. The 2015 Nigeria Malaria Indicator Survey (NMIS) revealed that about one in four children under 5 years tested positive for malaria. This represents 3. 35 per cent decline since the last malaria indicator survey in 2010, when more than 40 per cent children tested positive for the disease.
Nigeria accounts for 29 per cent of the global burden of malaria and has the highest number of cases of any country. Nationwide, malaria prevalence varies widely, ranging from 14 per cent in the South East zone to 37 per cent in the North West.
The decrease in malaria corresponds with expanded malaria prevention interventions. Interestingly, ownership of insecticide-treated mosquito nets (ITNs) has increased over eight-folds. Over one-third of pregnant women now take at least two doses of the SP medication to prevent malaria as part of intermittent preventive therapy for malaria-in-pregnancy (IPTp).