Ready the beat Malaria?

INTRODUCTION
Malaria, which potentially occurs in tropical areas, is a potentially life-threatening disease caused by infection with Plasmodium protozoan transmitted by an infective female Anopheles mosquito vector. Nearly half of the world's population is at risk of malaria. According to UNICEF malaria kills one child every 30seconds approximately 3000 children every year. It is a very common epidemic in Africa responsible for 90% of infant mortality in sub-tropical zones.
ETIOLOGY
Patients with malaria typically acquire the infection in an endemic area following a mosquito bite. Malaria Parasites belong to the genus Plasmodium. In humans it is caused by P. falciparum, P. malariae, P. ovale and P. vivax. P. falciparium has the highest recorded incidence rate (~70%) followed by P. vivax (~20%).

LIFE CYCLE
The vector, the Anopheles species of mosquito (definitive host), transmits a motile infective form called the sporozoite contained in its saliva while obtaining a blood meal. The sporozoites travel to the liver hepatocytes, where it matures asexually forming merozoites. These merozoites infect red blood cells and initiate a series of asexual reproductive cycles that produce 10-24 merozoites, at which point the cells burst and the new infective cycle begins anew. Other merozoite develop into gametocytes. When a mosquito bites an infected person, gametocytes are taken up with the blood and mature in the gut of the mosquito. The male and female gametocyte fuse together forming an ookinete. Ookinete develop into new sporozoites that migrate to the insect’s salivary glands, ready to infect new hosts.

CHALLENGES TOWARDS THE ERADICATION OF MALARIA
On scientific grounds, eradication malaria is complex and difficult. There are 4 species of human malaria. The two most common are P. falciparum and P. vivax. These 2 species respond differently to medicines, exhibit drug resistance in different ways making the development of a vaccine challenging.
Challenges towards the elimination of malaria in sub-Saharan Africa include:

1. Drug resistance
   Anti-malarial drug resistance has been defined as the ability of a parasite strain to survive or multiply despite the administration and absorption of a drug given in equal to or higher than those usually recommended but within tolerance of the subject. Resistance appears to occur through spontaneous mutation that confer reduced sensitivity to a given drug or class of drugs. For some drugs, only a single point mutation is required to confer resistance, while for other drugs, multiple mutation appear to be required.
   Resistance to antimalarial medicine is a threat to global efforts to control and eliminate malaria treatments has been a key contributing factor to the significant reduction in the malaria burden in recent years. Protecting the efficacy of the recommended malaria treatment is a top priority for malaria endemic countries and the global malaria community.

2. Insecticide resistance
   The control of vectors of malaria relies on the use of Long-Lasting Insecticide Nets and Indoor Residual Spraying. In Nigeria, vector resistance to DDT and pyrethroids have been reported. The emergence of DDT resistance in the major Afro-tropical malaria vectors would have considerable implications for the success of vector interventions and the monitoring of ongoing control programmes.

3. Climate Change and Global Warming
   Recent scientific data suggests that the temperature of the world is increasing. This increase in global temperature is mainly as a result of human activities including deforestation. Climatic factors play an important role in the distribution of malaria. Relative humidity and rainfall have also been associated with malaria transmission. Precipitation influences habitat suitability and can potentially shift the geographical range of malaria. Extremes of temperature may also decrease the survival of vectors leading to a decline in the incidence of malaria.

4. Difficulty in maintaining long term malaria funding and political support.
   Maintaining funding and political support for malaria control efforts especially in areas where successful control has led to low burden and pre-elimination stage is critical. Increased national funding can be considered as a sustainability factor especially in place where donor support is limited or declining because these countries are not considered as priority areas any more. International advocacy efforts are required to maintain political and financial support.

1. Poor quality of drugs and other commodities
   Due to high cost of effective anti-malaria drugs such as ACTs and the strong manufacturing capabilities of companies in the region, fake and substandard drugs are prevalent in Nigeria. Quality control processes for all intervention need to be in place and regional cooperation should be encouraged on this issue.

OPPORTUNITIES
Efforts to combat malaria encompass a continuum from control (reduction of malaria morbidity and mortality) to elimination (cessation of transmission in a defined geographical area) and eradication (global reduction of malaria incidence to zero). The global malaria eradication campaign of the mid-20th century eliminated malaria in 37 of 143 countries where malaria was endemic in 1950, and many other countries substantially decreases malaria incidence and deaths. However, the campaign did not eradicate malaria.
Today, malaria control in areas with high incidence is based on strategic implementation and scale-up of proven, cost-effective intervention. The aim is first to rapidly reduce malaria morbidity and mortality, particularly among high-risk groups such as children and pregnant women, followed by progressive reduction of transmission and elimination from malaria-endemic areas.
Four proven interventions currently are being scaled up across sub-Saharan Africa include:

1. Long-lasting insecticide-treated mosquito nets (ITNs)
2. Indoor residual spraying (IRS)
3. Diagnosis and treatment of infected persons with artemisinin-based combination therapy (ACT)
4. Protection of women with intermittent preventive treatment during pregnancy (IPTp)
   The availability of vaccines has been critical in targeting diseases for global eradication. Unfortunately, a highly effective vaccine for malaria control has not been found, although several promising candidate are in development.
   CONCLUSION
   Malaria is an enormous global disease burden, and its eradication is an ambitious goal. Although the tools for malaria control are much improved, to ensure continued progress, national programs, local communities, global health partners, and donors will have to build on initial successes, maintain a prolonged commitment, and invest in strategies for the future.