By Fred Nwaozor
ON Tuesday, April 25, the world commemorated the 2017 World Malaria Day. Due to widespread malaria infection and its deadly consequence, the World Health Organisation thought it wise to proclaim World Malaria Day during the sixtieth (60th) session of the World Health Assembly, in May 2007. The day was established to provide education and thorough understanding of malaria disease across the globe, especially in countries where the disease is endemic.
Malaria is a mosquito-borne infectious disease of humans and other animals caused by a group of single-celled parasitic micro-organisms known as protozoa belonging to the genus plasmodium. The disease is mainly transmitted by mosquito bites, and the symptoms often commence few days after the bite.
Malaria is transmitted most commonly by an infected female Anopheles mosquito. The mosquito bite introduces the parasite called plasmodium from the mosquito’s saliva into a person’s bloodstream. The parasites then travel to the liver where they mature and reproduce.
The signs and symptoms of malaria typically begin eight to twenty-five days following infection; however, symptoms may occur later in those who have taken anti-malarial medications in the past as prevention. Initial manifestations of the disease, which are common to all malaria species, are flu-like symptoms and can resemble other conditions such as septicemia, gastroenteritis and viral diseases.
The presentation may include headache, fever, shivering, joint pain, vomiting, haemolytic anaemia, jaundice, haemoglobin in the urine, retinal damage and convulsions. The classic symptom of malaria is paroxysm – a cyclical occurrence of sudden coldness followed by shivering and then fever and sweating; occurring every two days in P. Vivax and P. Malariae infection.
Severe malaria, which might lead to death, is usually caused by P. Falciparum – often referred to as ‘Falciparum Malaria’. Its symptoms arise nine to thirty days after contracting the infection. Individuals with cerebral malaria frequently exhibit neurological symptoms including abnormal posturing, nystagmus, conjugate gaze palsy i.e. failure of the eyes to turn together in the same direction, opisthotonus, seizure or coma.
There are several serious complications of malaria. Among these is the development of respiratory distress, which occurs in up to twenty-five percent (25%) of adults and forty percent (40%) of children with severe P. Falciparum malaria. Possible causes include respiratory compensation of metabolic acidosis, non-cardiogenic pulmonary oedema, concomitant pneumonia and severe anaemia. It is worthy to note that concurrent infection of HIV with malaria increases mortality rate. Malaria in pregnant women is the major cause of stillbirths, infant mortality, abortion and low birth weight, particularly in P. Falciparum infection.
Symptoms of malaria can recur after varying symptom-free periods. Depending upon the cause, recurrence can be classified as either recrudescence or relapse. Recrudescence is when symptoms return after a symptom-free period; it is caused by parasites living in the blood as a result of inadequate or ineffective treatment. Whilst, relapse is when symptoms reappear after the parasites have been eliminated from blood but persist as dormant hyponozoites in liver cells; relapse commonly occurs between eight to twenty-four weeks and is common among P. Vivax and P. Ovale infections.
Malaria infection develops via two major phases namely, one involving the liver known as exoerythrocytic phase, and one that involves the red blood cells, referred to as erythrocytic phase. When an infected mosquito pierces a person’s skin to take a blood meal, sporozoites in the mosquito’s saliva enter the bloodstream and migrate to the liver where they infect hepatocytes, multiplying asexually and asymptomatically for a period of eight to thirty days. After a potential dormant period in the liver, these organisms differentiate to yield thousands of merozoites, which, following rupture of their host cells, escape into the blood and infect the red blood cells to begin the erythrocytic stage of their life cycle.
The primary sources of mosquitoes include sewage, refuse, dirty stagnant water and untidy environment. In most cases, mosquitoes are peculiar to damp and dirty environments or substances such as gutters, pools, faeces, urine, among other solid and liquid waste materials. This is why residents of untidy localities are at a high risk of contracting malaria.
Methods used to prevent malaria include medications, mosquito elimination through fumigation coupled with regular environmental sanitation, as well as prevention of mosquito bites via regular cum proper use of mosquito nets, among others. Prevention of malaria, which is yet to have a vaccine, may be more cost-effective than treatment of the disease in the long run; though the initial costs required are out of reach of many of the world’s poorest people.
Owing to the non-specific nature of presentation of symptoms, diagnosis of malaria in non-endemic areas requires a high degree of suspicion. Malaria is invariably confirmed by the microscopic examination of blood films or by antigen-based Rapid Diagnostic Tests (RDT). Microscopy is the most commonly used method to detect the malaria parasite in the body. In spite of its widespread usage, diagnosis by microscopy suffers from two main drawbacks: many settings especially rural are not equipped to perform the test, and the accuracy of the results depends on both the skill of the lab technician and the levels of the parasite in the blood.
Malaria is widely treated with anti-malarial medications; the ones to be used solely depend on the type and severity of the disease. While medications against fever are commonly used, their effects on outcomes are not clear.
Uncomplicated malaria may be treated with oral medications; the most effective treatment for P. Falciparum infection is the use of artemisinins in combination with other anti-malarial drugs known as Artemisinin-Combination Therapy (ACT), which decreases resistance to any single drug component.
It is obvious that malaria is a killer disease. The World Health Organization (WHO) estimates that in 2010, there were about two hundred and ninety (219) million cases of malaria outbreak resulting to six hundred and sixty thousand (660,000) deaths. The majority of cases, about sixty-five percent (65%), occur in children under fifteen years. Survey also indicates that about one hundred and twenty-five (125) million pregnant women are at risk of infection each year; in Sub-Saharan Africa such as Nigeria, Angola, Chad, Congo, Benin, Ghana and several others, maternal malaria is associated with up to two hundred thousand (200,000) estimated infant deaths yearly.
In a nutshell, globally, about 3.3 billion individuals in 106 countries are at risk of malaria, mostly African children.
As Nigeria joins the rest of the world to commemorate the annual World Malaria Day, I urge every individual in the country regardless of age or status, to be extremely conscious of the outlook of his/her surroundings or immediate environment since malaria is mainly attributed to unhealthy vicinity.
Thus, we should always endeavour to properly dispose of any form of waste found within our place of residence as well as thoroughly sanitize our gutters and toilets at all times. In addition, we ought to ensure that our beds are always covered with treated mosquito nets.
Among all, we should endeavour to see our physician from time-to-time or whenever we notice any abnormality in our body system, for onward review of our health status. In the same vein, the various health workers/personnel across the country are expected to contribute meaningfully and immensely to the creation of awareness on the causes and possible effects of malaria.
Nwaozor writes from Owerri
Most importantly, we, in our individual or collective capacities, must always bear in mind that prevention is invariably better than cure.
Nwaozor writes from Owerri
Nwaozor writes from Owerri