Century-old human burden

A MAN in his early 40’s,and in company of his wife and three children (a boy of about 10 years old with two girls, aged eight and six years old) walked into the doctor’s consulting room.
The following conversation  ensued:-
  Man:-Good morning doctor.
Doctor:-Good morning sir, how do I be of assistance to you.
Man:-Doc, this is my family, my wife, son, and two daughters, we are here to receive malaria vaccination.
  Doctor:-Hmmm!!The world first malaria vaccine’ RTS S newly launched in Malawi, is presently undergoing clinical trials ,the vaccine is only made available to children up to two years. The other two African countries  for the trial are Ghana and Kenya.
Malaria remains one of the World’s leading killer’s claiming the life of one child every two minutes according to the World Health Organization and most of the death are in Africa where over 250,000 children dies from the disease every year.
VACCINES AGAINST MALARIA RTS,S/ASO1 (RTS,S) is the first and, to date, the only vaccine to show partial protection against malaria in young children. It acts against P.falciparum, the most deadly malaria parasite globally and the most prevalent in Africa. Among children who received 4 doses in large-scale clinical trials, the vaccine prevented approximately 4 in 10 cases of malaria over a 4year period.
In view of it’s public health potential, WHO’S top advisory bodies for malaria and immunization have jointly recommended phased introduction of the vaccine in selected areas of sub-Saharan Africa. The vaccine has been introduced in 3 pilot countries-Malawi,Ghana and Kenya.
The pilot programme will address several outstanding questions related to the use of the vaccine in real life settings. It will be critical for understanding how best to deliver the required four doses of RTS,S; the vaccine’s potential role in reducing childhood deaths; and its safety in the context of routine use.
MALARIA
This is a along life threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. It is preventable and curable.
Plasmodium parasites is the cause of malaria, it’s carried by a vector called Anopheles mosquitoes, they are 5 parasite species that causes malaria in human,and 2 of the species I.e P.falciparum and P.vivax poses a greater threat to human race.
In 2017,P.falciparum accounted for 99.7% of estimated malaria cases in the Africa region, as well as in the majority of cases in the South East Asia 68%,the Eastern Mediterranean 69% and the Western Pacific 71%. P.vivax is the predominant parasite in the Americas, representing 74.1% of malaria cases.
 SYMPTOMS
Malaria is an acute febrile illness. In a non immune individual, symptoms usually appear 10-15 days after the infective mosquito bite. The first symptoms are fever, headache, and chills-may be mild and difficult to recognize as malaria. 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 failure is also frequent In malaria endemic areas, people may develop partial immunity, allowing asymptomatic infections to occur.
In 2017, nearly half of the world’s population was at risk of malaria. Most malaria cases and deaths occur in sub Saharan Africa. However, South East Asia, Eastern Mediterranean, Western Pacific, and the Americas are also at risk. In 2017,87 countries and areas had ongoing malaria transmission. Some population groups are at considerably higher risk of contracting malaria, and developing severe disease, than others. These include:- infants, children under 5years of age, pregnant women and Patients with HIV/AIDS As well as non-immune migrants, Mobile populations Travellers.
  MALARIA BURDEN
World malaria report released in November 2018,recorded that there were about 219 million cases of malaria in 2017,up from 217 million cases in 2016.The estimated numbers of malaria deaths stood at 435,000 in 2017,a similar number to the previous year.
Africa region continues to carry a disproportionate high share of the global malaria burden.in 2017,the region was home to 92% of malaria cases and 93% of malaria deaths.
In 2017,5 countries accounted for nearly half of all malaria cases worldwide these are Nigeria with 25%,the Democratic Republic of Congo(11%),Mozambique (5%),India (4%),and Uganda(4%). Children under 5years of age are the most vulnerable group affected by malaria; in 2017,they accounted for 61%(266,000)of all malaria deaths worldwide.
  TRANSMISSION
It is transmitted through the bites of female Anopheles mosquitoes. There are more than 400 different species of Anopheles mosquito; around 30 are malaria vectors of major importance. All of the important vector species bites between dusk and dawn.
The intensity of transmission depends on factors related to the parasite, the vector, the human host, at the environment.
Anopheles mosquitoes lay their eggs in water, which hatch into larvae, eventually emerging as adult mosquitoes. The female mosquitoes seek a blood meal to nurture their eggs. Each species of Anopheles mosquito has its own preferred aquatic habitat for example, some prefer small, shallow collections of fresh water, such as puddles and hoof prints, which are abundant during the rainy season in tropical countries.
Transmission is more intense in places where the mosquito lifespan is longer (so that the parasite will have time to complete its development inside the mosquito),and where it prefers to bite humans rather than other animals. Then long lifespan and strong human biting habit of the Africa vector species is the main reason why approximately 90% of the world’s malaria cases are in Africa.
Transmission also depends on climatic conditions that may affect the number and survival of mosquitoes, such as rainfall patterns, temperature, and humidity. In many places ,transmission is seasonal, with the peak during and just after the rainy season. Malaria epidemics can occur when climate and other conditions suddenly favour transmission in areas where people have little or no immunity to malaria. They can also occur when people with low immunity move into areas with intense malaria transmission, for instance to find work, or as refugees.
Human immunity is another important factor, especially among adults in areas of moderate or intense transmission conditions. Partial immunity is developed over years of exposure, and while it never provides complete protection, it does reduce the risk that malaria infection will cause severe disease. For this reason, most malaria deaths in Africa occur in young children, where as in areas with less transmission and low immunity, all age groups are at risk.
 PREVENTION
Vector control is the main way to prevent and reduce malaria transmission, two forms of vector control are available
(1) Insecticide treated mosquito nets(ITN):-sleeping under ITN can reduce contact between mosquitoes and humans by providing both a physical barrier and an insecticidal effect.
(2) indoor residual spraying (IRS):-This is spraying with insecticides, it involves spraying the inside of a house with an insecticide.
  ANTIMALARIAL DRUGS
Travellers can use chemoprophylaxis  to prevent malaria, also for pregnant women living in endemic area,WHO recommend the use of intermittent preventive treatment with sulfadoxine-pyrimethamine,at each antenatal visit scheduled after the first trimester.
DIAGNOSIS:-
WHO recommends that all cases of suspected malaria be confirmed using PARASITE BASED DIAGNOSTICS testing, either microscopy or rapid diagnostic test, before administering treatment. Result of parasitological confirmation can be available in 30 minutes or less than.
TREATMENT:-
Early diagnosis and treatment of malaria reduces disease and prevent deaths. The best available treatment, particularly for P.falciparum, is ARTEMISININ based combination therapy (ACT).
 MAJOR PROBLEM:
This is the issue of recurring resistance to antimalarial medice, especially to P.falciparum malaria parasite.
 
Dr Azugo is a Senior Medical Officer in FCT Hospital Management Board, Abuja