Friday April 25 2014

Why malaria is the number one killer disease


1. Dr Pauline Byakika, a senior researcher on Malaria at the School of Medicine Makerere University College of Health Sciences says that when a person is bitten by a malaria-infected mosquito, the parasites that cause malaria are released into the blood infecting liver cells.

2. “A person will not notice symptoms for one week to one month. During this time, malaria parasites multiply in a person’s liver before invading red blood cells in the bloodstream. Once inside a person’s red blood cells, the parasites continue to multiply and spread the infection,” she explains.

3. Infected red blood cells eventually rupture, causing a person to experience flu-like symptoms that include sweating, high fevers and chills, and nausea as well as general body weakness in uncomplicated malaria.

4. “As the disease progresses, a person’s spleen and liver enlarge. Malaria may cause anaemia or jaundice [yellowing]. In some severe cases, it attacks the brain and creates neurological problems and after the early stages, life-threatening complications may develop rapidly and if not treated, serious complications or death can occur.” Dr Byakika says.

5. According to the World Health Organisation, severe malaria presents with clinical deterioration usually appears three to seven days after onset of fever with complications involving the nervous, respiratory, renal, liver systems.

The number of people who suffer from malaria annually

The percentage of severe malaria cases, which result into permanent damage of body organs or death

Dr Ivan Kisuule, a physician at Mulago Hospital says the parasites affect the bone marrow by suppressing it and preventing it from producing more blood cells. This therefore leads to anaemia as a result of the failure by the bone marrow to make more blood cells.

Consequently, this leads to enlargement of the heart as it struggles to supply oxygen to other distant body organs.
During pregnancy

As a result of reduced blood production by the bone marrow, the placenta – the main source of food for the foetus (growing baby) does not get enough blood too.

Dr Byakika further explains that as long as the placenta doesn’t get enough blood, this results into what is medically known as uterine retardation or low birth weight babies.

“And the risk of death of these babies in infancy is very high. In some cases women suffer miscarriages, aneamia both in babies and mothers as well as maternal deaths where malaria is severe,” she says.
Other complications include inability to feed, low blood pressure, breathing problems, circulatory shock, bleeding problems, pulmonary oedema (fluid buildup in the lungs) or acute respiratory distress syndrome (ARDS), which may occur even after the parasite counts have decreased in response to treatment.

The number of people malaria claims every year

Most vulnerable
According to Dr Myers Lugemwa, the Officer in Charge of the Malaria Control Programme at the Ministry of Health, women and Children are the two most vulnerable groups affected by malaria and people living with HIV.

“For the children, their immunity is just developing; as such they lack the passive immunity which comes as a result of several malaria infection exposures in adults. This makes them too weak to fight the infection and that’s why they get severe malaria in most cases,” he says.

Dr Byakika explains that in the process of the malaria parasites rapturing after they are released into the liver, the liver tissue gets damaged. “But most importantly, the liver manufactures glucose or blood sugar. And so when a person with malaria is not eating enough or vomiting what they eat, the liver cannot produce the glucose, the body is depleted of blood sugar.”

When oxygen supply is cut off, the kidneys whose primary role is to clean blood and remove waste products, are damaged. “And when there is kidney failure, it means that the toxins and waste products remain in the blood causing further damage on the kidneys. If not treated, this can further develop into kidney shock and subsequent shut down,” Dr Kisuule explains.

The spleen acts as a filter for blood, recycles, and stores blood cells. The spleen recognises malaria parasites as foreign bodies and therefore works hard to destroy them
Dr Kisuule says because the parasites are so many, the spleen is overworked in the process of fighting to destroy the parasites. As a result, it gets enlarged and sometimes raptures, causing more life-threatening internal bleeding.

When malaria parasites enter the blood cells, they become sticky and collect themselves in one pool. The sticky cells cause blockage in the blood vessels – causing a blood supply shortage in the brain. Dr Byarugaba Baterana, a senior consultant in malariology says, when the blood supply is cut off, there is also decreased oxygen supply to vital organs like the heart, the brain and lungs. As a result of oxygen shortage, the brain tissues swell causing cerebral malaria. Cerebral malaria presents with unconsciousness, vomiting, convulsions among others.


Since the burden of severe forms of malaria is concentrated in young children and pregnant women and people living with HIV, the World Health Organisation recommends effective use of long lasting insecticide treated nets, indoor residual spraying and early diagnosis and treatment of the disease.

“As with any malaria whether uncomplicated or severe, prevention remains the same,” says the commissioner for community health Dr Anthony Mbonye. He adds that pregnant women should sleep under mosquito nets from the first day of pregnancy and a preventive dose of fansider as a preventive drug to protect them against malaria three times during pregnancy.

And in HIV positive people, Dr Mbonye says a daily pill of septrine is recommended and offers protection against malaria and other infections.