MALARIA ALE LIZ /GLORIA BIOLOGY

P ATHOGEN Malaria is caused by single-celled organisms, called protozoans, of the genus Plasmodium. Different forms of malaria are caused by different species of Plasmodium.

The most severe and deadly form is caused by P. falciparum, which is responsible for 90% of the global deaths from malaria, the majority of these in Africa, and mostly in young children. Other species of Plasmodium which commonly infect humans include P. vivax, P. ovale and P. malariae. Recently, a fifth form, P. knowlesi, has been found infecting rural communities in south-east Asia.

Causative Agent Parasites of the Plasmodium genus. Transmission The malaria parasite typically is transmitted to people by mosquitoes belonging to the genus Anopheles.

“congenital" malaria. Because the malaria parasite is found in red blood cells, malaria can also be transmitted through blood transfusion, organ transplant, the shared use of needles or syringes contaminated with blood.

V ECTOR Plasmodium is transmitted in the saliva of female Anopheles mosquitoes, which inject saliva to prevent blood clotting when they feed on blood from a person. When a mosquito bites an infected person, Plasmodium is taken up into the mosquito's body and eventually reaches its salivary glands. The mosquito is said to be a vector for malaria.

E NDEMIC M ALARIA

Progress Between 2000 and 2015, malaria incidence (the rate of new cases of malaria) fell by 37% globally. During the same period, malaria mortality rates decreased worldwide by 60% among all age groups, and by 65% among children under 5. An estimated 6.2 million malaria deaths have been averted globally since An increasing number of countries are on the verge of eliminating malaria. In 2014, 13 countries reported zero cases of the disease and 6 countries reported fewer than 10 cases. The fastest decreases were seen in the Caucasus and Central Asia (which reported zero cases of malaria in 2014) and in Eastern Asia.

Children under five In areas with high transmission of malaria, children under five are particularly susceptible to infection, illness and death. More than two thirds (70%) of all malaria deaths occur in this age group. Vector control is the main way to prevent and reduce malaria transmission. Two forms of vector control are effective in a wide range of circumstances: insecticide-treated mosquito nets (ITNs) and indoor residual spraying (IRS).

M ORTALITY R ATE Cases, 2013 Globally: 198 million Deaths, 2013 Globally: % of all malaria deaths occur in sub-Saharan Africa and 78% occur in children under five Population at risk 3.2 billion (half of the world population), of whom 1.2 billion are at high risk Affected countries In 2014, 97 countries had on-going malaria transmission. 80% of estimated malaria deaths occur in 18 most affected countries. About 40% of malaria deaths occur in just two countries: Nigeria and the Democratic Republic of the Congo

M ALARIA IN A FRICA 528,000 deaths from malaria in % drop in mortality since % of at-risk people in sub-Saharan Africa have access to mosquito nets 70% of malaria patients could be treated but not all sick children are taken to a clinic 43% of pregnant women did not receive a single dose of preventative medicine WHO Malaria report 2014

Required health expenditure US$ 5.1 billion is needed every year In 2013, the global total of international and domestic funding for malaria was US$ 2.6 billion – less than half of what is needed. Economic cost Direct: USD 12 billion per year in direct losses, lost 1.3% of GDP growth per year for Africa

S YMPTOMS / C LINICAL F EATURES

V ARIATION IN S YMPTOMS In regions where malaria is present people who get infected many times may have the disease but have few or no symptoms. Also how bad malaria symptoms are can vary depending on your general health and the type of malaria parasite.

The time from the initial malaria infection until symptoms appear incubation periods typically ranges from: 9 – 14 days for P. falciparum. 12 – 18 days for P. Vivax. 18 to 40 days for P. Malariae.

R ESISTANCE There are 3 main ways to control Malaria: Reduce the number of mosquitoes. Avoid being bitten. Use drugs to prevent the parasite infecting people.

B IOLOGICAL CONTROL METHODS * STOCKING PONDS, IRRIGATION AND DRAINAGE DITCHES. * SPRAYING PREPARATION CONTAINING BACTERIUM B ACILLUS THURINGIENSIS, ( KILLS MOSQUITOES LARVAE. It is possible to kill the insect VECTOR and break the cycle. Oil can be spread over surfaces of water to make it impossible fro mosquitoes larvae to breathe.

A NTIMALARIA DRUGS

T REATMENT The primary objective of the treatment is to ensure the rapid and complete elimination of the malarial parasite, from the patients blood in order to avoid progression and transmission of the disease.

C ONCERNS OVER THE SPREAD An increase in drug resistance forms of Plasmodium An increase in the proportion of cases caused by p. Falciparum, the form that causes severe, often fatal malaria : difficulties in developing a vaccine An increase in the number of epidemics (climatic and environmental changes) favour the spread. The migration of people as a result of civil unrest and war.

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QUIZ Pathogen? Female or male mosquitoe? One way of transmission Gastric symptom? Increase or decrease in mortality rate? 1 anti malaria drug? Give 1 concern about this disease.