Malaria

Malarial parasite lifecycle

1. MALARIA PRESENTED BY Mrs.J.JEBA.,M.Sc.,M.Phil., ASSOCIATE PROFESSOR, ANNASAMY RAJAMMAL COLLEGE OF NURSING, ATHIYOOTHU.

2. MALARIA Malaria  is a mosquito-borne infectious disease that affects humans and other animals through the bites of infected female  Anopheles  mosquitoes. People who have malaria usually feel very sick with a high fever and shaking chills.

3. CAUSES Malaria is caused by a single-celled parasite of the genus plasmodium. The parasite is transmitted to humans most commonly through mosquito bites.

4. HISTORY The malaria  parasites  begins in 1880 with the  discovery  of the  parasites  in the blood of malaria patients by Alphonse Laveran.

5. Illustration drawn by Laveran of various stages of malaria parasites as seen on fresh blood. Dark pigment granules are present in most stages. The bottom row shows an exflagellating male gametocyte

6. RONALD ROSS Sir Ronald Ross demonstrated the life-cycle of the parasites of malaria in mosquitoes

7. Identification and Naming of the Malarial Parasites Camillo Golgi-- Italian neurophysiologist Camillo Golgi was the first to describe different species of malarial parasite (based on the frequency of attacks they caused and the number of parasites released once the red blood cells containing them ruptured), work for which he was awarded a Nobel Prize in 1906.

8. Italian researchers Giovanni Grassi and Raimondo Filetti first put a name to these, classifying P. vivax and P. malariae. Americans William Welch and John Stephens later contributed, respectively, the names P. falciparum and P. ovale.

9. SPECIES OF PLASMODIUM Plasmodium falciparum  is responsible for the majority of malaria deaths globally. Plasmodium vivax ,  is the second most significant species and is prevalent in Southeast Asia and Latin America.  P. ovale   and  Plasmodium malariae  represent only a small percentage of infections. A fifth species  Plasmodium knowlesi – a species that infects primates – has led to human malaria, but the exact mode of transmission remains unclear.

10. OTHER MODES OF TRANSMISSION The parasites that cause malaria affect red blood cells, people can also catch malaria from exposure to infected blood, including: From mother to unborn child Through blood transfusions By sharing needles used to inject drugs

11. RISKS OF MORE-SEVERE DISEASE People at increased risk of serious disease include: Young children and infants Older adults Travelers coming from areas with no malaria Pregnant women and their unborn children

12. MOSQUITO TRANSMISSION CYCLE Uninfected mosquito.  A mosquito becomes infected by feeding on a person who has malaria. Transmission of parasite.  If this mosquito bites a person in the future, it can transmit malaria parasites to others. In the liver.  Once the parasites enter to body, they travel to liver — where some types can lie dormant for as long as a year

13. Into the bloodstream.  When the parasites mature, they leave the liver and infect red blood cells. This is when people typically develop malaria symptoms. On to the next person.  If an uninfected mosquito bites at this point in the cycle, it will become infected with malaria parasites and can spread them to the other people it bites.

14. LIFE CYCLE OF PLASMODIUM Malaria parasites spread by successively infecting two types of hosts: female Anopheles mosquitoes and humans

15. LIFE CYCLE IN MAN The female anopheles mosquito is the one responsible for causing malaria and it is this species that sucks blood of humans and during this, it also infects humans with plasmodium parasite that cause malaria. The female anopheles mosquito sucks an infected blood containing the gametocytes from any infected individual In the gut of the mosquito, the gametocytes develop into  Sporozoites . This takes duration of about 7 to 20 days for the gametocytes to develop into sporozoites.

16. 3.The sporozoites when formed move to the salivary gland of the mosquito. 4.The sporozoites in the salivary gland are then inoculated into another human when the mosquito wants to bite and suck another blood. 5.This new human host becomes infected with malaria (this is why sporozoites are said to be the infective forms of plasmodium). 6.When your immune system is strong to destroy these infective forms, you can easily clear the infection and the malaria life cycle is terminated.

17. 7.When the immune system is unable to completely destroy and clear the sporozoites, they are then taken to the liver cells. 8 .Sporozoites develop and multiply to form  Merozoites  when they infect liver cells (this stage of the malaria life cycle is referred to as the  Hepatic sporogony ). 9 .This stage of the hepatic sporogeny occurs before the release into blood and before they infect the red blood cells; hence this stage is also called the  Pre-erythrocytic stage .

18. 10 .After multiplication for few days inside the liver cells, the merozoites rupture the hepatocytes (liver cells) and are released into the blood stream. In the life cycle of Plasmodium vivax and Plasmodium ovale, some parasites remain dormant in the liver and are called  Hypnozoites. 11 .  These dormant forms can become active and released into the blood anytime and can cause malaria even after treatment.

19. 12.The released Merozoites in the blood then infect red blood cells. 13.In the red blood cells, the parasites again develop and multiply into  Trophozoite , and then to  Schizont  and finally into new merozoites again. 14.When they form new merozoites, the erythrocyte (red blood cells) then rupture and release the new merozoites which then infect further red blood cells. (The cycle of merozoites changing and multiplying to schizonts and back to merozites is called  erythrocytic schizogony ).

20. 15.This stage takes about 48 hours in Plasmodium falciparum, Plasmodium vivax and Plasmodium ovale; whereas it takes about 72 hours in Plasmodium malariae. 16.In the red blood cells, instead of all the merozoites to develop into trophozoites, some develop into  gametocytes  and are not released from the red cells pending when another female anopheles mosquito takes it up to complete the malaria life cycle.

21. LIFE CYCLE IN MOSQUITO Blood stage parasites are responsible for the clinical manifestations of the disease. 1.The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an  Anopheles  mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . 2.While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes .

22. 3.The zygotes in turn become motile and elongated (ookinetes)  which invade the midgut wall of the mosquito. 4.They develop into oocysts . 5.The oocysts grow, rupture, and release sporozoites, which make their way to the mosquito’s salivary glands. 6.Inoculation of the sporozoites  into a new human host perpetuates the malaria life cycle

23. Facts about Malaria Life cycle in human body The Malaria Life cycle is the same as Plasmodium life cycle as the parasite is the cause of the malaria Gametocytes are the sexual forms of plasmodium parasites this simply means that the sexual forms represent the male and female forms that need to be taken in the blood by mosquitoes. The gametocytes are the ones that join to reproduce in the mosquito.

24. The asexual forms of plasmodium parasites include any other form apart from the gametocytes. The asexual forms include merozoites, trophozoites, and sporozoites. Plasmodium vivax and Plasmodium ovale mainly attack reticulocytes and young erythrocytes (red blood cells). Plasmodium malariae tends to attack older cells. Plasmodium falciparum attacks any stage of red blood cell.

25. SYMPTOMS Fever Chills General feeling of discomfort Headache Nausea and vomiting Diarrhea Abdominal pain Muscle or joint pain Fatigue Rapid breathing Rapid heart rate Cough

26. COMPLICATIONS Cerebral malaria.  If parasite-filled blood cells block small blood vessels to brain (cerebral malaria), swelling of brain or brain damage may occur. Cerebral malaria may cause seizures and coma. Breathing problems.  Accumulated fluid in lungs (pulmonary edema) can make it difficult to breathe. Organ failure.  Malaria can damage the kidneys or liver or cause the spleen to rupture.

27. Anemia.  Malaria may result in not having enough red blood cells for an adequate supply of oxygen to body's tissues (anemia). Low blood sugar.  Severe forms of malaria can cause low blood sugar (hypoglycemia) Very low blood sugar can result in coma or death

28. DIAGNOSIS Giemsa-stained peripheral blood smear Arrow A showing a classic, ring-shaped trophozoite of  Plasmodium falciparum . Arrow B showing a classic, headphone-shaped trophozoite of  P. falciparum . Arrow C showing two trophozoites of  P. falciparum  within the same red blood cell.

29. Jaswant Singh– Bhattacharji stain Jaswant  Singh– Bhattacharji  stain , commonly referred to as JSB  stain , is a rapid  staining  method for detection of  malaria . It is useful for the diagnosis of  malaria  in thick smear samples of blood. MOLECULAR TESTS –PCR SEROLOGICAL TESTS-IFA,ELISA

30. ANTIGEN DETECTION Various test kits are available to detect antigens derived from malaria parasites. Such immunologic (“immunochromatographic”) tests most often use a dipstick or cassette format Provide results in 2-15 minutes. These “Rapid Diagnostic Tests” (RDTs) offer a useful alternative to microscopy in situations where reliable microscopic diagnosis is not available

31. TREATMENT Chloroquine phosphate.   Chloroquine is the preferred treatment for any parasite that is sensitive to the drug. But in many parts of the world, parasites are resistant to chloroquine, and the drug is no longer an effective treatment. .

32. 2.Artemisinin-based combination therapies (ACTs).   ACT is a combination of two or more drugs that work against the malaria parasite in different ways. This is usually the preferred treatment for chloroquine-resistant malaria. Examples include artemether-lumefantrine (Coartem) and artesunate-mefloquine

33. Other common ant malarial drugs include: Atovaquone-proguanil (Malarone) Quinine sulfate (Qualaquin) with doxycycline (Oracea, Vibramycin, others) Primaquine phosphate

34. PREVENTION Cover your skin.  Wear pants and long-sleeved shirts. Tuck in shirt, and tuck pant legs into socks. Apply insect repellent to skin.  Use an insect repellent registered with the Environmental Protection Agency on any exposed skin. These include repellents that contain DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE), para-menthane-3,8-diol (PMD) or 2-undecanone. Do not use a spray directly on face. Do not use products with OLE or PMD on children under age 3.

35. Apply repellent to clothing.  Sprays containing permethrin are safe to apply to clothing. Sleep under a net.  Bed nets, particularly those treated with insecticides, such as permethrin, help prevent mosquito bites while sleeping.

36. Mesh doors Prevent mosquito breeding

37. VACCINES Vaccines . Although progress has been made in the last 10 years toward developing  malaria vaccines ,  there  is currently no licensed  malaria vaccine  on the market. A  malaria vaccine  is a vaccine that is used to prevent malaria. The only approved vaccine as of 2021 is RTS,S, known by the brand name Mosquirix. It requires four injections, and has a relatively low efficacy. Due to this low efficacy, the World Health Organization does not recommend the routine use of the RTS,S vaccine in babies between 6 and 12 weeks of age.