A report on Malaria and Parasitism

Malaria parasite connecting to a red blood cell

A fish parasite, the isopod Cymothoa exigua, replacing the tongue of a Lithognathus

Head (scolex) of tapeworm Taenia solium, an intestinal parasite, has hooks and suckers to attach to its host

The life cycle of malaria parasites. Sporozoites are introduced by a mosquito bite. They migrate to the liver, where they multiply into thousands of merozoites. The merozoites infect red blood cells and replicate, infecting more and more red blood cells. Some parasites form gametocytes, which are taken up by a mosquito, continuing the life cycle.

The parasitic castrator Sacculina carcini (highlighted) attached to its crab host

Micrograph of a placenta from a stillbirth due to maternal malaria. H&E stain. Red blood cells are anuclear; blue/black staining in bright red structures (red blood cells) indicate foreign nuclei from the parasites.

Human head-lice are directly transmitted obligate ectoparasites

Electron micrograph of a Plasmodium falciparum-infected red blood cell (center), illustrating adhesion protein "knobs"

Clonorchis sinensis, the Chinese liver fluke, is trophically transmitted

The blood film is the gold standard for malaria diagnosis.

The vector-transmitted protozoan endoparasite Trypanosoma among human red blood cells

Ring-forms and gametocytes of Plasmodium falciparum in human blood

Mosquitoes are micropredators, and important vectors of disease

An Anopheles stephensi mosquito shortly after obtaining blood from a human (the droplet of blood is expelled as a surplus). This mosquito is a vector of malaria, and mosquito control is an effective way of reducing its incidence.

Life cycle of Entamoeba histolytica, an anaerobic parasitic protozoan transmitted by the fecal–oral route

Man spraying kerosene oil in standing water, Panama Canal Zone, 1912

Cuscuta (a dodder), a stem holoparasite, on an acacia tree

Walls where indoor residual spraying of DDT has been applied. The mosquitoes remain on the wall until they fall down dead on the floor.

The honey fungus, Armillaria mellea, is a parasite of trees, and a saprophyte feeding on the trees it has killed.

Borrelia burgdorferi, the bacterium that causes Lyme disease, is transmitted by Ixodes ticks.

An advertisement for quinine as a malaria treatment from 1927.

Enterobacteria phage T4 is a bacteriophage virus. It infects its host, Escherichia coli, by injecting its DNA through its tail, which attaches to the bacterium's surface.

Deaths due to malaria per million persons in 2012

Restoration of a Tyrannosaurus with holes possibly caused by a Trichomonas-like parasite

Past and current malaria prevalence in 2009

Wolbachia bacteria within an insect cell

Ancient malaria oocysts preserved in Dominican amber

Biologists long suspected cospeciation of flamingos and ducks with their parasitic lice, which were similar in the two families. Cospeciation did occur, but it led to flamingos and grebes, with a later host switch of flamingo lice to ducks.

British doctor Ronald Ross received the Nobel Prize for Physiology or Medicine in 1902 for his work on malaria.

The protozoan Toxoplasma gondii facilitates its transmission by inducing behavioral changes in rats through infection of neurons in their central nervous system.

Chinese medical researcher Tu Youyou received the Nobel Prize for Physiology or Medicine in 2015 for her work on the antimalarial drug artemisinin.

Trait loss: bedbug Cimex lectularius is flightless, like many insect ectoparasites.

Artemisia annua, source of the antimalarial drug artemisinin

The dry skin of vertebrates such as the short-horned lizard prevents the entry of many parasites.

U.S. Marines with malaria in a field hospital on Guadalcanal, October 1942

Leaf spot on oak. The spread of the parasitic fungus is limited by defensive chemicals produced by the tree, resulting in circular patches of damaged tissue.

Members of the Malaria Commission of the League of Nations collecting larvae on the Danube delta, 1929

The rescuing from extinction of the California condor was a successful if very expensive project, but its ectoparasite, the louse Colpocephalum californici, was made extinct.

1962 Pakistani postage stamp promoting malaria eradication program

Parasites are distributed very unevenly among their hosts, most hosts having no parasites, and a few hosts harbouring most of the parasite population. This distribution makes sampling difficult and requires careful use of statistics.

A plate from Francesco Redi's Osservazioni intorno agli animali viventi che si trovano negli animali viventi (Observations on living animals found inside living animals), 1684

Ronald Ross won the 1902 Nobel Prize for showing that the malaria parasite is transmitted by mosquitoes. This 1897 notebook page records his first observations of the parasite in mosquitoes.

"An Old Parasite in a New Form": an 1881 Punch cartoon by Edward Linley Sambourne compares a crinoletta bustle to a parasitic insect's exoskeleton

Disability-adjusted life year for malaria per 100,000 inhabitants in 2004
no data
<10
0–100
100–500
500–1000
1000–1500
1500–2000
2000–2500
2500–2750
2750–3000
3000–3250
3250–3500
≥3500

Fictional parasitism: oil painting Parasites by Katrin Alvarez, 2011

Idiobiont parasitoid wasps immediately paralyse their hosts for their larvae (Pimplinae, pictured) to eat.

Koinobiont parasitoid wasps like this braconid lay their eggs inside their hosts, which continue to grow and moult.

Phorid fly (centre left) is laying eggs in the abdomen of a worker honey-bee, altering its behaviour.

A hyperparasitoid pteromalid wasp on the cocoons of its host, itself a parasitoid braconid wasp

The large blue butterfly is an ant mimic and social parasite.

In brood parasitism, the host raises the young of another species, here a cowbird's egg, that has been laid in its nest.

The great skua is a powerful kleptoparasite, relentlessly pursuing other seabirds until they disgorge their catches of food.

The male anglerfish Ceratias holboelli lives as a tiny sexual parasite permanently attached below the female's body.

Encarsia perplexa (centre), a parasitoid of citrus blackfly (lower left), is also an adelphoparasite, laying eggs in larvae of its own species

Parasites include single-celled protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the broomrapes.

- Parasitism

The mosquito bite introduces the parasites from the mosquito's saliva into a person's blood.

- Malaria

7 related topics with Alpha

Plasmodium falciparum

2 links

Laveran's drawing of various stages of P. falciparum as seen on fresh blood (1880).

Blood smear from a P. falciparum culture (K1 strain - asexual forms) - several red blood cells have ring stages inside them. Close to the center is a schizont and on the left a trophozoite.

Ring forms in red blood cells (Giemsa stain)

Plasmodium falciparum is a unicellular protozoan parasite of humans, and the deadliest species of Plasmodium that causes malaria in humans.

Anopheles

2 links

Genus of mosquito first described and named by J. W. Meigen in 1818.

Anopheles larva from southern Germany, about 8 mm long

Feeding position of an Anopheles larva (A), compared to that of a nonanopheline mosquito (B)

Resting positions of adult Anopheles (A, B), compared to a nonanopheline mosquito (C)

Key to the morphology of female Anopheles

About 460 species are recognised; while over 100 can transmit human malaria, only 30–40 commonly transmit parasites of the genus Plasmodium, which cause malaria in humans in endemic areas.

Some species are poor vectors of malaria, as the parasites do not develop well (or at all) within them.

Clockwise from top left: Blepharisma japonicum, a ciliate; Giardia muris, a parasitic flagellate; Centropyxis aculeata, a testate (shelled) amoeba; Peridinium willei, a dinoflagellate; Chaos carolinense, a naked amoebozoan; Desmarella moniliformis, a choanoflagellate

Protozoa

1 links

Class Protozoa, order Infusoria, family Monades by Georg August Goldfuss, c. 1844

John Hogg's illustration of the Four Kingdoms of Nature, showing "Primigenal" as a greenish haze at the base of the Animals and Plants, 1860

The ciliate Spirostomum ambiguum can attain 3 mm in length

Isotricha intestinalis, a ciliate present in the rumen of sheep.

Paramecium bursaria, is one example of a variety of freshwater ciliates that host endosymbiont chlorophyte algae from the genus Chlorella

Resting cyst of ciliated protozoan Dileptus viridis.

Life cycle of parasitic protozoan, Toxoplasma gondii

Trophozoites of the amoebic dysentery pathogen Entamoeba histolytica with ingested human red blood cells (dark circles)

Protozoa (singular protozoon or protozoan, plural protozoa or protozoans) is an informal term for a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris.

Some are harmless or beneficial to their host organisms; others may be significant causes of diseases, such as babesia, malaria and toxoplasmosis.

Mosquito

1 links

Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin culex meaning "gnat").

Image of pitcher plant mosquito Wyeomyia smithii, showing segmentation and partial anatomy of circulatory system

An egg raft of a Culex species, partly broken, showing individual egg shapes

Adult yellow fever mosquito Aedes aegypti, typical of subfamily Culicinae. Note bushy antennae and longer palps of male on left vs. females at right.

Aedes aegypti, a common vector of dengue fever and yellow fever

$Here an Anopheles stephensi female is engorged with blood and beginning to pass unwanted liquid fractions of the blood to make room in its gut for more of the solid nutrients.$

Female Ochlerotatus notoscriptus feeding on a human arm, Tasmania, Australia

Anopheles albimanus mosquito feeding on a human arm – this mosquito is the sole vector of malaria, and mosquito control is a very effective way of reducing the incidence of malaria.

Mosquitofish Gambusia affinis, a natural mosquito predator

A warning sign about mosquitoes in Sodankylä, Finland

A still from Winsor McCay's pioneering 1912 animated film How a Mosquito Operates

In this way, mosquitoes are important vectors of parasitic diseases such as malaria and filariasis, and arboviral diseases such as yellow fever, Chikungunya, West Nile, dengue fever, and Zika.

Typically, both male and female mosquitoes feed on nectar, aphid honeydew, and plant juices, but in many species the mouthparts of the females are adapted for piercing the skin of animal hosts and sucking their blood as ectoparasites.

Drug resistance

0 links

Reduction in effectiveness of a medication such as an antimicrobial or an antineoplastic in treating a disease or condition.

Malaria in 2012 has become a resurgent threat in South East Asia and sub-Saharan Africa, and drug-resistant strains of Plasmodium falciparum are posing massive problems for health authorities.

Examples of drug-resistant strains are to be found in microorganisms such as bacteria and viruses, parasites both endo- and ecto-, plants, fungi, arthropods, mammals, birds, reptiles, fish, and amphibians.

A scanning electron microscope image of a single neutrophil (yellow/right), engulfing anthrax bacteria (orange/left) – scale bar is 5 µm (false color)

Immune system

0 links

Network of biological processes that protects an organism from diseases.

A scanning electron microscope image of normal circulating human blood. One can see red blood cells, several knobby white blood cells including lymphocytes, a monocyte, a neutrophil, and many small disc-shaped platelets.

Overview of the processes involved in the primary immune response

An antibody is made up of two heavy chains and two light chains. The unique variable region allows an antibody to recognize its matching antigen.

The time-course of an immune response begins with the initial pathogen encounter, (or initial vaccination) and leads to the formation and maintenance of active immunological memory.

Joints of a hand swollen and deformed by rheumatoid arthritis, an autoimmune disorder

Skeletal structural formula of the immunosuppressive drug dexamethasone

Macrophages have identified a cancer cell (the large, spiky mass). Upon fusing with the cancer cell, the macrophages (smaller white cells) inject toxins that kill the tumor cell. Immunotherapy for the treatment of cancer is an active area of medical research.

Paul Ehrlich (1854–1915) was awarded a Nobel Prize in 1908 for his contributions to immunology.

They secrete chemical mediators that are involved in defending against parasites and play a role in allergic reactions, such as asthma.

Some examples of intracellular pathogens include viruses, the food poisoning bacterium Salmonella and the eukaryotic parasites that cause malaria (Plasmodium spp.) and leishmaniasis (Leishmania spp.).

Syrphus hoverfly larva (below) feed on aphids (above), making them natural biological control agents.

Biological pest control

0 links

Method of controlling pests such as insects, mites, weeds and plant diseases using other organisms.

A parasitoid wasp (Cotesia congregata) adult with pupal cocoons on its host, a tobacco hornworm (Manduca sexta, green background), an example of a hymenopteran biological control agent

Cactoblastis cactorum larvae feeding on Opuntia prickly pear cacti

Rodolia cardinalis, the vedalia beetle, was imported from Australia to California in the 19th century, successfully controlling cottony cushion scale.

The invasive species Alternanthera philoxeroides (alligator weed) was controlled in Florida (U.S.) by introducing alligator weed flea beetle.

Hippodamia convergens, the convergent lady beetle, is commonly sold for biological control of aphids.

An inverted flowerpot filled with straw to attract earwigs

Predatory lacewings are available from biocontrol dealers.

Predatory Polistes wasp searching for bollworms or other caterpillars on a cotton plant

The parasitoid wasp Aleiodes indiscretus parasitizing a gypsy moth caterpillar, a serious pest of forestry

Encarsia formosa, widely used in greenhouse horticulture, was one of the first biological control agents developed.

Life cycles of greenhouse whitefly and its parasitoid wasp Encarsia formosa

Green peach aphid, a pest in its own right and a vector of plant viruses, killed by the fungus Pandora neoaphidis (Zygomycota: Entomophthorales) Scale bar = 0.3 mm.

Cane toad (introduced into Australia 1935) spread from 1940 to 1980: it was ineffective as a control agent. Its distribution has continued to widen since 1980.

It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also involves an active human management role.

The sturdy and prolific eastern mosquitofish (Gambusia holbrooki) is a native of the southeastern United States and was introduced around the world in the 1930s and '40s to feed on mosquito larvae and thus combat malaria.