Malaria is a mosquito-borne infectious disease that affects humans and other vertebrates. Human malaria causes symptoms that typically include fever, fatigue, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. Symptoms usually begin 10 to 15 days after being bitten by an infected Anopheles mosquito. If not properly treated, people may have recurrences of the disease months later. In those who have recently survived an infection, reinfection usually causes milder symptoms. This partial resistance disappears over months to years if the person has no continuing exposure to malaria.
Plasmodium is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of Plasmodium species involve development in a blood-feeding insect host which then injects parasites into a vertebrate host during a blood meal. Parasites grow within a vertebrate body tissue before entering the bloodstream to infect red blood cells. The ensuing destruction of host red blood cells can result in malaria. During this infection, some parasites are picked up by a blood-feeding insect, continuing the life cycle.
Anopheles or Marsh Mosquitoes is a genus of mosquito first described and named by J. W. Meigen in 1818. About 460 species are recognized; 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. Anopheles gambiae is one of the best known, because of its predominant role in the transmission of the most dangerous malaria parasite species – Plasmodium falciparum.
Plasmodium falciparum is a unicellular protozoan parasite of humans, and the deadliest species of Plasmodium that causes malaria in humans. The parasite is transmitted through the bite of a female Anopheles mosquito and causes the disease's most dangerous form, falciparum malaria. It is responsible for around 50% of all malaria cases. P. falciparum is therefore regarded as the deadliest parasite in humans. It is also associated with the development of blood cancer and is classified as a Group 2A (probable) carcinogen.
Giovanni Battista Grassi was an Italian physician and zoologist, best known for his pioneering works on parasitology, especially on malariology. He was Professor of Comparative Zoology at the University of Catania from 1883, and Professor of Comparative Anatomy at Sapienza University of Rome from 1895 until his death. His scientific contributions covered embryological development of honey bees, on helminth parasites, the vine parasite phylloxera, on migrations and metamorphosis in eels, and on termites. He was the first to describe and establish the life cycle of the human malarial parasite, Plasmodium falciparum, and discovered that only female anopheline mosquitoes are capable of transmitting the disease. His works in malaria remain a lasting controversy in the history of Nobel Prizes, because a British army surgeon Ronald Ross, who discovered the transmission of malarial parasite in birds was given the 1902 Nobel Prize in Physiology or Medicine. But Grassi, who demonstrated the complete route of transmission of human Plasmodium, and correctly identified the types of malarial parasite as well as the mosquito vector, Anopheles claviger, was denied.
Plasmodium vivax is a protozoal parasite and a human pathogen. This parasite is the most frequent and widely distributed cause of recurring malaria. Although it is less virulent than Plasmodium falciparum, the deadliest of the five human malaria parasites, P. vivax malaria infections can lead to severe disease and death, often due to splenomegaly. P. vivax is carried by the female Anopheles mosquito; the males do not bite.
Plasmodium ovale is a species of parasitic protozoon that causes tertian malaria in humans. It is one of several species of Plasmodium parasites that infect humans, including Plasmodium falciparum and Plasmodium vivax which are responsible for most cases of malaria in the world. P. ovale is rare compared to these two parasites, and substantially less dangerous than P. falciparum.
Plasmodium malariae is a parasitic protozoan that causes malaria in humans. It is one of several species of Plasmodium parasites that infect other organisms as pathogens, also including Plasmodium falciparum and Plasmodium vivax, responsible for most malarial infection. Found worldwide, it causes a so-called "benign malaria", not nearly as dangerous as that produced by P. falciparum or P. vivax. The signs include fevers that recur at approximately three-day intervals – a quartan fever or quartan malaria – longer than the two-day (tertian) intervals of the other malarial parasite.
Plasmodium knowlesi is a parasite that causes malaria in humans and other primates. It is found throughout Southeast Asia, and is the most common cause of human malaria in Malaysia. Like other Plasmodium species, P. knowlesi has a life cycle that requires infection of both a mosquito and a warm-blooded host. While the natural warm-blooded hosts of P. knowlesi are likely various Old World monkeys, humans can be infected by P. knowlesi if they are fed upon by infected mosquitoes. P. knowlesi is a eukaryote in the phylum Apicomplexa, genus Plasmodium, and subgenus Plasmodium. It is most closely related to the human parasite Plasmodium vivax as well as other Plasmodium species that infect non-human primates.
Plasmodium berghei is a single-celled parasite causing rodent malaria. It is in the Plasmodium subgenus Vinckeia.
The Anopheles gambiae complex consists of at least seven morphologically indistinguishable species of mosquitoes in the genus Anopheles. The complex was recognised in the 1960s and includes the most important vectors of malaria in sub-Saharan Africa, particularly of the most dangerous malaria parasite, Plasmodium falciparum. It is one of the most efficient malaria vectors known. The An. gambiae mosquito additionally transmits Wuchereria bancrofti which causes lymphatic filariasis, a symptom of which is elephantiasis.
The history of malaria extends from its prehistoric origin as a zoonotic disease in the primates of Africa through to the 21st century. A widespread and potentially lethal human infectious disease, at its peak malaria infested every continent except Antarctica. Its prevention and treatment have been targeted in science and medicine for hundreds of years. Since the discovery of the Plasmodium parasites which cause it, research attention has focused on their biology as well as that of the mosquitoes which transmit the parasites.
Mandayam Osuri Tirunarayana Iyengar was an Indian medical entomologist who worked on management of filaria and malaria vectors. He was employed as an entomologist in the Department of Malaria Research, Bengal. The mermithid parasite Romanomermis iyengari and the mosquito species Culex iyengari are named after him.
Anopheles walkeri is a species of mosquito found predominantly throughout the Mississippi River Valley, with its habitat ranging as far north as southern Quebec, Canada. The eggs of A. walkeri are laid directly on the water surface in freshwater swamp habitats. Since its eggs are not resistant to desiccation, this species is restricted to swampy regions with plenty of water. Anopheles walkeri, as with many other anophelines, begins to become active later in the evening than most other mosquito species in its range. This species becomes especially active late at night when in search of a blood meal. Feeding activity is affected greatly by environmental conditions within its microclimate. Wind, low humidity and cool temperatures, are all negatively correlated with feeding aggression.
Anopheles albimanus is a species of mosquito in the order Diptera. It is found in coastal Central and South America, the Caribbean, and Mexico. It is a generalist species and capable of wide dispersion. A. albimanus is a common malaria vector.
Anopheles claviger is a mosquito species found in Palearctic realm covering Europe, North Africa, northern Arabian Peninsula, and northern Asia. It is responsible for transmitting malaria in some of these regions. The mosquito is made up of a species complex consisting of An. claviger sensu stricto and An. petragnani Del Vecchio. An. petragnani is found only in western Mediterranean region, and is reported to bite only animals; hence, it is not involved in human malaria.
Setaria is a genus of parasitic roundworms that infect domesticated mammals such as pigs, camels, cattle and horses. Some species also infect wild mammals such as deer and antelope. The genus consists of about 43 species. Members of the genus are uniquely parasites in the abdominal cavity of the body. They are mostly large-sized roundworms, possessing an elaborate head (cephalic) region that is characterised by spines, presence of four lips, and well-guarded mouth. Little is known about their pathogenic effects, but some are known to affect nervous system and eye. The larval infective forms are transmitted from one animal to another by the bite of mosquitoes and flies. In addition Setaria marshalli can be transmitted from the womb to new-born calf.
Anopheles (Cellia) karwari is a species complex of zoophilic mosquito belonging to the genus Anopheles. It is found in India, and Sri Lanka, Bangladesh, Sumatra, and Java. A. karwari is a member of the Maculatus Group and the second scarcest species reported from Indonesia. Female is blood sucking and involved in transmitting Plasmodium falciparum, thus an important malarial vector. It is considered a secondary vector in the Australian region, but its vectorial status in South-East Asia was unknown.
