Chemotherapy and avian malaria

Abstract

Malaria is endemic over a wide area of the earth's surface. Although popularly associated with tropical or subtropical countries, it occurs as far north as the south of Sweden and Lake Ladoga in Russia and as far south as Bechuanaland, Swaziland and Natal in South Africa and the Argentine in South America. Though most frequent in low-lying districts it may be found at altitudes as great as 6000–9000 ft.

New Antimalarial Drugs

“…Today, chloroquine-resistant strains of P. falciparum (and to some extent of P. vivax) are common in all endemic areas throughout the world. During World War II, British researchers developed proguanil (6, Figure 2), which in turn served as a lead compound for the development of pyrimethamine (7) in 1950. Faced with heavy losses as a result of chloroquine-resistant malaria during the Vietnam War, the development of new antimalarial drugs was encouraged by the American military and resulted in the development of mefloquine (8) and halofantrine (9).…”

“…The high incidence of resistance against chloroquine (5) and the anti-folate combination pyrimethamine-sulfadoxine (7)(8)(9)(10)(11) (Figure 2) Dr. Jochen Wiesner, born in 1971 in Bad Neustadt, Germany, studied biology at the University of Würzburg, where he received his doctorate in 1998 for his work in the group of Michael Lanzer on the interactions of the malaria parasite P. falciparum with the complement system and on the sodium-proton exchanger of P. falciparum as a potential drug target. Afterwards he worked at Jomaa Pharmaka GmbH in Giessen (Germany) on the development of fosmidomycin and other inhibitors of the mevalonateindependent isoprenoid biosynthesis pathway for the treatment of malaria.…”

“…Since the 1920s routine screening for antimalarial drugs has been carried out on canaries infected with the avian malaria parasite P. relictum. [7] In 1935, P. relictum was completely replaced by P. gallinaceum, which infects day-old chicks. Since the discovery of the rodent parasite P. berghei in 1948, murine malaria models have been used increasingly and still represent the most important in vivo test systems for new antimalarial drugs.…”

“…The parasites develop through the stages of rings (4), trophozoites (5), and schizonts (6). In the segmenter stage (7), each schizont typically divides into 16 erythrocytic merozoites, which are released by lysis of the erythrocyte and immediately invade new erythrocytes (8). Induced by stress factors, a small proportion of blood stages undergo differentiation into female (9) and male (10) gametocytes, which enter the mosquito when it bites an infected individual (11).…”

Neue Antimalaria‐Wirkstoffe

“…Seit den zwanziger Jahren wurden für das Routinescreening nach Antimalaria‐Wirkstoffen Kanarienvögel verwendet, die mit P. relictum , einer Vogel‐spezifischen Plasmodium‐Spezies, infiziert wurden 7 . P. relictum wurde 1935 vollständig durch P. gallinaceum verdrängt, mit dem die Infektion frisch geschlüpfter Küken möglich ist.…”