Acute Primary Attack Research Articles

Blood monocyte oxidative burst activity in acute P. falciparum malaria

The release of superoxide anion from blood monocytes was studied in eight patients with acute primary attack P. falciparum malaria. Before treatment a significant enhancement of the oxidative burst prevailed, which contrasts with previous findings of a depressed monocyte chemotactic responsiveness. During treatment and after clinical recovery the activity of superoxide anion release normalized in all patients.

Latency and long-term relapses in Benign Tertian malaria

The first relapse in B.T. malarial infections usually occurs several months after the treatment of the primary attack, and may be as long delayed as I year. A case is presented for considering that relapses are due to sporozoites which have been held up in tissue cells, a not improbable hypothesis when it is remembered that sporozoites are able to survive for many months in the tissue cells of the insect carrier. True latency is seen in those cases in which the primary attack occurs many months after infection, frequently after a delay of about 38 weeks. (The delay varies between 2 months and I year.)First relapses frequently occur at about the same period of time. Latency as defined in this paper occurs:(1) in nature; (2) following certain drug prophylaxis ;(3) when mixed infections of B.T. and M.T. malaria occur; (4) when patients who are immune to one strain of B.T. malaria are infected by a different strain. The significance of the drug pamaquin (plasmoquine) is that it prevents the onset of an attack for many months,whereas, compared with quinine and mepacrine in an acute primary attack its action on erythrocytic parasites is slight. It is suggested that relapses in B.T. malaria are due to a resting phase of the parasite and that a drug which successfully prevents relapses would also act as a successful causal prophylactic and vice-versa. Sporozoites are known to survive for many months in the tissue cells of the insect host and it is suggested that they also may be able to do so in the human host. The word “ prophylaxis ” has been used in this paper deliberately in preference to the word “ suppressive.” When quinine is used as a prophylactic against B.T. malarial infections, if the drug is discontinued a few days after exposure to infection, the onset of fever is delayed for at most a few days. When mepacrine or pamaquin is used, in one strain at least (Madagascar strain) fever seldom occurs within 2 months of infection; and usually the period is between 34 and 38 weeks. It is, therefore, considered that while the word suppressive is applicable to quinine it is less appropriate to mepacrine and pamaquin.