Drug-Resistant Malaria - libdoc.who.int - World Health Organization

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(h) specialized investigation of the pharmacokinetics,
pharmacodynamics and side effects of specific drugs with a view to
optimizing drug dosage and regimen.
Progress, Baseline Studies and Monitoring
Following the workshop on drug-resistant malaria held 1n
Manila in May 1978, Contractual Technical Services (CTS) agreements
were signed between the UNDP/World Hank/WHO Special Progrannne
for Research and Training in Tropic.!!.l Diseases (TDR) and
several institutions in the Region during 1979/1980 for the
assessment and monitoring of drug resistance, in particular the
response of P.falciparum to 4-aminoquinolines. The studies
carried out to date are summarized below.
(a) Australia. Malaria was eradicated several years ago.
Of the 628 cases of malaria reported in 1980, nearly all were
imported (625, with one death) 2 were introduced and there was one
relapsing introduced case. The majority of cases (529) were due
to P.vivax; 89 were P.falciparum infections. Since all P. falciparum
cases were treated with quinine/sulfadoxine/ pyrimethamine,
the number of chloroquine-resistant infections is unknown. The
Australian Army Malaria Research Unit carried out macro in vitro
tests on 7 cases from various hospitals: 2 were sensitive to
chloroquine, 3 resistant and 2 tests failed.
(b) China. In 1980 some 3.3 million eases of malaria were
reported, among which 12 867 were due to P.falciparum. All falciparum
malaria cases came from the southern provinces of Guizhou,
Hunan, Guangxi, Guangdong and Yunnan. In Guangdong Province most
cases are confined to Hainan Island. Chloroquine resistance has
been detected in border areas in Yunnan, the southern part of
Guangxi Autonomous Region and the hill areas of Hainan Island. Of
396 cases tested in vivo between 1973 and 1980, 124 were sensitive
and 272 resistant. Of 982 cases followed up for 7 days only, 258
were resistant (RII, RIll).
In vitro tests using microplates provided by WHO and plates
from the Institute of Parasitic Diseases in Shanghai showed no
difference in growth. Chloroquine resistance in Hainan was confirmed;
resistance to pyrimethamine was also observed in this
area.
Pyronaridine and Qinghaosu are used for the treatment of
chloroquine resistant P.falciparum and c(~plicated flaciparum
malaria. Piperaquine (13228 R.P.) is being used for chemoprophylaxis
and treatment of uncomplicated cases. While piperaquine is
currently in general production, pyronaridille and Qinghaosu and
its derivative 804-Na are in trial production only.
(c) ~L=a=o~ __ =P~e~o~p~l~e~'s~ ___ D~em==o~c=r=a=t~i~c~ __ ~R=e~p~1j.blic.
Chloroquine