Biology Reference
In-Depth Information
3.5. China's Use of MDA
The People's Republic of China has progressively controlled malaria during
the twentieth century, such that a country that was once very malarious is
now within sight of elimination (
Cui et al., 2011
). Except for the border
with Burma, all endemic malaria in China is vivax following the recent
disappearance of falciparum malaria from Hainan Island. However, the geo-
graphic extent and population numbers still within areas of malaria trans-
mission in China are enormous even if individual cases are very infrequent
outside of focal epidemics (
Dapeng et al., 1996
;
Zhou et al., 2011
;
Hui et al.,
2009
;
Xu et al., 2006
). In the 1970s, China experienced a massive upsurge of
vivax malaria with an estimated 30 million malaria cases occurring of which
95% were vivax (
Zhang and Deng, 1989
). In response, China employed the
mass administration of primaquine in treatment dosages (22.5 mg per day in
adults for 8 days) (
Sleigh et al., 1998
). Literally, tens of millions of individuals
in central China (e.g. Anhui Province) were treated with primaquine to stop
transmission and kill hypnozoites in the early part of the year prior to when
seasonal relapses would be expected. Public health interventions of such size
are difficult to evaluate as one can only use historical controls, but clearly the
transmission rates of vivax malaria in China have continued to drop. Except
for some ethnic minority groups, Chinese people have very low frequen-
cies of G6PD and thus a low risk of haemolysis when receiving primaquine.
Despite the low risk, the large numbers of people treated with primaquine
resulted in more than a handful of persons with acute haemolysis triggered
by primaquine. Order of magnitude estimates would indicate one severe
adverse event per 10,000 persons receiving MDA. Currently MDA with
primaquine is used in China focally for entire villages with vivax malaria
prevalence >3% and only in neighbouring households to known cases when
prevalence is 1-3%. Combined with re-locating the previous year's vivax
cases and re-treating them with primaquine during the spring, this extensive
use of primaquine has lowered the amount of vivax malaria in China (Prof
Gao Qi, Director Jiangsu Institute of Parasitology, Wuxi, China personal
communication, 2012). It is unclear if this type of strategy could be applied
in other areas of the world with different populations having a greater preva-
lence of G6PD deficiency (
Shekalaghe et al., 2010
;
Howes et al. 2012
).
3.6. Kyrgyzstan's Use of MDA
Central Asia, specifically, the republics of the former Soviet Union, was con-
sidered one of the GMEP success stories with malaria eliminated from the
