Biology Reference
In-Depth Information
characters that are amenable to control, for example, those that bite indoors
at night are conducive to control using ITNs and indoor resting facilitates
the effectiveness of IRS.
Asia summary
.
Plasmodium vivax
is an important public health problem
across large parts of Asia. Six of the 10 largest PAR estimates of the 95
Pv
MECs were in Asia and these countries accounted for 87% of the global
PAR. Control of
P. vivax
in
Pv
MECs in Asia would, therefore, dramatically
reduce the impact of this widespread disease. In Asia, in particular, densely
populated areas are endemic with stable
P. vivax
transmission. This is due
to environmental suitability as well as a vector species (
An. stephensi
) that is
well suited to urban transmission. The limits and endemicity maps produced
show that
P. vivax
has a wide geographic range in this region, across which
the level of transmission is generally low, with small pockets of intense stable
transmission (
Fig. 1.3
A1 and A2). In high-prevalence areas, such as those
found in parts of India (Orissa State) and Myanmar, the clinical character of
P. vivax
has been found to behave more like
P. falciparum
, resulting in cases of
severe disease and death (
Mendis et al., 2001
;
Baird, 2007
;
Price et al., 2007a
;
Kochar et al., 2009
;
Mahgoub et al., 2012
). Uncertainty estimates were high
throughout India and much of Myanmar and population-weighted esti-
mates emphasise the need to improve the estimates in India with more sur-
vey data (
Fig. 1.4
A1 and A2). Improved
P. vivax
surveillance in these regions
would greatly improve prevalence predictions. By 2012, several countries in
this region (Azerbaijan, Bhutan, China, Georgia, Korea DPR, Republic of
Korea, Kyrgyzstan, Sri Lanka, Tajikistan, Thailand, Turkey, Uzbekistan and
Viet Nam) had entered the malaria elimination phase (
The Global Health
Group and the Malaria Atlas Project, 2011
). Improved control in neigh-
bouring countries with intense, stable transmission, such as Myanmar, will
improve the success of those nations already working towards elimination
by reducing the potential for imported malaria from human migration
(
Tatem and Smith, 2010
). As elimination efforts continue, spatially detailed
mapping will be needed to capture focal areas of transmission that remain.
Further and improved vector surveillance using molecular techniques to
disaggregate species complexes is needed to illuminate which vectors are
truly the primary vector species of
P. vivax
to allow for appropriate control
measures to be deployed in this highly variable region.
4.2. Asia-Pacific
The Asia-Pacific region (defined for these purposes as the southern islands of
Asia-Pacific and the Malaysian Peninsula;
Fig. 1.2
) has amongst the highest
