Biology Reference
In-Depth Information
vivax ARDS autopsy did not show sequestration of parasitized RBCs in
the pulmonary vasculature (
Valecha et al., 2009
). As in ALI in other disease
settings, ARDS in vivax malaria probably results from soluble mediators,
diffuse alveolar-endothelial capillary damage, exacerbated by shock, with
increases in alveolar permeability and altered alveolar fluid clearance (
Tan
et al., 2008
;
Valecha et al., 2009
;
Suratt and Parsons, 2006
).
The majority of cases of vivax-associated ARDS develop after the start
of antimalarial chemotherapy (see
Taylor et al., 2012
;
Anstey et al., 2009
for
reviews) and gas transfer studies show progressive deterioration in alveo-
lar-capillary function following treatment (
Anstey et al., 2007
). This may
reflect exacerbation of an inflammatory response associated with parasite-
killing and/or monocyte/pigment accumulation (
Tan et al., 2008
;
Anstey
et al., 2007
), though vivax-associated ARDS can occur prior to the start
of antimalarial chemotherapy (
Valecha et al., 2009
;
Lomar et al., 2005
). As
chloroquine-resistance spreads, and other treatment regimens without the
anti-inflammatory effects of chloroquine become necessary (
Douglas et al.,
2010
), it is possible that the incidence of ARDS post-treatment may rise
(
Anstey et al., 2007
).
The majority of respiratory distress, in both falciparum and vivax malaria,
occurs in young children (
Tjitra et al., 2008
;
Genton et al., 2008
;
Marsh et al.,
1995
). ALI is reportedly rare in young children, but is described in recent
paediatric severe vivax malaria series (
Lanca et al., 2012
). An increase in
mortality in children with severe falciparum malaria receiving fluid boluses
(
Maitland et al., 2011
) suggests that pulmonary oedema in children with
severe malaria may be more prevalent than previously realized. Nevertheless,
while ALI appears to be a major cause of vivax-associated respiratory dis-
tress in adults, other causes are likely to be important in causing respiratory
distress in children. As in falciparum malaria, these may include metabolic
acidosis, reported in paediatric vivax-associated respiratory distress (
Kochar
et al., 2010
), as well as severe anaemia (
Tjitra et al., 2008
), pneumonia and/
or sepsis. Concomitant pneumonia was seen in 8% of children with severe
vivax malaria in a recent series (
Kaushik et al., 2012
).
11.2.3. Acute kidney injury
Mechanisms underlying AKI in vivax malaria are not clear. With its frequent
association with shock and multiorgan dysfunction, a sepsis-like syndrome
either from
P. vivax
itself (see below) or concomitant bacterial sepsis may be
a significant contributor to AKI. The extent to which acute tubular necrosis
underlies AKI in the setting of multiorgan dysfunction, as seen frequently
