with cough, dyspnoea and 'bronchitis' ( Falconer, 1919 ; Stirk, 1943 ;
Hyman, 1945 ). Cough, usually non-productive, occurs in approxi-
mately half of the adults with vivax malaria, in residents of both vivax-
endemic and -non-endemic areas ( Anstey et al., 2002 ; Anstey et al.,
2007 ). Tachypnoea may occur because of high fever, anaemia and/or
pulmonary pathology ( Kitchen, 1949a ; Taylor et al., 2012 ). As with falci-
parum malaria ( O'Dempsey et al., 1993 ), there is a clinical overlap with
symptoms suggestive of lower respiratory tract infection ( Hyman, 1945 ;
Anstey et al., 2007 ).
3.3. Malnutrition and Impaired Growth
In the pre-antibiotic era, untreated vivax malaria was associated with
chronic relapsing-remitting debilitating fevers, weight loss, cachexia, hypo-
proteinemia and oedema in adults and children (reviewed in Dobson, 1997 ;
Kitchen, 1949a ). In the antimalarial era, vivax malaria has also been clearly
associated with malnutrition in early childhood ( Williams et al., 1997 ). A
longitudinal Peruvian study has recently shown that a single episode of
vivax malaria results in impaired weight gain and growth persisting for at
least 6 months, with greater deficits per incident episode than either diar-
rhoeal disease or non-specific febrile illness ( Lee et al., 2012 ). The interac-
tion between P. vivax infection and malnutrition appears to be bidirectional.
As well as being caused by vivax malaria ( Lee et al., 2012 ), malnutrition is
associated with increased risk of severe and fatal outcome in those infected
with P. vivax (Section 7 ).
3.4. Impaired School Performance
Findings from Sri Lanka showed that acute malaria from either P. vivax or
P. falciparum resulted in a median of 5.4 days school absenteeism per episode
of malaria ( Fernando et al., 2003b ). Furthermore, acute malaria was associ-
ated with significant impairment of cognitive performance, persisting for
at least 2 weeks after the febrile episode. This effect was greater than that
due to non-malarial fever and independent of confounding socioeconomic
factors. The effects were cumulative, with repeated attacks of malaria having
a greater adverse impact on school performance ( Fernando et al., 2003a ).
Similar findings have been reported from Brazil ( Vitor-Silva et al., 2009 ).
In view of the relapsing nature of P. vivax and its propensity to occur in
children, the long-term social implications on education and development
could be substantial.