2. Introduction
Special consideration
Rarity
Delay in diagnosis
Treatment
Serious complications
1st reported in 1911
In non-endemic countries - incidence is low
Canada between 1994 and 1999 -3 cases , USA between
1990 and 1999 -14 cases ,UK since 1996 -2 case, Other
European countries-2 cases
US- <0.3 case/million transfused blood units
3.
4. Uniqueness - caused by injection of asexual
forms (Trophozoite)
Trophozoite-induced malaria Vs natural infection
pre- erythrocytic schizogony - absent
short incubation period
exo-erythrocytic schizogony - not seen
relapses do not occur
radical cure is possible
5.
6. In donor blood
Relapsing illness : P. vivax and P. ovale
Asymptomatic parasitemia- variable and
depends on species
P. vivax and P. ovale rarely persist > 3 years
P. falciparum rarely > 1-2 years(3 mo)
P. malariae parasites for decades
7. Donor-exclusion criteria's aim : balance between
risk of malaria and excluding uninfected donors
Drawback in prevention : screening techniques
not satisfactory
Criteria for suitable test for screening:
large-scale use design
high sensitivity and specificity
detect all 4 species of Plasmodium
8. Blood film microscopy
Traditional blood film microscopy –
large manpower
high technical skill
limited sensitivity
Microscopic exam (thick blood film-4 ml): A
single parasite equivalent to ∼10,000parasites in
a 450-mL unit of blood
9. Antibody detection test
Antibody detection: ELISA, immunofluorescence
assay (IFA)
Malaria antibody testing :95% sensitive and 99%
specific
In endemic malaria: PPV for this test is high
10. Malaria antibody screening
do not indicate active infection
high discarding of collected blood units (as Ab
may persist for several years after infection)
Residents in malaria-endemic countries: have anti-
malarial Ab-serologic tests are unhelpful for
screening donors
Donors from Endemic region: immunity to
malaria→ low levels of parasites without clinical
symptoms, undetectable levels of parasitaemia
11. Antigen detection test
Antigen detection by MAB (monoclonal
antibody) technique :
more sensitive
practically feasible screening test
PCR and antigen detection tests - limited
availability
12. Blood transfusion recipients
Nonimmune recipient - can become rapidly fatal
Young infants in malaria endemic regions-
nonimmune recipients
Clinical severity different : Endemic Vs Non
endemic
13. Blood products
Whole-blood and RBC concentrates -most
common source.
Platelets, FFP, and leukocytes may infrequently
transmit malaria.
As few as 15 parasites (one bite): can cause
malaria.
14. Prevention
Endemic countries: specific donor questioning
considering
Seasonal variation
Geographical distribution
Antigen detection by monoclonal Ab as a routine
screening procedure : in endemic countries
Anti-malarials to recipients may help to prevent
transmission
Prevention largely depends on careful questioning
donors
15. FDA recommends deferring residents
Endemic areas : 3 years
Had malaria/Chemo : 3 years (after they become
asymp.)
Non endemic : 1 year after return from malarious
area
In EU
Endemic area : 3 yrs
Non-endemic areas donors: 4-12 months
Some countries reject these donors(NED) for 3 years
or permanently (if resided for >6 months in the
endemic area)
16. Evidence based
Support for Recommendations:
97% and 99% of the reported malaria cases in
U.S. and foreign civilians occur within 1 and 3
years, respectively, of having been in a malarious
area
AABB: Uniform donor history questions
17. Travelers may donate blood 6 months after returning
from endemic areas if they have been free of symptoms
and have not taken antimalarial drugs
Persons who have had malaria or who had been taking
chemoprophylaxis shall be deferred from donating blood
for 3 years after either becoming asymptomatic or
stopping therapy or chemoprophylaxis
Immigrants or visitors from endemic areas may be
accepted as donors 3 years after departure if they are
asymptomatic in the interim
Donations for preparing plasma, plasma components, or
derivatives devoid of intact red blood cells are exempted
from these restrictions
