|These definitions and indices are important in epidemiological
surveillance and in planning the control strategy for malaria.
Endemic Malaria: Constant
incidence over a period of many successive years in an area.
Periodic or occasional sharp increase of malaria in a given indigenous community.
Amount of transmission is high without any marked fluctuation over years though seasonal
Amount of transmission changes from year to year.
proximity to malarious areas or liability to frequent influx of infected people or
Habitual presence of vector anophelines or existence of ecological factors.
Relief of symptoms without complete elimination of parasites.
Elimination of parasites actually responsible for attack of malaria.
clinical activity seen during the first 8-10 weeks after primary attack (short term
clinical activity seen around 30th - 40th week following primary attack (long term
Symptom less phase between primary attack and relapse with splenomegaly, no parasite seen
in peripheral smear.
Resistance: Development of resistance i.e. ability in strains of insects to tolerate
doses of toxicants which would prove lethal to the majority of the insect population of
the same species.
Annual Blood Examination
Rate (A.B.B.R.) = Smears examined in a year X 100 / Total population.
Incidence (A.P.I.) = Total no. of positive slides for parasite in a year x 1000 /
Incidence = Total positive PF in a year x 1000 / Total population.
Slide Positivity Rate
(S.P.R.) = Total positive x 100 / Total slides examined.
Slide Falciparum Rate
(S.F.R.) = Total positive PF x 100 / Slides examined.
Percentage (PF %) = Total positive for P. falciparum x 100 / Total positive
Adult vector density - Man
hour hand captures (per man hour density) = No. of mosquitoes collected/ No. of man hours
spent in search
Sporozoite Rate (%)
for each species = (No. of positive for sporozoites/ No. dissected) x 100
(I sincerely thank Dr.
P.P. Venugopalan, Former Medical Superintendent, Attavar Hospital and Professor
and Head of Community Medicine, Kasturba Medical College, Mangalore for his contribution)