DETERMINATION OF SERUM ZINC LEVELS IN CHILDREN WITH SEVERE AND UNCOMPLICATED MALARIA AT THE UNIVERSITY OF ILORIN TEACHING HOSPITAL, ILORIN

Abstract

Malaria is the most important parasitic disease afflicting human beings today. Several clinical
studies have revealed conflicting serum zinc levels (normal, elevated and deficiencies) in children
with malaria and also conflicting results of clinical manifestations and outcomes of malaria
following zinc supplementation. Some workers also concluded that zinc has no effect on malaria
disease. Against this background, there arose a need for knowledge of the serum zinc level in
children with malaria disease in Ilorin with a view to providing scientific data-base for advocacy or
otherwise for zinc supplementation strategy for Nigerian children.
The study was a prospective, comparative, cross sectional, analytical study conducted over a period
of eleven months. Children within the ages of six months to fourteen years with severe malaria were
recruited as subjects and those with uncomplicated malaria as controls. Admission diagnoses were
based on the presenting clinical findings, later supported with the relevant laboratory data. Blood
samples were taken to determine presence of malaria parasite, serum zinc, total protein and albumin.
The serum zinc was analyzed with a Jenway™ spectrophotometer to measure the optical density at
425nm, after an earlier preparation with the QuantiChrom™ zinc assay kit. Data analysis was with
Epi info 6 software.
A total of 160 children with severe malaria as subjects were compared with 180 children with
uncomplicated malaria as controls with male to female ratio of 1.5:1. Severe anaemia (38.8%),
cerebral malaria (33.1%), prostration, multiple convulsions, respiratory distress, shock/circulatory
collapse, jaundice, haemoglobinuria, hypoglycaemia, hyperpyrexia, hyperparasitaemia and others
were the forms of severe malaria diagnosed in the recruited subjects. The mean (SD) serum zinc
level of 33.4(23.8)μmol/dl in subjects was significantly higher than the corresponding value of
22.3(17.1)μmol/dl in the controls (p = < 0.001). The mean serum zinc level among the controls was
consistent with the reference values for normal subjects (9.2 – 25.2 µmol/dL). There was also a
positive correlation between serum zinc levels and the number of severe complications of malaria
at presentation, though not statistically significant (p = 0.453). There was a negative correlation between malaria parasite density and the serum zinc level among
the subjects, which was not statistically significant (r = -0.016 and p = 0.880), while in the controls,
the positive correlation was significant (r = 0.333 and p = < 0.001).
There were 16 (10.0%) mortalities among subjects while 2 (1.3%) survived with neurological
sequelae. Cerebral malaria occurred in 10 (62.5%) of the children that died while six (37.5%) had
severe anaemia. The mean serum zinc (SD) level of 38.3(25.5)μmol/dl among the subjects that died
was higher than 33.0(23.7)μmol/dl and 36.4(24.7)μmol/dl among subjects with full recovery and
sequelae respectively. The differences were not statistically significant (p = 0.400).
It was concluded that the mean serum zinc level was significantly higher in patients with severe
malaria compared with patients with uncomplicated malaria; the serum zinc level was higher
among subjects with higher number of severe complications of malaria than those with single
complication of severe malaria, though not statistically significant. There was a negative
correlation between the parasite density and the serum zinc levels among the subjects, but positive
correlation in those with uncomplicated malaria. Also the mean serum zinc level was higher
among patients that died than the levels in those with full recovery or with sequelae. It is
recommended that zinc supplementation in children with malaria may not be needed as the serum
zinc level was higher with increasing severity of malaria and a high serum zinc level is known to
be neurotoxic and also causes copper deficiency.

DETERMINATION OF SERUM ZINC LEVELS IN CHILDREN WITH SEVERE AND UNCOMPLICATED MALARIA AT THE UNIVERSITY OF ILORIN TEACHING HOSPITAL, ILORIN