MALARIA INFECTION AND VASO-OCCLUSIVE CRISIS IN NIGERIANS WITH SICKLE CELL DISORDER

Abstract

This study evaluated precipitating factors, clinical features, and
some laboratory parameters during Vaso-occlusive crisis (VOC) of sickle
cell disorder (SCD), with a view to determining the role of malaria infection.
Over a period of 16 months, 60 patients with SCD and VOC episodes
participated in the study. A questionnaire that was developed and
pretested was administered on the patients who were clinically examined.
The severity of pains was assessed using visual analogue scale (VAS). 10ml
of venous blood was collected for haematological (haematocrit, platelet,
leucocyte count); microbiological (malaria parasite density) and
immunological (Pf-IgG) tests. Data collected was analyzed using
descriptive and inferential statistics; a p-value <0.05 was significant.
The results showed that the study population consisted of 52 (87%) HbSS
and 8 (13%) HbSC with a mean (+SD) age of 25.3 years (+9.7) and a 95%
confidence interval (CI) of 23.0 – 27.7 and overall M: F ratio of 1:1.5. A
total of 65 VOC episodes were evaluated with moderate to severe pain
occurring in 51%. Malaria parasite was detectatable in 55% of patients,
with a mean malaria parasite density of 671 parasite/uL (+ 1087; CI
315.9-1026). Commonly observed symptoms included fever (40%),
jaundice (35.4%), headache (23.1%) and vomiting (13.8%). Severe anaemia
occurred in 12.2% of patients. Malaria parasitaemia occurred in 61% of
patients with fever, 73.9% of patients with jaundice and 75% of patients
with severe anaemia. The mean P. falciparum specific IgG (Pf-IgG)
absorbance for 44 patients was 2.166 (+0.712, CI 1.956-2.377), the mean
Pf-IgG absorbance of HbSC patients was significantly higher than that of
HbSS patients (p<0.05). The Pf-IgG in HbSS with splenomegaly
significantly correlated with splenic size (P<0.05), but not with parasite
density. Eighty percent of patients had used one or more types of
analgesics before presentation. The majority of patients (94%) used
malaria prophylaxis but with varied adherence and there was no
significant difference in the mean malaria parasite density of the different
types of prophylaxis.
In conclusion, malaria infection occurred in one in two (1:1) episodes of
VOC and was associated with fever, jaundice and vomiting to a certain
extent. Immunity against P.falciparum malaria correlated with splenic size
but not with malaria parasite density in HbSS patients.

MALARIA INFECTION AND VASO-OCCLUSIVE CRISIS IN NIGERIANS WITH SICKLE CELL DISORDER