Impact of Sickle Cell Hemoglobin Genotypes on Clinical Outcomes Among Plasmodium falciparum Malaria Patients in Luanda, Angola.

BACKGROUND

Sickle cell anemia (SCA) may influence malaria susceptibility and clinical outcomes in endemic regions. However, the interaction between hemoglobin genotypes and malaria severity remain poorly defined in endemic African settings, particulary in Angola, where SCA and malaria impose a substantial public health burden. Herein, we investigate associations between hemoglobin genotypes and clinical outcomes among malaria patients.

METHODS

This was a prospective cohort study conducted with 252 malaria patients in Luanda, the capital city of Angola, a sub-Saharan African country. Association between hemoglobin genotypes and demographic, geographic, parasitological, and clinical variables were assessed in relation to malaria outcomes.

RESULTS

HbAA was predominant (75.0%), followed by HbAS (16.7%) and HbSS (8.3%). Mean age did not differ significantly across genotypes (p = 0.289), whereas gender distribution differed significantly (p = 0.008), with a high proportion of females among HbAS individuals (73.8%). No significant differences were observed across genotypes in residence, ABO blood group, or parasitemia levels (p > 0.05). Clinical outcomes differed significantly by hemoglobin genotype (p = 0.016), with lower discharge rates (57.1%) and higher mortality (19.0%) among HbSS patients. Unfavorable outcomes were more frequent among adults with HbS (OR: 1.59), males (OR: 2.03), peri-urban residents (OR = 2.2), or blood group O (OR = 2.16), although no statistical significance was observed (p > 0.05). Among HbAA patients, low parasitaemia was significantly associated with favorable outcomes (OR = 0.35, p = 0.016).

CONCLUSIONS

Our findings suggest that HbSS may be associated with increased malaria morbidity and mortality in Angola. Further studies incorporating molecular characterization of malaria parasites are needed to elucidate clinical trajectories and parasite-host interactions.