Intestinal helminths as predictors of some malaria clinical outcomes and IL-1β levels in outpatients attending two public hospitals in Bamenda, North West Cameroon

This study aimed at determining the impact of intestinal helminths on malaria parasitaemia, anaemia and pyrexia considering the levels of IL-1 beta among outpatients in Bamenda. A cohort of 358 consented participants aged three (3) years and above, both males and females on malaria consultation were recruited in the study. At enrolment, patients' axillary body temperatures were measured and recorded. Venous blood was collected for haemoglobin concentration and malaria parasitaemia determination. Blood plasma was used to measure human IL-1 beta levels using Human ELISA Kit. The Kato-Katz technique was used to process stool samples. Five species of intestinal helminths Ascaris lumbricoides (6.4%), Enterobius vermicularis (5.0%), Taenia species (4.2%), Trichuris trichiura (1.1%) and hookworms (0.8%) were identified. The overall prevalence of Plasmodium falciparum and intestinal helminths was 30.4% (109/358) and 17.6% (63/358) respectively. The prevalence of intestinal helminths in malaria patients was 17.4% (19/109). Higher Geometric mean parasite density (GMPD +/- SD) (malaria parasitaemia) was significantly observed in patients co-infected with Enterobius vermicularis (5548 +/- 2829/mu L, p = 0.041) and with Taenia species (6799 +/- 4584/mu L, p = 0.020) than in Plasmodium falciparum infected patients alone (651 +/- 6076/ mu L). Higher parasitaemia of (1393 +/- 3031/mu L) and (3464 +/- 2828/mu L) were recorded in patients co-infected with Ascaris lumbricoides and with hookworms respectively but the differences were not significant (p > 0.05). Anaemia and pyrexia prevalence was 27.1% (97/358) and 33.5% (120/358) respectively. Malaria patients co-infected with Enterobius vermicularis and Ascaris lumbricoides had increased risk of anaemia (OR = 13.712, p = 0.002 and OR = 16.969, p = 0.014) respectively and pyrexia (OR = 18.07, p = 0.001 and OR = 22.560, p = 0.007) respectively than their counterparts. Increased levels of IL-1 beta were significantly observed in anaemic (148.884 +/- 36.073 pg/mL, t = 7.411, p = 0.000) and pyretic (127.737 +/- 50.322 pg/mL, t = 5.028, p = 0.000) patients than in non-anaemic (64.335 +/- 38.995pg/mL) and apyretic patients (58.479 +/- 36.194pg/mL). Malaria patients co-infected with each species of intestinal helminths recorded higher IL-1 beta levels (IL-1 beta > 121.68 +/- 58.86 pg/mL) and the overall mean (139.63 +/- 38.33pg/mL) was higher compared with levels in malaria (121.68 +/- 58.86 pg/mL) and helminth (61.78 +/- 31.69pg/mL) infected patients alone. Intestinal helminths exacerbated the clinical outcomes of malaria in the patients and increased levels of IL-1 beta were observed in co-infected patients with anaemia, pyrexia and higher parasitaemia. Author summary Malaria and intestinal helminthiasis are endemic parasitic diseases in Sub Sahara Africa including Cameroon that has been associated with poverty. Humans are co-infected with these diseases. Intestinal helminths have been reported to improve or exacerbate malaria severities in co-infected patients. The precise mechanism through which they exert this is not well elucidated but there are speculations about possible immunological implications. It is therefore crucial to understand the mechanism how these neglected tropical disease (helminthiasis) impact malaria severities to develop robust integrated public health intervention strategies and treatment protocols that can effectively manage these diseases in endemic zones. In this study, we focused on the impact of these helminths on malaria parasitaemia, anaemia and pyrexia. We examined each patient for malaria and helminth infections while also measuring their haemoglobin concentrations and body temperatures. We found out that patients infected with intestinal helminths had increased risk of malaria infection and exacerbated malaria parasitaemia, anaemia and pyrexia in co-infected patients. We also observed that increased levels of IL-1 beta were higher in these co-infected patients than in patients infected with malaria parasite or helminths alone. Our study is informative about the possible involvement of intestinal helminths with the immune responses of the host that consequently affects malaria severity.

Automated summary

This study aimed to determine the impact of intestinal helminths on malaria parasitaemia, anaemia, and pyrexia in outpatients in Bamenda. The study found that co-infection of intestinal helminths increased the risk of malaria infection and exacerbated malaria severity including parasitaemia, anaemia, and pyrexia. Higher IL-1 beta levels were observed in co-infected patients compared to those infected with malaria parasite or helminths alone, suggesting possible immune response implications.