Interactions and Potential Implications of Plasmodium falciparum-Hookworm Coinfection in Different Age Groups in South-Central Côte d'Ivoire

Abstract

BackgroundGiven the widespread distribution of Plasmodium and helminth infections, and similarities of ecological requirements for disease transmission, coinfection is a common phenomenon in sub-Saharan Africa and elsewhere in the tropics. Interactions of Plasmodium falciparum and soil-transmitted helminths, including immunological responses and clinical outcomes of the host, need further scientific inquiry. Understanding the complex interactions between these parasitic infections is of public health relevance considering that control measures targeting malaria and helminthiases are going to scale.MethodologyA cross-sectional survey was carried out in April 2010 in infants, young school-aged children, and young non-pregnant women in south-central Côte d'Ivoire. Stool, urine, and blood samples were collected and subjected to standardized, quality-controlled methods. Soil-transmitted helminth infections were identified and quantified in stool. Finger-prick blood samples were used to determine Plasmodium spp. infection, parasitemia, and hemoglobin concentrations. Iron, vitamin A, riboflavin, and inflammation status were measured in venous blood samples.Principal FindingsMultivariate regression analysis revealed specific association between infection and demographic, socioeconomic, host inflammatory and nutritional factors. Non-pregnant women infected with P. falciparum had significantly lower odds of hookworm infection, whilst a significant positive association was found between both parasitic infections in 6- to 8-year-old children. Coinfected children had lower odds of anemia and iron deficiency than their counterparts infected with P. falciparum alone.Conclusions/SignificanceOur findings suggest that interaction between P. falciparum and light-intensity hookworm infections vary with age and, in school-aged children, may benefit the host through preventing iron deficiency anemia. This observation warrants additional investigation to elucidate the mechanisms and consequences of coinfections, as this information could have important implications when implementing integrated control measures against malaria and helminthiases.

Malaria and soil-transmitted intestinal helminth co-infection and its effect on anemia: a meta-analysis

“…Among school-aged children, the pooled analysis of three studies (n¼476) 32,33,49 showed that there was comparable mean Hb levels in the two groups (MD: 0.47; 95% CI:20.1 to 1.03). The pooled estimates of two studies 43,51 gave a higher risk of anemia in those co-infected with A. lumbricoides (summary OR: 2.72; 95% CI: 1.11-6.7; I 2 : 0%).…”

“…Seven studies 34,42,43,45,47,49,51 assessed hookworm only, while four studies 25,27,31,50 assessed A. lumbricoides only. Three studies described STH without speciation.…”

“…35,36,46 Twelve studies 8,26,28,32,33,35,41,43,46,[49][50][51] assessed the impact of co-infection on anemia, using various measurements. Five studies 26,28,32,33,49 quantitatively reported anemia with the mean Hb level in various age groups and pregnant women. One study reported anemia with the Hb cut-off level.…”

Rationale for the Coadministration of Albendazole and Ivermectin to Humans for Malaria Parasite Transmission Control

“…38 Hookworm infection was a risk factor for P. falciparum infection in pre-school-aged children, adults, 39 and pregnant women 40 in Uganda, people of all ages in Colombia, 41 and school-aged children in Cote d'Ivoire, 42 Zimbabwe, 43 and Ghana, 44 and it was a risk factor for pregnant women along the Thai-Myanmar border for both P. falciparum and P. vivax infection. 45 Any STH infection was a risk factor for P. falciparum in pre-school-aged and school-aged children in Senegal, 46 school-aged children in Nigeria, 35 and people of all ages in Ethiopia.…”

“…48 Although numerous publications have documented no increased risk of Plasmodium infection associated with STH infection, there have been only two published negative associations that we are aware of including, P. falciparum and Ascaris infections in pregnant women along the ThaiMyanmar border 45 and P. falciparum and hookworm infections in young, non-pregnant women in Cote d'Ivoire. 42 Aside from coinfection risk factors, there may be other consequences of STH infection that could enhance Plasmodium transmission. Ascaris-infected people were more likely to have contemporaneous and successive mixed species infections of P. falciparum and P. vivax, 49 which may increase Plasmodium transmission, because coinfections increase the frequency of P. falciparum gametocyte carriage.…”