The Synergistic Effect of Concomitant Schistosomiasis, Hookworm, and Trichuris Infections on Children's Anemia Burden

Abstract

ObjectiveTo estimate the degree of synergism between helminth species in their combined effects on anemia.MethodsQuantitative egg counts using the Kato–Katz method were determined for Ascaris lumbricoides, hookworm, Trichuris trichiura, and Schistosoma japonicum in 507 school-age children from helminth-endemic villages in The Philippines. Infection intensity was defined in three categories: uninfected, low, or moderate/high (M+). Anemia was defined as hemoglobin <11 g/dL. Logistic regression models were used to estimate odds ratios (OR), 95% confidence intervals (CI), and synergy index for pairs of concurrent infections.ResultsM+ co-infection of hookworm and S. japonicum (OR = 13.2, 95% CI: 3.82–45.5) and of hookworm and T. trichiura (OR = 5.34, 95% CI: 1.76–16.2) were associated with higher odds of anemia relative to children without respective M+ co-infections. For co-infections of hookworm and S. japonicum and of T. trichiura and hookworm, the estimated indices of synergy were 2.9 (95% CI: 1.1–4.6) and 1.4 (95% CI: 0.9–2.0), respectively.ConclusionCo-infections of hookworm and either S. japonicum or T. trichiura were associated with higher levels of anemia than would be expected if the effects of these species had only independent effects on anemia. This suggests that integrated anti-helminthic treatment programs with simultaneous deworming for S. japonicum and some geohelminths could yield a greater than additive benefit for reducing anemia in helminth-endemic regions.

Soil-transmitted helminth infections and risk factors in preschool children in southern rural Lao People's Democratic Republic

“…Other studies showed that co-infections of hookworm and either Schistosoma japonicum or T. trichiura were associated with higher levels of anaemia. 28 In addition to the three mentioned STH infections, other parasite eggs were also detected, such as Opisthorchis viverrini (17 cases), Enterobius vermicularis (2 cases), Hymenolepis sp. (1 case) and the protozoa Giardia lamblia (25 cases).…”

Impact of Polyparasitic Infections on Anemia and Undernutrition among Kenyan Children Living in a Schistosoma haematobium-Endemic Area

“…1 However, it was not until recently that the combined detrimental effects of polyparasitism on childhood growth and development have emerged as a research focus. [2][3][4][5][6] The relationship between parasitic helminths and the subtle morbidities of undernutrition and anemia has been increasingly recognized in the past 20 years. 4,6 Previous studies have examined the overlapping effects of infection by soil-transmitted helminths (STHs), including hookworm, Ascaris lumbricoides, and Trichuris trichiura, on these outcomes, and more recently, studies have examined the combined effects of STH with schistosomiasis.…”

“…4,6 Previous studies have examined the overlapping effects of infection by soil-transmitted helminths (STHs), including hookworm, Ascaris lumbricoides, and Trichuris trichiura, on these outcomes, and more recently, studies have examined the combined effects of STH with schistosomiasis. 3,7,8 The public health importance of chronic malnutrition and anemia is in their intrinsically disabling effects. Related manifestations can often include reduced global functioning, 9 decreased physical performance, 10,11 and impaired cognition, 2,12,13 resulting in decreased human capital among adults in affected populations 14,15 with a related loss in years of healthy life.…”

Birthweight in Offspring of Mothers with High Prevalence of Helminth and Malaria Infection in Coastal Kenya

“…1 Furthermore, there is growing evidence that co-infection with multiple helminth species as well as with helminths and malaria parasites are the rule in many places with co-infection, resulting in synergistic adverse consequences. [2][3][4] Helminth infections with schistosomes, filarial worms and soil-transmitted helminths such as hookworm and Trichuris trichiura, are the cause of common and important neglected tropical diseases.…”