Synergistic associations between hookworm and other helminth species in a rural community in Brazil

Abstract

Summaryobjective To identify possible synergistic associations of hookworm and other helminths. method Cross-sectional survey of all households within 10 km 2 of Americaninhas, a rural community in Minas Gerais, Brazil. We determined the prevalence and intensity of single and multiple helminth species infection in an age-stratified sample of 1332 individuals from 335 households.results Hookworm was the most prevalent helminth infection (68.2%), followed by Ascaris lumbricoides (48.8%) and Schistosoma mansoni (45.3%). Overall, 60.6% of individuals harboured mixed helminth infections. Multivariate analysis indicated significant positive associations for co-infection with hookworm and S. mansoni and for co-infection with hookworm and A. lumbricoides. Co-infections with hookworm and A. lumbricoides resulted in higher egg counts for both, suggesting a synergistic relationship between these species, although, we found important age differences in this relationship. However, the intensity of S. mansoni or A. lumbricoides co-infection did not differ from that of monoinfection.conclusion These results have implications for the epidemiology, immunology and control of multiple helminth infections. More research is needed to examine the rates of re-infection and immune responses after chemotherapy, and to what extent the effects of polyparasitism are altered by chemotherapy.

Fatores associados à ocorrência de parasitoses intestinais em uma população de crianças e adolescentes

“…However, polyparasitism seems to be the norm rather than the exception, as its occurrence is higher than expected under assumptions of independence (16,17) , which stresses the need to better evaluate the occurrence and the impact of polyparasitism on human health.…”

Interactions Among Urogenital, Intestinal, Skin, and Oral Infections in Pregnant and Lactating Panamanian Ngäbe Women: A Neglected Public Health Challenge

“…74 This co-occurrence is typically explained by common exposure routes, common household factors, common immune response mechanisms, common host genetics, or facilitated establishment in the presence of the other pathogen. 75,76 Our data similarly revealed co-occurrence of Trichuris with hookworm, but Ascaris was not associated with hookworm or Trichuris in either χ 2 tests or in the multiple regression models of epg.…”

Helminth infections: the great neglected tropical diseases

“…Finally, an increasing number of studies of helminth epidemiology have shown that it is common for individuals to be infected with more than one species of helminth (21,(58)(59)(60)(61)(62)(63). There is also evidence suggesting synergism and antagonism in concurrent intestinal nematode and schistosome infections (62-64) as well as filarial nematode infection and soil-transmitted helminth infections (65).…”

“…These concerns, together with a need to better understand a number of fundamental clinical and epidemiological aspects of human helminth infections as well as their interactions with geographically overlapping coinfections (e.g., malaria and HIV/AIDS) have created an urgency for stepped up clinical research activities as they relate to largescale helminth control. Such activities have focused around three major areas: first, a reexamination of the health impact of human helminthic infections, with particular interest in the effects of mono- and polyparasitism on childhood growth and development as well as their effects on pregnancy and birth outcomes (63,(136)(137)(138)(139)(140); second, large-scale monitoring and evaluation of MDA and integrated control, along with operational research with goals to improve the access of populations to anthelminthic drugs and to monitor for possible drug resistance (141)(142)(143)(144)(145); and third, the development of new tools to control helminth infections, that is, drugs, diagnostics, and vaccines (19,146).…”