Scope and Limits of an anamnestic questionnaire in a control-induced low-endemicity helminthiasis setting in south-central Côte d'Ivoire

PLoS One. 2013 Jun 3;8(6):e64380. doi: 10.1371/journal.pone.0064380. Print 2014.

Abstract

Background: Schistosomiasis and soil-transmitted helminthiasis are two high-burden neglected tropical diseases. In highly endemic areas, control efforts emphasize preventive chemotherapy. However, as morbidity, infection, and transmission begin to decrease, more targeted treatment is likely to become more cost-effective, provided that comparatively cheap diagnostic methods with reasonable accuracy are available.

Methodology: Adults were administered an anamnestic questionnaire in mid-2010 during a cross-sectional epidemiological survey in the Taabo health demographic surveillance system in south-central Côte d'Ivoire. Questions pertaining to risk factors and signs and symptoms for schistosomiasis and soil-transmitted helminthiasis were included. The individuals' helminth infection status and their belonging to three different anthelmintic treatment groups were compared with the questionnaire results (i) to inform the local health authorities about the epidemiological and clinical footprint of locally prevailing helminthiases, and (ii) to explore the scope and limits of an anamnestic questionnaire as monitoring tool, which eventually could help guiding the control of neglected tropical diseases in control-induced low-endemicity settings.

Principal findings: Our study sample consisted of 195 adults (101 males, 94 females). We found prevalences of hookworm, Trichuris trichiura, Schistosoma haematobium, and Schistosoma mansoni of 39.0%, 2.7%, 2.1%, and 2.1%, respectively. No Ascaris lumbricoides infection was found. Helminth infection intensities were generally very low. Seven, 74 and 79 participants belonged to three different treatment groups. Multivariable logistic regression models revealed statistically significant (p<0.05) associations between some risk factors, signs, and symptoms, and the different helminth infections and treatment groups. However, the risk factors, signs, and symptoms showed weak diagnostic properties.

Conclusions/significance: The generally low prevalence and intensity of helminth infection in this part of south-central Côte d'Ivoire indicates that recent control efforts have turned our study area into a low endemicity setting. Our anamnestic questionnaire had low sensitivity and specificity to identify infected individuals or treatment groups.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cohort Studies
  • Cote d'Ivoire / epidemiology
  • Demography
  • Endemic Diseases / statistics & numerical data*
  • Female
  • Helminthiasis / diagnosis
  • Helminthiasis / epidemiology*
  • Helminthiasis / parasitology
  • Humans
  • Male
  • Mental Recall*
  • Multivariate Analysis
  • Patient Compliance
  • Prevalence
  • Risk Factors
  • Surveys and Questionnaires*

Grants and funding

The authors thank Fairmed for sustained funding that allowed us to establish and run the Taabo health demographic surveillance system in south-central Côte d’Ivoire, and the accompanying health interventions with the aim to reduce the mortality and morbidity due to malaria and neglected tropical diseases. TF is associated to the National Centre of Competence in Research North-South and received financial support through a Pro*Doc Research Module from the Swiss National Science Foundation (SNSF; project no. PDFMP3-123185). Furthermore, he is thankful for a personal stipend from the Freiwillige Akademische Gesellschaft Basel. JU and EKN are grateful to the SNSF (project no. IZ70Z-123900). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.