Open Access Highly Accessed Open Badges Research

Comparative cost assessment of the Kato-Katz and FLOTAC techniques for soil-transmitted helminth diagnosis in epidemiological surveys

Benjamin Speich12, Stefanie Knopp12, Khalfan A Mohammed3, I Simba Khamis3, Laura Rinaldi4, Giuseppe Cringoli4, David Rollinson5 and Jürg Utzinger12*

Author Affiliations

1 Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland

2 University of Basel, Basel, Switzerland

3 Helminth Control Laboratory Unguja, Ministry of Health and Social Welfare, Zanzibar, United Republic of Tanzania

4 Department of Pathology and Animal Health, Faculty of Veterinary Medicine, University of Naples 'Federico II', Regional Center for Monitoring Parasites (CREMOPAR) Regione Campania, Naples, Italy

5 Wolfson Wellcome Biomedical Laboratories, Department of Zoology, Natural History Museum, London, UK

For all author emails, please log on.

Parasites & Vectors 2010, 3:71  doi:10.1186/1756-3305-3-71

Published: 14 August 2010



The Kato-Katz technique is widely used for the diagnosis of soil-transmitted helminthiasis in epidemiological surveys and is believed to be an inexpensive method. The FLOTAC technique shows a higher sensitivity for the diagnosis of light-intensity soil-transmitted helminth infections but is reported to be more complex and expensive. We assessed the costs related to the collection, processing and microscopic examination of stool samples using the Kato-Katz and FLOTAC techniques in an epidemiological survey carried out in Zanzibar, Tanzania.


We measured the time for the collection of a single stool specimen in the field, transfer to a laboratory, preparation and microscopic examination using standard protocols for the Kato-Katz and FLOTAC techniques. Salaries of health workers, life expectancy and asset costs of materials, and infrastructure costs were determined. The average cost for a single or duplicate Kato-Katz thick smears and the FLOTAC dual or double technique were calculated.


The average time needed to collect a stool specimen and perform a single or duplicate Kato-Katz thick smears or the FLOTAC dual or double technique was 20 min and 34 sec (20:34 min), 27:21 min, 28:14 min and 36:44 min, respectively. The total costs for a single and duplicate Kato-Katz thick smears were US$ 1.73 and US$ 2.06, respectively, and for the FLOTAC double and dual technique US$ 2.35 and US$ 2.83, respectively. Salaries impacted most on the total costs of either method.


The time and cost for soil-transmitted helminth diagnosis using either the Kato-Katz or FLOTAC method in epidemiological surveys are considerable. Our results can help to guide healthcare decision makers and scientists in budget planning and funding for epidemiological surveys, anthelminthic drug efficacy trials and monitoring of control interventions.