An ODE model of yaws elimination in Lihir Island, Papua New Guinea

Presley Kimball; Jacob Levenson; Amy Moore; Jan Rychtar; Dewey Taylor

doi:10.7717/peerj.13018

An ODE model of yaws elimination in Lihir Island, Papua New Guinea

PeerJ. 2022 Mar 17:10:e13018. doi: 10.7717/peerj.13018. eCollection 2022.

Authors

Presley Kimball¹, Jacob Levenson², Amy Moore³, Jan Rychtar⁴, Dewey Taylor⁴

Affiliations

¹ Department of Mathematics, Creighton University, Omaha, NE, United States of America.
² Department of Mathematics, Washington and Lee University, Lexington, VA, United States of America.
³ Department of Mathematics and Statistics, Elon University, Elon, NC, United States of America.
⁴ Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, VA, United States of America.

Abstract

Yaws is a chronic infection that affects mainly the skin, bone and cartilage and spreads mostly between children. The new approval of a medication as treatment in 2012 has revived eradication efforts and now only few known localized foci of infection remain. The World Health Organization strategy mandates an initial round of total community treatment (TCT) with single-dose azithromycin followed either by further TCT or by total targeted treatment (TTT), an active case-finding and treatment of cases and their contacts. We develop the compartmental ODE model of yaws transmission and treatment for these scenarios. We solve for disease-free and endemic equilibria and also perform the stability analysis. We calibrate the model and validate its predictions on the data from Lihir Island in Papua New Guinea. We demonstrate that TTT strategy is efficient in preventing outbreaks but, due to the presence of asymptomatic latent cases, TTT will not eliminate yaws within a reasonable time frame. To achieve the 2030 eradication target, TCT should be applied instead.

Keywords: Eradication; Mathematical model; Morges strategy; Total community treatment; Total targeted treatment; Yaws.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anti-Bacterial Agents* / therapeutic use
Azithromycin / therapeutic use
Child
Humans
Papua New Guinea / epidemiology
Skin
Yaws* / drug therapy

Substances

Anti-Bacterial Agents
Azithromycin

Grants and funding

Presley Kimball, Jacob Levenson and Amy Moore were supported by the VCU REU program in mathematics funded by the National Security Agency grant number H98230-20-1-0011 and by the National Science Foundation grant number DMS1950015 awarded to Dewey Taylor. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.