Onchocerciasis-associated epilepsy in Maridi, South Sudan: Modelling and exploring the impact of control measures against river blindness.
Background Onchocerciasis, also known as "river blindness", is caused by the bite of infected female blackflies (genus Simuliidae) that transmit the parasite Onchocerca volvulus. A high onchocerciasis microfarial load increases the risk to develop epilepsy in children between the ages of 3...
Published in: | PLOS Neglected Tropical Diseases |
---|---|
Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Public Library of Science (PLoS)
2023
|
Subjects: | |
Online Access: | https://doi.org/10.1371/journal.pntd.0011320 https://doaj.org/article/34527ac0a0ec4e0fbd07dfa2ffb5144f |
id |
ftdoajarticles:oai:doaj.org/article:34527ac0a0ec4e0fbd07dfa2ffb5144f |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:34527ac0a0ec4e0fbd07dfa2ffb5144f 2023-07-02T03:31:35+02:00 Onchocerciasis-associated epilepsy in Maridi, South Sudan: Modelling and exploring the impact of control measures against river blindness. Samit Bhattacharyya Natalie V S Vinkeles Melchers Joseph N Siewe Fodjo Amit Vutha Luc E Coffeng Makoy Y Logora Robert Colebunders Wilma A Stolk 2023-05-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0011320 https://doaj.org/article/34527ac0a0ec4e0fbd07dfa2ffb5144f EN eng Public Library of Science (PLoS) https://doi.org/10.1371/journal.pntd.0011320 https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0011320 https://doaj.org/article/34527ac0a0ec4e0fbd07dfa2ffb5144f PLoS Neglected Tropical Diseases, Vol 17, Iss 5, p e0011320 (2023) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2023 ftdoajarticles https://doi.org/10.1371/journal.pntd.0011320 2023-06-11T00:32:50Z Background Onchocerciasis, also known as "river blindness", is caused by the bite of infected female blackflies (genus Simuliidae) that transmit the parasite Onchocerca volvulus. A high onchocerciasis microfarial load increases the risk to develop epilepsy in children between the ages of 3 and 18 years. In resource-limited settings in Africa where onchocerciasis has been poorly controlled, high numbers of onchocerciasis-associated epilepsy (OAE) are reported. We use mathematical modeling to predict the impact of onchocerciasis control strategies on the incidence and prevalence of OAE. Methodology We developed an OAE model within the well-established mathematical modelling framework ONCHOSIM. Using Latin-Hypercube Sampling (LHS), and grid search technique, we quantified transmission and disease parameters using OAE data from Maridi County, an onchocerciasis endemic area, in southern Republic of South Sudan. Using ONCHOSIM, we predicted the impact of ivermectin mass drug administration (MDA) and vector control on the epidemiology of OAE in Maridi. Principal findings The model estimated an OAE prevalence of 4.1% in Maridi County, close to the 3.7% OAE prevalence reported in field studies. The OAE incidence is expected to rapidly decrease by >50% within the first five years of implementing annual MDA with good coverage (≥70%). With vector control at a high efficacy level (around 80% reduction of blackfly biting rates) as the sole strategy, the reduction is slower, requiring about 10 years to halve the OAE incidence. Increasing the efficacy levels of vector control, and implementing vector control simultaneously with MDA, yielded better results in preventing new cases of OAE. Conclusions/significances Our modeling study demonstrates that intensifying onchocerciasis eradication efforts could substantially reduce OAE incidence and prevalence in endemic foci. Our model may be useful for optimizing OAE control strategies. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLOS Neglected Tropical Diseases 17 5 e0011320 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
spellingShingle |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 Samit Bhattacharyya Natalie V S Vinkeles Melchers Joseph N Siewe Fodjo Amit Vutha Luc E Coffeng Makoy Y Logora Robert Colebunders Wilma A Stolk Onchocerciasis-associated epilepsy in Maridi, South Sudan: Modelling and exploring the impact of control measures against river blindness. |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
Background Onchocerciasis, also known as "river blindness", is caused by the bite of infected female blackflies (genus Simuliidae) that transmit the parasite Onchocerca volvulus. A high onchocerciasis microfarial load increases the risk to develop epilepsy in children between the ages of 3 and 18 years. In resource-limited settings in Africa where onchocerciasis has been poorly controlled, high numbers of onchocerciasis-associated epilepsy (OAE) are reported. We use mathematical modeling to predict the impact of onchocerciasis control strategies on the incidence and prevalence of OAE. Methodology We developed an OAE model within the well-established mathematical modelling framework ONCHOSIM. Using Latin-Hypercube Sampling (LHS), and grid search technique, we quantified transmission and disease parameters using OAE data from Maridi County, an onchocerciasis endemic area, in southern Republic of South Sudan. Using ONCHOSIM, we predicted the impact of ivermectin mass drug administration (MDA) and vector control on the epidemiology of OAE in Maridi. Principal findings The model estimated an OAE prevalence of 4.1% in Maridi County, close to the 3.7% OAE prevalence reported in field studies. The OAE incidence is expected to rapidly decrease by >50% within the first five years of implementing annual MDA with good coverage (≥70%). With vector control at a high efficacy level (around 80% reduction of blackfly biting rates) as the sole strategy, the reduction is slower, requiring about 10 years to halve the OAE incidence. Increasing the efficacy levels of vector control, and implementing vector control simultaneously with MDA, yielded better results in preventing new cases of OAE. Conclusions/significances Our modeling study demonstrates that intensifying onchocerciasis eradication efforts could substantially reduce OAE incidence and prevalence in endemic foci. Our model may be useful for optimizing OAE control strategies. |
format |
Article in Journal/Newspaper |
author |
Samit Bhattacharyya Natalie V S Vinkeles Melchers Joseph N Siewe Fodjo Amit Vutha Luc E Coffeng Makoy Y Logora Robert Colebunders Wilma A Stolk |
author_facet |
Samit Bhattacharyya Natalie V S Vinkeles Melchers Joseph N Siewe Fodjo Amit Vutha Luc E Coffeng Makoy Y Logora Robert Colebunders Wilma A Stolk |
author_sort |
Samit Bhattacharyya |
title |
Onchocerciasis-associated epilepsy in Maridi, South Sudan: Modelling and exploring the impact of control measures against river blindness. |
title_short |
Onchocerciasis-associated epilepsy in Maridi, South Sudan: Modelling and exploring the impact of control measures against river blindness. |
title_full |
Onchocerciasis-associated epilepsy in Maridi, South Sudan: Modelling and exploring the impact of control measures against river blindness. |
title_fullStr |
Onchocerciasis-associated epilepsy in Maridi, South Sudan: Modelling and exploring the impact of control measures against river blindness. |
title_full_unstemmed |
Onchocerciasis-associated epilepsy in Maridi, South Sudan: Modelling and exploring the impact of control measures against river blindness. |
title_sort |
onchocerciasis-associated epilepsy in maridi, south sudan: modelling and exploring the impact of control measures against river blindness. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2023 |
url |
https://doi.org/10.1371/journal.pntd.0011320 https://doaj.org/article/34527ac0a0ec4e0fbd07dfa2ffb5144f |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 17, Iss 5, p e0011320 (2023) |
op_relation |
https://doi.org/10.1371/journal.pntd.0011320 https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0011320 https://doaj.org/article/34527ac0a0ec4e0fbd07dfa2ffb5144f |
op_doi |
https://doi.org/10.1371/journal.pntd.0011320 |
container_title |
PLOS Neglected Tropical Diseases |
container_volume |
17 |
container_issue |
5 |
container_start_page |
e0011320 |
_version_ |
1770270944542064640 |