Quantitative analyses and modelling to support achievement of the 2020 goals for nine neglected tropical diseases

Abstract

Quantitative analysis and mathematical models are useful tools in informing strategies to control or eliminate disease. Currently, there is an urgent need to develop these tools to inform policy to achieve the 2020 goals for neglected tropical diseases (NTDs). In this paper we give an overview of a collection of novel model-based analyses which aim to address key questions on the dynamics of transmission and control of nine NTDs: Chagas disease, visceral leishmaniasis, human African trypanosomiasis, leprosy, soil-transmitted helminths, schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. Several common themes resonate throughout these analyses, including: the importance of epidemiological setting on the success of interventions; targeting groups who are at highest risk of infection or re-infection; and reaching populations who are not accessing interventions and may act as a reservoir for infection,. The results also highlight the challenge of maintaining elimination ‘as a public health problem’ when true elimination is not reached. The models elucidate the factors that may be contributing most to persistence of disease and discuss the requirements for eventually achieving true elimination, if that is possible. Overall this collection presents new analyses to inform current control initiatives. These papers form a base from which further development of the models and more rigorous validation against a variety of datasets can help to give more detailed advice. At the moment, the models’ predictions are being considered as the world prepares for a final push towards control or elimination of neglected tropical diseases by 2020.

Countrywide Reassessment of Schistosoma mansoni Infection in Burundi Using a Urine-Circulating Cathodic Antigen Rapid Test: Informing the National Control Program

“…In some countries, such as in Burundi, control strategies have successfully reduced the prevalence of clinical schistosomiasis. Because the WHO and partners are now currently aiming to eliminate Schistosoma infection in selected countries in Africa,12 improved diagnostic tools, in terms of both performance and convenience for field surveys, are needed for countries that propose to move toward elimination of Schistosoma infections 2…”

Filarial infection influences mosquito behaviour and fecundity

“…Mathematical models are being used to guide decision making on the best strategies to eliminate lymphatic filariasis15. Slight changes in vector specific parameters can alter the likelihood of elimination and the most suitable approach to reach transmission breakpoints13.…”

Counting Down the 2020 Goals for 9 Neglected Tropical Diseases: What Have We Learned From Quantitative Analysis and Transmission Modeling?

“…Although there has been ongoing research into modeling of NTDs [7,8], this research has sometimes been limited by the extent of biological knowledge and data on which to base these models. The availability of more extensive data, together with strong partnerships between researchers in different fields, including by the NTD Modelling Consortium [9], has led to marked improvements in these efforts. Researchers have made contributions not only in informing treatment strategies but also in informing diagnostic development and the applicability of new tools or treatments and in understanding the natural history of disease.…”