Publication: Predicting factors for malaria re‑introduction: an applied model in an elimination setting to prevent malaria outbreaks
Issued Date
2016
Resource Type
Language
eng
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Mahidol University
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BioMed Central
Bibliographic Citation
Malar J. Vol. 15, (2016), 138
Suggested Citation
Mansour Ranjbar, Alireza Shoghli, Goodarz Kolifarhood, Seyed Mehdi Tabatabaei, Morteza Amlashi, Mahdi Mohammadi Predicting factors for malaria re‑introduction: an applied model in an elimination setting to prevent malaria outbreaks. Malar J. Vol. 15, (2016), 138. doi:10.1186/s12936-016-1192-y Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/2743
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Title
Predicting factors for malaria re‑introduction: an applied model in an elimination setting to prevent malaria outbreaks
Abstract
Background: Malaria re-introduction is a challenge in elimination settings. To prevent re-introduction, receptivity,
vulnerability, and health system capacity of foci should be monitored using appropriate tools. This study aimed to
design an applicable model to monitor predicting factors of re-introduction of malaria in highly prone areas.
Methods: This exploratory, descriptive study was conducted in a pre-elimination setting with a high-risk of malaria
transmission re-introduction. By using nominal group technique and literature review, a list of predicting indicators for
malaria re-introduction and outbreak was defined. Accordingly, a checklist was developed and completed in the field
for foci affected by re-introduction and for cleared-up foci as a control group, for a period of 12 weeks before re-introduction
and for the same period in the previous year. Using field data and analytic hierarchical process (AHP), each
variable and its sub-categories were weighted, and by calculating geometric means for each sub-category, score of
corresponding cells of interaction matrices, lower and upper threshold of different risks strata, including low and mild
risk of re-introduction and moderate and high risk of malaria outbreaks, were determined. The developed predictive
model was calibrated through resampling with different sets of explanatory variables using R software. Sensitivity and
specificity of the model were calculated based on new samples.
Results: Twenty explanatory predictive variables of malaria re-introduction were identified and a predictive model
was developed. Unpermitted immigrants from endemic neighbouring countries were determined as a pivotal factor
(AHP score: 0.181). Moreover, quality of population movement (0.114), following malaria transmission season (0.088),
average daily minimum temperature in the previous 8 weeks (0.062), an outdoor resting shelter for vectors (0.045),
and rainfall (0.042) were determined. Positive and negative predictive values of the model were 81.8 and 100 %,
respectively.
Conclusions: This study introduced a new, simple, yet reliable model to forecast malaria re-introduction and outbreaks
eight weeks in advance in pre-elimination and elimination settings. The model incorporates comprehensive
deterministic factors that can easily be measured in the field, thereby facilitating preventive measures.
