Spatiotemporal characterisation and risk factor analysis of malaria outbreak in Cabo Verde in 2017

Abstract

BackgroundCabo Verde is a country that has been in the pre-elimination stage of malaria since the year 2000. The country is still reporting cases, particularly in the capital of Praia, where more than 50% of the national population live. This study aims to examine the spatial and temporal epidemiological profile of malaria across the country during the 2017 outbreak and to analyse the risk factors, which may have influenced the trend in malaria cases.MethodsLongitudinal data collected from all malaria cases in Cabo Verde for the year 2017 were used in this study. The epidemiological characteristics of the cases were analysed. Local and spatial clusters of malaria from Praia were detected by applying the Cluster and Outlier Analysis (Anselin Local Moran’s I) to determine the spatial clustering pattern. We then used the Pearson correlation coefficient to analyse the relationship between malaria cases and meteorological variables to identify underlying drivers.ResultsIn 2017, 446 cases of malaria were reported in Cabo Verde with the peak of cases in October. These cases were primarily Plasmodium falciparum infections. Of these cases, 423 were indigenous infections recorded in Praia, while 23 were imported malaria cases from different African countries. One case of P. vivax infection was imported from Brazil. Spatial autocorrelation analysis revealed a cluster of high-high malaria cases in the centre of the city. Malaria case occurrence has a very weak correlation (r = 0.16) with breeding site location. Most of the cases (69.9%, R2 = 0.699) were explained by the local environmental condition, with temperature being the primary risk factor followed by relative humidity. A moderately positive relationship was noted with the total pluviometry, while wind speed had a strong negative influence on malaria infections.ConclusionsIn Cabo Verde, malaria remains a serious public health issue, especially in Praia. The high number of cases recorded in 2017 demonstrates the fragility of the situation and the challenges to eliminating indigenous malaria cases and preventing imported cases. Mosquito breeding sites have been the main risk factor, while temperature and precipitation were positively associated with malaria infection. In light of this study, there is an urgent need to reinforce control strategies to achieve the elimination goal in the country.

Updates on malaria epidemiology and profile in Cabo Verde from 2010 to 2019: The goal of Elimination

“…To ensure elimination can be sustained and to support the prevention to reintroduction phase, the malaria case data collected as part of routine surveillance from the decade before interruption can be valuable for characterizing the malaria epidemiology and identify risk factors for improved surveillance activities. Therefore, this research extends previous research about malaria cases in the country [13,14] and characterizes both individual and spatial risk factors for endemic and introduced malaria infections.…”

“…The sustained low levels of transmission, strong public health system and active malaria programs in the country indicate that the archipelago is a good candidate to achieve elimination in the African sub-region. [12,17] Although the epidemic that occurred in Praia in 2017 resulted in 423 locally acquired cases, there were no deaths and showed that the country is able to effectively contain transmission [14]. Given the likelihood of continued malaria importation from continental African countries the risk pro les of imported identi ed here will be helpful in prioritizing resources.…”

Knowledge, attitudes and practices about malaria in Cabo Verde: a country in the pre-elimination context

“…From 2010 to 2016, Cabo Verde has recorded a few cases of malaria [6], is considered by the WHO as potentially able to eliminate malaria by 2020. However, an increase in 2016 and the outbreak recorded in 2017 with 446 cases [7], demonstrated weaknesses and challenges in the disease control.…”

“…Malaria has been classified as the fifth of the six major diseases in the country, which is likely related to few malaria cases recorded in the country, between 2010 and 2016 compared to other countries in the sub-region [6,7,[22][23][24][25]. Therefore, the Cape Verdean population, excepted in the islands of Santiago and Boavista, are less in contact with malaria in their daily lives, thus losing their knowledge about malaria.…”

“…Despite the significant successes made so far against the disease, including its elimination twice from the archipelago in the past, it is worth noting the failure to consolidate and maintain the malaria-free status. Thegoal of achieving zero local transmission by 2020, has been challenged by the recent malaria outbreak with 423 indigenous cases recorded in 2017 [7].…”