BackgroundIn the last five decades, dengue has emerged as one of the most important infectious diseases, following a 30-fold increase in global incidence throughout tropical and sub-tropical regions of the world. The actual numbers of dengue cases are under-reported and many cases are misclassified.ObjectivesThis article describes the epidemiology, pathophysiology, clinical features and management of dengue. It also explores the implications of infection with this flavivirus for Nigeria, and similar countries.MethodsThe literature search for publications on dengue in West Africa was performed using PubMed, African Journals Online (AJOL), Google Scholar, Web of Science, databases and grey literature to identify all published papers regarding the topic. A snowballing strategy was adopted to identify additional publications.ResultsRecent reports suggest that dengue is a growing public health problem in Nigeria, the magnitude of which needs to be more clearly defined. Nigeria, the most populous country in Africa has an abundance of the Aedes aegypti mosquito which is known to transmit dengue, Zika, as well as chikungunya (CHIKV) and West Nile viruses.ConclusionThis article provides practical suggestions for strengthening the dengue virus control programme in Nigeria. The Nigerian health system shares similarities with health systems in many other sub-Saharan countries. Therefore, the practical suggestions provided at the end of this review are likely to be applicable to many other African countries.

Background: Progress made in the control of malaria vectors globally is largely due to the use of insecticides. However, success in the fight against malaria has slowed down or even stalled due to a host of factors including insecticide resistance. The greatest burden of the disease is felt in Africa, particularly Nigeria. Unfortunately, adequate information on insecticide resistance is lacking in many parts of the country, particularly the SouthEast Zone. Hence, this study aims to bridge the information gap in the Zone. Methods: The study was conducted from April to December 2016. Anopheles gambiae (s.l.) larvae and pupae were collected from one community each, in the five states of the SouthEast Zone and reared to the adult stage. The adults were subjected to bioassays for insecticide resistance in accordance with the World Health Organization test procedures, across the four classes of insecticides used in public health. The mosquitoes were also subjected to molecular identification to the species level, and genotyped for West African knockdown resistance mutation (L1014F) and insensitive acetylcholinesterase-1 resistance mutation (G119S). Results: The mosquitoes were susceptible (100%) to bendiocarb but resistant to pirimiphos-methyl (39.6%), deltamethrin (57%) and dichlorodiphenyltrichloroethane (DDT) (13%). Molecular analysis revealed that only An. gambiae (sensu stricto) was found in all the states except for Ebonyi, where only Anopheles coluzzii was present. High frequencies (0.6-0.9) of the L1014F mutation were found across the zone. The L1014F mutation was significantly higher in An. gambiae (s.s.) than in An. coluzzii (P < 0.0001). A relatively low frequency (0.2) of the G119S mutation was found in An. coluzzii, and only in Ebonyi State. Conclusion: The results show that mosquitoes collected from the SouthEast Zone of Nigeria were resistant to all insecticides used, except for bendiocarb. The presence of L1014F and G119S resistance mutations reported in this study calls for urgent attention to stop the growing threat of insecticide resistance in the country.

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Arbovirus transmission by Aedes mosquitoes has long been a significant problem in Africa. In West Africa, Aedes vector management faces significant challenges; lack of recent Aedes distributional data and potential distributional modeling hinder effective vector control and pose serious public health issues. In this study, larval and adult mosquitoes were collected from four study sites in Enugu State, Nigeria every other month between November 2017 and September 2018. A total number of 2997 Aedes mosquitoes were collected and identified, and 59 positive field occurrence points for both Aedes adult and larvae were recorded. A total of 18 positive occurrence points were used for modeling. Ecological Niche Models (ENMs) were used to estimate the current geographic distribution of Aedes species ( spp. ) in Enugu State, south-east Nigeria, and mosquito presence was used as a proxy for predicting risk of disease transmission. Maximum Entropy distribution modeling or “MaxEnt” was used for predicting the potential suitable habitats, using a portion of the occurrence records. A total of 23 environmental variables (19 bioclimatic and four topographic) were used to model the potential geographical distribution area under current climatic conditions. The most suitable habitat for Aedes spp. was predicted in the northern, central, and southeastern parts of Enugu State with some extensions in Anambra, Delta, and Edo States in the west, and Ebonyi State in the east. Seasonal temperature, precipitation of the wettest month, mean monthly temperature range, elevation, and precipitation of the driest months were the highest estimated main variable contributions associated with the distribution of Aedes spp. We found that Aedes spp. prefer to be situated in environmental conditions where precipitation of wettest month ranged from 265 to 330 mm, precipitation of driest quarter ranged from 25 to 75 mm while precipitation of wettest quarter ranged from 650 to 950 mm. Aedes mosquitoes, such as Ae. aegypti and Ae. albopictus, pose a significant threat to human health, hence, the results of this study will help decision makers to monitor the distribution of these species and establish a management plan for future national mosquito surveillance and control programs in Nigeria.

The mosquito fauna of Museum and Zoological Garden Complex (JZC), a major tourist attraction in Jos Metropolis of Nigeria, was studied The choice of the complex was out of public health curiosity. A total of 627 mosquitoes comprising 4 genera, Aedes, Culex, Coquilletidia and Eretmapodites, and 9 species were caught n two d fferent study trips. Five species, namely, Aedes aegypti, A. africanus, A. vittatus, Culex quinquefasciatus and Eretmapodites chrysogaster, caught by human bait method are known variously to be involved in the transmission of yellow fever and other viral diseases. Culex quinquefasciatus had the highest frequency followed by Aedes aegypti. Simpson's dominance and Shannon-Wiener diversity indices of 0.4942 and 0.4550 were respect vely recorded for the whole mosquitoes sampled by the human bait method. C. quinqefasciatus was the most frequent species with diversity values of 0.4444 (Simpson's) and 0.1174 (Shannon-Wiener), followed by A. aegypti with 0 0455 (Simpson's) and 0.1431 (Shannon-Wiener). Ecological statistics demonstrated a highly significant dif erence in diversity between samples in March, during the dry season, and June in the rainy season (P < 0.001). The presence of man-biting mosquitoes in JZC constitutes apparent public health danger and calls for regular surveillance and control operations on such disease vectors in the complex.