Ecological Niche Modeling of Aedes and Culex Mosquitoes: A Risk Map for Chikungunya and West Nile Viruses in Zambia

Abstract

The circulation of both West Nile Virus (WNV) and Chikungunya Virus (CHIKV) in humans and animals, coupled with a favorable tropical climate for mosquito proliferation in Zambia, call for the need for a better understanding of the ecological and epidemiological factors that govern their transmission dynamics in this region. This study aimed to examine the contribution of climatic variables to the distribution of Culex and Aedes mosquito species, which are potential vectors of CHIKV, WNV, and other arboviruses of public-health concern. Mosquitoes collected from Lusaka as well as from the Central and Southern provinces of Zambia were sorted by species within the Culex and Aedes genera, both of which have the potential to transmit viruses. The MaxEnt software was utilized to predict areas at risk of WNV and CHIKV based on the occurrence data on mosquitoes and environmental covariates. The model predictions show three distinct spatial hotspots, ranging from the high-probability regions to the medium- and low-probability regions. Regions along Lake Kariba, the Kafue River, and the Luangwa Rivers, as well as along the Mumbwa, Chibombo, Kapiri Mposhi, and Mpika districts were predicted to be suitable habitats for both species. The rainfall and temperature extremes were the most contributing variables in the predictive models.

Association of temperature and precipitation with malaria incidence in 57 countries and territories from 2000 to 2019: A worldwide observational study

“…However, caution is needed in attributing these shifts solely to global climate change, as local factors like land use, urbanization, and atmospheric circulation patterns may contribute [ 28 – 31 ]. Similarly, observed precipitation changes in Tuvalu, China, and South Korea signify localised variations, impacting vector habitats and malaria transmission [ 12 , 14 ]. While trends align with global climate change expectations, distinguishing global contributions from regional influences requires further investigation.…”

“…A systematic review predicted that further increasing temperatures would extend the seasonality of malaria transmission, enabling it to occur for up to six months annually in 2051–80 in European countries [ 11 ]. A modelling study showed that increased temperature variations were related to higher probabilities of Aedes species’ occurrence, and the optimal occurrence would take place when the temperature variations from the mean were above 25°C [ 12 ]. Conversely, a previous observational study found a negative relationship between temperature and malaria incidence rate, with a sharp decrease in incidence rate during 2000–03 and 2012–14, respectively, occurring with increasing average temperatures in Ghana and Nigeria [ 13 ].…”

“…The relationship between precipitation and malaria transmission is intricate. On one hand, precipitation-induced standing water provides a breeding habitat for mosquitoes; [ 14 ] on the other hand, high-intensity rainfall may wash away or kill both larvae and adult mosquitoes in some cases [ 12 ]. A study reported a positive correlation between rainfall and malaria prevalence in Thailand [ 15 ].…”

“…A study reported a positive correlation between rainfall and malaria prevalence in Thailand [ 15 ]. Another modelling study found that the probability of Aedes species’ occurrence increased to nearly 99% when precipitation was less than 100 mm during the warmest quarter of the year, but this probability quickly dropped as precipitation exceeded 300 mm, reaching 30% [ 12 ]. This complex relationship suggests that precipitation plays a dual role in promoting mosquito breeding and malaria transmission while, under extreme conditions, it may have adverse effects.…”

Predicting the distribution of potentially suitable habitat in China for Cirsium japonicum Fisch. ex DC. under future climate scenarios based on the R‐optimized MaxEnt model

“…Using the MaxEnt model to speculate the potential habitats of creatures has the characteristics of small distortion and good stability (Zheng et al., 2021 ). It has a wide range of applications and plays an important role in the study of the impacts of climate change on species distribution and the management and conservation of endangered species, involving a wide range of disciplines such as agronomy (Ali et al., 2023 ), forestry (Yousaf et al., 2022 ), virology (Velu et al., 2023 ; Zakharova et al., 2020 ), etc.…”