Mapping malaria transmission in West and Central Africa

Gemperli, Armin; Sogoba, Nafomon; Fondjo, Étienne; Mabaso, Musawenkosi; Bagayoko, Magaran; Briët, Olivier J. T.; Anderegg, Dan; Liebe, Jens; Smith, T.; Vounatsou, Penelope

doi:10.1111/j.1365-3156.2006.01640.x

Cited by 113 publications

(108 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A significant proportion of countries in sub-Saharan Africa report human malaria prevalence in excess of 50% during 4-6·month transmission seasons (Omumbo et al, 2005;Gemperli et al, 2006). These observations would suggest that our experimental design of provision of effective concentrations of insulin at each bloodmeal for the duration of mosquito lifespan could faithfully represent feeding conditions in highly endemic areas, with the prediction that natural mortality patterns of feeding mosquitoes could be impacted.…”

Section: Discussionmentioning

confidence: 91%

Insulin regulates aging and oxidative stress in Anopheles stephensi

Kang

Mott

Tapley

et al. 2008

Journal of Experimental Biology

View full text Add to dashboard Cite

SUMMARYObservations from nematodes to mammals indicate that insulin/insulin-like growth factor signaling (IIS) regulates lifespan. As in other organisms, IIS is conserved in mosquitoes and signaling occurs in multiple tissues. During bloodfeeding, mosquitoes ingest human insulin. This simple observation suggested that exogenous insulin could mimic the endogenous hormonal control of aging in mosquitoes, providing a new model to examine this phenomenon at the organismal and cellular levels. To this end, female Anopheles stephensi mosquitoes were maintained on diets containing human insulin provided daily in sucrose or three times weekly by artificial bloodmeal. Regardless of delivery route, mosquitoes provided with insulin at 1.7ϫ10 -4 and 1.7ϫ10 -3 ·mol·l -1 , doses 0.3-fold and 3.0-fold higher than non-fasting blood levels, died at a faster rate than controls. In mammals, IIS induces the synthesis of reactive oxygen species and downregulates antioxidants, events that increase oxidative stress and that have been associated with reduced lifespan. Insulin treatment of mosquito cells in vitro induced hydrogen peroxide synthesis while dietary supplementation reduced total superoxide dismutase (SOD) activity and manganese SOD activity relative to controls. The effects of insulin on mortality were reversed when diets were supplemented with manganese (III) tetrakis (4-benzoic acid) porphyrin (MnTBAP), a cell-permeable SOD mimetic agent, suggesting that insulin-induced mortality was due to oxidative stress. In addition, dietary insulin activated Akt/protein kinase B and extracellular signal-regulated kinase (ERK) in the mosquito midgut, suggesting that, as observed in Caenorhabditis elegans, the midgut may act as a ʻsignaling centerʼ for mosquito aging.

show abstract

Section: Discussionmentioning

confidence: 91%

Insulin regulates aging and oxidative stress in Anopheles stephensi

Kang

Mott

Tapley

et al. 2008

Journal of Experimental Biology

View full text Add to dashboard Cite

show abstract

“…A key result of studies on human malaria is that temperature strongly influences malaria transmission [27,45]. For example, it has been shown to increase with a rise in the maximum monthly temperature [28]. Recent research has shown that the variation in diurnal temperatures is also a critical factor that affects the period of Plasmodium sporogony in mosquito hosts [46].…”

Section: Discussionmentioning

confidence: 99%

Spatially explicit predictions of blood parasites in a widely distributed African rainforest bird

Sehgal

Buermann²,

Harrigan³

et al. 2010

Proc. R. Soc. B.

102

142

View full text Add to dashboard Cite

Critical to the mitigation of parasitic vector-borne diseases is the development of accurate spatial predictions that integrate environmental conditions conducive to pathogen proliferation. Species of Plasmodium and Trypanosoma readily infect humans, and are also common in birds. Here, we develop predictive spatial models for the prevalence of these blood parasites in the olive sunbird (Cyanomitra olivacea). Since this species exhibits high natural parasite prevalence and occupies diverse habitats in tropical Africa, it represents a distinctive ecological model system for studying vector-borne pathogens. We used PCR and microscopy to screen for haematozoa from 28 sites in Central and West Africa. Species distribution models were constructed to associate ground-based and remotely sensed environmental variables with parasite presence. We then used machine-learning algorithm models to identify relationships between parasite prevalence and environmental predictors. Finally, predictive maps were generated by projecting model outputs to geographically unsampled areas. Results indicate that for Plasmodium spp., the maximum temperature of the warmest month was most important in predicting prevalence. For Trypanosoma spp., seasonal canopy moisture variability was the most important predictor. The models presented here visualize gradients of disease prevalence, identify pathogen hotspots and will be instrumental in studying the effects of ecological change on these and other pathogens.

show abstract

“…Recent global maps created by the Malaria Atlas Project and Swiss Tropical Public Health Institute include uncertainty maps and use sophisticated statistical techniques to account for autocorrelation. 16,17 High-resolution maps may be useful for efficient and cost-effective targeting of interventions to the highest risk areas 8,12,[18][19][20][21][22] or in deciding to implement blanket coverage. The aims of this study were to generate and validate a high-resolution empirical risk map for household malaria risk in Nchelenge District, Luapula Province, Zambia.…”

Section: Introductionmentioning

confidence: 99%

Predictive Malaria Risk and Uncertainty Mapping in Nchelenge District, Zambia: Evidence of Widespread, Persistent Risk and Implications for Targeted Interventions

Pinchoff

Chaponda

Shields

et al. 2015

The American Society of Tropical Medicine and Hygiene

View full text Add to dashboard Cite

Abstract. Malaria risk maps may be used to guide policy decisions on whether vector control interventions should be targeted and, if so, where. Active surveillance for malaria was conducted through household surveys in Nchelenge District, Zambia from April 2012 through December 2014. Households were enumerated based on satellite imagery and randomly selected for study enrollment. At each visit, participants were administered a questionnaire and a malaria rapid diagnostic test (RDT). Logistic regression models were used to construct spatial prediction risk maps and maps of risk uncertainty. A total of 461 households were visited, comprising 1,725 participants, of whom 48% were RDT positive. Several environmental features were associated with increased household malaria risk in a multivariable logistic regression model adjusting for seasonal variation. The model was validated using both internal and external evaluation measures to generate and assess root mean square error, as well as sensitivity and specificity for predicted risk. The final, validated model was used to predict and map malaria risk including a measure of risk uncertainty. Malaria risk in a high, perennial transmission setting is widespread but heterogeneous at a local scale, with seasonal variation. Targeting malaria control interventions may not be appropriate in this epidemiological setting.

show abstract

Mapping malaria transmission in West and Central Africa

Cited by 113 publications

References 30 publications

Insulin regulates aging and oxidative stress in Anopheles stephensi

Insulin regulates aging and oxidative stress in Anopheles stephensi

Spatially explicit predictions of blood parasites in a widely distributed African rainforest bird

Predictive Malaria Risk and Uncertainty Mapping in Nchelenge District, Zambia: Evidence of Widespread, Persistent Risk and Implications for Targeted Interventions

Contact Info

Product

Resources

About