scholarly journals ImergardTMWP: A Non-Chemical Alternative for an Indoor Residual Spray, Effective against Pyrethroid-Resistant Anopheles gambiae (s.l.) in Africa

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 322 ◽  
Author(s):  
Jean M. Deguenon ◽  
Roseric Azondekon ◽  
Fiacre R. Agossa ◽  
Gil G. Padonou ◽  
Rodrigue Anagonou ◽  
...  
Keyword(s):  
Anopheles Gambiae ◽  
Mosquito Control ◽  
Residual Activity ◽  
Sub Saharan Africa ◽  
World Health ◽  
Wild Type ◽  
Anopheles Gambiae S.L ◽  
Sub Saharan ◽  
Health Organization ◽  
Assay Conditions

Malaria is the deadliest mosquito-borne disease and kills predominantly people in sub-Saharan Africa (SSA). The now widespread mosquito resistance to pyrethroids, with rapidly growing resistance to other insecticide classes recommended by the World Health Organization (WHO), may overturn the successes gained in mosquito control in recent years. It is of utmost importance to search for new, inexpensive, and safe alternatives, with new modes of action, that might improve the efficacy of current insecticides. The efficacy of a novel mechanical insecticidal mineral derived from volcanic rock, ImergardTMWP, was investigated to determine its efficacy as a stand-alone residual wall spray and as a mixture with deltamethrin (K-Othrine® Polyzone) in experimental huts in Cove, Benin. The evaluation was conducted with susceptible (Kisumu) and wild-type Anopheles gambiae (s.l.). Deltamethrin applied alone demonstrated 40–45% mortality (at 72 h post-exposure) during the first four months, which declined to 25% at six months for wild An. gambiae from Cove. ImergardTMWP alone and mixed with deltamethrin, under the same assay conditions, produced 79–82% and 73–81% mortality, respectively, during the same six-month period. ImergardTMWP met the 80% WHO bio-efficacy threshold for residual activity for the first five months with 78% residual activity at six months. ImergardTMWP can be used as a mixture with chemical insecticides or as a stand-alone pesticide for mosquito control in Africa.

scholarly journals Pyrethroid and Etofenprox Resistance in Anopheles gambiae and Anopheles coluzzii from Vegetable Farms in Yaoundé, Cameroon: Dynamics, Intensity and Molecular Basis

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5543
Author(s):  
Michael Piameu ◽  
Philippe Nwane ◽  
Wilson Toussile ◽  
Konstantinos Mavridis ◽  
Nadja Christina Wipf ◽  
...  
Keyword(s):  
Anopheles Gambiae ◽  
Mortality Rates ◽  
World Health ◽  
Anopheles Coluzzii ◽  
Cross Sectional ◽  
Metabolic Genes ◽  
Anopheles Gambiae S.L ◽  
Underlying Mechanisms ◽  
Health Organization ◽  
The City

Previous studies have indicated widespread insecticide resistance in malaria vector populations from Cameroon. However, the intensity of this resistance and underlying mechanisms are poorly known. Therefore, we conducted three cross-sectional resistance surveys between April 2018 and October 2019, using the revised World Health Organization protocol, which includes resistance incidences and intensity assessments. Field-collected Anopheles gambiae s.l. populations from Nkolondom, Nkolbisson and Ekié vegetable farms in the city of Yaoundé were tested with deltamethrin, permethrin, alpha-cypermethrin and etofenprox, using 1× insecticide diagnostic concentrations for resistance incidence, then 5× and 10× concentrations for resistance intensity. Subsamples were analyzed for species identification and the detection of resistance-associated molecular markers using TaqMan® qPCR assays. In Nkolbisson, both An. coluzzii (96%) and An. gambiae s.s. (4%) were found together, whereas only An. gambiae s.s. was present in Nkolondom, and only An. coluzzii was present in Ekié. All three populations were resistant to the four insecticides (<75% mortality rates―MR1×), with intensity generally fluctuating over the time between mod-erate (<98%―MR5×; ≥98%―MR10×) and high (76–97%―MR10×). The kdr L995F, L995S, and N1570Y, and the Ace-1 G280S-resistant alleles were found in An. gambiae from Nkolondom, at 73%, 1%, 16% and 13% frequencies, respectively, whereas only the kdr L995F was found in An. gambiae s.s. from Nkolbisson at a 50% frequency. In An. coluzzii from Nkolbisson and Ekié, we detected only the kdr L995F allele at 65% and 60% frequencies, respectively. Furthermore, expression levels of Cyp6m2, Cyp9k1, and Gste2 metabolic genes were highly upregulated (over fivefold) in Nkolondom and Nkolbisson. Pyrethroid and etofenprox-based vector control interventions may be jeopardized in the prospected areas, due to high resistance intensity, with multiple mechanisms in An. gambiae s.s. and An. coluzzii.

scholarly journals The Relationship Between the Global Burden of Influenza From 2017 to 2019 and COVID-19: Descriptive Epidemiological Assessment (Preprint)

2020 ◽  
Author(s):  
Stefan David Baral ◽  
Katherine Blair Rucinski ◽  
Jean Olivier Twahirwa Rwema ◽  
Amrita Rao ◽  
Neia Prata Menezes ◽  
...  
Keyword(s):  
Respiratory Infections ◽  
Temporal Trends ◽  
Sub Saharan Africa ◽  
World Health ◽  
Respiratory Pathogens ◽  
Modes Of Transmission ◽  
The World ◽  
Influenza Activity ◽  
Sub Saharan ◽  
Health Organization

BACKGROUND SARS-CoV-2 and influenza are lipid-enveloped viruses with differential morbidity and mortality but shared modes of transmission. OBJECTIVE With a descriptive epidemiological framing, we assessed whether recent historical patterns of regional influenza burden are reflected in the observed heterogeneity in COVID-19 cases across regions of the world. METHODS Weekly surveillance data reported by the World Health Organization from January 2017 to December 2019 for influenza and from January 1, 2020 through October 31, 2020, for COVID-19 were used to assess seasonal and temporal trends for influenza and COVID-19 cases across the seven World Bank regions. RESULTS In regions with more pronounced influenza seasonality, COVID-19 epidemics have largely followed trends similar to those seen for influenza from 2017 to 2019. COVID-19 epidemics in countries across Europe, Central Asia, and North America have been marked by a first peak during the spring, followed by significant reductions in COVID-19 cases in the summer months and a second wave in the fall. In Latin America and the Caribbean, COVID-19 epidemics in several countries peaked in the summer, corresponding to months with the highest influenza activity in the region. Countries from regions with less pronounced influenza activity, including South Asia and sub-Saharan Africa, showed more heterogeneity in COVID-19 epidemics seen to date. However, similarities in COVID-19 and influenza trends were evident within select countries irrespective of region. CONCLUSIONS Ecological consistency in COVID-19 trends seen to date with influenza trends suggests the potential for shared individual, structural, and environmental determinants of transmission. Using a descriptive epidemiological framework to assess shared regional trends for rapidly emerging respiratory pathogens with better studied respiratory infections may provide further insights into the differential impacts of nonpharmacologic interventions and intersections with environmental conditions. Ultimately, forecasting trends and informing interventions for novel respiratory pathogens like COVID-19 should leverage epidemiologic patterns in the relative burden of past respiratory pathogens as prior information.

Pregnancy intention and gestational age at first antenatal care visit in Lesotho

2021 ◽  
Vol 15 (1) ◽  
pp. 1-11
Author(s):  
Paul Mkandawire ◽  
Joseph Kangmennaang ◽  
Chad Walker ◽  
Roger Antabe ◽  
Kilian Atuoye ◽  
...  
Keyword(s):  
Antenatal Care ◽  
Gestational Age ◽  
Secondary Data ◽  
Universal Coverage ◽  
Sub Saharan Africa ◽  
World Health ◽  
Antenatal Visit ◽  
Life Saving ◽  
Sub Saharan ◽  
Health Organization

Background/aims With coverage of antenatal care in sub-Saharan Africa approaching a universal level, attention is now turning to maximising the life-saving potential of antenatal care. This study assessed the gestational age at which pregnant mothers make their first antenatal visit in the context of high antenatal coverage in Lesotho. Methods For the purposes of this study, secondary data from the Demographic and Health Survey of 2014 was analysed. These data were collected in 2014, via an interviewer administered questionnaire. Survival analysis was applied to the data, using Stata SE 15 to compute time ratios that estimate time to first antenatal visit in Lesotho. Results Despite near universal coverage, only 24% of mothers start antenatal care before 12 weeks of gestation, as recommended by the World Health Organization. In addition, mothers with unwanted pregnancies are most likely to delay antenatal care until later in gestation, followed by mothers with mistimed pregnancies. Education, but not wealth, correlates with the start of antenatal care. Conclusions Having achieved near universal coverage, emphasising a prompt start and adherence to recommended visits could optimise the life-saving potential of antenatal care in Lesotho.

scholarly journals A Systematic Review of the Incremental Costs of Implementing a New Vaccine in the Expanded Program of Immunization in Sub-Saharan Africa

2019 ◽  
Vol 4 (2) ◽  
pp. 238146831989454
Author(s):  
Joe Brew ◽  
Christophe Sauboin
Keyword(s):  
Systematic Review ◽  
Data Collection ◽  
Interquartile Range ◽  
Sub Saharan Africa ◽  
World Health ◽  
African Countries ◽  
Vaccine Type ◽  
Sub Saharan ◽  
Health Organization ◽  
The Cost

Background. The World Health Organization is planning a pilot introduction of a new malaria vaccine in three sub-Saharan African countries. To inform considerations about including a new vaccine in the vaccination program of those and other countries, estimates from the scientific literature of the incremental costs of doing so are important. Methods. A systematic review of scientific studies reporting the costs of recent vaccine programs in sub-Saharan countries was performed. The focus was to obtain from each study an estimate of the cost per dose of vaccine administered excluding the acquisition cost of the vaccine and wastage. Studies published between 2000 and 2018 and indexed on PubMed could be included and results were standardized to 2015 US dollars (US$). Results. After successive screening of 2119 titles, and 941 abstracts, 58 studies with 80 data points (combinations of country, vaccine type, and vaccination approach–routine v. campaign) were retained. Most studies used the so-called ingredients approach as costing method combining field data collection with documented unit prices per cost item. The categorization of cost items and the extent of detailed reporting varied widely. Across the studies, the mean and median cost per dose administered was US$1.68 and US$0.88 with an interquartile range of US$0.54 to US$2.31. Routine vaccination was more costly than campaigns, with mean cost per dose of US$1.99 and US$0.88, respectively. Conclusion. Across the studies, there was huge variation in the cost per dose delivered, between and within countries, even in studies using consistent data collection tools and analysis methods, and including many health facilities. For planning purposes, the interquartile range of US$0.54 to US$2.31 may be a sufficiently precise estimate.

scholarly journals All Nets are Equal, But Some Nets are More Equal Than Others

2020 ◽  
Vol 31 (1) ◽  
pp. 2-4
Author(s):  
Mark Rowland
Keyword(s):  
Sub Saharan Africa ◽  
World Health ◽  
Insecticide Treated Nets ◽  
Comparative Performance ◽  
Malaria Burden ◽  
Test Product ◽  
Dramatic Decline ◽  
The World ◽  
Sub Saharan ◽  
Health Organization

Much of the dramatic decline in malaria in sub-Saharan Africa since 2000 is due to the massive investment in long-lasting insecticide treated nets (LLIN). According to the latest figures from the World Health Organization (WHO), over half of Africa's population now has access to LLIN, increasing from 33% in 2010 to 57% in 2019 (WHO 2019). In 2018 alone, 197 million LLINs were delivered to Africa by manufacturers. Despite this, LLIN coverage has improved only marginally since 2015. The malaria burden worldwide has fallen only slightly from an estimated 231 million cases of malaria in 2017 to 228 million in 2018, and is at a standstill in Africa. WHO policy is to assess candidate 2nd-in-class products for entomological efficacy only. Due to the significant variation in the specifications of the candidates, to generate the required assurance of comparative performance to 1st in class, WHO has designed a non-inferiority trial design to demonstrate whether each candidate 2nd-in-class test product is no worse in experimental hut trials.

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