Objective:To determine the seroprevalence of toxoplasmosis in pregnant women,as well as the proportion of acutely infected and risk factors in the Democratic Republic of Congo.Methods:Thirty maternities in Kinshasa we...Objective:To determine the seroprevalence of toxoplasmosis in pregnant women,as well as the proportion of acutely infected and risk factors in the Democratic Republic of Congo.Methods:Thirty maternities in Kinshasa were randomly selected and women attending antenatal consultation were invited to participate.They were interviewed with a structured questionnaire about known risk factors(age,meat consumption,contact with soil,and presence of cat)and a venous blood sample was taken.Sera were analysed for total immunoglobulins(Ig)by VIDAS Toxo Competition using Enzyme Linked Fluorescent Assay.IgM was determined by VIDIA Toxo IgM and IgG avidity by VIDAS Toxo IgG avidity.Results:A total of 781 women were included.Median age was 28 years old(IQR:8.S).And 627women(80.3%;95%CI:77.5-83.1)were found to be positive to total Ig and 17 out of 387(4.4%;95%CI:2.3-6.4)were positive to IgM.IgC avidity was low for 2(11.8%)women,intermediate for 2(11.8%)and high for 13 women(76.4%).There was no statistically significant association between Toxoplasma gondii infection and any risk factors assessed.Conclusion:In Kinshasa,toxoplasmosis endemicity is highly prevalent.One woman out of twenty five had a recent toxoplasmosis infection and 20%were not protected against primoinfection,indicating a need for measures to prevent and control toxoplasmosis during pregnancy.展开更多
Background:New insecticides with a novel mode of action such as neonicotinoids have recently been recommended for public health by WHO.Resistance monitoring of such novel insecticides requires a robust protocol to mon...Background:New insecticides with a novel mode of action such as neonicotinoids have recently been recommended for public health by WHO.Resistance monitoring of such novel insecticides requires a robust protocol to monitor the development of resistance in natural populations.In this study,we comparatively used three different solvents to assess the susceptibility of malaria vectors to neonicotinoids across Africa.Methods:Mosquitoes were collected from May to July 2021 from three agricultural settings in Cameroon(Njombe-Penja,Nkolondom,and Mangoum),the Democratic Republic of Congo(Ndjili-Brasserie),Ghana(Obuasi),and Uganda(Mayuge).Using the CDC bottle test,we compared the effect of three different solvents(ethanol,acetone,MERO)on the efficacy of neonicotinoids againstAnopheles gambiae s.l.In addition,TaqMan assays were used to genotype key pyrethroid-resistant markers inAn.gambiae and odds ratio based on Fisher exact test were used to evaluate potential cross-resistance between pyrethroids and clothianidin.Results:Lower mortality was observed when using absolute ethanol or acetone alone as solvent for clothianidin(11.4-51.9% mortality in Nkolondom,31.7-48.2% in Mangoum,34.6-56.1% in Mayuge,39.4-45.6% in Obuasi,83.7-89.3% in Congo and 71.1-95.9% in Njombe pendja)compared to acetone+MERO for which 100% mortality were observed for all the populations.Similar observations were done for imidacloprid and acetamiprid.Synergist assays(PBO,DEM and DEF)with clothianidin revealed a significant increase of mortality suggesting that metabolic resistance mechanisms are contributing to the reduced susceptibility.A negative association was observed between the L1014F-kdr mutation and clothianidin resistance with a greater frequency of homozygote resistant mosquitoes among the dead than among survivors(OR=0.5;P=0.02).However,the I114T-GSTe2 was in contrast significantly associated with a greater ability to survive clothianidin with a higher frequency of homozygote resistant among survivors than other genotypes(OR=2.10;P=0.013).Conclusions:This study revealed a contrasted susceptibility pattern depending on the solvents with ethanol/acetone resulting to lower mortality,thus possibly overestimating resistance,whereas the MERO consistently showed a greater efficacy of neonicotinoids but it could prevent to detect early resistance development.Therefore,we recommend monitoring the susceptibility using both acetone alone and acetone+MERO(4μg/ml for clothianidin)to capture the accurate resistance profile of the mosquito populations.展开更多
基金Supported by the VLIR UOS Project(Grant N.VLIR:42/FA02000/13/5806),University of Antwerp and University of Kinshasa
文摘Objective:To determine the seroprevalence of toxoplasmosis in pregnant women,as well as the proportion of acutely infected and risk factors in the Democratic Republic of Congo.Methods:Thirty maternities in Kinshasa were randomly selected and women attending antenatal consultation were invited to participate.They were interviewed with a structured questionnaire about known risk factors(age,meat consumption,contact with soil,and presence of cat)and a venous blood sample was taken.Sera were analysed for total immunoglobulins(Ig)by VIDAS Toxo Competition using Enzyme Linked Fluorescent Assay.IgM was determined by VIDIA Toxo IgM and IgG avidity by VIDAS Toxo IgG avidity.Results:A total of 781 women were included.Median age was 28 years old(IQR:8.S).And 627women(80.3%;95%CI:77.5-83.1)were found to be positive to total Ig and 17 out of 387(4.4%;95%CI:2.3-6.4)were positive to IgM.IgC avidity was low for 2(11.8%)women,intermediate for 2(11.8%)and high for 13 women(76.4%).There was no statistically significant association between Toxoplasma gondii infection and any risk factors assessed.Conclusion:In Kinshasa,toxoplasmosis endemicity is highly prevalent.One woman out of twenty five had a recent toxoplasmosis infection and 20%were not protected against primoinfection,indicating a need for measures to prevent and control toxoplasmosis during pregnancy.
文摘Background:New insecticides with a novel mode of action such as neonicotinoids have recently been recommended for public health by WHO.Resistance monitoring of such novel insecticides requires a robust protocol to monitor the development of resistance in natural populations.In this study,we comparatively used three different solvents to assess the susceptibility of malaria vectors to neonicotinoids across Africa.Methods:Mosquitoes were collected from May to July 2021 from three agricultural settings in Cameroon(Njombe-Penja,Nkolondom,and Mangoum),the Democratic Republic of Congo(Ndjili-Brasserie),Ghana(Obuasi),and Uganda(Mayuge).Using the CDC bottle test,we compared the effect of three different solvents(ethanol,acetone,MERO)on the efficacy of neonicotinoids againstAnopheles gambiae s.l.In addition,TaqMan assays were used to genotype key pyrethroid-resistant markers inAn.gambiae and odds ratio based on Fisher exact test were used to evaluate potential cross-resistance between pyrethroids and clothianidin.Results:Lower mortality was observed when using absolute ethanol or acetone alone as solvent for clothianidin(11.4-51.9% mortality in Nkolondom,31.7-48.2% in Mangoum,34.6-56.1% in Mayuge,39.4-45.6% in Obuasi,83.7-89.3% in Congo and 71.1-95.9% in Njombe pendja)compared to acetone+MERO for which 100% mortality were observed for all the populations.Similar observations were done for imidacloprid and acetamiprid.Synergist assays(PBO,DEM and DEF)with clothianidin revealed a significant increase of mortality suggesting that metabolic resistance mechanisms are contributing to the reduced susceptibility.A negative association was observed between the L1014F-kdr mutation and clothianidin resistance with a greater frequency of homozygote resistant mosquitoes among the dead than among survivors(OR=0.5;P=0.02).However,the I114T-GSTe2 was in contrast significantly associated with a greater ability to survive clothianidin with a higher frequency of homozygote resistant among survivors than other genotypes(OR=2.10;P=0.013).Conclusions:This study revealed a contrasted susceptibility pattern depending on the solvents with ethanol/acetone resulting to lower mortality,thus possibly overestimating resistance,whereas the MERO consistently showed a greater efficacy of neonicotinoids but it could prevent to detect early resistance development.Therefore,we recommend monitoring the susceptibility using both acetone alone and acetone+MERO(4μg/ml for clothianidin)to capture the accurate resistance profile of the mosquito populations.
