Comparison of malaria diagnostic methods for detection of asymptomatic Plasmodium infections among pregnant women in northwest Ethiopia.

BACKGROUND: Malaria in pregnancy remains a major public health problem in the globe, especially in sub-Saharan Africa. In malaria endemic areas, most pregnant women remain asymptomatic, but malaria could still cause complications on the mother and her offspring; as well as serve as reservoirs to transmit infection. Despite these effects, no attention is given to the diagnosis of asymptomatic Plasmodium infections (APIs) using highly sensitive and specific laboratory diagnostic tools in Ethiopia. Therefore, the goal of this study was to compare the performance of Rapid Diagnostic Test (RDT), microscopy and real-time polymerase chain reaction (RT-PCR) to detect APIs among pregnant women. METHODS: A health facility based cross -sectional study was conducted among pregnant women attending antenatal care at Fendeka town health facilities Jawi district, northwest Ethiopia from February to March, 2019. A total of 166 participants were enrolled by using convenient sampling technique. Socio-demographic features were collected using a semi structured questionnaire. Dried blood spot (DBS) samples were collected for molecular analysis. Asymptomatic Plasmodium infection on pregnant women was diagnosed using RDT, microscopy and RT-PCR. Descriptive statistics were used to determine the prevalence of APIs. Method comparison was performed, and Cohen's kappa coefficient (k) was used to determine the degree of agreement among the diagnostic methods. Parasite densities were also calculated. RESULTS: The prevalence of API was 9.6%, 11.4% and 18.7% using RDT, microscopy and RT-PCR, respectively. The overall proportion of API was 19.3%. Sensitivity of the RDT was 83.3% as compared with microscopy. Rapid Diagnostic Test and microscopy also showed sensitivity of 50% and 60%, respectively, as compared with RT-PCR. The mean parasite density was 3213 parasites/µl for P falciparum and 1140 parasites/µl of blood for P. vivax. CONCLUSION: Prevalence of API in the study area was high. Both RDT and microscopy had lower sensitivity when compared with RT-PCR. Therefore, routine laboratory diagnosis of API among pregnant women should be given attention and done with better sensitive and specific laboratory diagnostic tools.

Prevalence of asymptomatic Plasmodium species infection and associated factors among pregnant women attending antenatal care at Fendeka town health facilities, Jawi District, North west Ethiopia: A cross-sectional study.

BACKGROUND: Malaria in pregnancy remains a major public health problem especially in sub-Saharan Africa. In malaria endemic areas, majority of pregnant women may remain asymptomatic but still associated with complications on the mother and her foetus. They also serve as reservoirs and act as transmitters of infection. Despite these effects, the prevalence of asymptomatic Plasmodium species infections among pregnant women attending antenatal care has not been yet studied at the study area. Therefore, the aim of this study was to assess the prevalence of asymptomatic Plasmodium species infections among pregnant women attending antenatal care at Fendeka town health facilities. METHODS: Health facility based cross -sectional study was conducted from February to March 2019. A total of 331 participants were enrolled by using convenient sampling technique. Socio-demographic and associated factors were collected by a face to face interview. All the 331 samples were tested using rapid diagnostic tests (RDTs) and microscopy. However, only 83 dried blood spot (DBS) samples out of 331 participants, were collected by using systematic random sampling technique for molecular analysis. Data was analysed using SPSS version 20. Descriptive statistics were used to determine the prevalence of asymptomatic Plasmodium species infections. Univariate logistic regression was employed to assess factors associated with asymptomatic Plasmodium species infection. Variables with P-value < 0.25 in the univariate logistic regression were selected for multivariate logistic regression analysis model. Odds ratios with 95% confidence intervals were calculated and P- values < 0.05 were considered as statistically significant. RESULTS: Overall, 37 (11.2%) asymptomatic Plasmodium species infections were detected using: RDTs, microscopy and real-time PCR altogether. The asymptomatic Plasmodium species infection prevalence was 17 (5.1%), 30 (9.1%) and 15(18.1%) using RDTs, microscopy and real-time PCR, respectively. Asymptomatic Plasmodium species infections were more likely to occur in primigravida (AOR: 4.51, 95% CI: 1.27-16.03), secundigravida (AOR: 3.87, 95% CI: 1.16-12.93), rural inhabitants (AOR: 4.51, 95% CI: 1.72-11.84) and in participants who did not use indoor residual spray (IRS) for the last one year (AOR: 3.13, 95% CI: 1.47-6.66). CONCLUSIONS: The prevalence of asymptomatic Plasmodium species infection was 11.2%. Pregnant women who reside in the rural area, primigravidae, secugravidae and those who did not utilize indoor residual spray for the last one year were at high risk of infection. Therefore, routine laboratory diagnosis of asymptomatic Plasmodium species infection among pregnant women should be adopted as a part of the antenatal care.

Composition of Asarum heterotropoides var. mandshuricum radix oil from different extraction methods and activities against human body odor-producing bacteria.

In this study, oils from Asarum heterotropoides were extracted by traditional solvent extraction and supercritical CO2 (SC-CO2) extraction methods and their antioxidant activities along with antimicrobial and inhibitory activities against five human body odor-producing bacteria (Staphylococcus epidermidis, Propionibacterium freudenreichii, Micrococcus luteus, Corynebacterium jeikeium, and Corynebacterium xerosis) were evaluated. The oil was found to contain 15 components, among which the most abundant component was methyl eugenol (37.6%), which was identified at every condition studied in different extraction methods. The oil extracted with n-hexane and ethanol mixture exhibited a strong antioxidant activity (92% ± 2%) and the highest ABTS and 2,2-diphenyl-1-picrylhydrazyl scavenging activities (89% ± 0.2%). The highest amounts of total phenolic content and total flavonoid content were 23.1±0.4 mg/g and 4.9±0.1 mg/g, respectively, in the traditional method. In the SC-CO2 method performed at 200 bar/50°C using ethanol as an entrainer, the highest inhibition zone was recorded against all the aforementioned bacteria. In particular, strong antibacterial activity (38±2 mm) was found against M. luteus. The minimum inhibitory concentration (MIC) for the oil against bacteria ranged from 10.1±0.1 µg/mL to 46±2 µg/mL. The lowest MIC was found against M. luteus. Methyl eugenol was found to be one of the major compounds working against human body odor-producing bacteria.