Developing a multivariate prediction model of antibody features associated with protection of malaria-infected pregnant women from placental malaria

Background: Plasmodium falciparum causes placental malaria, which results in adverse outcomes for mother and child. P. falciparum-infected erythrocytes that express the parasite protein VAR2CSA on their surface can bind to placental chondroitin sulfate A. It has been hypothesized that naturally acquired antibodies towards VAR2CSA protect against placental infection, but it has proven difficult to identify robust antibody correlates of protection from disease. The objective of this study was to develop a prediction model using antibody features that could identify women protected from placental malaria. Methods: We used a systems serology approach with elastic net-regularized logistic regression, partial least squares discriminant analysis, and a case-control study design to identify naturally acquired antibody features mid-pregnancy that were associated with protection from placental malaria at delivery in a cohort of 77 pregnant women from Madang, Papua New Guinea. Results: The machine learning techniques selected 6 out of 169 measured antibody features towards VAR2CSA that could predict (with 86% accuracy) whether a woman would subsequently have active placental malaria infection at delivery. Selected features included previously described associations with inhibition of placental binding and/or opsonic phagocytosis of infected erythrocytes, and network analysis indicated that there are not one but multiple pathways to protection from placental malaria. Conclusions: We have identified candidate antibody features that could accurately identify malaria-infected women as protected from placental infection. It is likely that there are multiple pathways to protection against placental malaria. Funding: This study was supported by the National Health and Medical Research Council (Nos. APP1143946, GNT1145303, APP1092789, APP1140509, and APP1104975)

Bacterial profile and drug susceptibility pattern of urinary tract infection in pregnant women at University of Gondar Teaching Hospital, Northwest Ethiopia

<p>Abstract</p> <p>Background</p> <p>Urinary tract infection (UTI) is a common health problem among pregnant women. Proper investigation and prompt treatment are needed to prevent serious life threatening condition and morbidity due to urinary tract infection that can occur in pregnant women. Recent report in Addis Ababa, Ethiopia indicated the prevalence of UTI in pregnant women was 11.6 % and Gram negative bacteria was the predominant isolates and showed multi drug resistance. This study aimed to assess bacterial profile that causes urinary tract infection and their antimicrobial susceptibility pattern among pregnant women visiting antenatal clinic at University of Gondar Teaching Hospital, Northwest Ethiopia.</p> <p>Methods</p> <p>A cross-sectional study was conducted at University of Gondar Teaching Hospital from March 22 to April 30, 2011. Mid stream urine samples were collected and inoculated into Cystine Lactose Electrolyte Deficient medium (CLED). Colony counts yielding bacterial growth of 10⁵/ml of urine or more of pure isolates were regarded as significant bacteriuria for infection. Colony from CLED was sub cultured onto MacConkey agar and blood agar plates. Identification was done using cultural characteristics and a series of biochemical tests. A standard method of agar disc diffusion susceptibility testing method was used to determine susceptibility patterns of the isolates.</p> <p>Results</p> <p>The overall prevalence of UTI in pregnant women was 10.4 %. The predominant bacterial pathogens were <it>Escherichia coli</it> 47.5 % followed by coagulase-negative staphylococci 22.5 %, <it>Staphylococcus aureus</it> 10 %, and <it>Klebsiella pneumoniae</it> 10 %. Gram negative isolates were resulted low susceptibility to co-trimoxazole (51.9 %) and tetracycline (40.7 %) whereas Gram positive showed susceptibility to ceftriaxon (84.6 %) and amoxicillin–clavulanic acid (92.3 %). Multiple drug resistance (resistance to two or more drugs) was observed in 95 % of the isolates.</p> <p>Conclusion</p> <p>Significant bacteriuria was observed in asymptomatic pregnant women. Periodic studies are recommended to check the outcome of asymptomatic bacteriuria and also monitor any changes in the susceptibility patterns of urinary tract pathogens in pregnant women.</p

Seroprevalence of hepatitis B and C viruses among medical waste handlers at Gondar town Health institutions, Northwest Ethiopia

<p>Abstract</p> <p>Background</p> <p>Viral hepatitis is an inflammation of the liver due to viral infections and there are groups of viruses that affects the liver of which hepatitis B and C viruses are the causative agents of sever form of liver disease with high rate of mortality. Medical waste handlers who undergo collection, transportation, and disposal of medical wastes in the health institutions are at risk of exposure to acquire those infections which transmit mainly as a result of contaminated blood and other body fluids including injury with sharp instruments, splash to the eye or mucous membrane. This study aimed to determine the prevalence of hepatitis B and/or C viruses and associated risk factors among medical waste handlers.</p> <p>Results</p> <p>A cross-sectional study was conducted from April, 2011 to June, 2011 in government health institutions at Gondar town. Socio-demographic and possible risk factors data from medical waste handlers were collected using pre-tested and well structured questionnaires. Venous bloods were collected and the serums were tested for hepatitis B surface antigen and anti-hepatitis C antibody using rapid Immunochromatography assay. Data was entered and analyzed using SPSS software package (version16). Chi-square and Fisher exact tests were used to assess risk of association. A p-value of < 0.05 was considered statistical significance.</p> <p>A total of 100 medical waste handlers and 100 non-clinical waste handlers were examined for HBV and HCV viruses. HBV was detected in 6 (6.0%) and 1 (1.0%) and HCV in 1 (1.0%) and 0 (0.0%) of medical waste handlers and non-clinical waste handlers, respectively. Significant differences were observed in the detection rates of HBV (OR = 6.3; <it>X</it>²= 4.1; <it>P = 0.04</it>) and overall infection rate (HBV + HCV) (OR = 7.5; <it>X</it>²= 5.2; <it>P: 0.02</it>) in medical waste handlers when compared with non-clinical waste handlers. It was found that none of the observed risk factors significantly associated with rate of hepatitis infection compared to others.</p> <p>Conclusions</p> <p>Prevalence of HBV and HCV were significantly higher in medical waste in relation to non-clinical waste handlers. There were poor waste management system which contributed for occurrence of higher degree of sharps injury and blood and body fluids splash.</p