Development of Lectin-Linked Immunomagnetic Separation for the Detection of Hepatitis A Virus

The accuracy and sensitivity of PCR-based methods for detection of hepatitis A virus (HAV) are dependent on the methods used to separate and concentrate the HAV from the infected cells. The pH and ionic strength affect the binding affinity of the virus to cells. In this study, we initially investigated the effects of pH (4.0–10.0) and metal ions (Fe²⁺, Co²⁺, Cu²⁺, Mg²⁺, K⁺, and Ca²⁺) on the binding of HAV to oyster digestive cells. The lowest relative binding (RB) of HAV to the cells was found at pH 4.0 and in FeSO₄ solution (64.6% and 68.1%, respectively). To develop an alternative to antibody-dependent immunomagnetic separation prior to detection of HAV using RT-PCR, the binding of HAV to five lectins, peanut agglutinin (PNA), Dolichos biflorus agglutinin (DBA), Helix pomatia agglutinin (HPA), Ulex europaeus agglutinin (UEA-1) and soybean agglutinin (SBA), was evaluated using ELISAs. SBA showed significantly higher RB to HAV than the other lectins tested. In addition, HAV could be concentrated within 30 min using SBA-linked magnetic bead separation (SMS) prior to the RT-PCR assay. Our findings demonstrate the feasibility of using SMS combined with RT-PCR to detect HAV at dilutions ranging from 10⁻¹–10⁻⁴ of a HAV stock (titer: 10⁴ TCID₅₀/mL).     

A cross-sectional study on factors associated with health seeking behaviour of Malawians aged 15+ years in 2016

IntroductionHealth seeking behaviour (HSB) refers to actions taken by individuals who are ill in order to find appropriate remedy. Most studies on HSB have only examined one symptom or covered only a specific geographical location within a country. In this study, we used a representative sample of adults to explore the factors associated with HSB in response to 30 symptoms reported by adult Malawians in 2016.MethodsWe used the 2016 Malawi Integrated Household Survey dataset. We fitted a multilevel logistic regression model of likelihood of ‘seeking care at a health facility’ using a forward step-wise selection method, with age, sex and reported symptoms entered as a priori variables. We calculated the odds ratios (ORs) and their associated 95% confidence intervals (95% CI). We set the level of statistical significance at P < 0.05.ResultsOf 6909 adults included in the survey, 1907 (29%) reported symptoms during the 2 weeks preceding the survey. Of these, 937 (57%) sought care at a health facility. Adults in urban areas were more likely to seek health care at a health facility than those in rural areas (AOR = 1.65, 95% CI: 1.19–2.30, P = 0.003). Females had a higher likelihood of seeking care from health facilities than males (AOR = 1.26, 95% CI: 1.03–1.59, P = 0.029). Being of higher wealth status was associated with a higher likelihood of seeking care from a health facility (AOR = 1.58, 95% CI: 1.16–2.16, P = 0.004). Having fever and eye problems were associated with higher likelihood of seeking care at a health facility, while having headache, stomach ache and respiratory tract infections were associated with lower likelihood of seeking care at a health facility.ConclusionThis study has shown that there is a need to understand and address individual, socioeconomic and geographical barriers to health seeking to increase access and appropriate use of health care and fast-track progress towards Universal Health Coverage among the adult population.