Factors associated with hepatitis B vaccination in Laos: findings from the multiple indicator cluster surveys in 2011/12 and 2017.

Background: Within Laos, the vaccination coverage rates with the monovalent hepatitis B birth dose vaccine and hepatitis B antigen-containing combination vaccines remain stagnant with 75% and 64%, respectively, in 2021. In this study, we used data from the Multiple Indicator Cluster Surveys to identify possible factors that represent barriers for receiving these childhood vaccinations. Methods: Data from the Multiple Indicator Cluster Surveys in 2011/12 and 2017 were analysed to examine factors associated with receiving the hepatitis B-containing vaccines using regression modelling. Data analyses were conducted in R. Findings: In 2011/12, the weight-adjusted coverage rate for receiving the hepatitis B birth dose was 48%, while the coverage with the hepatitis B antigen-containing combination vaccine was 55.1% based on both vaccination documents and recall; compared to 69.3% and 59.4% respectively in 2017. Ethno-linguistic group, maternal education, healthcare utilization and wealth were associated with receiving the vaccinations against hepatitis B. Interpretation: National estimates of vaccination coverage rates can conceal country-specific regional or socio-economic variations. Children from Hmong-Mien households, from less wealthier households and whose mothers were less educated and were not able to or did not utilize healthcare were identified as being less likely to receive the vaccinations. These findings indicate the need for improving access to healthcare, in particular for minority groups. Funding: This work was supported by the Ministry of Foreign and European Affairs, Luxembourg and the Luxembourg Institute of Health (project "Luxembourg-Laos Partnership for Research and Capacity Building in Infectious Disease Surveillance").

Malaria diagnosis challenges and pfhrp2 and pfhrp3 gene deletions using pregnant women as sentinel population in Nanoro region, Burkina Faso.

Malaria in pregnancy causes adverse consequences and prompt and accurate diagnosis is essential for case management. In malaria endemic countries, diagnosis is mainly based on rapid diagnostic tests (RDT) and microscopy. However, increasing reports of false negatives caused by low parasitemia and pfhrp2/3 deletions raise concerns about HRP2-based RDT usefulness. This study aimed to assess RDT and microscopy performance and to describe pfhrp2/3 deletions in a cohort of 418 pregnant women in Burkina Faso. Malaria was diagnosed using RDT and microscopy and blood samples were collected during antenatal care visits. Diagnostic results were compared to PCR as gold standard. Pfhrp2 and pfhrp3 deletions were characterized for patients with confirmed P. falciparum infection. RDT had better sensitivity (76%) but lower specificity (83%) than microscopy (sensitivity = 57%; specificity = 98%). Low parasitemia (<150 parasites/µL), especially in multigravidae, was the principal factor causing false negatives by both methods. Moreover, pfhrp2 deletion frequency among overall false negatives by RDT was 21.43%. Higher frequency of deletions was found among all samples, independently of RDT result, for example around 2% of samples had double deletions meaning that the majority of deletions had no effect on RDT testing. Finally, it was found higher pfhrp2 deletion in women with lower uterine height during the first trimester. Wider and National surveillance study of deletions is recommended among pregnant women and in Burkina Faso.