The epidemiology of Plasmodium falciparum and Plasmodium vivax in East Sepik Province, Papua New Guinea, pre- and post-implementation of national malaria control efforts

• Published in: Malaria Journal
• Main Authors: Johanna H. Kattenberg, Dulcie L. Gumal, Maria Ome-Kaius, Benson Kiniboro, Matthew Philip, Shadrach Jally, Bernadine Kasian, Naomi Sambale, Peter M. Siba, Stephan Karl, Alyssa E. Barry, Ingrid Felger, James W. Kazura, Ivo Mueller, Leanne J. Robinson
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2020
• Subjects: Malaria; Plasmodium falciparum; Plasmodium vivax; Epidemiology; Malaria control; Spatial heterogeneity; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/s12936-020-03265-x; https://doaj.org/article/9607af3bb0814c2aa440e512cc6cb2e8

Abstract Background In the past decade, national malaria control efforts in Papua New Guinea (PNG) have received renewed support, facilitating nationwide distribution of free long-lasting insecticidal nets (LLINs), as well as improvements in access to parasite-confirmed diagnosis and effective artemisinin-combination therapy in 2011–2012. Methods To study the effects of these intensified control efforts on the epidemiology and transmission of Plasmodium falciparum and Plasmodium vivax infections and investigate risk factors at the individual and household level, two cross-sectional surveys were conducted in the East Sepik Province of PNG; one in 2005, before the scale-up of national campaigns and one in late 2012-early 2013, after 2 rounds of LLIN distribution (2008 and 2011–2012). Differences between studies were investigated using Chi square (χ2), Fischer’s exact tests and Student’s t-test. Multivariable logistic regression models were built to investigate factors associated with infection at the individual and household level. Results The prevalence of P. falciparum and P. vivax in surveyed communities decreased from 55% (2005) to 9% (2013) and 36% to 6%, respectively. The mean multiplicity of infection (MOI) decreased from 1.8 to 1.6 for P. falciparum (p = 0.08) and from 2.2 to 1.4 for P. vivax (p < 0.001). Alongside these reductions, a shift towards a more uniform distribution of infections and illness across age groups was observed but there was greater heterogeneity across the study area and within the study villages. Microscopy positive infections and clinical cases in the household were associated with high rate infection households (> 50% of household members with Plasmodium infection). Conclusion After the scale-up of malaria control interventions in PNG between 2008 and 2012, there was a substantial reduction in P. falciparum and P. vivax infection rates in the studies villages in East Sepik Province. Understanding the extent of local heterogeneity in malaria transmission and the driving ...