Cysticercosis in Laos: Prevalence, risk factors and predictive mapping

• National datasets can be used for predictive mapping of cysticercosis • Cysticercosis has been widely detected outside of northern Laos for the first time • Sex, wealth and region were individual factors associated with cysticercosis • Distance from a city and poverty were village factors associated with cysticercosis • This dataset can be used for validation of non-biological risk mapping methods Neurocysticercosis due to Taenia solium is the leading cause of preventable epilepsy in low and middle-income countries. This study describes the first national cysticercosis serosurvey in the Mekong region and the first national predicted prevalence map in Asia. Two thousand two hundred and sixty-two individuals from 149 random villages across Laos provided serum samples that were tested for cysticercosis using the B158/B60 antigen ELISA. Participants answered individual questionnaires on risk factors for cysticercosis. Logistic regression with random spatial effects was used to determine significant factors. A second geostatistical model using readily available national datasets produced predicted prevalence maps across the country. The overall study prevalence was 5.31% (95% CI: 4.44 – 6.29%) with cases detected throughout the country. Prevalence varied significantly between villages with a minimum of 0.00% (95% CI: 0.00 – 5.78%) in some villages and maximum of 43.75% (95% CI: 22.16 – 67.39%) in others, supporting the evidence for cysticercosis hotspots. Sex, wealth index and region were all significant risk factors based on individual responses, whilst distance to the nearest city and poverty were the only significant factors in the national predictive model. Cysticercosis was found throughout Laos, challenging the previous belief that it was primarily a disease of northern Laos. The significant association with wealth and poverty in both models highlights the need for socioeconomic considerations in disease control. Many of the high predicted prevalence areas exist along the borders with Cambodia, Thailand and Vietnam suggesting that cross-border or regional approaches may be beneficial.