Highest frequencies of assay categories (= diseases) across the 15 provinces of Laos. In this histogram, which is a graphic rendition of data in Table 1, the high frequency of occurrence of the highest-scoring disease [= assay] categories in the provinces of Bolikhamsai, Champasak, Oudomxai, Savannakhet, Vientiane, and Xaignabouri are very obvious. For the provinces of Attapeu, Khammouan, Luang Namtha, Luang Prabang, Phongsali, Xekong and Xiangkhoang, due to the small numbers of frequency of occurrence of the disease [= assay] categories, the separation of the bars is not obvious.