Factors contributing to the abundance and spatial distribution of the invasive intermediate host snail (Pseudosuccinea columella) in uMgungundlovu district, KwaZulu-Natal, South Africa

Abstract

Fascioliasis is a parasitic disease commonly affecting cattle, goats, and sheep globally. Lymnaeidae snail species are important in the epidemiology and dispersal of fascioliasis since they are intermediate hosts of the Fasciola spp. Our study mapped at micro-geographical scale, the distribution and abundance of Pseudosuccinea columella in uMgungundlovu district, which is in the northern part of the KwaZulu-Natal province, and measured physicochemical parameters at potential transmission sites. The study examined the impact of physicochemical parameters and presence of other snail species on P.columella abundance and distribution in KwaZulu-Natal's uMgungundlovu district. Data were analyzed using R studio, a negative binomial mixed model, and various statistical tests, including the variance inflation factor and the Wilcoxon rank sum test. Overall, 1406 freshwater snails, distributed in 45 sampling sites. Pseudosuccinea columella (569) had a widespread coverage in 34 sites (75.6%) of them but not found at 11 sites. Water pH ranged between 6.60 ± 0.38 and 7.46 ± 0.15, while dissolved oxygen (DO) values varied across the sites. GLM analysis suggested that water pH had an influence on the abundance of P.columella. The intermediate host snail of Fasciola, P. columella is abundant and widely distributed across all the 7 municipalities in the uMgungundlovu district suggesting the need for increased snail monitoring to reduce its invasiveness and livestock productivity losses due to Fasciola infections.