Echinococcus multilocularis (fox tapeworm), with the red fox as the main definitive host, is a major foodborne parasite in Europe and is emerging in the Netherlands. While wild berry consumption is often communicated as a risk factor for foodborne E. multilocularis infection, contamination of commercially grown soft fruits remains poorly studied. This study assessed fox presence and E. multilocularis contamination on commercial soft fruit farms in Limburg, an endemic area in the Netherlands. During the 2024 harvest season (June–August), 220 soft fruit and 220 soil samples were collected on 22 plots across 14 farms. Fox presence was confirmed on 50% of farms using camera traps and molecular analysis of fecal samples, with footage showing foxes actively foraging on fruits. Using washing, sedimentation, DNA extraction, and a specific qPCR targeting a short fragment of the 12S mitochondrial gene, E. multilocularis DNA was detected in 10/220 (4.5%; 95% CI: 2.5–8.2%) soft fruit samples, all at low concentrations. Univariable analysis indicated longer harvest duration, presence of elevated racks, rain covers, and removal of fallen fruit to be associated with contamination (all p < 0.05). Moreover, contamination seemed to occur more often on strawberries than other soft fruits ( p = 0.05). As only E. multilocularis DNA was detected, no conclusions can be drawn regarding the viability or infectivity of the parasite material. Furthermore, the interpretation of potential predictors of contamination remains unclear. Nevertheless, the presence of foxes on soft fruit farms indicates a potential source of contamination and highlights the importance of further research on strategies to minimize the contamination risk of outdoor grown fruits.
Echinococcus multilocularis (fox tapeworm), with the red fox as the main definitive host, is a major foodborne parasite in Europe and is emerging in the Netherlands. While wild berry consumption is often communicated as a risk factor for foodborne E. multilocularis infection, contamination of commercially grown soft fruits remains poorly studied. This study assessed fox presence and E. multilocularis contamination on commercial soft fruit farms in Limburg, an endemic area in the Netherlands. During the 2024 harvest season (June–August), 220 soft fruit and 220 soil samples were collected on 22 plots across 14 farms. Fox presence was confirmed on 50% of farms using camera traps and molecular analysis of fecal samples, with footage showing foxes actively foraging on fruits. Using washing, sedimentation, DNA extraction, and a specific qPCR targeting a short fragment of the 12S mitochondrial gene, E. multilocularis DNA was detected in 10/220 (4.5%; 95% CI: 2.5–8.2%) soft fruit samples, all at low concentrations. Univariable analysis indicated longer harvest duration, presence of elevated racks, rain covers, and removal of fallen fruit to be associated with contamination (all p < 0.05). Moreover, contamination seemed to occur more often on strawberries than other soft fruits (p = 0.05). As only E. multilocularis DNA was detected, no conclusions can be drawn regarding the viability or infectivity of the parasite material. Furthermore, the interpretation of potential predictors of contamination remains unclear. Nevertheless, the presence of foxes on soft fruit farms indicates a potential source of contamination and highlights the importance of further research on strategies to minimize the contamination risk of outdoor grown fruits.
The helminth parasite Ascaris lumbricoides remains a major global health burden, yet factors influencing its fertility and infection intensity are not fully understood. This cross-sectional study explored associations between host characteristics, worm biometrics, and parasite reproductive output in a rural Venezuelan community. Complete fecal evacuations were collected from 128 participants (57% of consenting population) across 45 houses. Following descriptive analyses of worm-related variables (count, length, weight, sex, male-to-female ratio, maturity), egg-related variables (eggs per gr of feces [EPG], fertile and infertile EPG, infertile-to-fertile ratio), and host characteristics (gender, age, household), both univariate methods and multivariable regression analyses were performed to assess associations. Worm biometrics showed non-significant associations with infection type (unisexual vs. bisexual), although male worms in unisexual infections tended to be heavier. A non-significant crowding effect was observed, with higher worm counts often linked to lower average worm length and weight. Worm length and weight were strongly correlated with egg production, though this relationship weakened in bisexual infections, likely due to reduced female fecundity. Male worm presence appeared to be the main determinant of egg fertility, with higher male-to-female ratios showing borderline significant association with lower ratios of unfertilized to fertilized eggs. Host age and household clustering were associated with worm count, whereas host gender was not. These findings support key biological principles of A. lumbricoides , including density-dependent crowding effects and male worm presence in egg fertility. The study also highlights the complexity of worm-specific and host-related factors influencing infection intensity and fecundity, providing insights for future research and more targeted deworming strategies.
The helminth parasite Ascaris lumbricoides remains a major global health burden, yet factors influencing its fertility and infection intensity are not fully understood. This cross-sectional study explored associations between host characteristics, worm biometrics, and parasite reproductive output in a rural Venezuelan community. Complete fecal evacuations were collected from 128 participants (57% of consenting population) across 45 houses. Following descriptive analyses of worm-related variables (count, length, weight, sex, male-to-female ratio, maturity), egg-related variables (eggs per gr of feces [EPG], fertile and infertile EPG, infertile-to-fertile ratio), and host characteristics (gender, age, household), both univariate methods and multivariable regression analyses were performed to assess associations. Worm biometrics showed non-significant associations with infection type (unisexual vs. bisexual), although male worms in unisexual infections tended to be heavier. A non-significant crowding effect was observed, with higher worm counts often linked to lower average worm length and weight. Worm length and weight were strongly correlated with egg production, though this relationship weakened in bisexual infections, likely due to reduced female fecundity. Male worm presence appeared to be the main determinant of egg fertility, with higher male-to-female ratios showing borderline significant association with lower ratios of unfertilized to fertilized eggs. Host age and household clustering were associated with worm count, whereas host gender was not. These findings support key biological principles of A. lumbricoides, including density-dependent crowding effects and male worm presence in egg fertility. The study also highlights the complexity of worm-specific and host-related factors influencing infection intensity and fecundity, providing insights for future research and more targeted deworming strategies.
