Abstract:
Cryptosporidium infection is one of the most common causes of parasitic diarrhoea worldwide
in cattle and humans. In developing countries, human cryptosporidiosis is most prevalent
during early childhood and links between zoonotic infection and animal related activities
have been demonstrated. This study investigated the prevalence and species/genotype
distribution of Cryptosporidium among children (< 5 years) and calves (< 6 months) living in a
rural farming area adjacent to the Kruger National Park in South Africa, where interactions
between humans and wild and domestic animals are known to occur. Cryptosporidium oocysts
were detected in 8/143 stool samples of children recruited within the hospital system
(5.6%; 95% CI 2.4%, 10.7%) and in 2/352 faecal samples of calves (0.6%; 95% CI 0.1%, 2.0%)
using the modified Ziehl–Neelsen (MZN) staining technique. Microscopy positive samples
from children were further analysed by PCR targeting the 18S rRNA gene and identified as
Cryptosporidium hominis (3/4) and Cryptosporidium meleagridis (1/4). Regardless of the
microscopy outcome, randomly selected samples (n = 36) from calves 0–4 months of age were
amplified and sequenced at the 18S rRNA gene using nested PCR. Two calves tested positive
(5.6%; 95% CI 1.7%, 18.7%), and revealed the presence of Cryptosporidium parvum and
Cryptosporidium bovis. The detection of only two zoonotic species (C. parvum in one calf and
C. meleagridis in one child) suggests that zoonotic cryptosporidiosis is not currently widespread
in our study area; however, the potential exists for amplification of transmission in an
immunocompromised population.
