Role of cryptosporidium as a cause of diarrhoea among children attending Mathare North health centre, Nairobi

Diarrhoea is a leading cause of morbidity and mortality in children. Although a number of enteric pathogens have been identified in recent years, the causes of many episodes of diarrhea remain undetermined. Cryptosporidium has emerged as an important enteric pathogen but its role in paedriatic diarrhoea among poor communities in Kenya is not clearly understood. Consequently a prospective survey of children aged below 12 years was conducted in Mathare Health Centre from January to May 2006. Stool samples from 401 children were examined by modified acid fast staining. DNA extraction and genotyping were also carried out to confirm Cryptosporidium species. A pretested questionnaire was administered to the respondents to establish the risk factors and symptoms associated with cryptosporidiosis. Results showed an overall Cryptosporidium prevalence rate of 3.2%. The prevalence was highest among the 1-2 year age group with 7.1% and closely followed by the 0-1 year age group, which had a prevalence rate of 6.7%. The other age groups had a prevalence rate of less than 2%. There were no sex differences in the prevalence of Cryptosporidium. Investigation into the nature of enteric diseases prompting ova and cyst examination showed that 86% had recurrent diarrhoea, 75.1% had acute diarrhoea and 17% had chronic diarrhoea. The main symptoms were vomiting (51.1 %) and abdominal pain (87.3%). There were no sex differences in the occurrence of type of diarrhoea or symptoms. However there were statistically significant differences between age and the occurrence of recurrent diarrhoea, acute diarrhoea, vomiting, abdominal pain and abdominal swelling. Cryptosporidiosis was significantly associated with vomiting (X2 = 6.032, df = 1, P = 0.014). Genotype analysis based on the polymerase chain reaction-restriction fragment length polymorphism of the 188 rRNA gene fragment showed that 85% of the Cryptosporidium isolates were C. homonis while C. parvum, and C. felis were also identified from the isolates. Other parasites identified in the stool samples included Entamoeba coli (2.2%), Giardia intestinalis (5.2%), Entamoeba histolytica (1.5%), Trichuris trichiura (1%) Ascaris lumbricoides (3%) hookworm (0.5%) and Hymenolepis nana (0.5%). There was only one co-infection between Cryptosporidium and Giardia intestinalis. A majority of the respondents for the sampled children indicated that tap water was their main source of water. 71.3% of whom indicated that they treat their drinking water through boiling while only 28.7% of the respondents' use chemicals to treat their water. 87% of the respondents for the sampled children indicated that they lived in a single room with two family members. Ninety of the respondents for the sampled children indicated that they use pit latrines as their main feacal waste disposal method while 14 indicated that they use VIP latrine. One hundred and forty seven of the respondents for the sampled children indicated that they kept pets at home. However none of these socioeconomic factors were statistically significant for Cryptosporidium. These results show that Cryptosporidium is an important etiological agent of childhood diarrhoea in the study population and site. These results also suggest that anthroponotic transmission plays an important role in the epidemiology of cryptosporidiosis in the studied participants. It is recommended that Cryptosporidium should be identified in routine parasitologic tests of diarrhoeal stool samples.