Evaluation of risk and carriage rate of enteric pathogenic organisms in four rural communities in Hainan, China

Samantha Jeppsen, Martine Troy
University of Utah School of Medicine

Background: The annual global mortality of children under-five years of age is 8.8-10.6 million.  Diarrhea accounts for 18% of these deaths, with over 5000 children dying per day.  It is one of the top three causes of death in under-five children in developing countries.  Recent evidence documents that diarrhea can result in lasting effects on growth, fitness, cognition and schooling.  Few studies exist in the literature exploring the risk and etiologies of infectious gastrointestinal illness in certain rural parts of China.  Hainan Province is a tropical island off the southeast coast of mainland China with a population of 8.6 million, 16% of which are ethnic minority groups.  Some ethnic minority groups live inland as subsistence farmers.  Hainan Medical University (HMU) is partnering with University of Utah’s Global Health Initiative, to evaluate and promote community health in these rural communities. This project is a preliminary study focusing on the determinants and characteristics of childhood diarrheal disease in two counties in Hainan Province:

Lingshui County: population is 334,614 with 261,119 rural and Ding'an County: population is 338,720 with 239,971 rural.  Data was collected to assess infectious gastrointestinal risk and illness in children under-five years old.  Through a community-based participatory process the information will be utilized for developing strategies to reduce the burden of diarrheal disease in these communities.

Methods:  Local community health care providers randomly selected 413 children in the two counties. Stool samples were collected and stored in Cary Blair and frozen for analysis by BioFire Diagnostics, Inc. laboratory where 105 were tested by FilmArray GI panel (a lab-in-a-pouch multiplexed PCR device) for detection of protozoa.  O&P and EIA were used for reference methods. 150ml water samples were collected from each family’s water source. Samples were analyzed for coliform forming units and E. coli using colilert snap packs, and the most probable number (MPN) was calculated based on the sample volume and number of positive wells. Local public health students from HMU surveyed the primary care givers of the child at the time of stool and water sample colleciton.             

Results:  Children’s fecal specimens were positive for the  following pathogens using Biofire PCR technology:  EAEC 73%, ETEC 71%, EPEC 76%, STEC 19%, Campylobacter spp 15%, Shigella/EIEC 16%, , Aeromonas spp. 4%, P. shigelloides 6%, C. difficile 4%, Salmonella spp. 3%, V. cholerae 1%, G. lamblia 28%, Cryptosporidium spp.9%, Adenovirus F 40/41 6%, Norovirus GI/GII 5%, Human Astrovirus 2%, Sapovirus  2%, and Rotavirus A 1%. Water was contaminated with fecal flora in all communities studied. CFU were found in all water sources. The MPN showed: Unprotected well water 18,671 MPN/100mL, Protected well 17,073, Public tap/standpipe 10,733, Piped into dwelling 3,639,  Tubewell/borehole 2,938, Bottled water 925,  Piped 881 MPN/100mL,  Survey results showed that 23 children had active diarrhea at the time of data collection and 66 children did not.

Conclusions: Children in rural China have an increased number of enteric pathogens. There is variability among water sources and the amount of coliform forming units. Protected wells and public tap/standpipes were comparable to waters sources that had increased contamination, such as unprotected wells. The only water sources found to have consistently less contamination were bottled and piped water. Diarrhea risk was decreased in families with water piped into their dwelling.  We conclude that houses with indoor plumbing and toilet facilities  have a decreased risk of diarrhea compared with all other sources of water, suggesting that overall hygiene practices play a larger role in diarrheal prevalence than the drinking water source. We plan to promote healthy hygiene practices in the communities to decrease the levels of enteric pathogens in children under five and the overall incidence of diarrheal disease in these rural populations.

Author Contact: samjeppsen@gmail.com