Diarrhea In China Research Articles

Viral diarrhea in children in Beijing, China

A study was undertaken from November 1994 to August 1996 to determine the role of viruses in children (< or =5 years of age) hospitalized at Beijing Children Hospital, Beijing China, for acute diarrhea. Stool samples from diarrheal patients were investigated by ELISA, electron microscopy, and RT-PCR for the presence of rotavirus, calicivirus, astrovirus, and adenovirus. Group A rotavirus was detected in 55.9% of all diarrheal patients and comprised 82.5% of all viruses detected. Group A rotavirus samples were further characterized for their G-type specificity by RT-PCR. Four major G types (1-4) were identified. G1 to G4 accounted for 58.9%, 15.7%, 16.8%, and 6.3%, respectively, of the serotyped samples. Almost all rotavirus infections occurred in children less than 1 year of age, with a significant clustering during the winter months. Group C rotavirus was detected in one 18-month-old child. Astroviruses, caliciviruses, and adenoviruses were detected in 8.5%, 7.6%, and 2.5% of the hospitalized children, respectively. This, the first viral etiological study of childhood diarrhea in China, concludes that rotavirus G1-4 strains play an important role in severe diarrhea in Beijing children.

Polymerase chain reaction for identification and typing of Clostridium difficile isolated from Chinese patients

Objective: Toxigenic Clostridium difficile, the etiologic agent of C. difficile-associated diarrhea (CDAD), is the most common cause of hospital-acquired diarrhea in many developed countries. In spite of the endemic nature of diarrhea in China, few reports of C. difficile infection in this country have been documented in the literature. Methods: In this study, a polymerase chain reaction (PCR) assay was used to determine the presence of toxigenic C. difficile in the stools of 19 patients who developed diarrhea after antibiotic use in a hospital in China. Clostridium difficile was also cultured from the stool of these patients. After DNA extraction, PCR was performed with primers targeting C. difficile toxin A and toxin B gene sequences. Results: Toxin sequences were detected in 5 of 19 (26%) specimens analyzed. To determine strain identity, these isolates were genotyped using arbitrarily primed PCR (AP-PCR). Three APPCR profiles were identified among these isolates. Three of these isolates had the same DNA banding pattern, and they were isolated from patients who were at the same institution. Conclusions: These preliminary results indicate that C. difficile may be involved in some diarrhea cases in China. This study may aid in the understanding of the nature of endemic diarrhea in this country.

Etiology of childhood diarrhea in Beijing, China

To determine the role of recently recognized enteropathogens in childhood diarrhea in China, 221 children with diarrhea and 108 controls seen at the Beijing Children's Hospital were studied during April and May 1989. Stools were examined for ova, parasites, and rotavirus, cultured for bacterial pathogens, and probed for enterotoxigenic Escherichia coli (ETEC), enteroinvasive E. coli (EIEC), enterohemorrhagic E. coli (EHEC), and enteropathogenic adherence factor-positive (EAF+) E. coli. Pathogens were identified in 56.5% of children with diarrhea and 43.5% of controls (P = 0.04). Detection of enteropathogens was significantly greater in patients examined within 1 week of symptom onset (65%) than in patients examined later (39%; P = 0.01). ETEC was the most frequently detected pathogen in children with diarrhea, accounting for 20% of the cases. Other agents identified in patients included the following: salmonellae, 12%; rotavirus, 7%; EIEC, 7%; EHEC, 7%; members of the Aeromonas hydrophila group, 6%; EAF+ E. coli, 5%; Ascaris lumbricoides, 3%; shigellae, 3%; campylobacters, 2%; and Vibrio spp., 0.5%. The isolation rates of salmonellae (P = 0.02), EAF+ E. coli (P = 0.04), and mixed pathogens (P = 0.05) were significantly greater for diarrhea patients than for controls. Resistance to multiple antimicrobial agents occurred in 39% of the Salmonella isolates, 22% of the Aeromonas isolates, and 17% of the Shigella isolates. Multiresistant salmonellae (P = 0.05) and shigellae were recovered from diarrheal stools only. Ciprofloxacin, cefotaxime, and imipenem were the only agents tested to which all bacterial isolates were susceptible in vitro. These results suggest that both traditional and newly recognized agents are important causes of childhood diarrhea in Beijing and that therapy may be complicated by indigenous antimicrobial resistance.

Etiologic studies of the 1983 and 1984 outbreaks of epidemic diarrhea in Guangxi.

Studies are reported on two outbreaks of epidemic diarrhea in China involving 19,007 patients. The first outbreak occurred in the northern part of the Guangxi Autonomous Region and extended south from April through September 1983. In June 1984 a second outbreak of 6,570 cases occurred in Guanyang, a county in the northern part of Guangxi. 125 fecal samples from the two outbreaks were cultured for bacteria; all of the samples except one were negative. Rotavirus particles were detected in 44.1% (15/34) of stool specimens examined by immune electron microscopy. The two outbreaks appeared to be caused by non-group-A rotaviruses, based on the pattern of electrophoretic migration of the RNA genome segments in polyacrylamide gels and on the lack of a detectable common group antigen(s) when tested by an enzyme-linked immunosorbent assay for group A rotaviruses. Complement-fixation tests also indicated that 37.5% of convalescent-phase sera from patients produced antibody to the isolated rotavirus. The total molecular weight of the RNA segments in the new Guangxi strain was calculated to be 10.69 X 10(6), with the 11 genome segments having molecular weights (X 10(6)) of 2.19, 1.83, 1.56, 1.53, 0.82, 0.81, 0.60, 0.46, 0.35, 0.30, and 0.24. This study also reports comparative detection rates for direct and immune electron microscopy and for PAGE. PAGE proved to be the most sensitive detection method for these new rotaviruses.

Possible role for ovarian prostaglandin F 2α in stimulating luteal oxytocin release in ewes at luteolysis

Escherichia coli-associated diarrhoea is an important disease adversely affecting the pig industry. This study was conducted to investigate the frequency of virulence factors expressed by E. coli strains isolated from suckling pigs with diarrhoea in China. A total of 381 E. coli strains, obtained from 290 faecal samples from pigs on 38 farms, were tested for fimbriae (K88, K99, 987P, F41, F18, F17), non-fimbrial adhesins (AIDA-I, paa, CS31A, eae, saa), enterotoxin (LT-I, LT-II, STa, STb, EAST1), Shiga toxin (Stx1, Stx2, Stx2e), pathogenicity islands (HPI, LEE), α-haemolysin (hlyA), afa8 gene cluster (afaD, afaE) and sepA genes by PCR. Out of the 381 isolates, 206 carried at least one virulence gene. Of the 206 virulence positive isolates, the virulence factor genes detected were EAST1 (n = 120), irp2 (n = 59), paa (n = 50), STb (n = 41), AIDA-I (n = 34), LT-I (n = 23), ler (n = 11), hlyA (n = 9), K88 (n = 8), eae (n = 8), STa (n = 7), sepA (n = 6), F18 (n = 5), afaD (n = 3), afaE (n = 3), K99 (n = 2) and Stx2e (n = 1), with most isolates carrying multiple virulence genes. These results demonstrate that relatively few isolates from the study population express K88, K99, LT-I or STa, but that EAST1 (58%), irp2 (29%), AIDA-I (16.5%), paa (24%) and STb (20%) are frequent virulence factors expressed by E. coli strains isolated from suckling pigs with diarrhoea in China.

WATERBORNE OUTBREAK OF ROTAVIRUS DIARRHOEA IN ADULTS IN CHINA CAUSED BY A NOVEL ROTAVIRUS

During two epidemics of acute diarrhoea in China in late 1982/early 1983, more than 12 000 adults in two coal mining districts were affected. The virus isolated from stool samples resembled a rotavirus morphologically. Antigenically it lacked the group antigen shared by known rotaviruses. Like other rotaviruses it had a double-stranded RNA with 11 discrete segments, but the pattern of migration of the segments on polyacrylamide electrophoresis differed from those of other rotaviruses.