Epidemiological survey of cryptosporidiosis in Anhui Province China.
OBJECTIVE
To provide scientific evidence for prevention and controlling of cryptosporidiosis, the infection of Cryptosporidium parvum and its epidemiological characteristics were studied in some areas of Anhui Province.


METHODS
The oocyst of Cryptosporidium parvum in 5421 fresh stool samples from eleven areas of Anhui Province was tested by auramine-phenol stain and improved anti-acid stain respectively. The specific antibody of IgG, IgM and T subsets of 41 patients with positive Cryptosporidium parvum in stools were detected by ELISA and biotin-streptavidin (BSA) respectively.


RESULTS
The total infective rate of Cryptosporidium parvum was 1.33% (74/5421). Among them, the positive rates of oocyst in the areas of Huaibei (1.82%) and Fuyang (1.80%) were higher. The positive rates of oocyst in stools of infants, pupils, middle school students, college students, adults, patients with diarrhea, and those with immunodeficiency were 3.15%(28/889), 0.82% (9/1098), 0.82%(9/1092), 0.83%(8/969), 0.85% (9/1095), 2.88%(8/278) and 8.33%(3/36)% respectively. The positive rates of oocyst in infants and the patients with diarrhea and immunodeficiency were significantly higher than those in controls (P<0.01). The positive rate of oocyst in males was similar to that in females (P>0.05). The positive rate of oocyst in urban areas (1.13%) was significantly lower than those in rural areas (1.72%, P<0.01). The positive rates of specific IgG, IgM and IgG+IgM in sera of the patients with positive oocyst in stool were 63.4% (26/41), 17.1% (7/41), 19.5% (8/41) respectively. The number fractions of T subsets of CD(3)(+), CD(4)(+), CD(8)(+) and CD(4)(+)/CD(8)(+) of the patients were 0.66+/-0.07, 0.44+/-0.06, 0.28+/-0.04 and 1.58+/-0.32 respectively. The difference between the patients and the controls was significant (P<0.05). The main manifestations of the patients were subclinical infection, in forms of slight abdominal pain, mild diarrhea, and loose stool.


CONCLUSIONS
There are two infection peaks in infection of Cryptosporidium parvum and its infection can be found more often in infants, patients with diarrhea or immunodeficiency, and in rural areas. Subclinical infection is the main manifestation and might be easily misdiagnosed. When the therapeutic effectiveness is low for diarrhea, the infection of Cryptosporidium parvum should be considered, concerning their age and immune function.
Wang
Ke-Xia
KX
Department of Aetiology and Immunology, School of Medicine, Huainan Institute of Technology, Huainan 232001, Anhui Province, China. yxfy@hnit.edu.cn
Li
Chao-Pin
CP
Wang
Jian
J
Pan
Bo-Rong
BR
D000293:Adolescent; D000328:Adult; D000818:Animals; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003457:Cryptosporidiosis / Q000453:epidemiology* / Q000469:parasitology / Q000517:prevention & control; D016785:Cryptosporidium parvum / Q000502:physiology*; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D016176:T-Lymphocyte Subsets / Q000378:metabolism