Histopathological changes in experimental cholera with a non toxigenic non- O1 non-O139 Vibrio cholerae strain isolated from Kolkata, India.

This study was conducted to understand the pathophysiological changes in experimental rabbit ileal loop model using the Vibrio cholerae strain non-O1non-O139, isolated as sole pathogen from clinically diagnosed cholera patients in Kolkata. Significant amount of haemorrhagic fluid accumulation was observed in all the test loops of rabbit model where the strain of V.cholerae was inoculated as compared to control loops. Microscopic examination of the accumulated fluid showed the presence of erythrocytes and pus cells. Histology revealed structural alteration of the villous epithelium with inflammatory cells infiltration in all the layers of the gut mucosa including the nerve plexus region. Preliminary observation with a haemagglutinin protease extracted from the non-O1 non-O139 strain, was also studied in different concentrations in the same animal model which showed similar type of macroscopic and microscopic response in the ileal loops as seen with the original strain. The results highlight that along with other pathways, inflammatory cells and the enteric neurons have an important role in the pathophysiology of diarrhoea and the isolated protease may be the probable virulence factor in initiating the disease process in this non-O1non-O139 strain induced cholera.

Detection of faecal leucocytes & erythrocytes from stools of cholera patients suggesting an evidence of an inflammatory response in cholera.

BACKGROUND & OBJECTIVES: Detection of faecal leucocytes and RBCs in stool samples of cholera patients has been reported in a small number of studies. This study extends these observations by examining stool samples of cholera patients in Calcutta. METHODS: Out of 1562 diarrhoeal stool samples, Vibrio cholerae was isolated in 266 cases. Stool samples obtained were examined microscopically within two hours of collection. RBCs and faecal leucocytes were examined by normal saline and methylene blue stain. Stool culture was performed using selective and differential media for isolation of V. cholerae. RESULTS: Among 266 cholera patients, RBCs was detected in 58 per cent and faecal leucocytes in 88 per cent respectively. The extent of the changes correlated with clinical severity. INTERPRETATION & CONCLUSION: This study showed the presence of RBCs and faecal leucocytes in stools of patients of cholera caused by V. cholerae 01 and 0139 which indicates some inflammatory changes in the gut mucosa. Further study is required to elucidate the inflammatory mechanism involved in the underlying process(es).

Value of faecal leucocyte count as an indicator of invasiveness in mucoid diarrhoea.

Importance of faecal leucocyte count as an indicator of invasiveness in mucoid diarrhoea was studied. A total of 290 faecal specimen, 170 from mucoid diarrhoea and 120 from watery diarrhoea were examined for faecal leucocyte count under high power field (hpf) from rural children below four years of age during the period from November 1992 to October 1995. Faecal leucocyte count > 10/hpf was noted in 45.9% of mucoid diarrhoea as against 19.2% of watery diarrhoea (p < 0.0001) samples. From faecal samples with > 10 faecal leucocyte count, invasive pathogens could be recovered in 19 (24.5%) to none of 23 patients with watery diarrhoea (p < 0.006 Fisher exact test). This sample test appears to be of value as an indicator of invasiveness in mucoid diarrhoea in the absence of culture facility.

Intestinal parasitism: a childhood problem in rural Bengal.

A study was undertaken to assess the parasitic infection rate in a rural community of West Bengal amongst children below four years of age suffering from gastrointestinal complaints. A total of 221 faecal samples were examined during November 1992 to April 1994. G. lamblia (17.2%) and E. histolytica (8.1%) were the predominant protozoas, whereas E. vermicularis (12.2%) and A. lumbricoides (8.1%) were found to be common amongst helminthic infection. A significantly lower infection rate was observed in children below one year (24.4 per cent) as compared to older age groups (66.4 per cent).