Practical Guidelines for the Treatment of Cholera (original) (raw)
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Transactions of the Royal Society of Tropical Medicine and Hygiene, 1996
We prospectively compared the clinical features of cholera due to Vibrio cholerae 01 and I7 cholerae 0139 in 242 men 18-60 years of age, with a history of diarrhoea of 24 h or less, and moderate or severe dehydration. The antimicrobial susceptibility of all of the K cholerae strains isolated from these patients was determined, and in vitro cholera toxin production determined for 68 isolates. On admission, the 110 patients infected with V. cholerae 01 significantly more often had body temperature <36'C (85% vs. 66%, P sO.OS), faecal leucocyte count >50/high power microscope field (40% vs. 12%), and lower mean faecal chloride content (94 vs. 103 mmol/L) than did the 132 patients infected with V. cholerae 0139. Patients infected with V. cholerae 01 also initially had significantly higher median volumes of stool (13 vs. 11 mL per kg body weight per h), vomitus (1 ml/kg/h vs. nil), and intravenous fluid requirements (23 vs. 21 ml/kg/h). All V. cholerae 01 and 0139 isolates were susceptible to ciprofloxacin, all but one were susceptible to doxycycline and erythromycin, and the majority of both serogroups were resistant to co-trimoxazole (95% and 97%, respectively). V. cholerae 01 and 0139 susceptibilities differed for tetracycline (58% vs. 100%) and furazolidone (27% vs. 93%) (P ~0.001 in both cases). The amount of cholera toxin produced in vitro by strains of K cholerae 01 and 0139 was similar, and did not correlate with stool volume. The results demonstrated that V. cholerae 0139 does not cause more severe, or more invasive, disease than V. cholerae 01, as had been previously suggested, but that clinically important differences in antimicrobial susceptibility do exist among strains isolated in Bangladesh.
Cholera toxin - a foe & a friend
The Indian journal of medical research, 2011
After De΄s pivotal demonstration in 1959 of a diarrhoeogenic exo-enterotoxin in cell-free culture filtrates from Vibrio cholerae (of classical biotype), much insight has been gained about cholera toxin (CT), which is arguably now the best known of all microbial toxins. The subunit structure and function of CT, its receptor (the GM1 ganglioside), and its effects on the cyclic AMP system and on intestinal secretion were defined in the 1970s, and the essential aspects of the genetic organization in the 1980s. Recent findings have generated additional perspectives. The 3D-crystal structure of CT has been established, the CT-encoding operon has been shown to be carried by a non-lytic bacteriophage, and in depth knowledge has been gained on how the bacterium controls CT gene expression in response to cell density and various environmental signals. The mode of entry into target cells and the intracellular transport of CT are becoming clearer. CT has become the prototype enterotoxin and a w...
Current views and challenges on clinical cholera
Bioinformation
Cholera, an acute diarrheal infection has become a major global threat. Vibrio cholerae the causative agent of cholera has been responsible for six previous pandemics since 1817 that spanned four continents and Australia with the seventh pandemic ongoing since 1961. Two serogroups of V. cholerae O1 and O139 have the ability to secrete the enterotoxin with potential to cause epidemics. The prior six pandemics were caused by the classical biotype of the O1 serogroup. However, the emergence of the El Tor biotype and subsequent variants of El Tor with classical traits are the main isolates in the seventh pandemic. Cholera outbreaks have increased among vulnerable communities affected by war, earthquakes, conflicts and famines. Annually, 2.9 million cases of cholera occur globally in 69 endemic countries with 95,000 deaths. Early detection followed by prompt fluid and electrolyte replacement can reduce the case fatality ratio significantly. Improvements in water systems, sanitation and hygiene have effectively eliminated the transmission of cholera in high-income countries and reduced transmission in some developing nations. However, an estimated 1.8 billion are still at risk for cholera due to lack of potable water, inadequate sanitation and hygiene. Interventions focusing on hygiene in conjunction with proper disposal and treatment of sewage and provision of safe drinking water are likely to be effective in preventing the recurrence of cholera. Lastly, the use of current oral vaccines in endemic settings in combination with WASH interventions may be an effective approach to prevent and reduce the spread of cholera infection.
Cholera: Overview of epidemiologic, therapeutic, and preventive issues learned from recent epidemics
International Journal of Infectious Diseases, 1996
Cholera still represents a major public health problem in developing countries, and it is associated with significant morbidity and mortality in spite of the fact that more is known about its epidemiology, pathophysiology, and treatment than is known concerning any other diarrhea1 illness. During the past 5 years cholera has gained the attention of the scientific community because of three events: the extension of the seventh pandemic of El Tor V&io cholerae 01 to South and Central America in 1991; the appearance of a novel non-01 V: cholerae, referred to as \/: cholerae 0139 or "Bengal" strain in October 1992 in India and Bangladesh; and the explosive epidemic of multiple-resistant K cholerae 01 El Tor among Rwandan refugees in Zaire in 1994, with the highest mortality ever reported. This report presents data on recent epidemics of cholera, focusing on epidemiologic, clinical, therapeutic, and preventive issues. Lessons learned from these epidemics should help researchers to prevent or control future epidemics, More effective vaccines than are currently available, with broad coverage against new agents, clearly are needed.
Pathogenesis of Experimental Cholera: Preparation and Isolation of Choleragen and Choleragenoid
Journal of Experimental Medicine, 1969
Choleragen, a diarrheagenic protein enterotoxin elaborated by Vibrio cholerae, has been isolated from the supernate of fermenter cultures by steps involving ammonium sulfate precipitation, DEAE cellulose, Sephadex G-75, and Agarose A-5m chromatography. The resulting product appears to be pure according to immunoelectrophoretic, disc electrophoretic, ultracentrifugal, and immunologic criteria. Sephadex gel filtration and membrane filtration studies suggest a molecular size of 61,000. The isolated product is highly active in inducing experimental cholera in infant and adult rabbit models. It also elicits, in small dosage, an increased vascular permeability in skin. These observations indicate that choleragenicity and increased vascular permeability are intimately associated phenomena and may be manifestations of the same basic mechanism. An additional, antigenically identical, protein has also been isolated by the same procedures. The latter substance, termed "choleragenoid"...
Production of the new cholera toxin by environmental isolates of Vibrio cholerae non-O1
Journal of Medical Microbiology, 1996
One of five strains of Vibriu chulerae non-01 isolated from environmental sources caused fluid accumulation in an initial rabbit ileal loop (RIL) test. The four strains that caused little or no accumulation of fluid gave a positive response after one-to-three consecutive passages through RILs. The amount of fluid produced increased after each passage. Filtrates of cultures of all five environmental isolates caused fluid accumulation similar to that produced by live cells. The enterotoxin showed a precipitin band with new cholera antitoxin and was neutralised completely by new cholera antitoxin diluted 1 in 32, indicating its close immunobiological relationship to the new cholera toxin. The present study indicates that K cholerae non-01 strains produce an enterotoxin that is similar to the new cholera toxin.
Toxin(s), other than cholera toxin, produced by environmental non O1 non O139 Vibrio cholerae
Cellular & molecular immunology, 2006
A total of 39 Vibrio cholerae non O1 non O139 strains were isolated from surface waters of different parts of Dhaka City, Bangladesh. All these strains showed lack of ctx or zot gene, as demonstrated by the PCR analysis. Eighteen representative strains were tested for enterotoxin production using a rabbit ileal loop model, of which live cells of 8 strains and culture filtrates of 6 strains produced fluid accumulation in ileal loops. However, none of them produced heat stable toxin (ST), as detected by suckling mouse assay. On the other hand, 15% of isolates produced cytotoxin as detected by the Chinese Hamster Ovary (CHO) cell assay. Fifty times concentrated culture filtrates of the representative strains did not give any precipitin band against the anti-cholera toxin, suggesting the strains produced an enterotoxin, which is antigenically different from known cholera toxin (CT). Eighty percent of the total isolates were found to be positive for heat labile haemolysin detected by tub...
Vibrio cholerae enterotoxin and its mode of action
Bacteriological Reviews, 1971
These have been referred to as choleragen (34), skin permeability factor (73), vascular permeability factor (18), type-2 cholera toxin (16), cholera enterotoxin, and cholera exotoxin. Although different techniques have been employed to prepare and isolate these agents, the weight of present evidence strongly suggests that they contain the same diarrheagenic enterotoxin and that this enterotoxin is responsible for the production of the clinical cholera syndrome. In this review we have elected to employ the term cholera enterotoxin to describe this agent because its most important clinical effect is on the gut. CHARACTERLSTICS OF V. CHOLERAE ENTEROTOXIN Recently described preparations of cholera enterotoxin (16, 17, 34, 74), whether crude or highly purified, share a number of common characteristics, an observation which strongly suggests that they contain the same enterotoxic agent. In each, the diarrheagenic activity is heat Vol. 35, No. 1
Clinical Infectious Diseases, 2008
Background. From 2003 through 2007, Vibrio cholerae serogroup O75 strains possessing the cholera toxin gene were isolated from 6 patients with severe diarrhea, including 3 in Georgia, 2 in Alabama, and 1 in South Carolina. These reports represent the first identification of V. cholerae O75 as a cause of illness in the United States. V. cholerae O75 was isolated from a water sample collected from a pond in Louisiana in 2004. Subsequently, 3 V. cholerae isolates from Louisiana (2 from patients with diarrhea in 2000 and 1 from a water sample collected in 1978) that had been previously reported as serogroup O141 were also discovered to be serogroup O75. Results. All 8 patients who were infected with V. cholerae O75 were adults who became ill after consuming seafood; 2 had eaten raw oysters traced back to the Gulf Coast of the United States. All 10 isolates possessed the cholera toxin gene and were susceptible to 10 antimicrobials. One clinical isolate and 1 environmental (water) isolate had the same pulsed-field gel electrophoresis pattern; 4 clinical isolates shared a common pulsed-field gel electrophoresis pattern. Conclusions. The occurrence of these cases over many years and the concurrent identification of V. cholerae O75 in water from a Gulf Coast state suggest that these strains may survive for long periods in this environment. The patients' exposure histories suggest that infection can be acquired from consumption of raw oysters from the Gulf Coast. Clinicians and public health authorities should be vigilant for the occurrence of new toxigenic serogroups of V. cholerae that are capable of causing severe diarrhea.