Diseases cholera

A failure to turn off GTP-activated Ga has dire consequences. For example, in the disease cholera, cholera toxin produced by the bacterium Vibrio cholerae binds to Ga and prevents GTP hydrolysis, resulting in the continued excretion of sodium and water into the gut. 

The IHR (1969) addressed only four diseases cholera, plague, yellow fever and... 

V. cholerae is a gram-negative baciUus sharing similar characteristics with the family Enterobacteriaceae. Most pathology of cholera results from an enterotoxin (cholera toxin) produced by the bacteria. Conditions that reduce gastric acidity, such as the use of antacids, histamine-receptor blockers, or proton pump inhibitors or infections with Helicobacter pylori, increase the risk for clinical disease. Cholera toxin stimulates adenylate cyclase, which increases intracellular cAMP and results in inhibition of sodium and chloride absorption by microvillli and promotes the secretion of chloride and water by crypt cells. The toxin likely acts along the entire intestinal tract, but most fluid loss occurs in the duodenum. The net effect of the cholera toxin is isotonic fluid secretion (primarily in the small intestine) that exceeds the absorptive capacity of the intestinal tract (primarily the colon). This results in the production of watery diarrhea with electrolyte concentrations similar to that of plasma. 

However, the WHO Innovative and Intensified Disease Management (IDM) group considers only the following as neglected tropical diseases (NTDs) Buruli ulcer, Chaga s disease, cholera, human African tryapanosomiasis and leshmaniasis. They... 

Furthermore, in some cases the need for three-dimensional protein stractures becomes urgent, as with the bacterial proteins (cholera toxin) that are known to produce the disease cholera. These investigations have been ongoing since 1977 using protein crystals and x-ray diffraction methods. This knowledge is essential to produce new kinds of vaccines. 

Up to the advent of the twentieth century, the fight against microbes was devoted to disinfecting external wounds and to sanitizing drinking water. Since Pasteur s works, the objective was to treat infectious diseases cholera, tuberculosis, diphtheria, etc. Some vaccines were already available, but only for smallpox and rabies. 

After an incubation period of 12 to 72 hours, the disease suddenly presents with abdominal cramping and then painless, profuse rice water diarrhea (5—10 liters per day). Some patients may also have vomiting, weakness, and headache. Fever, if present, is low-grade. The response to infection varies greatly. Many patients have few or no symptoms (400 1 ratio of asymptomatic to symptomatic) others lose massive amounts of fluids and develop hypovolemic shock. As with other diseases, cholera is worse in the very young and very old. Deaths are from fluid loss and electrolyte abnormalities. 

Diarrhea is a common problem that is usually self-limiting and of short duration. Increased accumulations of small intestinal and colonic contents are known to be responsible for producing diarrhea. The former may be caused by increased intestinal secretion which may be enterotoxin-induced, eg, cholera and E. col] or hormone and dmg-induced, eg, caffeine, prostaglandins, and laxatives decreased intestinal absorption because of decreased mucosal surface area, mucosal disease, eg, tropical spme, or osmotic deficiency, eg, disaccharidase or lactase deficiency and rapid transit of contents. An increased accumulation of colonic content may be linked to increased colonic secretion owing to hydroxy fatty acid or bile acids, and exudation, eg, inflammatory bowel disease or amebiasis decreased colonic absorption caused by decreased surface area, mucosal disease, and osmotic factors and rapid transit, eg, irritable bowel syndrome. 

Antibiotic LL-E19020a and LL-E19020P are described as useful agents for the treatment of chronic respiratory disease, fowl cholera, and necrotic enteritis in birds (76) and as anthelmintics in monogastric and mminant animals (28). 

Bacteria are smaller than protozoa and are responsible for many diseases, such as typhoid fever, cholera, diarrhea, and dysentery. Pathogenic bacteria range in size from 0.2 to 0.6 /tm, and a 0.2 /tm filter is necessary to prevent transmission. Contamination of water supplies by bacteria is blamed for the cholera epidemics, which devastate undeveloped countries from time to time. Even in the U.S., E. coli is frequently found to contaminated water supplies. Fortunately, E. coli is relatively harmless as pathogens go, and the problem isn t so much with E. coli found, but the fear that other bacteria may have contaminated the water as well. Never the less, dehydration from diarrhea caused by E. coli has resulted in fatalities. 

Pathogenic organisms Bacteria, viruses or cysts which cause disease (typhoid, cholera, dysentery) in a host (such as a person). There are many types of bacteria (non-pathogenic) which do NOT cause disease. Many beneficial bacteria are found in wastewater treatment processes actively cleaning up organic wastes. 

There are some descriptions of water-borne outbreaks, or even small epidemics of acute gastroenteritis (diarrhoea), cholera and hepatitis E associated with catastrophic floods that occurred in developing countries, such as Sudan [34, 35], Nicaragua [36], Mozambique [37] and West Bengal [37]. On the contrary, no changes in the base-line outbreak incidence have been reported in developed countries after major floods [37, 38]. When infrastructures and water management are adequate, outbreaks of faecal-oral water-borne infectious diseases do not follow flood events, even in the case where water flooding has compromised the security of water facilities [37]. 

Glass WG, Lane TE (2003b) Functional expression of chemokine receptor CCR5 on CD4(-l-) T cells during virus-induced central nervous system disease. J Virol 77 191-198 Glass WG, Lim JK, Cholera R, Pletnev AG, Gao JL, Murphy PM (2005) Chemokine receptor CCR5 promotes leukocyte trafficking to the brain and survival in West Nile virus infection. J Exp Med 202 1087-1098... 

Bordetellapertussis, Corynehacterium diphtheriae, Vibrio cholerae). This is, to a large extent, a reflection of their inability to combat that host s deeper defences. Survival at these sites is largely due to firm attachment to the epithelial cells. Such organisms manifest disease through the production and release of toxins (see below). 

Cholera is a serious infection causing epidemics throughout Asia. Although a toxin-mediated disease, largely controlled with replacement of fluid and electrolyte losses, tetracycline has proved effective in eliminating the causative vibrio from the bowel, thereby abbreviating the course of the illness and reducing the total fluid and electrolyte losses. 

Propagated outbreaks of infection relate to the direct transmission of an infective agent from a diseased individual to a healthy, susceptible one. Mechanisms of such transmission were described in Chapter 4 and include inhalation of infective aerosols (measles, mumps, diphtheria), direct physical contact (syphilis, herpes virus) and, where sanitation standards are poor, through the introduction of infected faecal material into drinking water (cholera, typhoid). The ease oftransmission, and hence the rate of onset of an epidemic (Fig. 16.3) relates not only to the susceptibility status, and general state of health of the individuals but also to the virulence properties of the organism, the route oftransmission, the duration of the infective period associated with the disease. 

Cholera toxin and related toxins act as immune modulators, with potential use as adjuvants and as therapeutic agents in the treatment of immunologically mediated human disease. 

Cholera, the first reportable disease, is endemic in South Asia, particularly in the Ganges delta region.2 The biotypes of Vibrio cholerae responsible for pandemics are serogroup 01 (El Tor) and serogroup 0139.16,17 Cholera can be transmitted by water or by food contaminated with contaminated water, particularly undercooked seafood. V. cholerae grows well in warm temperatures, causing marked seasonality in the incidence of cholera.2... 

The cornerstone of cholera treatment is fluid replacement. Without treatment, the case-fatality rate for severe cholera is approximately 50%. For cholera, rice-based ORT is better than glucose-based ORT because it reduces the number of stools.21 Patients with significant disease should receive a short antibiotic course, 1 to 3 days, to shorten the duration of illness and decrease the number of stools. Doxycycline 300 mg once daily is the drug of choice. Other antibiotics shown to be effective include erythromycin, azithromycin, trimethoprim-sulfamethoxazole, and ciprofloxacin.2 Antibiotic resistance has been documented in V cholerae since 1977.2 Antibiotic prophylaxis is not warranted. 

New Orleans was also filthy, no different in this respect from Paris. Garbage and waste clogged the streets of both cities, and disease was epidemic. During Rillieux s last year in Paris, cholera killed 18,402 people, most of them desperately poor. The year Rillieux arrived home, yellow fever struck New Orleans 8000 people, one-sixth of the town s population, died. 

The cholera epidemic that reached Europe and North America in the early 1830s killed more than 20,000 people in England. It was during this epidemic that Queen Victoria s personal physician, Dr. John Snow, removed the handle from the polluted Broad Street pump in London in the first recorded, appropriate measure to prevent waterborne disease. 

Cholera is predominantly a disease of the poor. An official investigation of the 1832 cholera epidemic in Paris showed that up to 53 out of every 1000 inhabitants in the poorest neighborhoods died, compared to only 8 per 1000 in wealthy areas. The rich could flee, secure a supply of safe water, or, like the slave owners in New Orleans, drink claret even at breakfast. The poor drank from waterways that were their cesspools. 

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