Cholera

Cholera is an acute infection of the small intestine by Vibrio cholerae, which produces a toxin that causes severe watery diarrhea, which in turn lead to dehydration, oliguria and circulatory collapse. An infection typically occurs through contaminated water or seafood. The diagnosis is made by the cultural detection of pathogens or serologically. The treatment consists of an intensive fluid and electrolyte replacement plus doxycycline.

The causative agent V. cholerae serogroups O1 and O139, is a short, curved, movable aerobic rods which forms enterotoxin, a protein which causes hypersecretion of an isotonic electrolyte-containing secretion through the small intestine mucosa. These organisms do not penetrate into the intestinal wall; thus no or few leukocytes found in the stool.

Cholera is an acute infection of the small intestine by Vibrio cholerae, which produces a toxin that causes severe watery diarrhea, which in turn lead to dehydration, oliguria and circulatory collapse. An infection typically occurs through contaminated water or seafood. The diagnosis is made by the cultural detection of pathogens or serologically. The treatment consists of an intensive fluid and electrolyte replacement plus doxycycline. The causative agent V. cholerae serogroups O1 and O139, is a short, curved, movable aerobic rods which forms enterotoxin, a protein which causes hypersecretion of an isotonic electrolyte-containing secretion through the small intestine mucosa. These organisms do not penetrate into the intestinal wall; thus no or few leukocytes found in the stool. Both the El Tor biotype and classic biovars of V. cholerae 01 can lead to serious illness. However, a mild or asymptomatic infection is the currently prevailing biotype El Tor and non-01, non-0139 serogroups of V. cholerae much more common. Cholera is spread by eating water, seafood or other foods that have been contaminated by the feces of people with symptomatic or asymptomatic infection. Household contacts of patients with cholera are at high risk of infection, which is likely to occur through shared sources of contaminated food and water. The transmission between people is less likely because a large inoculum of the organism is required to transmit the infection. Cholera occurs in parts of Asia, the Middle East, Africa, South and Central America and the Gulf Coast of the U.S.A. endemic. To Europe, Japan and Australia is imported cases have led there to local outbreaks. In endemic areas, it is usually during the warm months to outbreaks. The incidence is highest in children. In newly affected areas an epidemic can occur in any season, and people of all ages are equally susceptible. Non-cholera Vibrioarten can cause minor gastroenteritis. The susceptibility varies for infection and is higher in people with blood group 0th Since vibrio on stomach acid sensitive, a hypochlorhydria and achlorhydria may constitute predisposing factors. People living in endemic areas acquire slowly natural immunity. Symptoms and signs The incubation period in cholera is 1-3 days. Cholera can subclinical, accompanied by a light and uncomplicated diarrhea episode or constitute a fulminant, potentially fatal disease. The typical initial symptoms include a sudden onset of painless, watery diarrhea and vomiting. A significant nausea usually missing. The fluid loss may exceed in adults 1 l / h, but is usually much lower. Often the feces of a white liquid consist free of faeces (rice water-chair). The consequent severe water and electrolyte loss leads to intense thirst, oliguria, muscle cramps, weakness and pronounced loss of tissue tension, with sunken eyes and wrinkling of the skin on the hands. It comes to hypovolemia, hemoconcentration, oliguria to anuria and severe metabolic acidosis with loss of K + (but normal Na + concentration). If cholera is not treated, it can lead to a circulatory collapse with cyanosis and stupor. A longer hypovolemia can cause Nierentubulusnekrose. In most patients, V. cholerae can within 2 weeks after cessation of diarrhea no longer be detected, only a few patients are chronic carriers of the virus (bile duct). Diagnostic stool culture and serotyping. The diagnosis of cholera is cultural evidence from the chair (the use of selective media is recommended) provided plus subsequent serotyping. Tests for V. cholerae are in reference laboratories available; a PCR test is also an option. Rapid dipstick tests for cholera are available for use in the public health sector in regions that have only limited access to laboratory tests. Cholera should be distinguished from clinically similar diseases caused by enterotoxigenic Escherichia coli strains and occasionally by Salmonella and Shigella. caused. Serum electrolytes, urea nitrogen and creatinine values ??should be measured fluid replacement therapy doxycycline, azithromycin, furazolidone, trimethoprim / sulfamethoxazole (TMP / SMX), or ciprofloxacin, depending on the result of the sensitivity test The fluid loss must be compensated for fluid replacement. Mild disease cases can be treated with standard oral rehydration. The rapid equalization of severe hypovolemia can be lifesaving. Also important is the prevention or correction of metabolic acidosis and hypokalemia. In hypovolemic and severely dehydrated patient fluid loss with isotonic fluids should be administered intravenously balanced (for details on fluid replacement, intravenous fluid replacement and oral rehydration). The patient should be encouraged in addition to drinking water. To compensate for the loss of potassium, for intravenous infusion 10-15 mEq / l KCl be added, alternatively, KHCO3 with 1 ml / kg p.o. be given a 100 g / l solution orally 4 times a day. The potassium supplements is especially important in children who tolerate hypokalemia poorly. Once the intravascular vessel volume is restored (Rehydrationsphase), the amount of the supplied liquid should be aligned with the stool volume (maintenance phase). A correct volume status is confirmed by a common clinical examination (pulse rate and strength, skin turgor, urine output). Plasma, plasma volume expanders and vasopressors should not be used to replace water and electrolytes. An oral glucose electrolyte solution is also suitable for the substitution of a chair loss and can be used after the initial intravenous rehydration; it can represent in endemic areas with limited supplies of parenteral fluids the only available volume replacements. Patients who have mild or moderate dehydration, and can drink can also be substituted with the oral solution (about 75 ml / kg in 4 hr). Patients with a more pronounced dehydration need more liquid, and this possibly should receive a nasogastric tube. The recommended by the WHO oral rehydration solution (ORS) containing 13.5 g of glucose, 2.6 g NaCl, 2.9 g of trisodium citrate dihydrate (or 2.5 g NaHCO3) and 1.5 g KCl per liter of drinking water. This solution is best prepared widely using available, metered, sealed package from glucose and salt; a packet is mixed with 1 liter of clean water. The use of such metered ORS packets to minimize the possibility of errors when untrained people mix the solution. If ORS packets are not available, an appropriate substitute may be prepared by mixing a small spoon half salt and 6 small spoon of sugar in 1 L of clean water. This ORS should be ad libitum continued after rehydration with amounts that are at least matched the continuous loss through stool and vomiting. Solid food should be given only after the vomiting and if return of appetite werden.Antimikrobielle drugs Early treatment with an effective oral antibiotic eradicates vibrios stool volume reduced by 50% and stops diarrhea within 48 hours. Selection of the appropriate antibiotic should be directed cholerae in the results of susceptibility testing of isolated in the Community v. Among the drugs that are effective in susceptible strains, including doxycycline: po For adults, a single dose of 300 mg or 100 mg of 2 times / day on day 1, then 100 mg of 1-times / day at day 2 and 3; or a single dose of azithromycin 1 g p.o. (Recommended for pregnant women) or 20 mg / kg for children furazolidone (not available in the US): po For adults, 100 mg for 72 hours four times a day, for children, 1.5 mg / kg 4 times daily for 72 h TMP / SMX: For adults, a double-strong tablet 2 once daily, for children 5 mg / kg (the TMP component) twice daily for 72 h ciprofloxacin: for adults, a single dose of 1 g po or 250 mg p.o. to prevent 1 times / day for 3 days Prevention To further spread of cholera, human waste must be disposed of properly and a supply of clean drinking water be ensured. In endemic regions, should be boiled or chlorinated drinking water and vegetables and fish are thoroughly cooked. Two dead whole cell oral vaccines are currently available internationally for use in children and adults, but not in the United States: Dukoral®: This vaccine contains only monovalent V. cholera-01 and El Tor bacteria plus a small amount of non- toxic B-subunit of cholera toxin; it has a large amount of the buffer liquid (buffer packet cold water is dissolved in about 140 g) are taken at the time of administration of the vaccine. Shanchol®: This newer bivalent vaccine containing both 01- and 0139 strains of V. cholera and has no other components, so that the requirement of excess fluid ingestion at the time of vaccination is not necessary. Both vaccines provide 60 to 85% protection for up to five years. Both require two doses and booster doses are recommended after 2 years for people with persistent risk of cholera. injectable vaccines offer less protection for shorter periods with more side effects and are not recommended if an oral vaccine is available. Antibiotic prophylaxis for household contacts of patients with cholera is not recommended because data to support this measure are missing. The important points V. cholerae serogroups 01 and 0139 but an enterotoxin from that can cause serious, sometimes fatal diarrhea that often break out due to the exposedness against contaminated water or food in a big way. Other V. cholerae serogroups can cause lighter, non-epidemic diseases. The diagnosis is made by stool culture and serotyping; a quick test strip is helpful in identifying outbreaks in remote areas. Rehydration is very important; an oral rehydration solution is sufficient in most cases, but patients with severe hypovolemia need infusions. Infected adults is given doxycycline or azithromycin (TMP / SMX for children), while the results of susceptibility testing pending.

Health Life Media Team

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