The incubation period of cholera ranges from several hours to 5 days (usually 2-3 days). The severity of clinical manifestations distinguish between worn, mild, moderate, severe and very severe forms, determined by the degree of dehydration. V.I. Pokrovsky distinguishes the following degrees of dehydration: I degree, when patients lose a volume of fluid equal to 1-3% of body weight (worn and light forms), II degree – losses reach 4-6% (moderate form). III degree – 7-9% (severe) and IV degree of dehydration with a loss of more than 9% corresponds to a very severe course of cholera. Currently, I degree of dehydration occurs in 50-60% of patients, II in 20-25%, III in 8-10%, IV in 8-10%.
With erased forms of cholera, there can only be once a loose stool with good health of patients and the absence of dehydration. In more severe cases, the disease begins acutely, without fever and prodromal phenomena. The first clinical signs are a sudden urge to defecate and discharge of mushy or, from the very beginning, watery bowel movements. Subsequently, these imperative urges are repeated, they are not accompanied by pain. The bowel movements are easily distinguished, the intervals between bowel movements are reduced, and the volume of bowel movements increases each time. The stool looks like “rice water”: translucent, dull-white in color, sometimes with floating flakes of gray color, odorless or with the smell of fresh water. The patient notes rumbling and discomfort in the umbilical region. In patients with a mild form of cholera, defecation is repeated no more than 3-5 times a day, their general state of health remains satisfactory, and feelings of weakness, thirst, and dry mouth are insignificant. The duration of the disease is limited to 1-2 days.
With moderate severity (dehydration of the II degree), the disease progresses, vomiting is added to the diarrhea, increasing in frequency. Vomit has the same kind of “rice broth” as the bowel movement. It is characteristic that vomiting is not accompanied by any tension or nausea. With the addition of vomiting, dehydration – exicosis – progresses rapidly. Thirst becomes excruciating, tongue dry with a “chalky coating”, skin and mucous membranes of the eyes and oropharynx turn pale, skin turgor decreases, the amount of urine decreases up to anuria. Stool up to 10 times a day, plentiful, does not decrease in volume, but increases. Single cramps of the calf muscles, hands, feet, chewing muscles, unstable cyanosis of the lips and fingers, hoarseness occur. Mild tachycardia, hypotension, oliguria, hypokalemia develop. The disease in this form lasts 4-5 days.
Severe cholera (grade III dehydration) is characterized by pronounced signs of exicosis due to very abundant (up to 1-1.5 liters per defecation) stool, which becomes such from the first hours of the disease, and the same profuse and repeated vomiting. Patients are concerned about painful cramps in the muscles of the limbs and abdominal muscles, which, as the disease develops, pass from rare clonic to frequent and even give way to tonic convulsions. The voice is weak, thin, often a little audible. The skin turgor decreases, the creased skin does not straighten for a long time. The skin of the hands and feet becomes wrinkled – the “hand of the laundress”. The face takes on the characteristic appearance of cholera: sharpened facial features, sunken eyes, cyanosis of the lips, auricles, earlobes, nose. On palpation of the abdomen, transfusion of fluid through the intestines, increased rumbling, noise of splashing fluid are determined. Palpation is painless. Liver, spleen not enlarged. Tachypnea appears, tachycardia increases to 110-120 beats / min. Pulse of weak filling (“threadlike”), heart sounds are deaf, blood pressure progressively drops below 90 mm Hg. Art. first maximum, then minimum and pulse. The body temperature is normal, urination decreases and soon stops. Blood thickening is moderate. Relative plasma density, hematocrit index and blood viscosity at the upper limit of normal or moderately increased. Hypokalemia of plasma and red blood cells, hypochloremia, moderate compensatory hypernatremia of plasma and red blood cells are expressed.
A very severe form of cholera (previously called algid) is characterized by rapid sudden development of the disease, starting with massive continuous bowel movements and profuse vomiting. After 3-12 hours, the patient develops a severe condition of algide, which is characterized by a decrease in body temperature to 34-35.5 ° C, extreme dehydration (patients lose up to 12% of body weight – IV degree dehydration), shortness of breath, anuria and hemodynamic disorders of the type hypovolemic shock. By the time patients are admitted to the hospital, they develop paresis of the muscles of the stomach and intestines, as a result of which the patients stop vomiting (gives way to convulsive hiccups) and diarrhea (gaping anus, free flow of “intestinal water” from the anus with slight pressure on the anterior abdominal wall). Diarrhea and vomiting occur again on the background or after the rehydration. Patients are in a state of prostration, drowsiness becomes stupor, then in a coma. A disorder of consciousness coincides in time with respiratory failure – from frequent superficial to pathological types of breathing (Chain-Stokes, Biota). The skin coloration in such patients acquires an ashen shade (total cyanosis), “dark glasses around the eyes” appear, sunken eyes, sclera are dull, eyes are unblinking, voice is absent. The skin is cold and clammy to the touch, the body is cramped (the pose of a “fighter” or “gladiator” as a result of general tonic convulsions). The abdomen is retracted, with palpation, a convulsive contraction of the rectus abdominis is determined. Cramps painfully aggravate even with mild abdominal palpation, which causes anxiety to patients. There is a pronounced hemoconcentration – leukocytosis (up to 20-109 / l), the relative density of blood plasma reaches 1.035-1.050, the hematocrit index is 0.65-0.7 l / l. The level of potassium, sodium and chlorine is significantly reduced (hypokalemia to 2.5 mmol / l), decompensated metabolic acidosis. Severe forms are more often observed at the beginning and in the midst of an epidemic. At the end of the outbreak and in the inter-epidemic time, light and erased forms prevail, indistinguishable from diarrhea of another etiology.
In children under the age of 3 years, cholera is most severe. Children are less likely to tolerate dehydration. In addition, they have a secondary lesion of the central nervous system: adynamia, clonic convulsions, convulsions, impaired consciousness up to the development of coma are observed. In children, it is difficult to determine the initial degree of dehydration. They cannot be guided by the relative plasma density due to the relative large extracellular fluid volume. It is therefore advisable, at the time of admission, to weigh the children for the most reliable determination of their degree of dehydration. The clinical picture of cholera in children has some features: a frequent increase in body temperature, more pronounced apathy, adynamia, a tendency to epileptiform seizures due to the rapid development of hypokalemia. The duration of the disease ranges from 3 to 10 days, its subsequent manifestations depend on the adequacy of substitution treatment with electrolytes. With emergency compensation for fluid and electrolyte losses, normalization of physiological functions occurs rather quickly and deaths are rare. The main causes of death with inadequate treatment of patients are hypovolemic shock, metabolic acidosis and uremia as a result of acute tubular necrosis.
When patients are in high temperature zones, contributing to a significant loss of fluid and electrolytes with sweat, as well as in conditions of reduced water consumption due to damage or poisoning of water sources, as with other similar causes of human dehydration, cholera proceeds most severely due to the development of a mixed mechanism dehydration resulting from a combination of extracellular (isotonic) dehydration, characteristic of cholera, with intracellular (hypertonic) dehydration. In these cases, the frequency of stool does not always correspond to the severity of the disease. Clinical signs of dehydration develop with a few bowel movements, and often in a short time a significant degree of dehydration develops, threatening the patient’s life.
Massive fecal contamination of water sources, the use of a significant amount of infected water by people who are in a state of neuropsychic shock (stress) or heat overheating, starvation and other factors that reduce the body’s resistance to intestinal infections, contribute to the development of mixed infections: cholera in combination with shigellosis , amoebiasis, viral hepatitis, typhoid paratyphoid and other diseases. Cholera has a more severe course in patients with various concomitant bacterial infections accompanied by toxemia. Due to blood clotting and decreased urination, the concentration of bacterial toxins becomes higher, which leads to pronounced clinical symptoms of the combined infectious process. So, with the combination of cholera with shigellosis, the clinical signs of enterocolitis and intoxication come to the fore – cramping abdominal pain and fever to febrile or subfebrile digits. Defecation is usually accompanied by tenesmus, in the stool is an admixture of mucus and blood (“rusty stool”). The syndrome of acute distal colitis is expressed, spasm, compaction and soreness of the sigmoid colon are noted. With sigmoidoscopy in these cases, catarrhal hemorrhagic manifestations characteristic of dysentery are revealed. However, after a few hours, the volume of bowel movements is rapidly increasing, which take the form of “meat slops.” In most cases, a concomitant shigellosis infection aggravates the course of cholera, but in some patients, both infections can proceed favorably. When cholera and amoebiasis are combined, the diagnosis of intestinal amoebiasis is verified by finding tissue forms of dysenteric amoeba in the feces.
The main clinical feature of the course of the disease in these cases is the duration of diarrhea, which in the absence of antiparasitic therapy is usually up to 2-3 weeks. Weighting of cholera is noted in those cases when it occurs in patients with a chronic intestinal form of amoebiasis with a relapsing course. In these patients, already on admission, signs of amoebic colitis are detected in the form of bloating, pain in the right ileal region, pain on palpation of the thickened cecum, flakes of vitreous mucus and blood impurities in the feces.
A severe course of the disease is also observed with cholera, which arose in a patient with typhoid parathyroid disease. The appearance of intense diarrhea on the 10-18th day of the disease is dangerous for the patient due to the threat of intestinal bleeding and perforation of ulcers in the ileum and cecum with the subsequent development of purulent peritonitis.
The occurrence of cholera in eggs with various types of malnutrition and a negative fluid balance leads to the development of a disease, the features of which are lower stool frequency and moderate volumes, as well as a moderate amount of vomit, an acceleration of the process of hypovolemia (shock!), Compared to the usual course of monoinfection azotemia (anuria!), hypokalemia, hypochlorhydria, other severe electrolyte imbalance, acidosis.
In case of blood loss due to various surgical injuries, cholera patients experience accelerated blood thickening (blood loss!), Decreased central blood flow, impaired capillary circulation, the occurrence of renal failure and subsequent azotemia, as well as acidosis. Clinically, these processes are characterized by a progressive drop in blood pressure, cessation of urination, severe pallor of the skin and mucous membranes, high thirst and all symptoms of dehydration, and subsequently – a disorder of consciousness and a pathological type