Cholera - Symptoms

Cholera has an incubation period that lasts from several hours to 5 days, usually 2-3 days, after which typical symptoms of cholera appear.

The symptoms of cholera provide grounds for dividing cholera into the following forms: latent, mild, moderate, severe and very severe, determined by the degree of dehydration.

V.I. Pokrovsky identifies the following degrees of dehydration:

• Stage I, when patients lose fluid volume equal to 1-3% of body weight (abrasive and mild forms);
• II degree - losses reach 4-6% (moderate severity);
• III degree - 7-9% (severe);
• Dehydration degree IV with a loss of over 9% corresponds to a very severe course of cholera.

Currently, grade I dehydration occurs in 50-60% of patients, grade II in 20-25%, grade III in 8-10%, and grade IV in 8-10%.

Assessing the severity of dehydration in adults and children

	Erased and light	Moderate severity	Heavy	Very heavy
	1-3	4-6	7-9	10 and more
Chair	Before (0 times)	Up to 20 times	More than 20 times	Without counting
Vomit	Up to 5 times	Up to 10 times	Up to 20 times	Multiple (untamed)
Thirst	Weak	Moderately expressed	Sharply expressed	Insatiable (or unable to drink)
Diuresis	Norm	Reduced	Oliguria	Anuria

It is believed that the symptoms of cholera do not fundamentally depend on the type of pathogen (its serotype and biovar); however, as observations show, the El-Tor V cholerae biovar often causes milder forms of the disease.

Features of the clinical course of cholera depending on the biovar of the pathogen

Clinical forms	V. cholerae
	Classical (Asian)	El Tor
Heavy	11%	2%
Medium-heavy	15%	5%
Lungs	15%	18%
Inapparent	59%	75%

With cholera, various clinical forms of disease development are observed - from asymptomatic carriage of vibrios and subclinical forms to extremely severe and even fulminant forms with rapidly developing dehydration and possible death of patients within 4-6 hours from the onset of the disease.

In some cases (10-15%), the acute onset of the disease is preceded by prodromal symptoms of cholera, which last from several hours to a day. During this period, patients note the appearance of weakness, malaise, dizziness, headache, vegetative disorders in the form of sweating, palpitations, cold extremities.

In typical cases, cholera begins acutely, without fever or prodromal symptoms. The first symptoms of cholera are a sudden urge to defecate and the passage of mushy or initially watery stools. Subsequently, these imperative urges are repeated. The stools lose their fecal character and often look like rice broth: translucent, cloudy-white in color, sometimes with floating gray flakes, odorless or with the odor 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, the general state of health remains satisfactory, the sensations of weakness, thirst, dry mouth are insignificant. The duration of the disease is limited to 1-2 days.

In moderate cases (dehydration of the second degree), the disease progresses, vomiting joins the diarrhea, increasing in frequency. Vomiting has the same appearance of rice broth as feces. It is characteristic that vomiting is not accompanied by any tension or nausea. With the addition of vomiting, exsicosis progresses rapidly. Thirst becomes excruciating, the tongue is dry, with a "chalky coating", the skin, mucous membranes of the eyes and oropharynx turn pale, skin turgor decreases. Stool up to 10 times a day, abundant, in volume does not decrease, but increases. Single cramps of the calf muscles, hands, feet, chewing muscles, unstable cyanosis of the lips and fingers, hoarseness of the voice occur. Moderate tachycardia, hypotension, oliguria, hypokalemia develop.

Cholera in this form lasts 4-5 days. Severe form of cholera (degree III dehydration) is characterized by pronounced signs of exsicosis due to abundant (up to 1-1.5 liters per bowel movement) stool, which becomes so already in the first hours of the disease, and the same abundant and repeated vomiting. Patients are bothered by painful cramps of the muscles of the limbs and abdomen, which as the disease progresses go from rare clonic to frequent and even give way to tonic cramps. The voice is weak, thin, often barely audible. Skin turgor decreases, the skin gathered in a fold does not straighten out for a long time. The skin of the hands and feet becomes wrinkled ("washerwoman's hand"). The face takes on the appearance characteristic of cholera: sharpened features, sunken eyes, cyanosis of the lips, auricles, earlobes, nose.

Abdominal palpation reveals fluid flowing through the intestines and the sound of fluid splashing. Palpation is painless. Tachypnea appears, tachycardia increases to 110-120 per minute. The pulse is weak ("thread-like"), the heart tones are muffled. Arterial pressure progressively falls below 90 mm Hg, first the maximum, then the minimum and pulse. Body temperature is normal, urination decreases and soon stops. Blood thickening is moderate. The indices of relative plasma density, hematocrit index and blood viscosity are at the upper limit of normal or moderately increased. Plasma and erythrocyte hypokalemia, hypochloremia, moderate compensatory hypernatremia of plasma and erythrocytes are expressed.

A very severe form of cholera (previously called algid) is characterized by a violent sudden development of the disease, beginning with massive continuous bowel movements and profuse vomiting. After 3-12 hours, the patient develops a severe algid condition, which is characterized by a decrease in body temperature to 34-35.5 °C, extreme dehydration (patients lose up to 12% of their body weight - grade IV dehydration), shortness of breath, anuria and hemodynamic disturbances such as hypovolemic shock. By the time patients are admitted to hospital, they develop paresis of the stomach and intestinal muscles, as a result of which the patients stop vomiting (replaced by convulsive hiccups) and diarrhea (gaping anus, free flow of "intestinal water" from the anus with light pressure on the anterior abdominal wall). Diarrhea and vomiting recur during or after the end of rehydration. Patients are in a state of prostration. Breathing is frequent, shallow, in some cases Kussmaul breathing is observed. The skin color of such patients takes on an ashen shade (total cyanosis). "Dark glasses around the eyes" appear, the eyes are sunken, the sclera is dull. The gaze is unblinking, the voice is absent. The skin is cold and sticky to the touch, easily gathers into a fold and does not straighten out for a long time (sometimes for an hour) ("cholera fold").

Severe forms of cholera are more often observed at the beginning and at the height of the epidemic. At the end of the outbreak and in the interepidemic period, mild and latent forms prevail, which are indistinguishable from forms of diarrhea of other etiologies. In children under 3 years of age, cholera symptoms are most severe: they tolerate dehydration worse. In addition, children develop secondary damage to the central nervous system: adynamia, clonic seizures, impaired consciousness, and even coma are observed. It is difficult to determine the initial degree of dehydration in children. In such cases, it is impossible to rely on the relative density of plasma due to the large extracellular volume of fluid. Therefore, it is advisable to weigh patients at the time of admission in order to most reliably determine the degree of dehydration. The clinical picture of cholera in children has some features: body temperature often rises, apathy, adynamia, and a tendency to epileptiform seizures due to the rapid development of hypokalemia are more pronounced.

The duration of the disease ranges from 3 to 10 days, its subsequent manifestations depend on the adequacy of electrolyte replacement therapy.

Since the most important primary clinical signs of cholera are loose watery stools and vomiting, leading to dehydration, the severity of the disease and its prognosis are determined by its severity. One of the main signs of cholera is the rapid development of dehydration, which is not typical for other acute diarrheal infectious diseases. Dehydration of the IV degree can develop in patients already during the first day of the disease.

Currently, the clinical classification of cholera proposed by V.I. Pokrovsky et al. (1978) is used in practice, according to which four (I-IV) degrees of dehydration are distinguished, depending on the amount of water loss relative to body weight and, accordingly, reflecting the severity of the disease.

Dehydration of the 1st degree. The level of fluid loss does not exceed 3% of body weight. Patients note a sudden urge to defecate, accompanied by mushy or watery stool. Subsequently, such urges are repeated, but there is no pain in the intestines. Most often, the frequency of bowel movements in the 1st degree of dehydration does not exceed 5-10 times per day. Vomiting is recorded in no more than half of the patients and does not exceed 1-2 times per day. Patients note only dry mouth, thirst and slight weakness, their general condition and well-being remain satisfactory.

Dehydration of the 2nd degree. Fluid losses are in the range from 4 to 6% of body weight. The presence of more intense water-electrolyte losses is manifested by frequent watery stools (more than 10 times a day) and repeated vomiting (5 to 10 times a day). Characteristic rice-water-type stool is recorded in no more than 1/3 of patients. In some cases, vomiting may dominate the clinical picture, while the stool in these patients will remain fecal in nature.

Patients complain of the following symptoms of cholera: dry mucous membranes of the oropharynx, severe thirst, weakness. An objective examination reveals pale skin, and in a quarter of cases, cyanosis of the nasolabial triangle and acrocyanosis. The tongue is dry and coated. Tachycardia, decreased blood pressure, and oliguria are noted. About a third of cases, patients experience short-term convulsive twitching of the muscles of the extremities.

Dehydration of the III degree. Fluid loss corresponds to 7-9% of body weight. Since water-electrolyte losses occur due to the vascular bed, clinical signs of dehydration in such patients are sharply expressed. Due to the maintenance of life-supporting functions of the cardiovascular system at a minimum level, this stage is sometimes designated as subcompensated.

Already from the first hours of the disease, patients experience profuse, repeated stools and uncontrollable vomiting, which quickly lead to dehydration. Long, recurring, painful cramps in the limbs appear early, possibly spreading to other muscle groups (for example, the abdominal wall muscles). Due to the decrease in BCC, a progressive decrease in arterial pressure, tachycardia, and the development of oliguria are observed.

Dehydration of the fourth degree. The severity of water and electrolyte disorders is maximum, fluid loss corresponds to 10% or more of body weight. The variant of the course of cholera with dehydration of the fourth degree is characterized by a very rapid development of the clinical picture of the disease, as a result of which increasing signs of dehydration in most patients are detected already after 6-12 hours from the onset of the disease. Previously, this degree of dehydration was classified as algid due to the detection of hypothermia in patients. The condition of patients is extremely serious. Due to electrolyte disorders, paresis of the smooth muscles of the gastrointestinal tract sometimes develops, accompanied by the cessation of vomiting and the appearance of hiccups. A decrease in the tone of the anus is manifested by a free outflow of intestinal fluid, which intensifies even with light palpation of the abdomen. Generalized convulsions are typical. In the first hours with dehydration of the fourth degree, patients are conscious, but they are drowsy, apathetic, verbal contact with them is difficult due to severe weakness and aphonia. As the water-electrolyte and acid-base imbalances progress, they may develop stupor, turning into a coma. Despite the fact that patients have critical water-electrolyte losses, manifested by a sharp drop in blood pressure, absence of a pulse in the peripheral arteries, anuria, all changes are reversible, and the success of treatment depends on the timing of the start of rehydration therapy and its adequacy.

In addition to clinically manifest forms, when the symptoms of cholera are clearly expressed, the disease can occur in a subclinical form and in the form of vibrio carriage. Vibrio carriage can be convalescent (after clinically manifest or subclinical forms) and "asymptomatic", in which the development of the infectious process is limited only to the formation of carriage. Clinical and laboratory examination of "asymptomatic" carriers shows that in the overwhelming majority of cases (95%), patients have a subclinical form of the disease.

Clinical and epidemiological features of cholera caused by the El-Tor biotype:

• an increase in the number of latent, subclinical forms and carriage of vibrios;
• prolongation of the period of convalescent carriage of vibrios;
• a decrease in the effectiveness of etiotrol therapy due to the growth of antibiotic resistance of vibrio strains.

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Complications of cholera

Due to hemostasis and microcirculation disorders, myocardial infarction, mesenteric thrombosis, and acute cerebral circulatory failure are observed in older patients. Phlebitis is possible (during venous catheterization), and pneumonia often occurs in severe patients.

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