Yellow fever - are all mosquitoes dangerous?
Yellow fever is not a European disease, but it does not mean that we are insured against it. You can avoid the consequences of the disease only knowing its causes.
Yellow fever is a disease that is transmitted with its bite by infected mosquitoes. The disease is defined as a viral hemorrhagic acute. According to the WHO rules, the disease is subject to international registration and applies to quarantine.
Symptoms of yellow fever
Yellow fever, like any disease, has a period of incubation. Most often it lasts a week, in rare cases ten days. Then the symptoms of the disease begin to appear. In the first stage, the infected person suddenly has a fever, chills, then there is a headache, and myalgia is possible. There are pains in the muscles of the back, nausea, rolls of vomiting, excitement, which goes into a stage of delirium.
Medical examination reveals hyperemia of the vessels of the eyeball, puffiness of the upper body up to the thorax, lacrimation. Pronounced signs are hyperemia of the mucosa and tongue. If the patient has tachycardia, then it abruptly passes into the bradycardia, hypertension is replaced by hypotension. The liver is slightly enlarged, in rare cases - the spleen. The kidneys begin to release less urine, protein appears in the urine , the number of leukocytes in the blood drops. There is a cyanotic color of the skin and pinpoints all over the body. The first phase lasts no more than four days.
Then remission begins, which develops only a few hours. During the remission, body temperature decreases. If the form of the disease is mild, recovery may soon begin. But much more often the fever returns and the reactive period begins. Particularly severe cases result in venous stasis. What remains is the pallor and cyanosis of the skin, the sclera is colored yellow, just like the conjunctiva and the soft palate. Cyanosis and jaundice quickly spread throughout the body. Hemorrhages in the skin lead to petechiae, purpura, and ecchymosis. Continues blood vomiting, bleeding gums, bleeding from different organs. The amount of urine released falls. If an infectious-toxic shock occurs, it results in an average death in a week. Possible encephalitis. Lack of kidney and liver also leads to death in a few days.
As complications of yellow fever occur pneumonia, gangrene, myocarditis or sepsis. If the patient can recover, the immunity will last for life.
Causes of the disease
Yellow fever is divided into three types. The first is a jungle fever. It infects wild mosquitoes and infects healthy mosquitoes that carry the virus to people walking in the forest. Usually it concerns workers. This type of fever has almost no epidemics.
The second type is an intermediate variant of a fever. It develops in African savannahs with an increased form of moisture. Mosquitoes can infect a maximum of several villages. But in this case the mortality rate is much lower than in the third type - urban. Under the urban version, the epidemic takes over vast areas. Yellow fever is no longer tolerated by monkeys, but by migrants. The danger of the epidemic is especially threatening for densely populated areas.
Diagnosis of yellow fever
Diagnosis of fever can be performed at the clinic through differential diagnosis. Particular attention is paid to the replacement of two phases, when the patient is then subjected to hyperemia, or venous stasis. The initial stage of the disease is manifested by a decrease in the blood of leukocytes, platelets, neutrophils. Then these signs deepen and turn into leukocytosis, the blood increases the amount of hematocrit, potassium and nitrogen. Also, the amount of protein increases in it, erythrocytes appear, followed by the development of the epithelial cells of the cylinders. Bilirubins begin to exceed the limits of normal.
Timely diagnosis of the disease can be done using serological methods or by examining liver biopsy histologically. It is also possible to conduct a biochemical blood test to reveal the activity of liver enzymes, most often it is AST.
In specialized laboratories, the virus can be isolated from the blood and placed in experimental mice. But this is possible only in the initial period of the disease.
Methods of treatment
Yellow fever is treated only in a stationary way in the department of infectious diseases. Since there is no way to eliminate the cause of this disease, the process of treatment consists in maintaining the functions of immunity and alleviating the symptoms.
Patients are assigned bed rest, food that is easily digested and rich in calories, with a high content of vitamins C, K, R. Transfusion is carried out every two days, from drugs prescribe anteanemine and campolon. Stitch the enzyme intramuscularly to compensate for blood loss. Complex therapy includes the appointment of antihistamines, anti-inflammatory, gemostatikov, tablets or potions to maintain the cardiovascular system. In some cases, therapy is strengthened by the appointment of resuscitation.
Acetylsallicylic acid is categorically contraindicated. At a high probability of a lethal outcome, glucocorticosteroids are used. These drugs can be natural or synthetic, perform the functions of the adrenal cortex.
The probability of a lethal outcome varies from 5 to 20 percent, in the case of an epidemic it grows to 60.
Folk methods are very ineffective in controlling yellow fever. They can only soften the symptoms. But they can be used only after consultation with the attending physician. Since folk remedies often interact with medications, self-medication can cause irreparable harm.
Yellow fever is a serious disease, but it can be saved from a timely vaccine. In the case of infection, the implementation of all the recommendations of doctors can save your life.
Prophylaxis of the disease
As an individual prophylaxis it is possible to use the means that protect against the bites of various insects. For specific prevention, it is sufficient to administer a live vaccine of weakened action. Anyone who travels to areas prone to the spread of the virus must be vaccinated against yellow fever no later than one week before his departure.
In general, the vaccination against yellow fever is considered the best preventive measure. It is done using two kinds of live vaccine. Revaccination is necessary every ten years. WHO recommends regular vaccination in children and adults in countries where the risk of disease is high.
So far, for the vaccination against yellow fever have the following contraindications: the age of children under 6 months; Pregnancy of the woman (except outbreaks of the epidemic); Severe allergy to egg white; HIV or AIDS; Disorders of the thymus gland; Severe form of infectious or malignant diseases. Side effects were seen in isolated cases. Basically, they are manifested headache, general malaise, a slight increase in temperature.