How Do I Treat Dengue Fever?

Dengue is an acute vector-borne disease caused by mosquito-borne transmission of dengue virus. Dengue virus infection can cause recessive infection, dengue fever, and dengue hemorrhagic fever. Dengue hemorrhagic fever is rare in China. The typical clinical manifestations of dengue fever are sudden onset, high fever, headache, severe soreness of muscles, bones and joints, rash, bleeding tendency, lymphadenopathy, decreased white blood cell count, and thrombocytopenia in some patients. The disease is mainly endemic in tropical and subtropical areas. Guangdong, Hong Kong, Macao and other places in China are endemic areas of dengue fever. Because the disease is transmitted by Aedes mosquitoes, the epidemic has a certain seasonality, generally in May to November of each year, the peak is in July to September. In newly endemic areas, the population is generally susceptible, but the incidence is mainly adult. In endemic areas, the incidence is mainly children.

Basic Information

English name

dengue

Visiting department

Infectious Diseases

Common causes

Dengue virus

Common symptoms

Severe sore muscles, bones and joints, rash, bleeding tendency, lymphadenopathy, decreased white blood cell count, thrombocytopenia, etc. in some patients

Contagious

Have

way for spreading

Mosquito-borne

Causes of Dengue Fever

Dengue virus is a genus of flaviviruses in the Flaviviridae family. It is a single-stranded positive-strand RNA virus. The virus is resistant to low temperatures. It can survive for 5 years at -20 ° C in human serum, and can survive for more than 8 years at -70 ° C, but it is not resistant. Heat, it can be inactivated in 30 minutes at 50 ° C or 2 minutes in 100 ° C. It is not acid resistant. It can be inactivated with detergent, ether, ultraviolet light and 0.65% formaldehyde solution. Four serotypes of dengue virus have been isolated, all of which are pathogenic. Aedes mosquitoes (including Aedes aegypti and Aedes albopictus) are the main hosts, and patients and recessive infections are the main sources of infection. The patients were most contagious within 1 day to 3 days after the onset. A small number of patients can also isolate the virus from the blood on the third day after fever regression.

Dengue virus enters the human body through the bite of Aedes mosquito, enters the blood circulation after proliferation of capillary endothelial cells and monocyte-phagocytic system, and forms the first toxemia. It is then re-localized in the monocyte-phagocytic system and in the lymphatic tissue, where it is released into the blood again, forming a second toxemia. Dengue virus forms an immune complex with anti-dengue virus antibodies produced by the body, activating the complement system, resulting in increased vascular permeability. At the same time, the virus can inhibit the bone marrow, causing leukocytes, thrombocytopenia, and bleeding tendency.

Clinical manifestations of dengue fever

The incubation period is 3 to 14 days, with an average of about 4 to 7 days. Dengue is clinically classified as typical, light, and severe.

Typical dengue fever

(1) The onset of fever is mostly sudden, and the body temperature quickly reaches above 39 ° C, usually lasting for 2 to 7 days. The heat pattern is irregular, and in some cases, the body temperature drops to normal on the 3rd to 5th days, and then rises again after 1 day. Bimodal or saddle heat. Childhood onset is slower and fever is lower. It is accompanied by systemic symptoms such as headache, back pain, muscle and joint pain, orbital pain, and posterior eyeball pain. May have gastrointestinal symptoms such as hypersensitivity, nausea, vomiting, abdominal pain, poor appetite, diarrhea and constipation. Congestion on the face and eyes, flushing of the neck and upper chest. Relatively slow pulses can occur during the fever phase.

(2) The rash appears on the 2nd to 5th days after the onset. The palm, sole or torso and abdomen are seen initially, and the neck and limbs are gradually spread. Some patients are seen on the face, which can be maculopapular, measles-like rash, scarlet fever-like rash, erythema There is a slight itch. On the last day of fever or after the heat has subsided, there are fine blemishes on the feet, back of legs, ankles, back of wrists, armpits, etc., which subsides within 1 to 3 days, and brown spots remain for a short time. Body temperature subsided at the same time.

(3) Bleeding 5 to 8 days after the onset of bleeding , about half of the cases may have bleeding at different locations and to varying degrees, such as epistaxis, skin stasis, gastrointestinal bleeding, hemoptysis, hematuria, vaginal bleeding and so on.

(4) Other systemic lymph nodes may be slightly swollen, with light touch pain. Hepatomegaly and splenomegaly are rare. Individual cases have jaundice. Patients often feel weak and weak after their illness, and full recovery often takes several weeks.

2. Light Dengue Fever

Symptoms and signs are milder than typical dengue fever, fever and general body pain are mild, rashes are rare or not seen, there is no bleeding tendency, superficial lymph nodes are often swollen, and their clinical manifestations are similar to influenza, which is easily overlooked and healed in 1 to 4 days.

3. Heavy Dengue Fever

The early manifestations of the patient were similar to typical dengue fever, and the condition suddenly worsened on the 3rd to 5th course of the disease, with severe headache, nausea, vomiting, disturbance of consciousness, and cervical meningitis. Some manifest as major gastrointestinal bleeding and hemorrhagic shock. This type often develops rapidly due to illness, mostly due to central respiratory failure and hemorrhagic shock within 24 hours.

Dengue Fever

Routine inspection

(1) The total number of white blood cells of patients with dengue fever in peripheral blood is reduced at the time of onset, especially during the period of rash; the percentage of neutrophils is also reduced, and the lymphocytes are relatively increased. The poisonous particles and obvious nuclear left shift are visible, and there are abnormalities. Lymphocytes, and the blood returned to normal one week after fever. Thrombocytopenia in 1/4 to 3/4 cases can be as low as 13 × 10 ⁹ / L.

(2) Urine routine There may be a small amount of protein, red blood cells, white blood cells, and sometimes casts.

2. Virus isolation

Blood from early patients was inoculated into Aedes albopictus cell line (C6 / 36), and the virus must be identified by specific neutralization test or hemagglutination inhibition test after virus isolation.

3. Serum immunological examination

The detection of specific IgM antibodies in patients' serum by ELISA is positive to help the early diagnosis of dengue fever. If the dengue virus antigen is detected in the patient's serum, it can also be used as a clear diagnosis basis.

4. Dengue virus nucleic acid detection

The detection of dengue virus RNA in patients' serum is more sensitive than virus isolation and can be used for early rapid diagnosis and serotype identification, but the technical requirements are higher.

Dengue fever diagnosis

According to the epidemiological characteristics of the epidemic area and the onset of the rainy season, the patient developed two degrees of high fever, pain in the whole body, obvious fatigue, rash on the first fever or second fever, swollen lymph nodes, and decreased white blood cell count, etc. Considered as dengue fever. The antibody titer in the recovery phase of the double serum is more than 4 times higher than that in the acute phase, or the antibody titer of the complement test in the acute phase is 1:32 or more, and the diagnosis can be made. Pay attention to identification with influenza, leptospirosis, measles, scarlet fever, typhoid fever, malaria, and yellow fever.

Dengue fever treatment

At present, there is no precise and effective pathogen treatment for this disease, and support and symptomatic treatment measures are mainly adopted.

General treatment

The patient lives in an isolation ward with anti-mosquito equipment. In the acute phase, you should rest in bed until your body temperature and platelet count return to normal, and there is no tendency to bleeding before you can move properly. Diet should be liquid or semi-liquid rich in nutritious and easy to digest food. Take care to clean your mouth and skin and keep your stools open.

2. Reduce body temperature

For patients with high fever, physical cooling should be used first, such as ice packs, alcohol swabs, and painkillers and antipyretic drugs should be used with caution. For those with high fever and severe toxemia, a short-term application of a small dose of adrenocortical hormone, such as oral prednisone.

3. Rehydration

For those who sweat more and have diarrhea, take oral rehydration first, and pay attention to water, electrolyte and acid-base balance. Intravenous rehydration should be used when necessary to correct dehydration, hypokalemia, and metabolic acidosis, but the possibility of inducing cerebral edema, intracranial hypertension, and cerebral hernia should always be watched.

4. Reduce intracranial pressure

In cases of severe headache and intracranial hypertension, a rapid intravenous drip of 20% mannitol injection should be applied in time. At the same time, intravenous infusion of dexamethasone can help reduce cerebral edema and reduce intracranial pressure. For patients whose respiratory center is inhibited, an artificial respirator should be applied in time.

5. Hemostasis

Those who have bleeding tendency, give carbachol, vitamin K and other general hemostatic drugs. When the amount of bleeding is large, whole blood or platelets can be transfused.

Dengue prognosis

Dengue fever is a self-limiting infectious disease. The duration of uncomplicated patients is about 10 days. The disease usually has a good prognosis. Most of the deaths were severe patients.

Dengue fever prevention

1. Manage the source of infection

Endemic or probable areas should do a good job of monitoring and forecasting the dengue epidemic, early detection, early diagnosis, and timely isolation and treatment. Specific laboratory tests should be performed as soon as possible to identify light patients. Suspicious patients should be medically observed. Patients should be isolated in the ward with screens and screens. The isolation time should be no less than 5 days. Strengthen border health quarantine.

2. Cut off the transmission route

Anti-mosquito and anti-mosquito are the fundamental measures to prevent this disease. Improve the sanitary environment, eliminate the breeding ground of Aedes mosquitoes, and clear up the accumulated water. Spray insecticides to eliminate adult mosquitoes.

3. Protect vulnerable people

Improve the population's disease resistance, pay attention to a balanced diet, work and rest, exercise appropriately, and enhance physical fitness. Apply insect repellents to susceptible people during epidemics to prevent mosquito bites.

Detect infection

In March 2019, the University of Bath announced that researchers at the school are developing a small device to detect dengue virus infections earlier in order to treat patients more efficiently and avoid deterioration. The team believes that better understanding of how these cells behave after infection can lead to more precise ways to detect dengue virus ^[1] .