What Is Rift Valley Fever?

Rift Valley Fever (RVF) is caused by Rift Valley Fever virus. It is an acute viral zoonotic disease transmitted by mosquito vectors or contact. It mainly affects animals but can also infect humans. The initial symptoms are: fever, headache, fatigue, joint and muscle pain, sometimes nausea and vomiting, and some patients will have conjunctivitis and photophobia; severe cases may cause bleeding, shock, encephalitis or hepatitis, and even It is death.

Basic Information

English name

Rift Valley fever

Visiting department

Infectious Diseases

Common causes

Rift Valley fever virus

Common symptoms

Fever, headache, fatigue, joint and muscle pain, nausea, vomiting, conjunctivitis and photophobia, bleeding, shock, encephalitis, hepatitis, death

Contagious

Have

way for spreading

Mosquito vector or contact transmission

Rift Valley Fever virus is a member of the family Phenuiviridae, which is one of the 12 virus families of the Buniaviridae ^[1]

The incubation period is 3 to 6 days. Onset is rapid, with high fever of 38 ° C to 40 ° C, which can be bimodal, with a heat course of up to 1 week. He also had photophobia, severe headache, myalgia, and relatively slow pulse. There is often no rash, occasional small bleeding of the skin and mucous membranes, and rare major bleeding. Complications can include central, serous retinitis, and central dark spots. A few can cause retinal detachment; rare encephalitis (mostly occurring 3 to 12 days after fever).

Blood routine

Within 1 to 2 days of the disease, the white blood cells increased slightly or normally, with neutrophils increased, and then the white blood cells decreased, which can be lower than 2 × 10 / L. Thrombocytopenia may occur, and the clotting time is significantly prolonged. Factors II, V, VII, and IX were significantly reduced. Decreased fibrinogen and increased fibrin degradation products.

2. Urine routine

Visible small amounts of urinary protein, red blood cells, casts.

3. Renal function

Increased serum creatinine and urea nitrogen.

4. Liver biochemistry

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were elevated.

5. Virus detection

virus isolation and inoculation; blood tests such as enzyme-linked immunoassay ("ELISA" or "EIA"); specific IgM virus antibodies; antigen detection test; amplified ribonucleic acid genome (RT-PCR )Wait.

Preliminary diagnosis can be made based on epidemiological data and clinical manifestations. The diagnosis can be confirmed by virus isolation (inoculation of mice with sera from the first 3 days of the patient's illness), or the increase in titer of specific antibodies in duplicate sera. Acute rift valley fever can be diagnosed by different methods, and the virus can be detected in the early stages of onset or in autopsy tissues. Blood tests such as enzyme-linked immunoassay ("ELISA" or "EIA") can confirm the presence of specific immunoglobulin M (IgM) virus antibodies. Various methods, including virus isolation (in cell culture or inoculated animals), antigen detection tests, and amplified ribonucleic acid genome (RT-PCR), can be performed in the early stages of disease or in autopsy Out of this virus.

Mainly symptomatic treatment and antiviral treatment.

Symptomatic and supportive treatment

(1) Physical cooling is given to high fever , and small doses of antipyretic and analgesics can also be used to avoid excessive sweating.

(2) Metoclopramide tablets and vitamin B _{6 were} given for vomiting .

(3) Diffuse intravascular coagulation (DIC) is found in bleeding. Heparin sodium can be used early, and hemostatic sensitivity, vitamin C, etc. can be used to supplement blood volume, plasma, albumin, whole blood, fibrinogen, platelets and other alternative therapies to treat DIC. .

(4) Glycyrrhizic acid preparation can be used for liver injury, liver protection, yellowing and nutritional support.

(5) Intracranial hypertension was closely observed for changes in vital signs, respiratory rhythms, pupils, etc., and 20% mannitol was given rapid intravenous drip dehydration.

(6) Hemodialysis should be actively performed for renal failure such as oliguria, anuria, and hyperkalemia. At the same time, pay attention to maintaining water, electrolyte, acid-base balance.

2. Antiviral treatment

Ribavirin has anti-rift valley fever virus (RVFV) effects in animal experiments and cell culture, and may be considered for early trials.