Can cause dengue fever pleural effusion in the lungs

Dengue

Dengue fever is caused by flaviviruses transmitted by mosquitoes. Dengue fever usually leads to an abrupt onset with high fever, headache, myalgias, arthralgias, and generalized lymphadenopathy, followed by rash, which occurs when the temperature rises a second time after an afebrile stage. It can lead to respiratory problems such as B. cough, sore throat and rhinorrhea. Dengue can lead to a potentially fatal hemorrhagic fever with a tendency to bleed and shock. The diagnosis includes serological tests and polymerase chain reaction. Therapy is symptomatic and, in the case of hemorrhagic dengue fever, includes adequate volume replacement therapy.

Dengue occurs in tropical regions between the 35th north and 35th south latitude. Recently, the incidence has also increased in Central and South America. Outbreaks are most common in Southeast Asia, but they can also occur in the Caribbean, including Puerto Rico and the American Virgin Islands, in Australia / Oceania and the Indian subcontinent. Only about 100 to 200 cases of returning tourists are introduced to the US each year, but an estimated 50 to 100 million cases occur worldwide with about 20,000 deaths. Limited local broadcast has occurred in Hawaii, Florida, Long Island, New York, and Texas.

The causative agent, a flavivirus with 4 serogroups, is caused by the bite of mosquitoes of the genus Aedes transfer. The virus circulates in the blood of infected people for 2-7 days; AedesMosquitoes can acquire the virus if they suck blood from infected people during this period.

Symptoms and ailments

After an incubation period of 3–15 days, there is an abrupt fever, chills, headache, retroorbital pain with double vision, lumbar back pain and severe malaise. During the first few hours there is extreme pain in the legs and joints, which has led to the traditional term "bone breaker fever". The temperature rises rapidly up to 40 ° C, with relative bradycardia. Conjunctival involvement as well as transient reddening of the skin or a pale pink macular rash (especially on the face) can occur. Often the cervical, epitrochlear, and inguinal lymph nodes are enlarged.

The fever and other symptoms persist for 48–96 hours, followed by a rapid defervation with intense sweating. The patients feel relatively well for about 24 hours, after which the fever can come back ("saddle roof profile"), typically with a lower maximum temperature than during the first ascent. At the same time, a pale maculopapular rash spreads from the trunk to the extremities and face.

Sore throat, gastrointestinal symptoms (e.g. nausea, vomiting) and hemorrhagic symptoms may occur. Some patients develop dengue hemorrhagic fever. Neurological symptoms are rare and can include encephalopathy and seizures; Some patients develop Guillain Barre syndrome.

Mild cases of dengue fever, usually without lymphadenopathy, remit in <72 h. In more severe cases, the debilitating phase can last for several weeks. Fatalities are rare. Long-term immunity to the infecting strain occurs, whereas immunity to other strains only lasts for 2–12 months.

More severe illness can result from antibody-dependent aggravation of the infection, in which patients have a non-neutralizing antibody from a previous infection with one dengue serotype and then another infection with another dengue serotype.

diagnosis

  • Serological tests during the acute phase and the convalescence period

Dengue fever is suspected in patients traveling to or living in endemic areas if they suddenly develop fever, severe retro-orbital headache, myalgia, and lymphadenopathy, especially if they have a characteristic rash or recurrent fever. Alternative diagnoses, in particular malaria and leptospirosis, should be excluded as part of the investigation.

Diagnostic studies include acute and convalescent serological tests, antigen detection, and blood polymerase chain reaction. Serological tests include a hemagglutination inhibition test or a complement fixation reaction with paired sera, but cross-reactions with other flaviviruses do occur. Plaque reduction neutralization tests are more specific and are considered the gold standard for serological diagnosis. Antigen detection is available and a polymerase chain reaction is usually only carried out in laboratories with special expertise. The usefulness of these examinations in the context of clinical care does not only arise in times of a health system characterized by flat-rate case fees.

Although it is rarely done and difficult, cultures can be vaccinated with Toxorhynchites Mosquitoes or specialized cell lines can be done in specialized laboratories.

The blood count may show leukopenia on the second day of the fever. Around the 4th or 5th day the white blood cell count can be between 2000 and 4000 / μl, with only 20-40% granulocytes. The urinalysis may show moderate albuminuria and isolated casts. Thrombocytopenia can also be present.

therapy

Dengue therapy is only possible symptomatically. Paracetamol can be used, but NSAIDs, including aspirin, should be avoided as there is a risk of bleeding. Since aspirin increases the risk of Reye's syndrome, it should be avoided in children.

prevention

People in endemic areas should try to avoid mosquito bites. Certainly the most effective prevention for Central Europeans is to refrain from avoidable trips to endemic areas. To prevent further transmission by mosquitoes, dengue patients in the endemic areas should remain under a mosquito net until the second fever has subsided.

Several tetravalent vaccine candidates are currently being evaluated. A tetravalent vaccine was licensed in Mexico in December 2015 for use in people aged 9-45 living in endemic areas. However, vaccinating children who have never had dengue fever seems to put them at risk of more serious illnesses if the children are later infected with dengue fever1). This effect caused the Philippine health authorities to discontinue dengue vaccination in this country.

Advice on prevention

  • 1. WHO: Revised SAGE recommendation on use of dengue vaccine. 2018. Accessed on July 5th, 2018.

Important points

  • The dengue virus is caused by the bite of mosquitoes of the genus Aedes transfer.

  • Dengue fever typically causes sudden fever, severe retroorbital headache, myalgia, lymphadenopathy, a characteristic rash, and extreme pain in the legs and joints during the first few hours.

  • Dengue fever can cause potentially fatal hemorrhagic fever with a tendency to bleed and shock (dengue hemorrhagic fever and dengue shock syndrome).

  • Expect dengue fever if patients who live or have traveled to endemic areas have typical symptoms; diagnose using serological tests, antigen tests or polymerase chain reaction of blood.

Dengue hemorrhagic fever

(Filipino, Thai, or Southeast Asian hemorrhagic fever; dengue shock syndrome)

Dengue hemorrhagic fever (DHF) with dengue shock syndrome is a clinical variant that occurs mainly in children <10 years of age who live in dengue endemic areas. DHF often requires previous dengue virus infection.

DHF is an immunopathological disease; Dengue virus-antibody immune complexes already present from a previous event trigger a massive release of vasoactive mediators by macrophages. The mediators increase vascular permeability, causing vascular leakage, hemorrhagic manifestations, hemoconcentration, and severe effusions that can lead to circulatory collapse (hence the synonym dengue shock syndrome).

Symptoms and ailments

Dengue hemorrhagic fever often begins with an abrupt fever and headache and is initially indistinguishable from classic dengue fever. Warning signs predicting possible development of severe dengue include

  • Severe abdominal pain and tenderness

  • Nosebleeds or bleeding from the gums

  • Black, tarry stools (melena)

  • Lethargy, confusion, restlessness

  • Hepatomegaly, pleural effusion, or ascites

  • Significant change in temperature (from fever to hypothermia)

A state of shock and progressive symptoms can quickly develop 2–6 days after the onset of the disease.

Bleeding tendencies manifest themselves as follows:

  • Usually as purpura, petechiae, or ecchymosis at the injection sites

  • Sometimes as a hematemesis, melena, or nosebleed

  • Occasionally as subarachnoid hemorrhage

Bronchopneumonia with or without bilateral pneumonic infiltrates is common. Myocarditis can occur.

Mortality is typically <1% in experienced clinical centers, but can be up to 30% otherwise.

diagnosis

  • Clinical diagnosis, anamnesis of a previous dengue fever, possibly corroborated by laboratory criteria

Dengue hemorrhagic fever is suspected in children according to the defined clinical-diagnostic criteria of the World Health Organization:

  • Sudden fever that stays high for 2 to 7 days

  • Hemorrhagic manifestations

To the hemorrhagic manifestations Include at least one positive tourniquet test and petechiae, purpura, ecchymosis, bleeding gums, hematemesis, or melena. The tourniquet test is performed by inflating a blood pressure cuff over 15 minutes to a value between systolic and diastolic blood pressure. The number of petechiae that form in a circle 2.5 cm in diameter is counted; > 20 petechiae suggest increased capillary fragility.

A blood count, coagulation tests, liver values ​​and dengue serology should be carried out. Coagulation abnormalities include

  • Thrombocytopenia (≤ 100,000 platelets / mcL)

  • PTT activated longer

  • Increased amount of fibrin breakdown products

Hypoproteinemia, mild proteinuria, and an increase in AST may occur. "Complement fixation" antibody titers against flaviviruses are usually high (demonstration of a 4-fold or greater change in reciprocal IgG or IgM antibody titers to ≥ 1 dengue virus antigens in serum pairs).

Disease is suspected in patients with clinical findings according to World Health Organization criteria plus thrombocytopenia (≤ 100,000 / μl) or hemoconcentration (Hk increase of ≥ 20%) (see the CDC'sDengue Virus: Clinical Guidance).

therapy

Patients with dengue hemorrhagic fever usually require intensive medical treatment to maintain a balanced fluid status. Both hypovolemia (which can lead to shock) and overhydration (which can cause acute respiratory failure syndrome) should be avoided. The urine output as well as the extent of the hemoconcentration can be used to monitor the intravascular volume.

Previously known antivirals could not improve the result.

Important points

  • Dengue hemorrhagic fever (DHF) is most common in children <10 years of age who live in areas where dengue is indigenous. Prior infection with the dengue virus is required.

  • DHF may initially resemble dengue fever, but certain findings (e.g. severe abdominal pain and tenderness, persistent vomiting, hematemesis, nosebleeds, tarry stools) indicate the possible development of severe dengue.

  • The diagnosis is made based on specific clinical and laboratory criteria.

  • Maintaining Euvolemia is vital.

additional Information