Infectious Disease Online
Pathology of Dengue Virus
Infection and Dengue
Dengue the most prevalent arthropod-borne viral (Arborvirus) disease of humans caused by four serotypes of dengue virus (DENV 1-4) of the genus Flavivirus.
It is transmitted to man by mosquito Aedes aegypti.
Source: Man is infective to mosquito and mosquito transmits the disease to man.
Clinically, symptoms start 6 days after of infection as malaise and headache, followed by sudden onset of fever, intense backache and generalized pains, mainly in the orbital and periarticular areas.
After an afebrile interval of 24 to 48 hours, there is recurrence of fever for a day or two (‘saddleback fever’).
There may be skin rash and lymphadenopathy.
In persons, previously exposed to Dengue virus, antiviral antibodies may enhance the uptake of virus into host cells and cause disseminated intravascular coagulation, shock and death (hemorrhagic dengue).
Biopsy studies of the rash seen in nonfatal dengue fever show a lymphocytic vasculitis in the dermis.
In cases of fatal dengue hemorrhagic fever the gross findings are petechial hemorrhages in the skin and hemorrhagic effusions in the pleural, pericardial and abdominal cavities.
Hemorrhage and congestion are seen in many organs.
Histopathological examination show hemorrhage, perivascular edema and focal necrosis but no vasculitic or endothelial lesions.
It is believed that most of the morphologic abnormalities seen result from disseminated intravascular coagulation and shock.
Related post: Chikungunya virus infection
Differential diagnosis : Includes malaria , typhoid fever, leptospirosis, West Nile virus infection, measles , rubella, acute human immunodeficiency virus conversion disease, Epstein–Barr virus infection, viral hemorrhagic fevers, rickettsial diseases, early severe acute respiratory syndrome (SARS), and any other disease that can manifest in the acute phase as an undifferentiated febrile syndrome.
Diagnosis: A confirmed diagnosis is established by culture of the virus, polymerase-chain-reaction (PCR) tests, or serologic assays.
The diagnosis of dengue hemorrhagic fever is made on the basis of the following triad of symptoms and signs:
- Hemorrhagic manifestations;
- A platelet count of less than 100,000 per cubic millimeter; and
- Objective evidence of plasma leakage, shown either by fluctuation of packed-cell volume (greater than 20 percent during the course of the illness) or by clinical signs of plasma leakage, such as pleural effusion, ascites, or hypoproteinemia.
Hemorrhagic manifestations without capillary leakage do not constitute dengue hemorrhagic fever.
Liver histopathology and biological correlates in five cases of fatal dengue fever in Vietnamese children.
October 7th: With
one more person dying on Saturday, dengue has claimed 46 lives in the
country as 84 fresh cases were reported taking the number of patients to
over 3,300 in at least14 states.
Of the states affected by the mosquito-borne disease, Delhi has reported the maximum number of 19 deaths as 82 persons were admitted to hospitals since last night taking the total number of cases in the national capital to 825.
Official reports said the number of dengue cases reported from Kerala so far were 713, Gujarat 411, Rajasthan 326, West Bengal 314, Tamil Nadu 306, Maharashtra 228, Andhra Pradesh 90, Uttar Pradesh 79, Karnataka 59 and Haryana 50. Other affected states include Bihar, Uttaranchal and Punjab.
Dengue outbreak in India kills 38, infects thousands. 05 Oct 2006: Read more....
Dengue Outbreak Kills 14 in India - NEW DELHI, Oct. 3, 2006 : Read more...
Dengue fever outbreak overwhelms Delhi hospitals - October 3, 2006: Read more...
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