Dengue fever classification: Difference between revisions
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| style="font-size: 90%; padding: 0 5px; background: #DCDCDC;" align=left | ❑ '''''Hemorrhagic tendencies, evidenced by at least <u>one</u> of the following:''''' <BR> ❑ A positive tourniquet test <sup>†</sup><BR> ❑ Petechiae, ecchymoses, or purpura<BR> ❑ Bleeding from the mucosa, gastrointestinal tract, injection sites or other locations<BR> ❑ Hematemesis or melena | | style="font-size: 90%; padding: 0 5px; background: #DCDCDC;" align=left | ❑ '''''Hemorrhagic tendencies, evidenced by at least <u>one</u> of the following:''''' <BR> ❑ A positive tourniquet test<sup>†</sup><BR> ❑ Petechiae, ecchymoses, or purpura<BR> ❑ Bleeding from the mucosa, gastrointestinal tract, injection sites or other locations<BR> ❑ Hematemesis or melena | ||
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<SMALL> <sup>†</sup> The tourniquet test is performed by inflating a blood pressure cuff on the upper arm to a point midway between the systolic and diastolic pressures for 5 minutes. A test is considered positive when 20 or more petechiae per 2.5 cm (1 inch) square are observed. The test may be negative or mildly positive during the phase of profound shock. It usually becomes positive, sometimes strongly positive, if the test is conducted after recovery from shock.</SMALL> | <SMALL> <sup>†</sup> The tourniquet test is performed by inflating a [[Sphygmomanometer|blood pressure cuff]] on the upper arm to a point midway between the [[SBP|systolic]] and [[DBP|diastolic pressures]] for 5 minutes. A test is considered positive when 20 or more [[petechiae]] per 2.5 cm (1 inch) square are observed. The test may be negative or mildly positive during the phase of profound [[shock]]. It usually becomes positive, sometimes strongly positive, if the test is conducted after recovery from [[shock]].</SMALL> | ||
===2009 WHO Classification=== | ===2009 WHO Classification=== | ||
A newer classification published by WHO in 2009 categorizes the disease into '''probable dengue''' or '''laboratory-confirmed dengue''' (''with or without warning signs'') and '''severe dengue''' (encompassing ''severe plasma leakage'', ''severe bleeding'', and ''severe organ involvement''). However, it has been criticized as overly inclusive for several reasons:<ref name=CDC>{{cite web | title = Infectious Diseases Related To Travel | url = http://wwwnc.cdc.gov/travel/yellowbook/2014/chapter-3-infectious-diseases-related-to-travel/dengue }}</ref> | |||
* It allows several different ways to qualify for severe dengue. | * It allows several different ways to qualify for severe dengue. | ||
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| style="font-size: 90%; padding: 0 5px; background: #DCDCDC;" align=left | ❑ '''''<u>Two</u> of the following criteria:''''' <BR> ❑ Nausea or vomiting <BR> ❑ Rash <BR> ❑ Aches and pains <BR> ❑ Tourniquet test positive <sup>†</sup><BR> ❑ Leukopenia <BR> ❑ Any warning sign | | style="font-size: 90%; padding: 0 5px; background: #DCDCDC;" align=left | ❑ '''''<u>Two</u> of the following criteria:''''' <BR> ❑ Nausea or vomiting <BR> ❑ Rash <BR> ❑ Aches and pains <BR> ❑ Tourniquet test positive<sup>†</sup><BR> ❑ Leukopenia <BR> ❑ Any warning sign | ||
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| style="padding: 0 5px; font-size: 90%; background: #F5F5F5; font-weight: bold; font-style: italic;" align=center | Warning Signs | | style="padding: 0 5px; font-size: 90%; background: #F5F5F5; font-weight: bold; font-style: italic;" align=center | Warning Signs | ||
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| style="padding: 0 5px; font-size: 90%; background: #F5F5F5; font-weight: bold; font-style: italic;" align=center | Severe Organ Involvement | | style="padding: 0 5px; font-size: 90%; background: #F5F5F5; font-weight: bold; font-style: italic;" align=center | Severe Organ Involvement | ||
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| style="font-size: 90%; padding: 0 5px; background: #DCDCDC;" align=left | ❑ '''''Severe organ involvement indicated by:'''''<BR> ❑ Liver: AST or ALT ≥1000 IU/L<BR> ❑ CNS: impaired consciousness<BR> ❑ Heart or other organs | | style="font-size: 90%; padding: 0 5px; background: #DCDCDC; height: 81px;" align=left | ❑ '''''Severe organ involvement indicated by:'''''<BR> ❑ Liver: AST or ALT ≥1000 IU/L<BR> ❑ CNS: impaired consciousness<BR> ❑ Heart or other organs | ||
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<SMALL> <sup>†</sup> The tourniquet test is performed by inflating a blood pressure cuff on the upper arm to a point midway between the systolic and diastolic pressures for 5 minutes. A test is considered positive when 20 or more petechiae per 2.5 cm (1 inch) square are observed. The test may be negative or mildly positive during the phase of profound shock. It usually becomes positive, sometimes strongly positive, if the test is conducted after recovery from shock.</SMALL> | <SMALL> <sup>†</sup> The tourniquet test is performed by inflating a [[Sphygmomanometer|blood pressure cuff]] on the upper arm to a point midway between the [[SBP|systolic]] and [[DBP|diastolic pressures]] for 5 minutes. A test is considered positive when 20 or more [[petechiae]] per 2.5 cm (1 inch) square are observed. The test may be negative or mildly positive during the phase of profound [[shock]]. It usually becomes positive, sometimes strongly positive, if the test is conducted after recovery from [[shock]].</SMALL> | ||
====Laboratory Tests for Confirmed and Probable Dengue Infection==== | |||
A diagnosis of dengue infection is | * A diagnosis of '''confirmed dengue infection''' is established by isolation of the [[virus]], detection of viral [[genome]] or NS1 [[antigen]], or [[seroconversion]] of [[IgM]] or [[IgG]] (from negative to positive [[IgM]]/[[IgG]] or fourfold increase in the specific [[antibody]] titer) in paired [[serum|sera]]. | ||
* A positive [[IgM]] [[serology]] or a [[hemagglutination inhibition assay|hemagglutination inhibition assay (HIA)]] [[antibody]] titer of 1280 or higher (or comparable figures by [[ELISA]] in a single specimen), are diagnostic of a '''probable dengue infection'''. Both probable and confirmed dengue cases should be notified to health authorities.<ref name=WHO2012>{{cite web | title = Handbook for Clinical Management of dengue | url = http://apps.who.int/iris/bitstream/10665/76887/1/9789241504713_eng.pdf?ua=1 }}</ref> | |||
{| style="border: 0px; font-size: 85%; margin: 3px;" align=center | {| style="border: 0px; font-size: 85%; margin: 3px;" align=center | ||
! style="background: #4479BA; width: 100px;" | {{fontcolor|#FFF|Definition}} | ! style="background: #4479BA; width: 100px;" | {{fontcolor|#FFF|Definition}} | ||
! style="background: #4479BA; width: 100px;" | {{fontcolor|#FFF|Method}} | ! style="background: #4479BA; width: 100px;" | {{fontcolor|#FFF|Method<sup>†</sup>}} | ||
! style="background: #4479BA; width: 100px;" | {{fontcolor|#FFF|Interpretation}} | ! style="background: #4479BA; width: 100px;" | {{fontcolor|#FFF|Interpretation<sup>†</sup>}} | ||
! style="background: #4479BA; width: 100px;" | {{fontcolor|#FFF|Sample Characteristics}} | ! style="background: #4479BA; width: 100px;" | {{fontcolor|#FFF|Sample Characteristics}} | ||
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! style="padding: 5px 5px; background: #DCDCDC;" | IgG seroconversion | ! style="padding: 5px 5px; background: #DCDCDC;" | IgG seroconversion | ||
| style="padding: 5px 5px; background: #DCDCDC;" | From negative IgG to positive IgG in paired sera or 4-fold increase IgG levels among paired sera | | style="padding: 5px 5px; background: #DCDCDC;" | From negative IgG to positive IgG in paired sera or 4-fold increase IgG levels among paired sera | ||
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! style="padding: 5px 5px; background: #F5F5F5;" rowspan=2 | Probable Dengue Infection | ! style="padding: 5px 5px; background: #F5F5F5;" rowspan=2 | Probable Dengue Infection | ||
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! style="padding: 5px 5px; background: #F5F5F5;" | High IgG levels | ! style="padding: 5px 5px; background: #F5F5F5;" | High IgG levels | ||
| style="padding: 5px 5px; background: #F5F5F5;" | High IgG levels by ELISA or | | style="padding: 5px 5px; background: #F5F5F5;" | High IgG levels by ELISA or hemagglutination inhibition assay (≥1280) | ||
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<SMALL> <sup>†</sup> ELISA = enzyme-linked immunosorbent assay; IgG = immunoglobulin G; IgM = immunoglobulin M; NS1 Ag = non-structural protein 1 antigen; RT-PCR = reverse transcriptase polymerase chain reaction</SMALL> | |||
==Referemces== | ==Referemces== | ||
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[[Category:Flaviviruses]] | [[Category:Flaviviruses]] | ||
[[Category:Hemorrhagic fevers]] | [[Category:Hemorrhagic fevers]] | ||
[[Category:Insect-borne diseases]] | [[Category:Insect-borne diseases]] | ||
[[Category:Neglected diseases]] | [[Category:Neglected diseases]] | ||
[[Category:Tropical disease]] | [[Category:Tropical disease]] | ||
[[Category:Viral diseases]] | [[Category:Viral diseases]] | ||
[[Category:Emergency medicine]] | |||
[[Category:Disease]] | |||
[[Category:Up-To-Date]] | |||
[[Category:Infectious disease]] | |||
[[Category:Hematology]] | |||
[[Category:Cardiology]] | |||
[[Category:Gastroenterology]] |
Latest revision as of 21:16, 29 July 2020
Dengue Fever Microchapters |
Diagnosis |
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Treatment |
Case Studies |
Dengue fever classification On the Web |
American Roentgen Ray Society Images of Dengue fever classification |
Risk calculators and risk factors for Dengue fever classification |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alonso Alvarado, M.D. [2]
Overview
Current WHO guideline classifies dengue into non-severe and severe disease depending on whether there is severe plasma leakage, severe bleeding, or severe organ impairment. For practical purposes, non-severe cases can be further divided into two subgroups: those with warning signs and those without them. Patients with suspected dengue should be triaged and managed accordingly.
Classification
1997 WHO Classification
Historically, symptomatic dengue virus infections were classified as dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. The case definitions were found too difficult to apply in resource-limited settings and too specific, as it failed to identify a substantial proportion of severe dengue cases, including cases of hepatic failure and encephalitis.
The tables below describe the 1997 WHO dengue case classification:[1]
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† The tourniquet test is performed by inflating a blood pressure cuff on the upper arm to a point midway between the systolic and diastolic pressures for 5 minutes. A test is considered positive when 20 or more petechiae per 2.5 cm (1 inch) square are observed. The test may be negative or mildly positive during the phase of profound shock. It usually becomes positive, sometimes strongly positive, if the test is conducted after recovery from shock.
2009 WHO Classification
A newer classification published by WHO in 2009 categorizes the disease into probable dengue or laboratory-confirmed dengue (with or without warning signs) and severe dengue (encompassing severe plasma leakage, severe bleeding, and severe organ involvement). However, it has been criticized as overly inclusive for several reasons:[2]
- It allows several different ways to qualify for severe dengue.
- Nonspecific warning signs are used as diagnostic criteria.
- Severity determination is dependent on individual judgment due to the lack of explicit clinical criteria for establishing severe dengue.
The tables below describe the 2009 WHO dengue case classification:[3][4]
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† The tourniquet test is performed by inflating a blood pressure cuff on the upper arm to a point midway between the systolic and diastolic pressures for 5 minutes. A test is considered positive when 20 or more petechiae per 2.5 cm (1 inch) square are observed. The test may be negative or mildly positive during the phase of profound shock. It usually becomes positive, sometimes strongly positive, if the test is conducted after recovery from shock.
Laboratory Tests for Confirmed and Probable Dengue Infection
- A diagnosis of confirmed dengue infection is established by isolation of the virus, detection of viral genome or NS1 antigen, or seroconversion of IgM or IgG (from negative to positive IgM/IgG or fourfold increase in the specific antibody titer) in paired sera.
- A positive IgM serology or a hemagglutination inhibition assay (HIA) antibody titer of 1280 or higher (or comparable figures by ELISA in a single specimen), are diagnostic of a probable dengue infection. Both probable and confirmed dengue cases should be notified to health authorities.[3]
Definition | Method† | Interpretation† | Sample Characteristics |
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Confirmed Dengue Infection | Viral isolation | Virus isolated | Serum (collected at 1–5 days of fever) or necropsy tissues |
Genome detection | Positive RT-PCR or positive real-time RT-PCR | ||
Antigen detection | Positive NS1 Ag | ||
Positive immunohistochemical | Necropsy tissues | ||
IgM seroconversion | From negative IgM to positive IgM in paired sera | Acute serum (days 1–5) and convalescent serum (15–21 days after first serum) | |
IgG seroconversion | From negative IgG to positive IgG in paired sera or 4-fold increase IgG levels among paired sera | ||
Probable Dengue Infection | Positive IgM | Positive IgM | Single serum collected after day 5 |
High IgG levels | High IgG levels by ELISA or hemagglutination inhibition assay (≥1280) |
† ELISA = enzyme-linked immunosorbent assay; IgG = immunoglobulin G; IgM = immunoglobulin M; NS1 Ag = non-structural protein 1 antigen; RT-PCR = reverse transcriptase polymerase chain reaction