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close this bookWHO Recommended Surveillance Standards (WHO; 1999; 157 pages)
View the documentAcknowledgements
View the documentAcronyms
View the documentIntroduction
View the documentNational Coordination of Communicable Disease Surveillance
View the documentExplanatory notes
View the documentSurveillance activities: criteria and WHO Department
View the documentCommunicable disease contacts in Regional Offices
close this folderDiseases
View the documentB20-B21-B22-B23-B24 AIDS
View the documentA22 Anthrax
View the documentA23 Brucellosis
View the documentA00 Cholera
View the documentA81.0 Creutzfeldt-Jakob disease
View the documentA90, A91 Dengue fever (A90) including Dengue haemorrhagic fever (DHF) & Dengue shock syndrome (DSS, A91)
View the documentA36 Diphtheria
View the documentB72 Dracunculiasis (Guinea worm disease)
View the documentA98.3, A98.4 Ebola-Marburg viral diseases
View the documentA83.0 Japanese encephalitis
View the documentB74 Lymphatic filariasis
View the documentB96.3 Haemophilus influenzae type b
View the documentB15-B17 Acute viral hepatitis
View the documentB20-B24 HIV infection
View the documentJ10, J11 Influenza
View the documentA96.2 Lassa fever
View the documentA48.1 Legionellosis
View the documentB55.1, B55.2 Cutaneous leishmaniasis
View the documentLeishmania / HIV co-infections
View the documentB55.0 Visceral leishmaniasis
View the documentA30 Leprosy
View the documentA27 Leptospirosis
View the documentB50-54 Malaria
View the documentB05 Measles
View the documentA39 Meningococcal disease
View the documentA87 Viral meningitis
View the documentB73 Onchocerciasis
View the documentA37.0 Pertussis
View the documentA20 Plague
View the documentA36 Poliomyelitis
View the documentA82 Rabies
View the documentA02.0 Salmonellosis
View the documentB65 Schistosomiasis
View the documentA50-52 Syphilis
View the documentA33 Tetanus, neonatal
View the documentB56-0, B56-1 African trypanosomiasis
View the documentB57 American trypanosomiasis
View the documentA15-A19 Tuberculosis
View the documentA75.3 Scrub typhus
View the documentA95.9 Yellow fever
open this folder and view contentsSyndromes
View the documentAnnex 1 Software free and in the public domain
View the documentAnnex 2 Proposed surveillance definitions
View the documentAnnex 3 Role and use of Geographic Information Systems (GIS) and mapping for epidemiological surveillance

A90, A91 Dengue fever (A90) including Dengue haemorrhagic fever (DHF) & Dengue shock syndrome (DSS, A91)


Dengue fever, including DHF and DSS, is the most significant arthropodborne viral disease worldwide. It occurs in over 100 countries and territories and threatens the health of over 2 500 million people in tropical and subtropical regions. Dengue fever is a severe disease with high epidemic potential. An estimated 500 000 patients, 90% of them below the age of 15, are hospitalized with DHF/DSS every year. WHO aims to accelerate the final development of an attenuated dengue vaccine.



Clinical description

An acute febrile illness of 2-7 days duration with 2 or more of the following: headache, retro-orbital pain, myalgia, arthralgia, rash, haemorrhagic manifestations, leucopenia.

Laboratory criteria for diagnosis

One or more of the following:


• Isolation of the dengue virus from serum, plasma, leukocytes, or autopsy samples

• Demonstration of a fourfold or greater change in reciprocal IgG or IgM antibody titres to one or more dengue virus antigens in paired serum samples

• Demonstration of dengue virus antigen in autopsy tissue by immunohistochemistry or immunofluorescence or in serum samples by EIA

• Detection of viral genomic sequences in autopsy tissue, serum or CSF samples by polymerase chain reaction (PCR)

Case classification

Suspected: A case compatible with the clinical description.

Probable: A case compatible with the clinical description with one or more of the following:


• supportive serology (reciprocal haemagglutination-inhibition antibody titre ≥1280, comparable IgG EIA titre or positive IgM antibody test in late acute or convalescent-phase serum specimen).

• occurrence at same location and time as other confirmed cases of dengue fever.

Confirmed: A case compatible with the clinical description, laboratory-confirmed.


A probable or confirmed case of dengue and

Haemorragic tendencies evidenced by one or more of the following:


• Positive tourniquet test
• Petechiae, ecchymoses or purpura
• Bleeding: mucosa, gastrointestinal tract, injection sites or other
• Haematemesis or melaena

And thrombocytopenia (100 000 cells or less per mm3)

And evidence of plasma leakage due to increased vascular permeability, manifested by one or more of the following:


• ≥20% rise in average haematocrit for age and sex
• ≥20% drop in haematocrit following volume replacement treatment compared to baseline
• signs of plasma leakage (pleural effusion, ascites, hypoproteinaemia)


All the above criteria, plus evidence of circulatory failure manifested by rapid and weak pulse, and narrow pulse pressure (≤20 mm Hg) or hypotension for age, cold, clammy skin and altered mental status.


Areas where no dengue transmission has been detected but where

Aedes aegypti occurs

Surveillance of suspected cases with investigation of clusters of suspected cases for dengue.

Countries where disease is endemic with seasonal variations in transmission, and areas where epidemic dengue occurs

Routine weekly/monthly reporting of aggregated data of suspected, probable and confirmed cases from peripheral to intermediate and central levels.


Case-based data at the peripheral level


• Case classification (suspected/probable/confirmed), serotype, DHF/DSS present (Y/N)
• Unique identifier, name of patient, age, sex, geographical information
• Date of onset
• Hospitalized (Y/N)
• Outcome
• Travel history during past 2 weeks

Aggregated data for reporting


• Number of cases by age group
• Number of confirmed (and serotype)
• Number of DHF/DSS cases by age group
• Number of hospitalizations and deaths


Percentage of DHF/DSS cases and of hospitalizations.

Case-fatality rate.



• Target high risk areas for intervention
• Monitor changes in serotype and rate of DHF/DSS
• Monitor trends in endemic disease or re-emergence of disease


Parallel to disease surveillance, vector surveillance of both larval and adult populations of Ae. aegypti and Ae. albopictus.


Regional Offices

See Regional Communicable Disease contacts on section "Communicable disease contacts in Regional Offices".

Headquarters: 20 Avenue Appia, CH-1211 Geneva 27, Switzerland

Communicable Diseases Surveillance and Response (CSR)


E-mail: arthurr@who.ch / outbreak@who.ch
Tel: (41 22) 791 2658/26367 2111
Fax: (41 22) 791 48 78
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