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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
 

A75.3 Scrub typhus

(Mite-borne typhus, Tsutsugamushi disease)

RATIONALE FOR SURVEILLANCE

Scrub typhus (mite-borne typhus, Tsutsugamushi disease) is an acute infectious disease that is emerging and re-emerging in South-East Asia and the south-western Pacific region. It can have a case-fatality rate of up to 30% if untreated. Epidemics occur when susceptible individuals are brought into endemic areas (e.g., during military operations). In some countries (e.g., Japan) it is a notifiable disease. Multi-drug resistance has been documented in Thailand.

Surveillance is essential to a better understanding of the epidemiology of the disease and to the detection of outbreaks. Training in diagnostic techniques is often required.

RECOMMENDED CASE DEFINITION

Clinical description

A disease with a primary "punched out" skin ulcer (eschar*) where the bite(s) occurred, followed by acute onset fever after several days, along with headache, profuse sweating, conjunctival injection and lymphadenopathy. Within a week, a dull maculo-papular rash** appears on the trunk, extends to the extremities and disappears in few days. Cough is also common. Defervescence within 48 hours following tetracycline therapy strongly suggests a rickettsial etiology.

 

* Eschar may be absent in some geographic areas and in highly endemic areas where reinfection is frequent.

** Rash may be overlooked in patients with dark or sunburned skin.

Laboratory criteria for diagnosis

Isolation of Orientia* tsutsugamushi by inoculation of patient blood in white mice (preferably treated with cyclophosphamide at 0.2 mg/g intraperitoneally or intramuscularly on days 1,2 and 4 after inoculation).

 

* Formerly Rickettsia.

Serology:

Detection of specific IgM

 

at 1:100 or higher by Enzyme Immunoassay (EIA)

 

or 1:32 dilution or higher by Immunoperoxidase (IP)

 

or 1:10 dilution or higher by Indirect Immunofluorescence (IF).

Case classification

 

Suspected: A case that is compatible with the clinical description.
Confirmed: A suspected case with laboratory confirmation.

 

Note: Serological tests are complicated by the antigenic differences between various strains of the causal agent.

RECOMMENDED TYPES OF SURVEILLANCE

Immediate case-based reporting of all suspected cases from the peripheral level to the intermediate and central level. All suspected cases and outbreaks must be confirmed. A parallel laboratory surveillance system reports all confirmed cases to central level.

RECOMMENDED MINIMUM DATA ELEMENTS

Case-based data to report

 

• Case classification (suspected/confirmed)
• Unique identifier, age, sex, geographical information
• Date of report
• Hospitalization (Y/N)
• Response to tetracycline therapy
• Outcome

Aggregated data to report

 

• Number of cases by case classification, age, sex, geographical information, date of report
• Number of hospitalizations
• Number of deaths

RECOMMENDED DATA ANALYSES, PRESENTATION, REPORTS

Graphs: Number of cases by date of report.

Tables: Number of cases by age, geographical area.

Maps: Number of cases, and if appropriate, deaths, by geographical area.

PRINCIPAL USES OF DATA FOR DECISION-MAKING

 

• Detect outbreaks
• Monitor trends in endemic disease
• Monitor changes in epidemiology and pattern of disease

SPECIAL ASPECTS

The distribution of O. tsutsugamushi extends north to Japan, Russia, and the Primorske Karai region in the Russian Far East, south to northern Australia and the western Pacific islands, and west to Afghanistan, Pakistan, and areas bordering the Central Asian Republics.

Human O. tsutsugamushi occurs widely in these regions, but not everywhere.

Scrub typhus is probably one of the most underdiagnosed and underreported febrile illnesses requiring hospitalization in the region. The absence of definitive signs and symptoms combined with a general dependence upon serological tests make the differentiation of scrub typhus from other common febrile diseases such as murine typhus, typhoid fever and leptospirosis quite difficult.

CONTACT

Regional Offices WHO Regional Office for South-East Asia (SEARO)

Dr Vijay Kumar, Director, Integrated Control of Diseases (ICD)

 

Tel: 00 91 11 331 7804 ext 523/524
Fax: 00 91 11 331 8412

Dr M.V.H. Gunaratne, Regional adviser on Communicable Diseases (CDG)

 

Tel: 91 11 3318412
Fax: 91 11 331 8607
E-mail: GUNARATNEM@WHOSEA.ORG

Dr A.G. Andjaparidze, Regional Adviser on Communicable Diseases (CDA)

 

Tel: 00 91 11 331 7804 to 7823
Fax: 00 91 11 331 8412
E-mail: ANDJAPARIDZEA@WHOSEA:ORG

Dr Deoraj (Harry) CAUSSY, Regional Epidemiologist

 

Tel: 00 9111 331 7804 to 7823
Fax: 00 9111 331-8412 and 8607
E-mail: CAUSSYD@WHOSEA.ORG

Should you experience difficulties in reaching the above, call Fax 91 11 332 7972

WHO REGIONAL OFFICE FOR THE WESTERN PACIFIC (WPRO)

A/Regional Adviser in Communicable Diseases, CDS (Dr Chris Maher)

 

Tel: 00 632 522 9964
Fax: 00 632 528 1036
E-mail: maherc@who.org.ph

Dr Reiko Muto, Associate Professional Officer, CDS

 

E-mail: mutor@who.org.ph

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 2658/2636/2111
Fax: (41 22) 791 4878
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