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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

B74 Lymphatic filariasis


Lymphatic filariasis remains a major cause of overt or hidden clinical disease in much of Asia, Africa, the Western Pacific and certain parts of the Americas. It is the second leading cause of permanent long-term disability. The prevalence is increasing world-wide, with at least 120 million people affected at different stages of the disease. Both diethylcarbamazine (DEC) and ivermectin, given as single doses, have been shown to be very effective in reducing microfilaraemia, especially when administered together, or singly with a single dose of albendazole.

Because of highly effective diagnostic and treatment tools, filariasis was identified by the International Task Force on Disease Eradication as one of 6 potentially eradicable diseases. Current WHO policy is to achieve elimination of infection in humans mainly through single-dose drug combinations administered once a year to all 'at risk' populations. Management of disease induced by lymphatic damage from the infection (especially elephantiasis and genital damage) is the second essential element in WHO policy. Surveillance is essential to identify previously undetected foci of infection and to monitor the reduction of microfilariae resulting from elimination efforts.


Clinical case definition

Hydrocoele or lymphoedema in a resident of an endemic area for which other causes of these findings have been excluded.

Laboratory criteria for diagnosis

Microfilaria positive, antigen positive or biopsy positive.

Case classification


Suspected: Not applicable.

Probable: A case that meets the clinical case definition.

Confirmed: A person with laboratory confirmation even if he/she does not meet the clinical case definition.


There are currently three options and the choice will depend on the local situation:


• Routine monthly reporting of aggregated data on probable and confirmed cases from periphery to intermediate level and to central level or

• Sentinel population surveys (standardized and periodical) or

• Active case finding through surveys of selected groups or through mass surveys

International: Annual reporting from central level to WHO (for a limited number of countries).


Case-based data at peripheral level


• Case classification (probable/confirmed)
• Unique identifier
• Geographical information (location)
• Laboratory result

Aggregated data for reporting


• Number of new cases
• Number of laboratory-confirmed cases
• Number of chronic conditions (hydrocoele or lymphoedema)



• Number of cases by geographical area and by year

• Monthly and yearly incidence, point prevalence (if active case detection), by geographic origin, by sex, by parasitological diagnosis



• Estimate the magnitude of the problem and define populations at risk
• Improve and focus the elimination activities
• Improve the management and follow-up of filariasis-infected patients
• Identify technical and operational difficulties




Regional Offices

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

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

Eradication and Elimination of Diseases (CEE/CDS)/Lymphatic Filariasis

Elimination Project (FIL)


E-mail: ottesene@who.ch / Surveillancekit@who.ch
Tel: (41 22) 791 3225/2726/2111
Fax: (41 22) 791 4777
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