DENGUE FEVER IN TANZANIA Challenges and Opportunities

Moses Gwamaka

Rufiji HDSS

Ifakara Health Institute

The official population of Tanzania is now 44,929,002 people. - 43,625,434 (Mainland) and - 1,303,568 (Zanzibar)

Urbanization Rate of urbanization: 4.7% annual rate of change Urban population: 26% of total population Major city – population = 3.207 million (DSM)

POPULATION AND URBANIZATION

RISK FACTORS FOR DENGUE INFECTIONS

Bull World Health Organ. 1972;47(3):433-7.

Bull World Health Organ. 1972;47(2):245-55.

Bull World Health Organ. 1971;45(4):529-31.

VECTORS In Urban areas …………………………….. 1970 survey

Vectors In rural areas ……………………………..1970 survey

Dengue like epidemics are not new in TZ

East Afr Med J. 1964 Jun;41:271-5.

AN EPIDEMIC OF AN ILLNESS RESEMBLING DENGUE

IN THE MOROGORO DISTRICT OF TANGANYIKA.

WILLIAMS MC, WOODALL JP

RECENT REPORTS OF DENGUE SUGGESTING PRESENCE OF DENGUE IN TANZANIA

Evidence of Dengue Presence in Tanzania

870 Consecutive febrile admissions were enrolled at 2 hospitals in Moshi - North Tanzania (2007) Lab analysis- Duke National University of Singapore Results: Anti DENV IgM- 747 tested for Serology 71(9.5%) were positive Anti- DENV IgM-751 Tested , 80(10.7%) were positive PCR 700 were tested – No participant tested positive for DENV

Conducted in 2007 in 2 hospitals In Pemba (Zanzibar) and Tosamaganga (Tanzania Mainland) 202 consecutive febrile out patients were studied for antibodies and viral RNA Results: Seroprevalence - Pemba = 7.7% - Tosamaganga = 1.8%

Seroprevalence of dengue infection: a cross-sectional survey in mainland Tanzania and on Pemba Island, Zanzibar. Int J Infect Dis. 2012 Jan;16(1):e44-6. Vairo F et al 2012

2010 Outbreak of Dengue type 3 virus infections in TZ

http://library.tephinet.org/es/node/1963

Reports of Dengue fever in Travelers returning from Tanzania

Samples were collected from suspected Dengue fever from 4 hosp. in Dar

Case definition: febrile illness (>38.5°C), body or joint aches, and any of the

following symptoms: headache, rash, nausea, vomiting, or hemorrhagic

manifestations.

Serum samples were drawn at initial examination and tested for presence of the

virus using the Polymerase Chain Reaction (PCR)

Results: Of the 139 suspected dengue cases, 40 (29%) were PCR-positive for

dengue. 21 (52.5%) were travelers/expatriates.

Although there was co-infection with P. falciparum (4 cases), malaria was not

associated with dengue fever (X2=0.475, P=0.788

Ifakara Health Institute (lHI)

Non-profit research and training institute whose

mission is to develop and sustain a district-based

health research and resource centre capable of

generating new knowledge and relevant

information for public health policy and actions

IHI is among the leading health research institutes

in Africa

Malaria, tuberculosis, HIV/AIDS

Non-communicable diseases (specifically diabetes)

Combinations of disease (co-morbidity)

Correlates of protection for vaccines (immunological biomarkers), and

Molecular surveillance of Emerging and Re-Emerging Infectious Diseases.

Main Research Areas

Surveillance platforms:

– Health Demographic Surveillance System (HDSS)

– Sentinel Panel of Districts (SPD)

– Clinical Surveillance System (CSS)

Modern laboratories

OPPORTUNITIES

Health Demographic Surveillance System (HDSS)

• is part of the of INDEPTH network

• is monitoring basic demographic events, like birth, migration, marital status, pregnancy and cause of death

• is monitoring social demographic information, like education and socio-economic status

• is monitoring interventions or programs in the respective districts

• is monitoring the progress of the Millennium Development Goals

• 3 sites in Tanzania:

Rufiji – about 60 km south of DSM

Ifakara – 400 km SW DSM

Kigoma – western Tanzania

In total the surveillances area cover an area of 4341 square kilometers (58 Villages) 1813 in Rufiji (33 villages), 2400 Ifakara (25villages) and 128 Kigoma (144 streets in Kigoma urban). Within HDSS – several studies use this platform Currently, the INESS project uses this platform to look for the following information

- History of fever for last 2weeks and - if any treatment have been given for that in any nearby health facility

≈ 800,000 individuals ≈ 1,500 facilities

SPD

FBIS SAVVY

1. Facility Based Information System

2. Sample Vital Registration with Verbal Autopsy

IHI - Sentinel Panel of Districts (SPD)

IHI Clinical Surveillance System (CSS)

• CSS monitors childhood admissions in mainland Tanzania, focusing on inpatient morbidity and mortality in under five years olds. Very recently, outpatient facilities were also added.

Kilombero

Bagamoyo

Ulanga

• Inpatient (1994-2010): St Francis Designated District Hospital

• Outpatient (2010-2012): Idete and Mbigu Dispensaries

• Inpatient (2004-2012): Bagamoyo District Hospital

• Outpatient (2004-2012): Kiwangwa, Kongo, Yombo and Fukayosi Dispensaries

• No inpatient monitoring

• Outpatient (2010-2012): Lupiro Health Centre and Milola dispensary

St. Francis hospital – Semi-urban Tanzania

IHI - Two laboratories Ifakara and Bagamoyo Genotyping for anti malaria drugs – drugs efficacy

Genotyping to MDR – TB - MassArray

Molecular evolution of ART – HIV (CD4, VL …sequencing)

Plasmodium falciparum clonal diversity and malaria

transmission

Gene flows of the main malaria vectors – Anopheles gambiae and A. arabiensis

Mosquitoes speciation – Species responsible for transmission of malaria

Molecular bloodmeal analysis – to identify reservoir of host (DNA).

Infectivity to mosquitoes- understanding the

transmission Dynamics, intensity of transmission, disease risk etc etc

IHI-Lab a reference centre for the WHO Combination Therapy Trials

Sao Tomè

WHO-CT trial sites

Challenges - HDSS

1. Funding to sustain our HDSS Staff – few

studies are ongoing

2. Lack of Diagnostic capabilities at the point of care – require efficient means of transporting samples to the lab

3. In most areas – lack of sustainable electricity supply

4. Accessibility of some sites during rain season

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