1. DENGUE FEVER IN TANZANIA
Challenges and Opportunities
Moses Gwamaka
Rufiji HDSS
Ifakara Health Institute
2. 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
3. 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
5. 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
8. 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
9. 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
10. 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
11. 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
12. 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
13. Surveillance platforms:
– Health Demographic Surveillance System (HDSS)
– Sentinel Panel of Districts (SPD)
– Clinical Surveillance System (CSS)
Modern laboratories
OPPORTUNITIES
14. 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
15. 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
16.
17. ≈ 800,000 individuals≈ 1,500 facilities
SPD
FBIS SAVVY
1. Facility Based Information System
2. Sample Vital Registration with Verbal Autopsy
19. 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
21. 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
22. 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
23. IHI-Lab a reference centre for the WHO Combination Therapy Trials
Sao Tomè
WHO-CT trial sites
25. 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
