The
Tanzania National Malaria Control Program (NMCP), in collaboration with
partners, has made significant strides in the fight against malaria,
resulting in remarkable reduction in malaria burden. The National
Malaria Strategic Plan (NMSP) 2021-2025 aims to reduce even further the
malaria prevalence in children under 5 years old from 7% in 2017 to less
than 3.5% in 2025 . NMSP 2021-2025 has three core strategies, i.e.
integrated malaria vector control (IMVC); malaria diagnosis, treatment
and preventive therapies (MDTPT); surveillance, monitoring and
evaluation (SME) and three supportive strategies, i.e. program
management; commodities and logistics management; social behaviour
change and advocacy.
Under IMVC, NMCP has mainly been
implementing two interventions: i) distribution of Long Lasting
Insecticide-treated Nets (LLINs) across the country through various
channels, ii) Indoor Residual Spraying (IRS) in select high endemic
councils. In addition to these two interventions, there is a strong
desire from the government to add Larval Source Management (LSM) as
another vector control intervention across the country. However, World
Health Organization (WHO) recommends LSM as a supplemental vector
control intervention, suitable mostly in urban settings and where
breeding habitats are few, fixed and findable.
NMCP
has partnered with the Swiss Tropical and Public Health Institute
(Swiss TPH) in a project funded by the Swiss Agency for Development and
Cooperation (SDC) titled Towards Elimination of Malaria in Tanzania
(TEMT). The TEMT project plans to implement LSM in three councils in
Tanga region (Handeni District Council-DC, Lushoto District Council-DC,
and Tanga City Council-CC). The councils were selected to represent both
rural and urban settings, as well as different malaria risk strata: low
‘Lushoto DC with 0.1%’, moderate ‘Tanga CC with 17.7%’ and high
‘Handeni DC with 37.6%’ prevalence. The experiences and evidence
gathered during implementation will be used to advise the government
(and NMCP) on scale-up and financing of LSM intervention to other
councils.
1. What is LSM?
LSM
is the management of water bodies that are potential mosquito breeding
sites in order to prevent completion of mosquito’s life cycle2. It
controls immature aquatic stages of mosquitoes (larvae), hence reducing
abundance of adult mosquito vectors. There are four types of LSM: i)
habitat modification (a permanent alteration of the environment e.g.
land reclamation); ii) habitat manipulation (a recurrent activity e.g.
flushing of streams); iii) larviciding (regular application of
biological or chemical insecticides to water bodies); and iv) biological
control (introduction of natural predators to water bodies).
2. Structure and modality of implementation of LSM intervention
Guidelines and Standard Operating Procedures:
NMCP, in collaboration with Swiss TPH – TEMT project and other
partners, has developed Standard Operating Procedures (SOPs) to guide
LSM implementation. Six (6) SOPs have been developed. Each SOP provides
guidance to one of the six key areas of LSM implementation. These are:
i) advocacy, community mobilization and engagement, ii) participatory
mapping and habitat identification (baseline data collection); iii)
setup and logistics; iv) application of biolarvicide; v) monitoring and
evaluation; and vi) environmental management for vector control.
Structure of LSM implementation:
LSM is coordinated at the national level by NMCP and Swiss TPH – TEMT
project. Implementation of LSM follows a community-based approach
whereby community members (Community Owned Resource Persons – CORPs) are
responsible for mapping, identification of breeding habitats, and
application of biolarvicide within their areas. Two (2) CORPs are
selected per village. CORPs are supervised by officers at village, ward,
council and regional levels using existing local government structures.
Biolarvicide products: The program is using two biolarvicide products: BACTIVEC (Bacillus thuringiensis var. israelensis - Bti) and GRISELESF (Bacillus sphaericus
- Bs) which are produced locally, in Kibaha (Pwani region) by Tanzania
Biotech Products Limited (TBPL). These are biological products whose
active ingredient targets only larvae stages of mosquitoes. Both
products are safe to humans, animals and the environment.
Application of biolarvicide:
Both products (BACTIVEC and GRISELESF) have a residual effect of seven
(7) days when applied to breeding habitats. Therefore, the products need
to be re-applied weekly. As per developed SOPs, the application of
biolarvicide follows a temporal approach based on rainfall pattern, i.e.
councils with a unimodal rainfall pattern apply biolarvicide for two
rounds in a year (before and after the rain season), while councils with
a bimodal rainfall pattern apply biolarvicide for three rounds in a
year (before the first rain season, between the two rain seasons, and
after the second rain season). Each round of application of biolarvicide
comprises of eight (8) weeks whereby biolarvicide is applied in weeks
1, 2, 3, 4, 6 and 8 and skipped in weeks 5 and 7.
3. Launch of LSM intervention:
The
current strategy of implementation of LSM intervention as per developed
guidelines and SOPs was launched nationally by the Tanzania Minister of
Health, Hon. Ummy A. Mwalimu, on 19th July 2022 in Tanga CC (as Tanga
CC is one of the three councils implementing LSM intervention). The
event was also attended by Ambassador of Switzerland to Tanzania and
Representative to the East African Community, Didier Chassot.
The
Minister’s key messages during the inauguration were for: i) the region
and councils to ensure LSM is implemented effectively within their
areas and reports are submitted timely, ii) everyone to take proactive
measures to destroy breeding habitats and keep the environment clean,
and iii) effective analysis of the results to inform the government
during scale-up of LSM intervention to other councils.
The
Ambassador of Switzerland expressed the continued support and
collaboration of the Government of Switzerland with the Government of
Tanzania on health and other sectors.
Both
the Minister and the Ambassador, with other officials had the chance to
visit one of the breeding habitats for a demonstration on how to apply
biolarvicide and to officially launch the intervention. See pictures
below.
4. Status of LSM implementation
The following activities have been conducted towards implementation of LSM intervention:
- Development of Standard Operating Procedures and M&E tools for LSM
Standard Operating Procedures (SOPs) for LSM were developed
by NMCP and Swiss TPH, in collaboration with other
organizations/institutions, including: President's Office - Regional
Administration and Local Government (PO-RALG), National Institute for
Medical Research (NIMR), Sokoine University of Agriculture (SUA),
Ifakara Health Institute (IHI), Research Triangle Institute (RTI
International), USAID’s Vector Control Activity project (TVCA), Vector
Link, TBPL, and WHO. A total of six (6) SOPs, with respective M&E
tools, have been developed. All SOPs were reviewed by an External
Reviewer and after addressing all inputs, the final SOPs were translated
to Kiswahili for use at the council and sub-council levels.
- Advocacy for LSM intervention – Tanga:
Advocacy
meetings were conducted in July 2021 in each of the three (3) councils;
Handeni DC, Lushoto DC and Tanga CC, as well as the regional level. The
meeting at the regional level was chaired by Regional Commissioner and
meetings at the council levels were chaired by the respective District
Commissioners. The meetings were conducted for two days whereby day one
focused on introduction to LSM program structure and implementation
modality, while day two focused on LSM council microplanning.
- LSM Orientation/Training of National level trainers
Cascaded
training was conducted from August to December 2021. Training of
national level trainers was conducted in August 2021 whereby 20
participants were trained. Training for regional and council teams was
conducted in September 2021 whereby eight (8) participants from each
council and three (3) participants from the regional level were trained.
At the sub-council level, two participants per ward (Ward Executive
Officer-WEO and Ward Health Officers), two participants per
village/street (Village/ Mtaa Executive Officer-VEO/MEO, chairperson)
and two CORPs per village were trained. Sub-council level training was
conducted from October to December 2021. Across all levels, a total of
1,421 participants have been trained on LSM intervention through
in-class theory sessions as well as practical sessions in the field.
- Procurement and distribution of biolarvicides, equipment, and M&E tools/forms
As
per SOPs, the following equipment are required for implementation of
LSM intervention: spray pumps, gumboots, larval trays and dippers.
Quantification of each equipment was based on the number of CORPs. All
equipment were procured and transported to the respective councils
together with SOPs and M&E tools/forms. Moreover, 17,240 litres of
biolarvicide have been procured from TBPL and distributed to the
councils to be used during the first round of application of
biolarvicide.
- Mapping and baseline data collection on breeding habitats
All
three councils conducted mapping and baseline data collection on
breeding habitats in February 2022. Data on breeding habitats (including
type, size, larvae, and pupa count) was collected weekly for 4 weeks.
The average number of breeding habitats (and estimated size in m²) was
15,333 (471,539 m²) across all three councils; 12,203 (325,701 m²) in
Handeni DC, 2,126 (92,122 m²) in Lushoto DC and 1,005 (53,717 m²) in
Tanga CC.
- Application of biolarvicide – Round
First round of application of biolarvicide across all three councils started in June 2022, after rain season (masika), and concluded in July 2022, completing 8 weeks of application.
5. Next steps
- Feedback
meetings with regional and council teams discussing the facilitators
and barriers to smooth implementation of LSM intervention
- Analysis of entomological and epidemiological data following completion of the first round of application of biolarvicide
- Preparation for second round of application of biolarvicide across all three councils
- Cost-benefit analysis report to support the government’s planning, resource allocation, and policy decision making
6. Conclusion
This
approach of LSM implementation as guided by SOPs using exclusively
governmental mechanisms as well as locally produced biolarvicide
products is expected to contribute important real-world experience on
the potential of this form of vector control across a range of ecologies
and transmission situations. Results of this approach will advise the
government during scale-up on this intervention in other councils.
More information:
Contact:
Dennis Kailembo (author)
Noela Kisoka (co-author)
Swiss Tropical and Public Health Institute, Tanzania
Photo:
Demonstration
of application of biolarvicide on breeding habitats with the Tanzania
Minister of Health – Hon. Ummy A. Mwalimu and Ambassador of Switzerland
to Tanzania – H.E. Didier Chassot ©TEMT Project