GHS, others train health workers on larval source management in Upper East


The National Malaria Control Programme (NAMCOP) and its partners – Ghana Health Service (GHS), Noguchi Memorial Institute of Medical Research (NMIMR) and Zoomlion Ghana Limited (ZGL) – have organised a one-day training workshop in Larval Source Management (LSM) for key stakeholders in the Upper East Region capital, Bolgatanga.

The LSM training, which will be replicated across the country, brought together about 70 health workers from 10 districts in the Upper East.

The participants were equipped with knowledge and techniques in LSM – a vector control tool targetted at mosquito breeding sites with the aim of reducing mosquitoes breeding in the country.

Speaking at the opening ceremony in Bolgatanga on Monday, May 10, 2021, a Senior Research Fellow at NMIMR, Dr. Kwadwo Frempong, said it is not the first time his outfit is engaging in such an exercise.

He said the exercise basically brings together health workers under the Malaria Control Programme, GHS staff members and Zoomlion workers to undergo training in LSM implementation.

“It involves helping them [the participants] to identify mosquito species, and then helping them to know the sources where mosquitoes basically breed,” he explained.

He noted that the training will be an add-on to the already existing Malaria control programmes in the country, which are indoor residual spraying (IRS) and the use of long-lasting insecticide nets (LLINs).

“And this Larval Source Management is going to support these two major control programmes, being that there are quite a number of advantages to this Larval Source Management,” the research fellow at NMIMR said.

According to Dr. Frimpong, some of the advantages of LSM include support to the insecticide resistant challenges, and also helping to control mosquitoes at the larva stage.

“LSM also helps control behavioural issues/changes in adult mosquitoes, which the IRS and LLINs do not but only target mosquitoes that rest and feed indoors,” he added.

He said the LSM when implemented well will accrue to the enormous benefit of communities, adding that “We can have a community supporting the control of mosquitoes because we have one aspect of it, which is environmental management, wherein the community is involved”.

Speaking to journalists after the workshop, a Senior Vector Control Officer of Zoomlion Ghana Limited, Mr. Abel Djangmah, described the training as “good and successful”.

“There was full cooperation among the stakeholders,” he expressed.

He said the project was centred on mosquito larvae: “That is, the baby mosquito and not the mosquito itself”.

He went on to disclose that the chemical used by his outfit to fight the mosquito larvae and which only works in water-bodies is a biological product.

“Last year, we were using Bacillus thuringiensis subspecies israelensis (Bti). It works best when you put it into water-bodies. One challenge we had with what we were using previously, that was 2009 and 2020, is that the chemical or the biological agent was able to last just one week. So, every week you would have to go and do reapplication,” he said.

That process, Mr. Djangmah indicated, was quite exhaustive and time-consuming; which put a lot of financial constraints on the project.

“But thankfully, this time around we are shifting from the one-week spraying to monthly larviciding. So, instead of doing the spraying every week, the product is able to last within the environment for one month. Hence, after a one-month duration you go back and do the reapplication,” he said.

Thus, he insisted, this year’s product has a long-lasting effect compared to what was being used previously.

LSM, a vector control tool for managing mosquito breeding sites, is only recommended as a supplementary malaria vector control measure that adds on to other core vector control interventions, such as long-lasting insecticidal treated nets (LLINs) and indoor residual spraying (IRS).
There are four main types of LSM: including habitat modification, which means a permanent alteration to the environment, e.g. land reclamation or surface water drainage; habitat manipulation, which refers to a recurrent activity e.g. water-level manipulation, flushing of streams, the shading or exposure of habitats; larviciding, which involves regular application of a biological or chemical insecticide to water-bodies; and biological control, which involves the introduction of natural predators into water-bodies; for example, predatory fish or invertebrates to feed on mosquito larvae or pupae (WHO LSM Operational Manual, 2013).

When appropriately implemented, LSM can contribute to reducing the numbers of both indoor and out-door biting mosquitoes; and in malaria control, it can be a useful addition to programme tools to reduce the mosquito population in remaining malaria ‘hotspots’. Where appropriate, it can also help programmes to reduce their overall dependence on insecticides, thereby making a contribution to preventing the emergence of insecticide resistance. LSM can also be useful to help control other vector-borne diseases, especially dengue, and also solve socio-cultural issues in indoor residual spraying programmes as well as LLIN.

WHO recommends larviciding in areas where mosquito breeding sites are few, fixed and findable; and where the sites are easy to identify, map and treat.

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