WHO has prescribed standards for entomological testing to assist the global fight against vector-borne diseases including malaria, dengue fever as well as Zika. Transmission of these diseases occurs via vectors such as mosquitoes, ticks, and fleas, which are major threats to human health, especially in tropical and subtropical regions.  WHO guidelines for entomology testing provides standard protocols for the collection, testing, and evaluation of insect populations, insecticides, and repellents, guiding laboratories, public health agencies, and product manufacturers in conducting tests for vector control strategies to strengthen disease prevention.

Importance of Entomological Testing 

Effective Vector Control and Decrease in the Burden of Vector Borne Diseases 

Entomological testing is the basis of vector control programs. Monitoring for insect populations enables researchers to determine the risk of disease transmission and assess control measures such as insecticides and repellents. Without standardized testing, different ways of evaluation may be ineffective, thus producing inconsistent results. Improperly evaluated vector control products may lead to inappropriate vector control thus supporting the transmission of vector borne diseases.  

WHO Guidelines for Entomology Testing Services

Standardized Collection Methods

The first step in entomological testing is vector sampling. WHO guidelines for entomology testing recommend standardized methods for ensuring that samples are representative of the insect population in an area. E.g., traps such as CDC light traps are employed in collecting mosquitoes. In addition, the WHO recommends selecting the best sites and times for collection to ensure that the information represents the peak activity period of the target insects.

Laboratory Test Methods

After collection, the samples are taken to the laboratory for various tests, which determine factors such as resistance to insecticides, repellency, and pathogens carried by them. Some of the tests to be conducted are provided in the WHO guidelines for entomology testing, including bioassays to determine the effectiveness of the insecticides. The laboratories are expected to follow the guidelines to ensure uniformity in the results obtained from the various testing areas.

Monitoring of Insecticide Resistance

Another priority area included in WHO guidelines for entomology testing is monitoring insecticide resistance. Most of the insects in different parts of the world have gradually developed complete resistance to commonly used insecticides, which might reduce the efficacy of vector control programs. For this reason, the WHO recommends regular monitoring of insecticide resistance through a set of tests, including the WHO susceptibility bioassay and the CDC bottle bioassay. The results of such tests address the level of resistance of an insect population against a particular insecticide and inform public health authorities on the choice of suitable alternatives.

Testing Repellents 

Besides insecticides, repellents are an important means of protection against bites and represent one of the most efficient ways of reducing vector-borne diseases. WHO guidelines for entomology testing prescribe certain methods for repellent efficacy testing. Such tests necessarily include exposure of insects to skin or surfaces treated with the test substance and measures duration and level of protection given by the repellent. These tests can guarantee that a product that has been commercially launched for personal protection does meet necessary standards of effectiveness.

Compliance and Regulatory Aspects

International Standards Alignment

 WHO guidelines ensure that the entomological testing is as per some of the globally recognized standards. This would enable the laboratories and the manufacturers to obtain credible and comparable data, hence, facilitating international collaborations in combating various vector-borne diseases.

Regulatory Framework:

WHO guidelines often provide a basis for governments and regulatory agencies in crafting their own laws and regulations pertaining to vector control products. To manufacturers and laboratories, WHO guidelines are at the core of the regulatory approval of insecticides, repellents, and other forms of vector control products..

Challenges in Implementing WHO Guidelines

While the WHO guidelines are comprehensive guides to entomological testing, there are some difficulties in their implementation, particularly in resource-limited settings. Many laboratories lack infrastructure, equipment, or even trained personnel to conduct the tests in accordance with WHO standards. It includes:

Limitation of Resources

• Most of them, like developing and underdeveloped countries with lower financial resources,  cannot fully follow the WHO guidelines. This may be because they lack the appropriate equipment, materials, trained personnel, and infrastructure as set out in the standards.

Technical Expertise

• The guidelines generally demand specialized knowledge in entomology, molecular biology, and statistical analysis as per WHO recommendations. A shortage of skilled personnel with expert knowledge in carrying out and interpreting the entomological tests results in inconsistent application of the guidelines and impacts the reliability of the data

 Regulatory and Policy Barriers

• Sometimes, national governments lack the necessary legislative framework and governance system to implement the WHO’s recommendations, which require amendments and adjustments in the prevalent laws and regulations.

 Data Collection and Monitoring

• Most of the WHO guidelines on communicable diseases require surveillance, collection, and monitoring of data for compliance assessment and the evaluation of the effectiveness of interventions. This can be specifically challenging in areas with a weak health information system or lack of technological capabilities.

Environmental and Ecological Variability

• The testing of field interventions-insecticides or vector control methods-is often performed under the diverse ecological conditions. As a result, the environment of such tests cannot be standardized; for example, variations in climate, topography, and local vector behavior will render these tests inconsistent.

Conclusion

WHO guidelines for entomology testing services are a fundamental means of ensuring that the efficacy, precision, and dependability of vector control interventions are taken into account. These guidelines provide a means to standardize methodologies to ensure that testing services completely adhere to global best practices, contributing to better disease control outcomes. At MIS we offer testing services like arm-in-cage tests and room tests, in compliance with WHO guidelines for entomology.  Our expert team utilizes advanced testing protocols to ensure your products provide reliable protection, helping you meet industry standards and consumer expectations. Contact us today to learn more about our services.