The importance of heterogeneity on the management of vector borne diseases

February 1, 2018, Liverpool School of Tropical Medicine

Researchers at LSTM have been working with colleagues in the NTD modelling consortium to look at the role that heterogeneity in mosquito biting plays within the transmission of disease and what impact vector control has on that heterogeneity.

While it is well known that some individuals within the same community may be exposed to a different number of , very few studies have been carried out to measure the causes of that , or variance, to understand its impact on the control of vector-borne diseases in a way that is relevant to decision making.

In a paper published today in the journal Proceedings of the Royal Society B the team, including LSTM's Dr. Lisa Reimer, uses modelling and surveillance data to investigate the relationship between spatial and individual heterogeneity in the context of , finding that both measures are qualitatively different with profoundly different policy implications.

Vector borne disease control often relies on universal distribution of interventions, such as long-lasting insecticide treated bednets for malaria and mass drug administration for filariasis. These interventions are distributed in a heterogeneous environment—where humans experience different levels of exposure, due to both individual and spatial factors. Dr. Reimer said: "In this study, we explored the links between heterogeneous mosquito bite exposure and filariasis infection and how relationships change with the distribution of bednets. We concluded that the sources of heterogeneity within a transmission system have different implications for the success of mass drug administration (MDA) in achieving elimination."

Using infection and mosquito bite data for five villages in Papua New Guinea the team measured biting characteristics to model the impact of bednets on disease control and combined this with geospatial modelling. They found that when individual heterogeneity is high, a very high coverage of MDA would be needed to ensure the small group of individuals contributing to transmission are treated, and targeted treatment may be necessary. When spatial heterogeneity is high, different villages may have very different prevalence and the use of sentinel sites to determine regional elimination will not give an accurate picture.

"Our research in Papua New Guinea shows that the distribution of bednets increased heterogeneity in exposure," continued Dr. Reimer, "which could potentially lengthen the number of rounds of MDA required. However, we also found that the introduction of bednets reduced nightly biting enough to offset this effect. What is clear following this research is the importance of understanding sources of heterogeneity to the control and elimination of ."

Explore further: Insecticide-treated bed nets critical to global elimination of filariasis

More information: Michael A. Irvine et al. Understanding heterogeneities in mosquito-bite exposure and infection distributions for the elimination of lymphatic filariasis, Proceedings of the Royal Society B: Biological Sciences (2018). DOI: 10.1098/rspb.2017.2253

Related Stories

Insecticide-treated bed nets critical to global elimination of filariasis

August 21, 2013
An international team of scientists have demonstrated that a simple, low-cost intervention holds the potential to eradicate a debilitating tropical disease that threatens nearly 1.4 billion people in more than six dozen countries.

Malaria—should we abandon insecticide-treated bednets?

July 12, 2016
In Africa, some malaria-carrying mosquitoes have found ways to survive exposure to insecticides. This means that bednets treated with these chemicals may become less effective at preventing malaria. A new study we've published ...

Researchers decipher molecular basis of resistance in the African vector Anopheles funestus

November 2, 2015
Researchers at LSTM have shown the means by which one of the major species of mosquito responsible for transmitting malaria in Africa is becoming resistant to the insecticides used to treat the bednets which protect people ...

A new way to thwart disease-spreading mosquitoes

January 29, 2018
(HealthDay)—It sounds like science fiction, but researchers say they have taken the first step toward creating female mosquitoes that don't bite and spread disease.

Factor that doubles the risk of death from breast cancer identified

January 19, 2018
Researchers at Karolinska Institutet in Sweden have discovered that the risk of death from breast cancer is twice as high for patients with high heterogeneity of the oestrogen receptor within the same tumour as compared to ...

Recommended for you

Dengue: Investigating antibodies to identify at-risk individuals

May 23, 2018
Using an original mathematical and statistical analysis method, a team of scientists from the Institut Pasteur partnered with researchers from the United States and Thailand to analyze a Thai cohort that has long been a focus ...

Fatty liver disease research set to benefit from stem cell advance

May 23, 2018
Scientists have developed a lab-based system for studying the most common type of liver disease, paving the way for research into new therapies.

More frequent checks control MRSA in newborns, but can hospitals afford them?

May 22, 2018
The more often a hospital can check its newborns for deadly MRSA germs, the more likely it will be that they are contained, according to a new study.

Could we predict the next Ebola outbreak by tracking the migratory patterns of bats?

May 22, 2018
Javier Buceta, associate professor of bioengineering, Paolo Bocchini, associate professor of civil and environmental engineering, and postdoctoral student Graziano Fiorillo of Lehigh University have created a modeling framework ...

Helping preterm infants grow bigger kidneys would prevent kidney disease later in life

May 21, 2018
Nephrons are the microscopic blood-filtering units inside our kidneys that convert waste products into urine, regulate our electrolyte levels and our blood pressure.

Kidney docs worry over no dialysis for undocumented immigrants

May 21, 2018
(HealthDay)—Undocumented immigrants in the United States are often denied treatment for kidney failure until they have a life-threatening emergency. Now a new study finds that the doctors and nurses who treat them are frustrated ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.