Nav: Home

Google searches for 'chickenpox' reveal big impact of vaccinations

May 30, 2016

ANN ARBOR -- Countries that implement government-mandated vaccinations for chickenpox see a sharp drop in the number of Google searches for the common childhood disease afterward, demonstrating that immunization significantly reduces seasonal outbreaks.

That's one of the findings from a new University of Michigan-led study that analyzed thousands of Google searches for "chickenpox." The researchers downloaded and analyzed freely available Google Trends data from 36 countries on five continents, covering an 11-year period starting in 2004.

The technique is sometimes called digital epidemiology and has previously been used to identify outbreaks of diseases like influenza, rotavirus and norovirus. But the chickenpox study is the first to use digital epidemiology to show the effectiveness of a vaccine, said Kevin Bakker, a doctoral student in the U-M Department of Ecology and Evolutionary Biology.

"It is really exciting to see human information-seeking behavior -- Google searches -- being reduced by vaccination implementation," Bakker said. "It's a very clear signal, and it shows that the vaccine is having a strong effect."

He said the approach offers a novel way to track the global burden of childhood diseases and to illustrate the population-level effects of immunization -- especially for diseases, like chickenpox, where clinical case data are scarce. However, the technique is limited to countries where internet service is widely available.

Bakker is lead author of a paper on the topic scheduled for online publication May 30, 2016 in the Proceedings of the National Academy of Sciences. The work will also be a chapter in his doctoral dissertation.

The study is one of the most comprehensive digital epidemiology efforts to date, Bakker said. Examining data from several dozen countries enabled the researchers to identify the seasonality of chickenpox outbreaks, which occurred in the springtime worldwide, he said.

The main idea behind digital epidemiology studies is that the number of Google searches spikes in response to an infectious-disease outbreak as worried parents and others seek information about symptoms, treatment, vaccines and related topics.

To demonstrate that internet queries about chickenpox can be used as a reliable proxy for disease incidence, Bakker and his colleagues had to show that Google Trends data accurately reflected clinical cases. But chickenpox is not included in the World Health Organization's global monitoring system for vaccine-preventable diseases, and only a handful of countries report cases to national-level public health officials.

Bakker and his colleagues found that in the three countries that require reporting of chickenpox cases but do not require vaccination against the disease--Mexico, Thailand and Estonia--Google searches for "chickenpox" were strongly correlated with reported cases. In the United States and Australia, two countries that report chickenpox and require the vaccine, the correlation still held but was weaker.

These correlations enabled the researchers to create a forecasting model to predict the timing and magnitude of chickenpox outbreaks based on Google Trends data.

"These results suggest that information seeking can be used for rapid forecasting, when the reporting of clinical cases is unavailable or too slow," the authors wrote.

But the most interesting results, according to Bakker, were analyses showing a reduction in searches for "chickenpox" following the implementation of a government-mandated vaccination program for the disease.

This effect was most striking in Germany, which gradually increased its vaccination requirements over the course of several years, beginning in 2004. Google Trends data are available for the full period and show stepwise drops in Google searches for "chickenpox" following each new vaccination requirement.

"These results demonstrate that if you institute nationwide vaccination for chickenpox there is a very clear reduction in searches, which is a way to infer a strong reduction in total disease incidence," Bakker said.

One of the strengths of the study is that chickenpox is a disease with distinct symptoms, unlike influenza and other illnesses that have been studied using digital epidemiology, Bakker said.

Chickenpox is a highly contagious disease caused by the varicella zoster virus. It causes a blister-like rash, itching, tiredness and fever. The rash appears first on the stomach, back and face and then spreads over the entire body, causing between 250 and 500 itchy blisters, according to the Centers for Disease Control and Prevention. In adults, the same virus can cause shingles.

Since U.S. vaccinations began in 1996, the annual number of chickenpox cases in the country has declined by 92 percent, the annual number of hospitalizations has dropped by 84 percent, and the annual number of deaths has decreased by 90 percent, according to CDC.
-end-
Bakker's co-authors on the PNAS paper are Micaela Martinez-Bakker of Princeton University, Barbara Helm of the University of Glasgow and Tyler Stevenson of the University of Aberdeen. Bakker was supported by a Michigan Institute in Computational Discovery and Engineering Fellowship.

University of Michigan

Related Disease Articles:

Findings support role of vascular disease in development of Alzheimer's disease
Among adults who entered a study more than 25 years ago, an increasing number of midlife vascular risk factors, such as obesity, high blood pressure, diabetes, high cholesterol and smoking, were associated with elevated levels of brain amyloid (protein fragments linked to Alzheimer's disease) later in life, according to a study published by JAMA.
Dietary factors associated with substantial proportion of deaths from heart disease, stroke, and disease
Nearly half of all deaths due to heart disease, stroke, and type 2 diabetes in the US in 2012 were associated with suboptimal consumption of certain dietary factors, according to a study appearing in the March 7 issue of JAMA.
Study links changes in oral microbiome with metabolic disease/risk for dental disease
A team of scientists from The Forsyth Institute and the Dasman Diabetes Institute in Kuwait have found that metabolic diseases, which are characterized by high blood pressure, high blood sugar, and obesity -- leads to changes in oral bacteria and puts people with the disease at a greater risk for poor oral health.
Fatty liver disease contributes to cardiovascular disease and vice versa
For the first time, researchers have shown that a bi-directional relationship exists between fatty liver disease and cardiovascular disease.
Seroprevalence and disease burden of chagas disease in south Texas
A paper published in PLOS Neglected Diseases led by researchers at the National School of Tropical Medicine at Baylor College of Medicine suggests that the disease burden in southern Texas is much higher than previously thought.
Maternal chronic disease linked to higher rates of congenital heart disease in babies
Pregnant women with congenital heart defects or type 2 diabetes have a higher risk of giving birth to babies with severe congenital heart disease and should be monitored closely in the prenatal period, according to a study published in CMAJ.
Citrus fruits could help prevent obesity-related heart disease, liver disease, diabetes
Oranges and other citrus fruits are good for you -- they contain plenty of vitamins and substances, such as antioxidants, that can help keep you healthy.
Gallstone disease may increase heart disease risk
A history of gallstone disease was linked to a 23 percent increased risk of developing coronary heart disease.
New disease gene will lead to better screening for pediatric heart disease
Cardiomyopathy, or a deterioration of the ability of the heart muscle to contract, generally leads to progressive heart failure.
Early weight loss in Parkinson's disease patients may signify more serious form of disease
A study led by a Massachusetts General Hospital investigator finds evidence of an association between weight loss in patients with early Parkinson's disease and more rapid disease progression.

Related Disease Reading:

Disease: The Story of Disease and Mankind's Continuing Struggle Against It
by Mary Dobson (Author)

Wear and bending to dust jacket. Pages are free of writing and markings. View Details


Prevent and Reverse Heart Disease: The Revolutionary, Scientifically Proven, Nutrition-Based Cure
by Caldwell B. Esselstyn Jr. (Author)

The New York Times bestselling guide to the lifesaving diet that can both prevent and help reverse the effects of heart disease

Based on the groundbreaking results of his twenty-year nutritional study, Prevent and Reverse Heart Disease by Dr. Caldwell Esselstyn  illustrates that a plant-based, oil-free diet can not only prevent the progression of heart disease but can also reverse its effects.  Dr. Esselstyn is an internationally known surgeon, researcher and former clinician at the Cleveland Clinic and a featured expert in the acclaimed documentary Forks... View Details


Dr. Dean Ornish's Program for Reversing Heart Disease: The Only System Scientifically Proven to Reverse Heart Disease Without Drugs or Surgery
by Dean Ornish (Author)

The Ornish Diet has been named the “#1 best diet for heart disease” by U.S. News & World Report for seven consecutive years!

Dr. Dean Ornish is the first clinician to offer documented proof that heart disease can be halted, or even reversed, simply by changing your lifestyle. Based on his internationally acclaimed scientific study, which has now been ongoing for years, Dr. Ornish's program has yielded amazing results. Participants reduced or discontinued medications; their chest pain diminished or disappeared; they felt more energetic, happy, and calm; they lost... View Details


The Prevent and Reverse Heart Disease Cookbook: Over 125 Delicious, Life-Changing, Plant-Based Recipes
by Ann Crile Esselstyn (Author), Jane Esselstyn (Author)

The long-awaited cookbook companion to the revolutionary New York Times bestseller Prevent and Reverse Heart Disease.

“I hope you'll treat yourself to one of these recipes and just open that door. I guarantee you won't close it!"
—Samuel L. Jackson

 
Hundreds of thousands of readers have been inspired to turn their lives around by Dr. Caldwell B. Esselstyn’s Jr.’s bestseller, Prevent and Reverse Heart Disease. The plant-based nutrition plan Dr. Esselstyn advocates based on his twenty-year nutritional study—the most... View Details


Pathophysiology of Heart Disease: A Collaborative Project of Medical Students and Faculty
by Leonard S. Lilly MD (Author)

Publisher’s Note:   Products purchased from 3rd Party sellers are not guaranteed by the Publisher for quality, authenticity, or access to any online entitlements included with the product.

Specifically designed to prepare medical students for their initial encounters with patients with heart disease, this award-winning text bridges basic cardiac physiology with clinical care. Written by internationally recognized Harvard Medical School faculty and select medical students, Pathophysiology of Heart Disease, Sixth Edition provides a solid foundation of knowledge... View Details


Robbins & Cotran Pathologic Basis of Disease, 9e (Robbins Pathology)
by Vinay Kumar MBBS MD FRCPath (Author), Abul K. Abbas MBBS (Author), Jon C. Aster MD PhD (Author)

Dependable, current, and complete, Robbins and Cotran Pathologic Basis of Disease, 9th Edition is the perennially best-selling text that you’ll use long after your medical student days are behind you. A world-class author team headed by Drs. Vinay Kumar, Abul Abbas, and Jon Aster, delivers the latest, most essential pathology knowledge in a readable, interesting manner, ensuring optimal understanding of the latest basic science and clinical content. High-quality photographs and full-color illustrations highlight new information in molecular biology, disease... View Details


The Cure for All Diseases: With Many Case Histories
by Hulda Regehr Clark (Author)

All diseases have simple explanations and cures once their true cause is known. Doctor Hulda Clark explains the causes of both common and extraordinary diseases and gives specific instruction for their cure through natural remedies and an electrical device you can build at home. View Details


The Disease Delusion: Conquering the Causes of Chronic Illness for a Healthier, Longer, and Happier Life
by Jeffrey S. Bland (Author), Mark Hyman (Foreword)

For decades, Dr. Jeffrey Bland has been on the cutting edge of Functional Medicine, which seeks to pinpoint and prevent the cause of illness, rather than treat its symptoms. Managing chronic diseases accounts for three quarters of our total healthcare costs, because we’re masking these illnesses with pills and temporary treatments, rather than addressing their underlying causes, he argues. Worse, only treating symptoms leads us down the path of further illness.

In The Disease Delusion, Dr. Bland explains what Functional Medicine is and what it can do for you. While... View Details


Pathophysiology: The Biologic Basis for Disease in Adults and Children, 7e
by Kathryn L. McCance (Editor), Sue E. Huethe (Editor)

With easy-to-read, in-depth descriptions of disease, disease etiology, and disease processes, Pathophysiology: The Biologic Basis for Disease in Adults and Children, 7th Edition helps you understand the most important and the most complex pathophysiology concepts. More than 1,200 full-color illustrations and photographs make it easier to identify normal anatomy and physiology, as well as alterations of function. This edition includes a NEW Epigenetics and Disease chapter along with additional What’s New boxes highlighting the latest... View Details


Celiac Disease (Newly Revised and Updated): A Hidden Epidemic
by Peter H.R., M.D. Green (Author), Rory Jones (Author)

From Dr. Peter H.R. Green, internationally renowned expert on celiac disease and director of the Celiac Disease Center at Columbia University, and medical writer Rory Jones, this is the definitive book on celiac disease, one of the most underdiagnosed autoimmune diseases in the U.S. 

Do you suffer from gastrointestinal complaints, fatigue, headaches, joint pain, anemia, and/or itchy skin conditions? Have you consulted numerous doctors, and been prescribed drugs and diets that have only temporarily alleviated some symptoms? If so, you may have celiac disease, a... View Details

Best Science Podcasts 2017

We have hand picked the best science podcasts for 2017. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Simple Solutions
Sometimes, the best solutions to complex problems are simple. But simple doesn't always mean easy. This hour, TED speakers describe the innovation and hard work that goes into achieving simplicity. Guests include designer Mileha Soneji, chef Sam Kass, sleep researcher Wendy Troxel, public health advocate Myriam Sidibe, and engineer Amos Winter.
Now Playing: Science for the People

#448 Pavlov (Rebroadcast)
This week, we're learning about the life and work of a groundbreaking physiologist whose work on learning and instinct is familiar worldwide, and almost universally misunderstood. We'll spend the hour with Daniel Todes, Ph.D, Professor of History of Medicine at The Johns Hopkins University, discussing his book "Ivan Pavlov: A Russian Life in Science."