Technology is Changing the Way Infectious Diseases are Tracked

~Written by Theresa Majeski (Contact: theresa.majeski@gmail.com; Twitter: @theresamajeski)

Technology is progressively becoming a bigger part of our lives. This holds true in high-income countries and in low- and middle-income countries. By 2012, three quarters of the world’s population had gained access to mobile phones, pushing mobile communications to a new level. Of the over 6 billion mobile subscriptions in use worldwide in 2012, 5 billion of them were in developing countries. The Pew Research Center’s Spring 2014 Global Attitudes survey indicated that 84% of people owned a mobile phone in the 32 emerging and developing nations polled. Internet access is also increasing in low- and middle-income countries. The 2014 Pew Research Center survey indicated that the Internet was at least occasionally used by a median of 44% of people living in the polled countries.

The increase in Internet and mobile phone access has significant implications for how infectious diseases can be better tracked around the world. Although robust and validated traditional methods of data collection rely on established sources like governments, hospitals, environmental, or census data and thus suffer from limitations such as latency, high cost and financial barriers to care. An example of a traditional infectious disease data collection method is the US Centers for Disease Control and Prevention’s (CDC) influenza-like illness (ILI) surveillance system. This system has been the primary method of measuring national influenza activity for decades but suffers from limitations such as differences in laboratory practices, and patient populations seen by different providers, making straightforward comparisons between regions challenging. On an international scale, the WHO receives infectious disease reports from its technical institutions and organizations. However, these data are limited to areas within the WHO’s reach and may not capture outbreaks until they reach a large enough scale.

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Figure 1. CDC Flu View Interactive dashboard: http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html

Compared to traditional global infectious diseases data collection methods, crowdsourcing data allows researchers to gather data in near real-time, as individuals are diagnosed or even before diagnosis in some instances. Furthermore, getting individuals involved in infectious disease reporting helps people become more aware of and involved in their own health. Crowdsourcing infectious disease data provides previously hard to gather information about disease dynamics such as contact patterns and the impact of the social environment. Crowd-sourced data does have some limitations, including data validation and low specificity.

Internet-based applications have resulted in new crowd-sourced infectious disease tracking websites. One example is HealthMap. HealthMap is a freely available website (and mobile app) developed by Boston Children’s Hospital which brings together informal online sources of infectious disease monitoring and surveillance. HealthMap crowd-sources data from libraries, governments, international travelers, online news aggregators, eyewitness reports, expert-curated discussions, and validated official reports to generate a comprehensive worldwide view of global infectious diseases. With HealthMap you can get a worldwide view of what is happening and also sort by twelve disease categories to see what is happening within your local area. 

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Figure 2. HealthMap. http://www.healthmap.org/en/

Another crowd-sourced infectious disease tracking platform was Google’s Flu Trends, and also their Dengue Trends. Google was using search pattern data to estimate incidence of influenza and dengue in various parts of the world. Google’s Flu Trends was designed to be a syndromic influenza surveillance system acting complementary to established methods, such as CDC’s surveillance. Google shut down Flu Trends after 2014 due to various concerns about the validity of the data. As an initial venture into using big data to predict infectious diseases, Flu (and Dengue) Trends have provided information that researchers can use to improve future big data efforts. 

With the increase of mobile phone access around the world, organizations have started using short message service (SMS), also known as text messaging, as a method of infectious disease reporting and surveillance. Text messaging can be used for infectious disease reporting and surveillance in emergency situations where regular communication channels may have been disrupted. After a 2009 earthquake in Sichuan province, China, regular public health communication channels were damaged. The Chinese Center for Disease Control and Prevention distributed solar powered mobile phones to local health-care agencies in affected areas. The phones were pre-loaded with necessary software and one week after delivery, the number of reports being filed returned to pre-earthquake levels. Mobile phone reporting accounted for as much as 52.9% of total cases reported in the affected areas during about a two-month time period after the earthquake. 

Text message infectious disease reporting and surveillance is also useful in non-emergency settings. In many malaria-endemic areas of Africa, health system infrastructure is poor which results in a communication gap between health services managers, health care workers, and patients. With the rapid expansion and affordability of mobile phone services, using text-messaging systems can improve malaria control. Text messages containing surveillance information, supply tracking information and information on patients’ proper use of antimalarial medications can be sent from malaria control managers out in the field to health system managers. Text messaging can also be sent by health workers to patients to remind them of medication adherence and for post-treatment review. Many text message based interventions exist, but there is a current lack of peer-reviewed studies to determine the true efficacy of text message based intervention programs.

Increasing global access to the Internet and mobile phones is changing the way infectious diseases are reported and how surveillance is conducted. Moving towards crowd-sourced infectious disease reporting allows for a wider geographical reach to underserved populations that may encounter outbreaks, which go undetected for a delayed period. While crowdsourcing such data does have limitations, more companies than ever are working on using big data and crowd-sourced data in a reliable way to inform the world about the presence of infectious diseases.

Climate Change and Health, Part 3: Infectious Disease

~Written by Joann Varickanickal (Contact: joann.varickanickal@gmail.com)

This is my final post of a three part series on climate change and health. The first post looked at how climate change will influence the onset and severity of droughts in some areas. The second post examined how some regions are predicted to see an increase in droughts, which would decrease food supply; thus, increasing nutrient deficiencies in those areas. This post will briefly discuss the influence of climate change on waterborne diseases.

Change in climate, including the increases in temperature and changes in rainfall patterns may lead to an increase in waterborne diseases, where insect vectors contaminate the water (Shuman, 2010). Often, higher temperatures are needed for some insects to complete their life cycle. This is the case for mosquitoes, as they live in warm, aquatic habitats (Shuman, 2010). With an increase in temperature and more flooding, there will be an increase in mosquitoes (Shuman, 2010). Thus, there may be an increase in the transfer of dengue and malaria (Ramasamy & Surendran, 2011). These warm, aquatic habitats will also be ideal for snails, which transfer schistomiasis (Ramasamy & Surendran, 2011). Furthermore, with a rise in sea levels, there is likely to be an increase in saline levels (Ramasamy & Surendran, 2011). Certain types of mosquitoes and snails have a high tolerance for salt water and are thus able to breed in water with high salt concentrations (Ramasamy & Surendran, 2011).

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Taken from: Watts N, Adger W N, Agnolucci P, Blackstock J, Byass, P, Cai W, Costello A (2015). Health and climate change: policy responses to protect public health. The Lancet, 6736(15)

The relationship between climate change and health is complex because there are many different contributing factors and there is limited scientific evidence for many regions, several of which are under-resourced (New York Times, 2015). Furthermore, areas of high-resource have not been impacted in the same way, due to advantages as simple as air conditioning (New York Times, 2015). Thus, more scientific evidence is needed, to determine more ways in which climate change could possibly influence the health of a population. More recognition also needs to be given to this issue so that contingency plans can be made for possible outbreaks of diseases that were discussed in this blog post.

References:

Shuman, E. K. (2010). Global Climate Change and Infectious Diseases. The New England Journal of Medicine , 362 (12), 1061-1063.

Ramasamy, R., & Surendran, S. (2011). Possible impact of rising sea levels on vector-borne infectious diseases. BMC Infectious Diseases , 11 (18).

Tavernise, S. (2015, July 13). Unraveling the Relationship Between Climate Change and Health. Retrieved September 10, 2015, from http://www.nytimes.com/2015/07/14/health/unraveling-the-relationship-between-climate-change-and-health.html?_r=0

Sustaining the Fight against Malaria

~ Written by Randall Kramer, PhD, M.E. (Professor of Environmental Economics and Global Health, Duke University) & Leonard Mboera, PhD, MSc (Chief Scientist, Tanzania National Institute for Medical Research)

*Also published on the Duke Global Health Institute Website 

On World Malaria Day, April 25, there’s much to celebrate and acknowledge when it comes to the fight against malaria. Over the past 15 years, we’ve seen a huge ramp-up of international funding, and the latest statistics show impressive progress—a 46% decrease in malaria infections among children in sub-Saharan Africa and an estimated 4.3 million deaths averted globally over time.

One of the most effective malaria control measures has been the free distribution of several hundred million insecticide-treated mosquito nets that protect people from mosquitoes while sleeping. In 2004, only 3% of at-risk people in sub-Saharan Africa had an insecticide-treated mosquito net available to them, compared to 49% in 2014 after an international campaign.

The U.S. government is among the major funders of malaria control, and it’s one of the few international assistance programs that has garnered bipartisan support through the Bush and Obama terms. But despite the upsurge in spending and the laudable success of these programs, malaria remains one of the leading causes of death in poorer and tropical parts of the world.

The need for continued support is critical; it’s estimated that eliminating malaria as a major global disease threat would require double the current $3 billion invested annually in malaria control. But in the face of so many other pressing needs, why should we continue to invest in malaria?

In the last year, nearly 200 million people suffered from malaria, and its death toll—more than 500,000—was 50 times greater than that of the widely publicized outbreak of Ebola in West Africa. And malaria takes a particularly devastating toll on the young. More than 80% of the deaths from malaria are in children under five, and those who manage to survive the illness often suffer lasting effects on development, school performance and lifetime earnings.

Because malaria is such a resilient killer, we can expect to see these malaria losses continue and potentially rise in the absence of continued financial support. In fact, with temperatures steadily increasing throughout the world as a result of global warming, malaria-transmitting mosquitoes have begun to take residence in new regions, raising the specter of malaria spreading far beyond its current boundaries.

In addition to the physical suffering malaria causes, the disease stunts national economic progress.

Studies by Columbia University economist Jeffrey Sachs suggest that, if not for malaria keeping children out of school and agricultural workers out of the fields, the rate of economic development in sub-Saharan Africa would have been much higher in the past few decades.

And lastly, we can’t underestimate the goodwill generated by our investments in mosquito nets and other malaria-defeating approaches in recipient countries. As one community member told our research team in rural Tanzania, “Mosquito nets have been a great help to us. The day when mosquito nets were distributed, people were very happy, because many people in our community could not afford to buy the mosquito nets.”

The malaria parasite, a resilient and opportunistic pest, has successfully co-inhabited with humans for thousands of years, and it continues to adapt and evolve, damaging populations and economies across the globe. We now have the knowledge, technology and health systems to significantly reduce its devastating human impacts. But putting these assets into action will require renewed political will and financial commitment from rich and poor countries around the globe—including the U.S.

Malaria is a Tricky Foe

~Written by Theresa Majeski (Contact: theresa.majeski@gmail.com)

Malaria has been described in literature dating 4,000 years ago but has probably been around longer and has certainly had an influence on the history of humanity. Even though malaria has been around for thousands of years we haven’t done a very good job of eradication. Yes, we have eliminated malaria from some parts of the world, notably most of the northern hemisphere, but malaria still killed an estimated 584,000 people in 2013.

So why haven’t we been able to eradicate malaria from the tropical regions of the world? It can’t be just due to the mosquitos because mosquitos that can carry malaria are found lots of places in the world.

Figure 1 Geographical location of mosquito species capable of carrying malaria, Courtesy of the CDC

According to Sonia Shah in this superb TED talk, there are four reasons malaria still exists:

1.       Scientific challenges – malaria is an incredibly complex parasite that undergoes multiple changes in humans and mosquitos so it’s hard to develop new drugs against it

2.       Economic challenges – malaria is found in lower income areas of the world and malarial episodes make it hard for people to continue with their daily lives and work which contributes to the lower income status of these areas

3.       Cultural challenges – people living in malarial areas don’t view malaria as we in the West do, they view it as a part of life just like we view the deadly influenza virus as a part of life

4.       Political challenges – eliminating or eradicating a disease takes a large concerted effort with involvement and resources from governments and some malarious countries just don’t have the drive to eliminate malaria

Even though it seems like malaria eradication from the world is an unachievable goal, work is being done to decrease the burden of malaria in affected countries. One way we’re fighting malaria is with the use of bed nets, which persons sleep under every night to prevent them from being bitten by malaria carrying mosquitos that feed during the night. However there are drawbacks to bed nets. You may have also seen the recent article in the New York Times featuring an interview with a fisherman who is using his bed net to catch fish so his family doesn’t starve. A second way we’ve been fighting malaria is with indoor residual spraying. This is where workers spray down the indoor walls of houses with insecticide to prevent the mosquitos from coming into the house. Another method in the fight against malaria may be a little less known, and that is with biological methods. Biological methods are things like using fungi or bacteria to control mosquito populations, or using fish to eat the mosquito larvae.

While every method has its drawbacks, researchers are still trying to find new methods to help control malaria. One method caused a small media storm a couple weeks ago, the use of genetically modified mosquitos. Controversial sounding isn’t it? Basically, researchers give male mosquitos a gene preventing their offspring from surviving. So the males mate with the females (who are the only ones who bite to get blood to make baby mosquitos) and those offspring die, as do the original male and female once they’ve lived out their lifespans. But as with all things involving any sort of genetic engineering, people are hesitant. Work is still continuing on for a vaccine for malaria with hope for licensure of at least one vaccine in 2015. There’s also a TED talk (can you tell I love TED talks?) by Bart Knols that demonstrates a pill people take which results in the death of mosquitos who bite them. Bart Knols also discusses using dogs and their powerful sense of smell to help workers find mosquito larval breeding groups so those breeding grounds can be treated with insecticide. It can be hard to find all of the mosquito breeding grounds during the rainy seasons as every little indent in the ground can fill with water and provide an excellent breeding ground for mosquitos.

While malaria continues to cause high numbers of death and a high disease burden, researchers are continuing to get creative with methods of controlling malaria in the hopes of one day eradicating it. That goal may be a ways off yet, but at least one researcher thinks we may one day be shooting mosquitos out of the sky with lasers.