Disease Surveillance

Infectious Diseases, Research, Vaccination, Health Systems, Government Policy

Defeating Tuberculosis: A Possibility?

~Written by Sarah Khalid Khan (Contact: sk_scarab@yahoo.com)

Disease has always played a part in reforming community and geographical distribution of people through the ages. The bubonic plague, the Spanish flu, cholera and tuberculosis (TB), are some of the illnesses that have altered human history. Interestingly, TB has been glorified in literature more than others. The characters, Mimi in La boheme, Fantine in Les Miserables and Satine in Moulin Rouge all met with a similar fate at the hands of this disease.

According to the Global Tuberculosis Report 2015, the year 2015 is considered a turning point for TB as the global community progressed from Millennium Development Goals (MDGs) to Sustainable Development Goals (SDGs). TB mortality has decreased by 47% since 1990. Between 1990 and 2014, as a result of correct and timely diagnosis, 43 million lives were saved. We have made progress by moving from the “Stop TB Strategy” to the “End TB Strategy”. According to the latter, the targets for 2030 are to reduce the number of TB deaths by 90% and incidence by 80% (1).

Source: TBAlert.org

These statistics give us hope for a world without TB. But, having worked in a tertiary hospital in a low middle-income country, I have my doubts. Although the statistics reported by the World Health Organization (WHO) are the best available at the moment, these are estimates with very wide confidence intervals and may not provide a precise idea of the current situation in low and low middle income countries (LIC and LMICs).

In the surgical ward where I worked, one-third of the abdominal procedures were for perforation due to abdominal TB. To my knowledge, patient records were maintained through an electronic health system on the hospital server. Hard copies of the records were kept in nurses’ offices or junior doctors; duty rooms. These were put in storage, usually available for 4 to 5 years. The conditions of the storage area were extremely shabby and damp, where paper records could hardly survive. Electronic records, however, were said to be available in perpetuity. No one knew if these records were ever shared with the WHO to help with estimates. Popular opinion was that if the world knew the actual incidence and prevalence of diseases like TB in countries like ours it would be an embarrassment. Regardless, it is essential to have as accurate as possible estimates to converge efforts towards a TB free world.

Despite the best intentions and apparently achievable goals, the situation remains grim. According to the WHO, TB still imposes a great burden on the world. In 2014, 9.6 million new cases of TB were diagnosed while 1.5 million people died as a result of TB (2). Despite the history of this disease, research for newer TB drugs has been limited (3). In 2012, a new drug for multidrug resistant TB was introduced after a drought of 50 years (4). In addition, though BCG vaccines are part of immunization programs in countries where the disease is endemic, the current vaccine was developed in 1921 and is not entirely effective (5). A systemic review and meta-analysis that included articles from 1950 to 2013 reported 19% efficacy against TB in vaccinated children compared to non-vaccinated children (6). Although current research is encouraging there are questions of affordability of newer drugs for low resource countries where TB is more prevalent. Furthermore, five percent of the global burden of TB is due to multidrug resistant strains (7). The research required for averting these cases poses additional problems of affordability, availability and accessibility in LICs and LMICs.

Children present another area of grave concern. It is estimated that 550,000 children are infected with TB each year. The condition is frequently overlooked in children, often due to delayed and inefficient diagnosis (8). Adoption of the latest recommended diagnostic tools by the WHO is a challenge in itself because accessibility, affordability and availability again come into play in LICs and LMICs. Since TB flourishes in poor living conditions, the current global refugee and migrant situation has increased concerns about TB exposure, infection and transmission (9).

It is time that LICs and LMICs focus on establishing the true burden of major diseases like TB, and work towards adopting recommended diagnostic tools and treatment for all forms of TB. Unless the state actors and international community work together, the policies and aid provided will continue to fall short and the target to end TB will remain out of reach.



1. World Health Organization. Global Tuberculosis Report 2015. 2015.

2. World Health Organization. Research for Tuberculosis Elimination. 2014.

3. Frick M. 2014. Report on Tuberculosis Research Funding Trends, 2005-2013. [Internet]. Treatment Action Group. 2015. Available from: http://www.treatmentactiongroup.org/sites/tagone.drupalgardens.com/files/tbrd2012 final.pdf

4. Médecins Sans Frontières, International Union Against Tuberculosis and Lung Disease. DR-TB Drugs Under the Microscope. Sources and prices for drug-resistant tuberculosis medicines. 2nd edition. 2013.

5. World Health Organization. Tuberculosis vaccine development [Internet]. World Health Organization; 2015 [cited 2016 Mar 19]. Available from: http://www.who.int/immunization/research/development/tuberculosis/en/

6. A Roy et al. Effect of BCG vaccination against Mycobacterium tuberculosis infection in children: systemic review and meta-analysis.  BMJ 2014; 349:g4643

7. World Health Organization. Multidrug Resistant Tuberculosis (MDR-TB). 2015.

8. World Health Organization. Combating Tuberculosis in Children. 2015.

9. World Health Organization. Tuberculosis prevention and care for migrants. 2014.

Disease Outbreak, Health Systems, Infectious Diseases, Innovation, mHealth, Research

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.

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. 

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.