As 2018 comes to a close, we want to take the opportunity to reflect on our Outbreak Thursday (OT) coverage from the past year. Continuing our tradition from last year, when we revisited some of 2017’s biggest stories in the realm of outbreaks, we look back on an eventful 2018, and share with you some updates and new insights on selected posts.

Before jumping in to the countdown, we want to emphasize again that these topics are not ranked in any particular order and that the associated numbers do not represent any attempt to compare their impact, in either magnitude or severity. We would also like to acknowledge that some of our coverage spans multiple categories, and that our attempt to sort the posts was to only done to provide structure. With that understanding, let’s jump right into our countdown.

10. Cholera Around the World

Cholera was one of the earliest topics for OT’s 2018 coverage. The diarrheal disease, caused by the bacteria Vibrio cholerae, affects nearly 2.9 million people each year, largely in areas lacking established water/sewage treatment systems. The bacteria enter the human system when ingested and are often found in food and water that has come into contact with contaminated material.

Since the risk of contamination can often be mitigated with effective hygiene and sanitation systems in place, cholera outbreaks frequently reflect a larger public health issue. In last year’s reflection, Yemen’s humanitarian crisis was highlighted as the most significant health event in 2017. Like many of the health challenges facing Yemen, the cholera epidemic persisted into the new year, and there were concerns early in the spring that a new wave of cases would hit an already devastated population. Although cholera remains a major concern in the region, there is a silver lining with the reintroduction of a vaccination campaign in early May and successful attempts at reaching thousands of children with oral cholera vaccine.

Concerningly, reports emerged in October that cholera incidence was once again on the rise, at more than 10,000 new cases per week. Official reporting has been inconsistent, however, with only two EMRO Epidemiology Bulletins since weekly reporting stopped in June (and the most recent report from October 8-14 is unavailable on the WHO EMRO website). The most recent identified data—published in another EMRO report, the Weekly Epidemiological Monitor, from December 16—shows a total of 1,343,363 cases and 2,751 deaths in Yemen, up from 1,121,189 cases and 2,326 deaths at our last check-in.

Cholera continued to raise concerns around the world, providing challenges in for new governments and highlighting gaps in public health systems.

Find some more of this year’s OT cholera coverage in the posts below:

Cholera in Zambia:

WHO Warns of Possible “Third Wave” of Cholera in Yemen:

Cholera on Vancouver Island, Canada:

Zimbabwe Cholera Outbreak Test of New Government:

9. Disease Eradication Efforts

Disease eradication or elimination efforts present a number of tremendous benefits for continuing efforts in public health. Polio has been the target of global eradication efforts for nearly five decades. In this time, there have been tremendous successes in reducing the number of countries feeling the burden of the disease, but in 2018, it was clear that there are still sizable gaps to close. In late November, OT covered the WHO IHR Emergency Committee statement reaffirming the spread of poliovirus as a Public Health Emergency of International Concern (PHEIC). Data supporting this report showed that the three remaining countries experiencing polio outbreaks are facing significant difficulties with their vaccination efforts as the result of in-country conflicts, a theme that will re-emerge later in the countdown as a common challenge in 2018.

In addition to continued efforts to eradicate polio, there were conversations that looked to advance efforts to eradicate tuberculosis (TB) as well. The UN General Assembly held a high-level meeting dedicated to a discussion on this topic, inspiring an OT post about the possibility of eliminating TB in the United States. These goals may still be slightly out of reach, but their promise holds benefits that would positively impact public health for generations to come.

Read more about OT’s coverage of disease eradication efforts in the posts below:

Polio in 2018 Still a Health Emergency:

Polio in Venezuela:

Progress Toward TB Eradication in The United States:

8. Emerging Infectious Diseases

Keeping tabs on outbreaks of emerging infectious diseases (EIDs) can provide an interesting view of public health challenges occurring around the globe. In 2018, OT reported on a number of these outbreaks, and when available, provided updates on their current status.

Two outbreaks from the first half of 2018 received updates from the OT team. The first, a Nipah outbreak in India, last received an update in mid-June. At that point, Indian health officials announced that the outbreak was over, with 18 total cases, and since then, there have been no newly identified cases. The second reviewed the occurrence of Lassa fever in Nigeria. In OT’s most recent report, the team noted that the incidence of Lassa cases had decreased dramatically, an encouraging report for outbreak control efforts. After the outbreak’s occurrence, there was a search for answers that could explain how the disease spread on such a large scale. A recent analysis found evidence that the spread of this outbreak was facilitated by the virus’ ability to spread through a breed of rat found in Nigeria. This will be an important development in future Lassa surveillance efforts and could play a role in mitigating outbreak spread.

The identification of two monkeypox cases in the UK was a high-profile example of the risk posed by EIDs around the world. This OT post, from September of this year, shared insights about how the disease arrived in the UK, the challenges of containing a resurgence of monkeypox in Nigeria, and prospects for possible control. Since its publication, there have been developments on both the UK and Nigerian fronts. In the UK, a third case was identified in a healthcare worker that had worked with one of the initial patients. This was the final case reported in the UK, ending the outbreak and emphasizing the importance of protecting healthcare workers in future disease outbreaks. In Nigeria, the most recent WHO report from early October reported 37 confirmed cases across 14 states.

The last post this section will revisit an outbreak of extensively drug-resistant (XDR) typhoid fever in Pakistan. Pakistan is still addressing this major public health concern, but few updates are available. This outbreak of a highly antimicrobial-resistance pathogen shined a spotlight on a major concern for future public health practitioners, spurring discussions of potential solutions but without much progress on the current outbreak.

Calling attention to EID outbreaks is one of the core tenants of the OT series. EIDs are spreading around the world, and each provide important lessons for future outbreak response. In the upcoming year, the OT team will continue to highlight these occurrences to inform our readers, contribute to a global conversation, and serve as a regular reminder that these outbreaks occur, even if they do not make major international headlines.

Read more about OT’s coverage of EIDs in the links below:

Lassa Fever in Nigeria:

Lassa Fever- An Update:

Nipah in India:

Update: Nipah in India:

Monkeypox in the UK:

XDR Typhoid Fever in Pakistan:

Brazil Battles Yellow Fever Outbreak:

7. Mysterious Occurrences:

Sometimes, outbreaks emerge in new locations or populations or with novel presentations, which compound the challenges of outbreak response. 2018 saw several of these mysterious occurrences, including several outbreaks covered by OT.

This past June, OT reported on a case of Usutu virus identified in the south of France. Usutu, a mosquito-borne disease that predominantly occurs outside of human hosts has been identified in a slightly more than 20 individuals since its discovery in the late 1950s. This most recent case was identified as the result of a retrospective study, and its discovery prompted calls for improved surveillance across humans, animals, and other vectors.

In the US, an ongoing acute flaccid myelitis (AFM) outbreak continues to puzzle health experts. As mentioned in the first OT post, AFM is condition that has impacted a number of young children across the US over the several years. Although outbreaks of the condition have been seen over the past decade, a definitive causative agent is still unknown. Since our last report, this year’s outbreak has surpassed previously recorded numbers to become the largest occurrence in recent history with 182 confirmed cases across 39 US States. Public health professionals are still searching for a definitive cause of this condition, and they have faced communication challenges due to the considerable uncertainty surrounding this outbreak. The US CDC formed a task force dedicated to solving this problem, with hopes that this year’s cases have already peaked.

Read more about these and other mysterious occurrences in the posts below:

Acute Flaccid Myelitis in the US:

Newly Identified Human Infection with Usutu Virus:

6. The Plight on Your Plate

Although frequently discussed amongst a myriad of holiday puns in our OT coverage, foodborne illnesses continue to be a major concern for the health and well-being of people around the globe. While OT does not routinely cover foodborne outbreaks, we do like to take the opportunity, on occasion, to remind our readers of associated outbreaks and health risks. Despite our best efforts, it is difficult to keep up with every new foodborne outbreak; even major stories like the recent E. coli outbreak in romaine lettuce are often overshadowed by ongoing struggles around with diseases like cholera and Ebola. We hope you enjoy reading our lighthearted foodborne disease posts as much as we enjoy writing them.

Read more about 2018’s OT foodborne illness coverage in the links below:

Cookie Doughn’t:

Of Mice and Microbes... Or the Grapes or Rats:

Danger Zone:

Salmonella: This Thanksgiving’s Unwelcome Guest:

5. Vaccine Preventable Diseases

Unfortunately, 2018 saw several high-profile outbreaks of vaccine preventable diseases. These stories are the continuation of a disconcerting trend in public health and raise many concerns for the health and well-being for the global population. OT’s coverage shared insights on measles’ resurgence in the Americas, chickenpox in an undervaccinated community, and the politics that influence vaccination in Europe. These articles build on our 2017 coverage of the same issue, a collection big enough to warrant a similar spot in last year’s countdown.

This year, parts of Europe reported record-high numbers of measles cases for the first six months of the year. It seems that this will continue to be a major issue for years to come, and it will be the continued burden of the global public health force to battle against a resurgence of vaccine preventable disease.

Read more about OT’s coverage of vaccine preventable disease in the posts below:

Measles Resurgence? :

The Politics of Measles in Europe:

The Resurgence of Chickenpox:

4. Influenza’s Yearly Toll

As 2018 was the first full calendar year for Outbreak Observatory, we were able to cover both the end of the 2017-18 northern hemisphere flu season and the beginning of the 2018-19 season.

In OT’s first update, we looked more closely at how new information changed the projected outcome for the 2017-18 flu season as the season progressed. This update was paired with another a few months later that shared developments since the initial reports and addressed challenges in discussing vaccine efficacy. Preliminary estimates for the 2017-18 flu season indicated that it could have accounted for 80,000 deaths in the US alone, and at its peak, it was the most severe since the 2009 H1N1 pandemic.

OT’s coverage of the 2018-19 flu season started with a post that rehashed details from the previous season and dove more deeply into current vaccination efforts and the impact of new technologies. Flu activity has recently elevated across the nation, and it seems that this year’s season is beginning to ramp up. In the coming months, OT will continue to monitor new developments and report on this seasonal occurrence.

Read more about OT’s coverage of seasonal flu in the posts below:

Winter is Coming …. So is Flu:

US Influenza - Update:

Update #2 on US Flu Season and Vaccine Efficacy:

3. Operational Lessons

As we wind down with this yearly review, we thought it would be fitting to highlight some OT posts that reflect more broadly the goals of the Outbreak Observatory. One of Outbreak Observatory’s fundamental aims is to “improve sharing of operational knowledge to strengthen preparedness.” This is mentioned at some level in the majority of OT posts, but this year, a few posts were dedicated more specifically to operational challenges and lessons.

In November of this year, OT shared a post that highlighted this need directly. This post provided a synthesis of a recently published paper titled, “Evaluating the frequency of operational research conducted during the 2014-16 West Africa Ebola epidemic.” This analysis, conducted by several members of the Outbreak Observatory team, demonstrated the need for purposeful efforts to facilitate the transformation of lessons from disease outbreaks to to peer-reviewed operational research. An additional commentary from late May highlighted operational challenges of coordinating simultaneous outbreak responses at the global level. This post focused on common limitations of outbreak responses, even across seemingly unrelated diseases. Another post from this summer outlined some of the economic costs associated with outbreak response, specifically focusing on the economic burden of disease response in the context of measles, a particularly contagious infectious disease. Economic factors are an important part of operational response, and this post addressed just some of the ways they may affect response decision-making. Finally, OT published a brief interview with Dr. Joseph Fair, who provided his firsthand insight into the operational challenges facing the Ebola response in North Kivu, DRC.

Read more of OT’s coverage on outbreak response operations in the posts below:

Reflections on the Need for operational Research:

When it Rains, It Pours: The Simultaneous Occurrence of Ebola, MERS & Nipah:

Cost of Outbreak Response:

Ebola in DRC: Q&A with Dr. Joseph Fair:

2. Ebola in the DRC

Ebola in the DRC has commanded significant attention from the OT team, spanning 2 outbreaks in 2018. Posts have tracked the development of these outbreaks, shared insight on the impact new technologies and therapeutics/vaccines, discussed the considerable challenges and limitations of surveillance efforts, and addressed broadly applicable lessons from this outbreak response.

Considering the high number of posts on Ebola in the DRC this year, we would like to direct your attention to a post published 2 weeks ago. In this post, we shared a number of questions that we are asking about the Ebola outbreak and the response and encouraged others to submit their own. These questions are the synthesis of our continued information-gathering efforts and a reflection of the complicated nature of this disease outbreak. At that time, the DRC Ministry of Health had reported 515 total cases and 303 deaths (as of December 12). These counts climbed to 585 total cases and 356 deaths as of December 25. The inability to bring this outbreak under control demonstrates the need for answers on outstanding operational questions, including the deployment of critical response resources, and further illustrates that sufficient global public health response capacity still does not exist.

Read all of OT’s coverage of Ebola in the DRC in the posts below:

Questions We Should Be Asking About The Ebola Outbreak in DRC:

Urgent Calls to Enhance the Response to Ebola in DRC:

Ebola Vaccine and the Crucial Roles of Healthcare Workers:

Ebola - Contact Tracing and Monitoring in DRC:

Vaccine Adds New Dimension to Ebola Response in DRC:

DRC’s Neighbors on the Alert for Ebola:

DRC Ebola Outbreak Update:

Ebola Strikes Back in DRC:

1. Conflict Zones and Disease Outbreaks

The final category for this year-in-review post is an underlying theme across several severe disease situations. Armed conflict has been a major factor in the impact of disease on affected populations in 2018. In last year’s OT review, we highlighted the grave situation facing the citizens of Yemen as the most severe outbreak of 2017. This humanitarian crisis, fueled by war and famine, presented a number of health challenges and and the associated political and security issues exacerbating the situation. In March of this year, OT revisited this crisis and sadly saw that much remained the same. Earlier in this year’s review, we again referenced the uphill battle that Yemen continues to face and the staggering impact of the ongoing conflict on health.

This year, the ongoing Ebola outbreak in the DRC added more evidence to this assertion, owing to armed conflict between the DRC army and rebel groups in areas affected by the outbreak. A post from earlier this year provided an overview of the current challenges facing the response in the DRC and discussed how conflict increases the difficulty of performing necessary epidemiological practices such as disease surveillance. Shortly following that post, news broke of the murder of seven UN Peacekeepers visiting Beni, which dramatically illustrated the safety and security risks to those responding to the outbreak and broader humanitarian crisis. Security concerns have limited the availability of outside resources, particularly trained response personnel, and greatly hindered efforts to bring the outbreak under control

Unfortunately, it is highly likely that 2019 will see similar challenges, and the global community will need to develop plans to facilitate effective response in areas facing security threats. Read more about OT’s 2018 coverage of disease outbreaks in conflict areas in the posts below:

Yemen Crisis- Update:

Displaced Populations and the Threat of Disease:

Ebola in Conflict Affected Areas:

To conclude, it has been our pleasure to relay this information to our readers each week. We wish everyone a safe and happy 2019, and we look forward to continuing this work into the new year!

Photo courtesy of Pixabay.

Outbreak Observatory aims to collect information on challenges and solutions associated with outbreak response and share it broadly to allow others to learn from these experiences in order to improve global outbreak response capabilities.