The latest in outbreaks of note

Updates on monkeypox, ebola, influenza and acute flaccid myelitis

Monkeypox in the U.S.

Figure 2. Epidemiological curve of monkeypox cases by date (defined as the earliest among the date of illness onset, positive laboratory test report date, CDC call center reporting date, or case data entry date into CDC’s emergency response common operating platform, DCIPHER) as of October 21, 2022. Source.

The U.S. Centers for Disease Control and Prevention has released a new technical report on the monkeypox epidemic. It is the agency’s fourth monkeypox technical report and the fifth overall (the inaugural report, which I helped with when I was at the agency, was for the pediatric acute hepatitis outbreak).

There are now 27,881 reported cases of monkeypox in the U.S.; I never thought I would see a poxvirus outbreak of this size. The good news is that the number of new cases has declined dramatically in most jurisdictions, from a daily average high of 446 nationwide to an average of 30 this week. It’s worth noting that not all jurisdictions are improving right now. Texas is seeing a rebound, and Illinois has plateaued (albeit at a very low level).

Epidemiological curve of 7-day moving average of monkeypox cases per 100,000 population by date (defined as the earliest among the date of illness onset, positive laboratory test report date, CDC call center reporting date, or case data entry date into CDC’s emergency response common operating platform, DCIPHER) from top six jurisdictions reporting cases as of October 21, 2022 (California (CA), New York (NY), Florida (FL), Texas (TX), Georgia (GA), Illinois (IL)). Source.

The majority (97%) of monkeypox cases are in people who were born male, continuing a long-standing trend. Although sexual history is no longer being reliably reported, it is likely that men who have sex with men remain the most-affected subpopulation. This data missingness probably explains a trend I commented on two months ago, when a growing fraction of cases were in men who did not report recent sexual contact with men. I now understand “report” to be the operative word.

To date, there have been six confirmed deaths, and several additional suspected or probable deaths are being investigated. Women and children still constitute a tiny minority of cases.

Will the virus be eliminated?

In the risk assessment portion of the technical report, the agency assesses that the number of new cases will likely continue to fall, though some flare ups may occur. I agree with this assessment, given the declines that have been sustained for over two months now.

The bigger question is whether the number of new cases will dwindle all the way to zero. Here is the agency’s take:

Domestic transmission in the United States is unlikely to be eliminated in the near future due to the possibility of continued travel related introductions and of domestic transmission.  Elimination could occur if monkeypox remains concentrated in a subset of MSM more likely to experience exposure, long-term vaccination efforts are focused on this exposure group, and these efforts are effective in preventing infection.

To achieve and maintain elimination, extensive efforts would be required, including ongoing vaccination efforts as new individuals enter the high-risk population, and non-pharmaceutical interventions to control future travel-related introductions from countries with ongoing transmission.  Concerted global action to control monkeypox will increase the likelihood of elimination in the United States as well as globally.

I still firmly believe that elimination is possible, but we won’t get there easily. I continue to feel that an approach guided by metrics and targets is an important piece of the puzzle, in addition to vaccination, non-pharmaceutical interventions and global coordinated action. Plenty of data is now available, so there has been a big improvement in transparency, but what we’re missing is goals for contact tracing performance, testing and time to isolation.

We need simple, transparent metrics to pursue monkeypox containment

Conclusion

I want to commend the agency for two things. First, these technical reports continue to be terrific resources for the public health and medical communities, and I hope they become standard operating procedure for outbreak response. Second, this technical report contains downloadable data, which is a resource the outbreak response community has needed for a long time. Congratulations to my colleagues at CFA and the monkeypox response team for making these reports so valuable.

Ebola in Uganda

The Ebola outbreak in Uganda continues to grow, putting it among the largest on record. There are now 121 confirmed cases and 32 confirmed deaths across seven affected districts (up from five last week). The cordon sanitaire I wrote about last week was extended yesterday to Kagadi, Kyegegwa, and Bunyangabu districts.

Local transmission is now occurring in the capital city of Kampala, with at least 14 reported cases in the metro area, six of whom are in schoolchildren. This development is especially concerning, as Kampala is a large and dense city that also serves as a regional transportation hub. No cordon measures have been announced for the city, though the president of the Uganda Medical Association has recommended it.

Situation reports from the Ministry of Health and partners describe a robust and well-executed response that is nonetheless struggling to keep up with the outbreak’s growing footprint. Some indicators I’m watching:

• The follow up rate among the 1,844 active contacts under follow up is excellent, at 99%. Over 1,000 additional contacts have already completed their 21-day monitoring period, meaning they are no longer at risk from their original exposure.

• On-site testing in Mubende remains well-resourced. I do wish the Ministry would report probable case numbers and not just confirmed counts. Probable cases have not yet received a test result, so monitoring trends in that category can give insight into whether testing is a bottleneck.

• The Safe and Dignified Burial (SDB) teams are working with a backlog. SDB teams are important because the bodies of people who have died from Ebola are highly infectious. Funerary practices were a major driver in previous outbreaks.

• An additional facility for isolation and treatment is being built to accommodate the surge in cases.

I don’t think we have seen the peak of this outbreak yet, but I hope the aggressive measures the Ministry of Health and partners are implementing will get ahead of the virus soon.

Flu season

Influenza season is coming in like a lion. The proportion of outpatient visits that are for influenza like illness (ILI) is at a level not usually seen until December or later. Twelve jurisdictions are already reporting high or very high levels of ILI activity. Children ages 0-4 continue to experience a high burden of ILI; some 1 in 7 outpatient visits in that age group are for ILI symptoms like fever, cough and sore throat.

Moreover, large outbreaks in schools are being reported across the country. Here are excerpts from a recent ProMED post (archive number: 20221027.8706389):

In Maryland

Multiple cases of influenza B have been reported in middle school-aged children [10-14-year-olds] in the greater Annapolis [Maryland] area. It is unknown if any of the cases are co-infected with RSV [respiratory syncytial virus] which is also circulating widely in the area.

and Virginia:

A Virginia high school will remain open even as hundreds of students continue to stay home because of flu-like illnesses.

Stafford High School, located in Fredericksburg, Virginia, had a "high number of student and staff illnesses" reported last week [week of 17 Oct 2022], prompting the school to shut down all activities and athletics scheduled from Friday through Sunday, the school said. The school, which has roughly 2100 students, saw 1000 student absences on Friday [21 Oct 2022]. On Monday, 670 students were absent, and on Tuesday, 526 students -- about a quarter of the student population -- continued to miss school, the district's chief communications officer Sandra Osborn told CBS News.

and Mississippi:

Enterprise [Mississippi] students are learning from home Tuesday and Wednesday [25-26 Oct 2022] due to a virus outbreak.

The district released a notice saying, "due to an outbreak of the flu virus that has greatly impacted our students (nearly 30%) and teachers, the Enterprise School District will conduct virtual learning."

All this is to say, get your flu shot! And your updated covid booster, too.

Acute flaccid myelitis

There have been 27 reported cases of acute flaccid myelitis (AFM) reported to CDC this year. AFM is a polio-like paralytic illness that is thought to be a rare complication of enterovirus-D68 infection. Earlier this year, CDC sent out a Health Alert Network notice warning of a possible surge in AFM cases this fall. Thankfully, that has not come to pass, at least not to the same degree as the 2014, 2016 and 2018 seasons.

Happy Halloween

Happy Halloween, to those who celebrate! I hope you have a safe and fun holiday. If you want Halloween public health tips (doesn’t everyone?) there are many to browse on food safety, COVID-19 prevention, and general safety.