Ebola Outbreak Finally Receding in Sierra Leone; CDC Modeling Was Incredibly Accurate

Back in late September, just a week before Ebola panic hit a peak in the US when a patient in Dallas was diagnosed with the disease, the CDC produced a remarkable study in which they modeled the expected number of Ebola cases both with and without intervention. That study received a huge amount of press coverage, primarily because the model predicted that without intervention by public health authorities, as many as 1.4 million people could be infected. By contrast, with a program of isolating infected patients and educating survivors on proper burial techniques, the model showed that the outbreak would be much less widespread. The modeling projected cases through yesterday’s date, January 20.

Less reported in the media at the time was the projected number of cases under the scenario of intervention. The model predicted an actual number of cases between 25,000 and 30,000 by this week and a reported number of cases of nearly 10,000. Here are the two projections placed alongside one another:

CDC modeling of projected number of Ebola cases without (left) and with (right) improved patient isolation and safe burial practices.

CDC modeling of projected number of Ebola cases without (left) and with (right) improved patient isolation and safe burial practices.

The latest data from WHO indicate just over 21,000 cases as of January 11. That is a remarkable achievement by the team that developed the model. The observed actual number of reported cases fell squarely within the range predicted by the model. With the influx of health professionals to the region to provide care for infected patients, it seems likely to me that the correction factor applied in the CDC model to correct from the reported number of cases to the actual number would be very different now, so that the reported number and actual number would be much closer to one another, making the prediction even more accurate.

Last time I posted on progress in stopping the spread of the virus, we saw that the rate of appearance of new cases was dropping rapidly in Liberia but was still accelerating in Sierra Leone. The good news is that the improved practices have finally been implemented sufficiently in Sierra Leone that the rate is now dropping there. Here are the plots of weekly new cases in the two countries from the latest WHO Situation Report:

Weekly number of new cases of Ebola in Liberia (left) and Sierra Leone (right). Control of the virus was achieved about two months later in Sierra Leone than in Liberia.

Weekly number of new cases of Ebola in Liberia (left) and Sierra Leone (right). Control of the virus was achieved about two months later in Sierra Leone than in Liberia.

Although the battle is not yet over, all indications are that the outbreak is well past the worst phase and should end soon. Considering how closely the CDC model predicted the eventual size of the outbreak with the control measures that were implemented, it seems safe to say that the world would have witnessed a truly horrific level of spread of the virus had improved safety measures not been implemented. As of the January 14 WHO Situation Report, a total of 825 health care workers have been infected, with 493 of them dying. Without their sacrifices, many more would have been lost.

Ebola Outbreak Receding in Liberia, Still Strong in Sierra Leone

Back in late September, the press had a field day with a mathematical model developed by CDC that estimated that if left unchecked, the Ebola outbreak in West Africa could wind up infecting over 1.4 million people. Almost missed in the hysteria over that high number was the fact that this same model predicted that even with key public health measures (patient isolation, monitoring of at-risk population who had contact with infected people and safe burial practices) falling short of 100% implementation, the outbreak could be brought under control around January of next year.

Word has been leaking out for a while now that the rate of new Ebola infections in Liberia is falling. Reports in the Washington Post on October 29 and November 3 told us as much. A chart in the WHO Situation Report for November 5 drives home just how dramatic the decline in new cases has become:

WHO Ebola Situation Report November 5, 2014

WHO Ebola Situation Report November 5, 2014

As can be seen in the chart, the rate of new infections for the two most recent weeks is less than one fourth the rate at the peak of the outbreak. Unfortunately, the news for Sierra Leone is not as good. While the rate of new infections may be leveling off, it is not yet falling appreciably:

WHO Ebola Situation Report November 5, 2014

WHO Ebola Situation Report November 5, 2014

Digging into the WHO report a bit further, we can find some evidence for how this dramatic drop in new cases has been brought about. We see that 52% of cases are now isolated. The WHO target for December 1 has been set at 70%, with a target of 100% by January 1. When it comes to management of dead bodies, though, the December 1 target has already been surpassed. WHO reports that 87% of the dead are being “managed in a safe and dignified manner” while the targets were set at 70% for December 1 and 100% for January 1. Also, although no benchmarks are reported, WHO states that 95% of registered contacts were reached daily (although in the text of the report, there are suggestions this number may be somewhat overstated).

It should come as no surprise that progress in implementing these basic measures has had a huge impact on bringing down the rate of new infections. It fits perfectly with the CDC mathematical model and it also addresses the known biology of Ebola infections. Patients are most infectious at or near death, so establishing safe burial practices is vitally important. Conversely, identifying infected individuals through daily monitoring of the at-risk population and then isolating infected individuals once symptoms begin means that far fewer people are exposed to people producing large amounts of virus.

Sadly, those who remain exposed are the health care workers who are providing care to those who are infected. Despite shortages of equipment and supplies, WHO and other organizations are doing their best to overcome those shortages and to beef up training to reduce risk to these brave people on the front lines in the work to control the virus. As of this November 5 report, 546 health care workers have been infected, with 310 of them dying. Only four new infections were reported for the week ending November 2, so it is hoped that this rate is also dropping.

Had the alarmists who insisted that this was a new super-strain of Ebola capable of airborne transmission (or even a strain developed in a bioweapons laboratory), it is doubtful that these basic public health measures would have had such a dramatic impact on the rate of new infections. Perhaps those folks can go back to railing about chemtrails or the evils of vaccines, because basic boring science appears to be on the road to controlling the current outbreak before all of mankind succumbs.

In the meantime, we are at about two weeks into the three week incubation period both for anyone “exposed” by Craig Spencer or for Kaci Hickox (or anyone she “exposed”) to show symptoms. No reports of transmission so far, and the odds of any cases showing up are dropping very rapidly from the already very low levels where they started.

No, We Aren’t All Going to Die Because Ebola Patients Are Coming to US for Treatment


Scary, color-enhanced electron micrograph of Ebola virus particles. Creative Commons license courtesy of Thomas W. Geisbert, Boston University School of Medicine.

With the death toll now over 700 in an Ebola outbreak that has been building since February, Americans are suddenly up in arms about the virus, but only because it was announced yesterday that up to two Americans infected with the virus may be transported to Atlanta for treatment. Yes, the virus is especially deadly, with a death rate of 70-90% of infected patients, but the virus does not spread particularly efficiently and is not airborne. Writing at, biologist Laurie Garrett points out a disaster scenario for the virus. Rather than an outbreak in the US, which seems extremely unlikely, Garrett outlines how the virus could spread in the much more densely populated Nigeria rather than the more remote areas of Guinea, Sierra Leone and Liberia where it is now concentrated.

Before getting into the details of the current outbreak and its possible spread to Nigeria, a little background on the virus. From the World Health Organization, we have this information on how the virus spreads:

Ebola is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals. In Africa, infection has been documented through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest.

Ebola then spreads in the community through human-to-human transmission, with infection resulting from direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and indirect contact with environments contaminated with such fluids. Burial ceremonies in which mourners have direct contact with the body of the deceased person can also play a role in the transmission of Ebola. Men who have recovered from the disease can still transmit the virus through their semen for up to 7 weeks after recovery from illness.

Of particular relevance to the two patients who may be transported to Atlanta for treatment (they work for Samaritan’s Purse, an aid organization) and the tragic death of Sheik Umar Khan, Sierra Leone’s top Ebola doctor, the information from WHO continues:

Health-care workers have frequently been infected while treating patients with suspected or confirmed EVD. This has occurred through close contact with patients when infection control precautions are not strictly practiced.

The fact that these health care givers become infected because standard infection control precautions are not strictly practiced in no way should suggest that they are uninformed or careless. Instead, Garrett points out in her article the stark realities facing health care providers in the three countries where the outbreak rages:

To show how ill-equipped these nations are to battle disease, per capita spending on health care, combining personal and governmental, amounts to only $171 a year in Sierra Leone, $88 a year in Liberia and $67 a year in Guinea, according to the Kaiser Foundation.

For those who want more detail on the virus, this succinct summary of the structure of the Filovirus family of viruses and their mode of operation is very informative.

For the panic-motivated hypochondriacs among us, initial symptoms of this virus mimic the onset of most other viral infections.

The most recent update from WHO on the outbreak can be read here. The update summarizes the assistance that is being provided to the countries where the outbreak is ongoing. Significantly, WHO is not advocating travel restrictions at this time.

Returning to Garrett’s article, she points out the factors that would lead to chaos should Ebola spread in Nigeria:

Were Ebola to take hold in that country [Nigeria], spreading from person-to-person in a densely populated, chaotic city such as Lagos, the worldwide response would swiftly spin into uncharted political and global health territory.

Consider the following: Nigerian physicians are on strike nationwide; hundreds of girls have been kidnapped from their schools and villages over the past six months by Boko Haram Islamist militants — and none has been successfully freed from their captors by the Abuja government.

Nigeria is in the midst of national election campaigning. President Goodluck Jonathan’s government is, at best, weak. The nation is torn apart by religious tension, pitting the Muslim north against the Christian south. Islamists in the north have long distrusted Western medicine. They have opposed polio vaccination and have kidnapped and assaulted central government health providers.

Garrett’s plea is for an already-planned African summit on Monday to be used to develop a coordinated plan for dealing with the virus:

One way or another, Obama must take advantage of Monday’s Africa summit to press the case for calm and appropriate responses. These would include specific post-Ebola financial commitments to Liberia, Sierra Leone and Guinea.

The possibility that the epidemic might take hold in Nigeria must be confronted, and plans of action must be considered. The world cannot afford to make decisions in the heat of panic about such things as international airport closures, withdrawal of foreign oil workers, negotiations for outbreak responses with northern imams, hospital and clinic infection control training across thousands of Nigerian health facilities, deployment of international assistance teams for rapid diagnostics and lab assistance and countless other contingencies.

Sadly, Garrett points out important information on the damage that has already been done in this outbreak:

When this Ebola epidemic eventually ends, the health budgets of these nations [Liberia, Sierra Leone and Guinea] will have been bankrupted, and many of their most skilled and courageous physicians, nurses, Red Cross volunteers and hospital workers will have perished.

Let’s hope that Monday sees the beginning of stronger coordination to put more resources where they are needed to halt the spread of this ongoing disaster.

Yellowcake In the Soles of His Shoes

Splash page of, where it would appear that Patrick Campbell became Cassim and was unable to exit with his treasure.

Splash page of, where it would appear that Patrick Campbell became Cassim and was unable to exit with his treasure.

Last night, The Smoking Gun and then CBS reported on the latest sting carried out by our government to keep us safe from people too stupid for their own good. This time, instead of the FBI setting up the security theater sting, it was an undercover agent for ICE, or Immigration and Customs Enforcement within the Department of Homeland Security. The criminal complaint (pdf) filed yesterday is written by an ICE Special Agent working out of Miami (I’ll return later to the ironic job position she holds).

Once again, as we see repeatedly in the government’s adventures in security theater, we appear to have ensared a small-time hustler but will undoubtedly play this up as a major interdiction of international terrorism. The hustler this time is one Patrick Campbell, who stands accused of brokering a deal to sell U3O8 to Iran. Campbell apparently was promising to ship 1000 tons of the processed uranium ore, but was arrested in New York yesterday Wednesday when he entered the country from Sierra Leone, where he reportedly lives.

How was Campbell caught? Here is how the complaint describes the elaborate trap ICE devised:

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Yup. Everybody knows that Iran absolutely would go shopping for uranium on Note that ICE does not appear to be able to get their high-tech document production equipment to produce subscripts. There really is no such thing as Uranium 308 or U308. Writing it that way makes it look like they are referring to a uranium isotope. The naturally occurring isotopes of uranium are listed here, where we see that the atomic masses range from 232 (= U-232) to 238 (=U-238). The isotope of interest is U-235, which occurs in nature as only 0.7% of the uranium atoms. Uranium is mined as raw ore which is chemically treated to produce U3O8, which is otherwise known as yellowcake. For further processing, the yellowcake is then converted to UF6 gas and then put into gas centrifuges where the mixture is selectively enriched for the U-235 isotope. Low-grade enriched uranium has the U-235 enriched from the naturally occurring 0.7% to the range of 3-5%. Iran has also produced mid-grade uranium at 20% U-235 for its research reactor used to produce medical isotopes, but this still falls short of the 90% or so U-235 needed for a nuclear weapon.

It would appear that ICE ran this scam on such a short budget that they wouldn’t even front Campbell the money for travel to the US from Sierra Leone. In his negotiations with the undercover agent, Campbell demonstrated a pitiful level of awareness of operational security. The complaint notes many communications with Campbell by email, telephone and Skype. There is no indication that any of the communications were encrypted. The extent of his op-sec appears to be his brilliant use of an acronym to refer to the transaction:



Campbell finally made it to New York yesterday Wednesday, where he was promptly arrested. Here is how The Smoking Gun opened their report:

A foreigner who agreed to sell undercover Homeland Security agents 1000 tons of yellowcake uranium for shipment to Iran was arrested yesterday when he flew into the United States with uranium samples hidden inside the soles of shoes in his luggage, The Smoking Gun has learned.

Wow. He tried to hide his yellowcake samples in the soles of his shoes, which he then put into checked baggage.

This whole episode is stupid and wasteful on a wide range of levels.

First, Iran purchased huge stockpiles of yellowcake back in the days of the Shah. Read more