Ebola Scan for Jul 24, 2015

News brief

Ebola study notes afebrile patients, calls into question WHO criteria

Researchers found that the World Health Organization (WHO) Ebola case definition has a specificity of only 31.5%, and they noted that 9% of Ebola patients reported neither a fever nor any Ebola risk exposure, calling into question WHO norms, according to a large study yesterday in The Lancet Infectious Diseases.

Researchers from Britain and Sierra Leone analyzed data on 850 suspected and 724 lab-confirmed Ebola patients who presented to the holding unit of Connaught Hospital in Freetown from May 29 to Dec 8, 2014. Fever or history of fever (n=599, 83%), intense fatigue or weakness (495, 68%), vomiting or nausea (365, 50%), and diarrhea (294, 41%) were the most common presenting symptoms in suspected cases.

Based on data from these patients, the investigators found the sensitivity of the WHO case definition to be 79.7%, which means about 20% of true Ebola cases would be missed (false-negatives). They found the specificity of the case definition to be 31.5%, which means 68.5% of patients who would be selected for admission would not actually have Ebola virus disease (false-positives).

In a subgroup analysis, 15 (9%) of 161 lab-confirmed Ebola patients reported neither a history of fever nor a risk factor for Ebola exposure.

The team also found that including these conditions increased the accuracy of the case definition: intense fatigue, confusion, conjunctivitis, hiccups, diarrhea, or vomiting. A combination of three or more of any these symptoms tripled the odds of a confirmed Ebola diagnosis by yielding a sensitivity of 58% and specificity of 71%.

The authors conclude, "The finding that 9% of Ebola virus disease cases had no fever or history of fever and no risk factor for exposure to the virus shows that existing case definitions that typically include these features as criteria (eg, the existing WHO case definition) have insufficient sensitivity to identify all cases of Ebola virus disease." They add that existing clinical criteria cannot discriminate Ebola from other diseases like malaria and typhoid fever.

They write, "A highly specific Ebola virus disease screening algorithm could reduce the risk of patient-to-patient transmission within holding units, which is a major clinical concern."

A related commentary says previous studies have also found the WHO case definition to lack sensitivity and warns that overreliance on it can lead to increased healthcare spread.
Jul 23 Lancet Infect Dis study
Jul 23 Lancet Infect Dis


US study finds 18% uneasy toward Ebola-volunteer colleague

Almost one in five public health colleagues of a volunteer physician who returned to New Hampshire from West Africa's outbreak region expressed discomfort with the responder returning to work even though she was considered low-risk, according to a study today in Emerging Infectious Diseases.

Public health colleagues in the infectious disease program, however, expressed no such unease.

New Hampshire researchers conducted a Web survey involving 178 New Hampshire Division of Public Health Services (DPHS) staff members (71.2% response rate) after the physician returned to the DPHS after her volunteer stint at Ebola treatment units in Sierra Leone. The survey included two scenarios: that the volunteer physician had contact with Ebola patients or did not have contact with Ebola patients.

Even given the no-contact scenario, 32 respondents (18%) said they would be uncomfortable with the responder returning to work. That rate rose to 35% and higher—even if the volunteer had no Ebola patient contact—in these situations: helping her if she fainted (35.0%), sitting next to her (35.6%), eating food made by her (37.6%), and attending a party at her home (46.7%).

If the physician had contact with Ebola patients, the percentage of coworkers expressing discomfort in those four situations rose to 53.7%, 49.7%, 54.0%, and 70.6%, respectively. And 42.7% of coworkers would be uncomfortable if she showed up for work after having contact with Ebola patients.

Responses, however, varied by professional background, with no worker in the DPHS infectious disease program showing discomfort with the volunteer returning to work, despite the fact that this group would have the most contact with her. Those not in the infectious disease program had an almost 11 times higher likelihood of expressing discomfort, and those with an education below a bachelor's degree had an almost three times higher likelihood.
Jul 24 Emerg Infect Dis study

News Scan for Jul 24, 2015

News brief

New Saudi MERS case; study notes impact of high viral load

As Saudi Arabia's Minister of Health (MOH) today confirmed a new MERS-CoV case—the sixth in 4 days—a study found higher viral loads to be associated with more severe disease.

The new MERS-CoV (Middle East respiratory syndrome coronavirus) case, like four of the five previous ones, is in Riyadh. The patient is a 28-year-old male expatriate who is hospitalized in stable condition. He had recent contact with a MERS patient in the community or a healthcare setting, but he is not a health worker, the MOH said.

His case brings the country's total since 2012 to 1,054, including 465 fatal cases. Eight MERS-CoV patients are still undergoing treatment.
Jul 24 Saudi MOH update

In related news, high viral loads of MERS-CoV appear to cause more severe disease, according to a study today in Emerging Infectious Diseases.

Researchers from the US Centers for Disease Control and Prevention (CDC) and Jeddah, Saudi Arabia, analyzed data on 102 Jeddah-area patients who were hospitalized in March through May 2014. They measured cycle threshold (Ct) values, which are inversely related to viral load. Median Ct was 31.0 for 41 patients who died and 33.0 for 61 survivors, which was statistically significant.

They conclude, "More data are needed to determine whether modulation of virus load by therapeutic agents affects clinical outcomes."
Jun 24 Emerg Infect Dis study


H3N2v case reported in Minnesota

Minnesota officials have reported the country's first case of variant H3N2 influenza (H3N2v) this year, the CDC said in its weekly FluView update today.

The infected person was hospitalized as a result of his or her illness, the CDC said. "No human-to-human transmission has been identified, and the case reported close contact with swine in the week prior to illness onset," the agency said in its update, giving no other information about the patient.

This is the first H3N2v case reported in the country this year, but two cases of variant H1N1 have been confirmed, in Minnesota in January and in Ohio in May. The Ohio case proved fatal.

H3N2v viruses first emerged in 2011, but concern spiked in the summer of 2012 when the CDC reported 306 cases. Cases have since declined dramatically.
Jul 24 CDC FluView update


Cases of Cyclospora illness in Texas reach 203

The Texas Department of State Health Services (TDSHS) reported 21 new Cyclospora infections in the past week, lifting the outbreak total to 203 cases, higher than last year's total, the agency said in an update today.

So far 40 of the state's 254 counties have reported cases, an increase of 5 counties. Travis County, which includes Austin, has reported by far the most illnesses, with 77, and Dallas County is second with 17.

Cyclosporiasis is a parasitic infection caused by consuming contaminated food or water. Its main symptom is watery diarrhea that can last from days to months. A similar outbreak in Texas last summer caused 200 illnesses, some of which were tied to cilantro from Mexico's Puebla region.
Jul 24 TDSHS update
Jul 17
CIDRAP News scan on previous update


Rotary says Nigeria has gone a year without polio

Rotary International announced today that Nigeria, the only remaining polio-endemic country in Africa, has gone a full year with no new cases, but the World Health Organization (WHO) said it was still compiling data and not yet ready to confirm the milestone.

Rotary, a service organization that has played a prominent role in the fight to eradicate polio, said Nigeria's last polio case occurred Jul 24, 2014, in southern Kano state, and added that Africa as a whole has not seen a polio case since Aug 11, 2014.

"The World Health Organization (WHO) may soon remove Nigeria from the list of polio endemic countries," Rotary said. "When Nigeria and every country in Africa go three years without a case of polio, WHO will certify the region as polio-free."

WHO spokesman Gregory Hartl said on Twitter that official WHO confirmation of the 1-year milestone would come "in a few weeks." The agency needs a few weeks to collect all of Nigeria's data through today, he explained.

Rotary officials cautioned that the world must keep up the polio fight: "The next two years will be critical to ensuring Nigeria remains on-track and prevent a resurgence of the disease. The support of donors, governments and partners is needed more than ever to ensure high-quality polio campaigns."

Nigeria, Afghanistan, and Pakistan are the only countries where polio is still classified as endemic.
Jul 24 Rotary press release
Gregory Hartl Twitter feed


Louisiana officials detect Naegleria fowleri in drinking water

The amoeba Naegleria fowleri has been found in the water system of St. Bernard Parish in Louisiana for the second time in 2 years, the Louisiana Department of Health and Hospitals (LDHH) said on Jul 22.

Officials will conduct a 60-day "chlorine burn" to eradicate the pathogen, which can infect the brain and cause death. The water system serves 44,000 residents. The LDHH said the water is safe to drink but urged parish residents to avoid getting it in their noses.

N fowleri was also identified in the St. Bernard water system in the summer of 2013, and the CDC confirmed its absence in February 2014 after testing. The LDHH tests public drinking water systems every summer for the amoeba when temperatures rise.
Jul 22 LDHH news release


Niger's epidemic of meningitis C was Africa's largest, WHO says

Niger's recent meningitis epidemic reached 8,500 suspected cases and 573 deaths, making it the largest outbreak of Neisseria meningitidis serogroup C in Africa's meningitis belt, the WHO announced yesterday.

The epidemic peaked between May 4 and 10, when 2,182 cases and 132 deaths were reported, the WHO said. It then declined substantially, with only 11 cases and 2 deaths recorded from Jun 22 through 28.

"Thirteen districts in Niger crossed the epidemic threshold," the agency said. "The five districts of Niamey, Niger's capital and largest city, reported 5,267 suspected cases and 260 deaths." All districts are now below the epidemic threshold.

Laboratory tests confirmed the predominance of serogroup C in the affected areas, although serogroup W was identified in 12% of positive samples, the agency said. "Although serogroup C has been the predominant cause of meningitis in wealthy countries, it has never been of high concern in Africa," it added.

The WHO and its partners helped Niger's government carry out mass vaccination campaigns and other emergency control measures. The International Coordinating Group on Vaccine Provision for Epidemic Meningitis Control released more than 1.1 million doses of meningitis vaccines, and the government obtained 200,000 vaccine doses from the government of Mali.

Other efforts that helped stop the outbreak included enhanced surveillance, social mobilization, and case management activities.
Jul 23 WHO statement

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