News Scan for May 08, 2014

News brief

Two more Ebola deaths reported in Guinea

Guinea's health ministry has reported two more deaths in the country's Ebola virus disease (EVD) outbreak, raising the fatality number to 157, according to an update today from the World Health Organization (WHO). No other probable or suspected cases have been reported, and the overall EVD illness count is 235.

The number of confirmed cases stands at 127, the same as in the last update on May 6. The latest illness onset appears to be in Conakry, the country's capital, on Apr 22. The WHO said the case numbers are subject to change based on several factors, including a recently introduced serology test used for clinical cases that test negative by polymerase chain reaction.

No new cases have been reported in Liberia or Sierra Leone, but in the latter, 10 Lassa fever infections have been found during testing. That disease is endemic in Sierra Leone.
May 8 WHO update

In other Ebola developments, the current outbreak in West Africa shows that the world has a limited ability to respond to rare, highly virulent communicable diseases, according to a commentary by Heinz Feldmann, MD, an Ebola researcher and virologist at the National Institute of Allergy and Infectious Diseases (NIAID) Rocky Mountain Laboratories in Hamilton, Mont.

He wrote in the New England Journal of Medicine yesterday that the lack of interventions such as vaccines or drugs makes quick diagnosis a key element of the response. He added that tests may fail when new variants are involved, such as in the current outbreak. Real-time sharing of data, especially sequence information, is critical, he said.

Rapid, reliable diagnostics need to be available closer to areas where the diseases are endemic so that health officials don't have to rely on far-away reference labs, Feldmann wrote.

So far researchers have found little pathogenicity differences in various Zaire Ebola viruses, and it's not a given that the West Africa variant is more virulent, he said. If the 70% case fatality rate is confirmed, it could even reflect a less virulent strain, he added.
May 7 N Engl J Med perspective

CDC notes effort to curb top neglected parasitic infections

More than 60 million US residents are chronically infected with the parasite that causes toxoplasmosis, 40 million with the parasite that causes toxocariasis, and 300,000 with the parasite that causes Chagas disease, the Centers for Disease Control and Prevention (CDC) said today as it announced an effort to target the top five neglected parasitic infections (NPIs) in the country.

CDC scientists detail those NPIs—Chagas disease, cysticercosis, toxocariasis, toxoplasmosis, and trichomoniasis—and epidemiologic profiles in a special supplement to the American Journal of Tropical Medicine and Hygiene. These NPIs often go unnoticed, with few symptoms, but many times they cause serious illness, including seizures, heart failure, and death.

"They're more common in the US than people realize, and yet there is so much we don't know about them," said CDC Director Tom Frieden, MD, MPH, in a CDC press release. "We need research to learn more about these infections and action to better prevent and treat them."

The CDC noted these facts about the five NPIs in the United States:

More than 300,000 people are infected with Trypanosoma cruzi, the parasite that causes Chagas disease, and more than 300 infected babies are born every year.
There are at least 1,000 hospitalizations for symptomatic cysticercosis per year.
At least 14% of the population has been exposed to Toxocara, the parasite that causes toxocariasis, and each year at least 70 people—most of them children—are blinded by resulting eye disease.
More than 60 million people are chronically infected with Toxoplasma gondii, the parasite that causes toxoplasmosis; new infections in pregnant women can lead to birth defects, and infections in those with compromised immune systems can be fatal.
The Trichomonas parasite is extremely common, affecting 3.7 million people, and is easily treatable. Trichomoniasis can cause pregnancy problems and increase the risk of other sexually transmitted diseases, including HIV.

The good news is that most parasitic infections can be prevented, and many are treatable, the CDC said.
May 8 CDC press release
May Am J Trop Med Hygiene special supplement

CDC reports another Salmonella outbreak linked to live chicks

The CDC today announced yet another live-poultry Salmonella outbreak linked to a mail-order hatchery in Ohio, this one sickening 60 people in 23 states.

The patients range in age from less than 1 year to 95, with a median age of 29 years, the CDC said in an update. Of 32 case-patients with available information, 10 (31%) were hospitalized. Of 38 patients interviewed, 31 (82%) reported contact with live poultry before falling ill.

Nineteen (90%) of 21 ill people with available information reported buying live baby poultry from five different feed or farm store companies in multiple states. "Epidemiologic and traceback findings have linked this outbreak of human Salmonella Infantis and Salmonella Newport infections to contact with chicks, ducklings, and other live baby poultry from Mt. Healthy Hatcheries in Ohio," the CDC said.

"This is the same mail-order hatchery that has been associated with multiple outbreaks of human Salmonella infections linked to live poultry in the past, including in 2012 and 2013," the agency added.

States with the most cases are Pennsylvania, with 8, and Kentucky, New York, and Ohio, all of which have 6. No other state reported more than 4 cases (see CDC map below).
May 8 CDC update

CDC Map: Persons infected with the outbreak strains of Salmonella Infantis or Newport, by state*

*n=60 for whom information was reported as of May 7, 2014

Flu Scan for May 08, 2014

News brief

H7N9 detected in four more China markets

As part of ongoing avian influenza surveillance, China's agriculture ministry yesterday reported H7N9 detections in four live-poultry markets in three provinces, including one—Ningxia—that hasn't reported any human cases.

Officials detected the viruses at different times in mid to late April and described the findings, which also occurred in Guangdong and Fujian provinces, yesterday in a report to the World Organization for Animal Health (OIE).

Ningxia province is in northwestern China, far from outbreak hot spots in the southern and eastern parts of the country. On Apr 25 authorities collected 80 chicken samples and 10 environmental samples from a live-bird market in Wuzhong, a city of about 1.3 million people in the central part of the province. One poultry sample tested positive for the virus.

In Fujian province, tests detected the virus at two live-poultry markets, one in Fuzhou and one in Xiaomen. Sampling involved chickens, ducks, and the environment. Two of 50 chicken samples were positive for the virus in Fuzhou, and one poultry sample was positive from the Xiaomen market.

In Guangdong province, tests on195 samples from a market in Huizhou yielded 1 positive sample.
May 7 OIE report

Epidemiologic report from Zhejiang finds short H7N9 incubation

An epidemiologic analysis of H7N9 infections during the outbreak's first wave in Zhejiang province, the hardest hit area during that time frame, found some unusual patterns. The report from Chinese researchers appeared today in BMC Infectious Diseases.

Their study included 46 lab-confirmed cases that occurred from Mar 31 to Sep 31, 2013. Unlike in other provinces, a larger percentage of patients (34.78%) were rural residents.

The team said it's not clear why Zhejiang province had more rural cases, but reasons could include accelerated integration between urban and rural areas in Zhejiang, which may have allowed live poultry to enter the areas after urban sales were temporarily suspended. They wrote that it's not clear if the rural residents were infected by backyard or market poultry.

Also, the median incubation period at 2 days was shorter than reported in other studies, which the researchers said could reflect multiple exposures to poultry and their environments, which were reported by eight of the patients.

Less than 5% of the case contacts had respiratory symptoms, and all of them tested negative for the virus. Researchers said all of the cases were sporadic, with no epidemiologic links between them.
May 8 BMC Infect Dis abstract

Meta-analysis highlights avian, swine strains causing human flu

A meta-analysis by leading European researchers published today in Eurosurveillance detailed more than 1,400 confirmed human cases of avian and swine influenza since 1959 and noted that, when H5N1 was taken out of the picture, the two types appear to be equally common. It should be noted, however, that the report does not include almost 200 of the most recent H7N9 cases.

The investigators included 89 of 6,955 potential articles in their review and focused exclusively on cases confirmed using virologic evidence. They detailed 1,419 distinct cases, of which 648 involved H5N1 avian flu. Among the others, 375 were associated with other avian flu subtypes and 396 with swine flu strains.

The leading non-H5N1 strain by far among the avian flu viruses was H7N9, accounting for 251 cases. The analysis, however, was limited to cases confirmed by the World Health Organization through Jan 31. The most recent H7N9 tally by FluTrackers, an infectious disease news board, is 435. The second leading avian flu strain was H7N7, accounting for 89 cases, followed by H9N2, at 15.

Swine strains were led by a large margin by variant H3N2, at 340 cases, followed by H1N1, at 47, and non-variant H3N2, at 7.

Not surprisingly, direct exposure to birds or pigs was the most likely source of infection for the cases that had available information. The researchers note that both avian and swine strains may be underrepresented in their report. Some avian strains cause only mild illness, and the symptoms of swine-origin flu often parallel those of seasonal flu.

The authors conclude, "To be prepared for a potentially emerging influenza virus of animal origin in humans, enhanced global surveillance in animal populations is therefore indicated to monitor evolution and circulation of viruses with yet unknown public health risks.
May 8 Eurosurveillance report