Rare Flu-like Virus on the Rise in the U.S., Japan and Philippines: 100 Sickened, Three People Killed

The seasonality of the HEV68 clusters described in this report typically fall within or later than the typical enterovirus season in the areas from which cases were reported. These recent clusters confirm that HEV68 is associated with outbreaks of respiratory illness severe enough to require hospitalization, and in some cases, might contribute to patient death. New-onset wheezing or asthma exacerbation were notable symptoms. However, in each cluster, respiratory specimens typically were collected from persons who had sought medical care or were hospitalized, which would have biased these reports toward more severe disease. The spectrum of illness caused by HEV68 remains unclear. HEV68, like other enteroviruses, has been associated with central nervous system disease. Further investigation could help clarify the epidemiology and spectrum of disease caused by HEV68. Some diagnostic tests might not detect HEV68 or might misidentify it as an HRV. - Clusters of Acute Respiratory Illness Associated with Human Enterovirus 68 -- Asia, Europe, and United States, 2008-2010, Centers for Disease Control and Prevention, September 30, 2011

Rare Flu-like Virus on the Rise

September 30, 2011

AFP - A rare virus has killed three people and sickened nearly 100 in Japan, the Philippines, the United States and the Netherlands over the past two years, US health authorities said Friday.

The culprit is human enterovirus 68 (HEV68), and its respiratory symptoms can be particularly dangerous to children, the US Centers for Disease Control and Prevention said in its Morbidity and Mortality Weekly Report.

In six separate clusters of the virus that showed up worldwide, patients commonly experienced cough, difficulty breathing and wheezing.

The highest number of cases were found in Japan, where local public health authorities reported more than 120 cases last year.

However, the CDC said it could only confirm clinical data for 11 of those patients, all children, one of whom died.

The Philippines had 21 cases in late 2008 and early 2009, causing two deaths, the CDC said.

Other cases surfaced in the Netherlands and the US states of Georgia, Pennsylvania and Arizona, for 95 total confirmed cases over two years.

The virus was first discovered in four children who were sick with pneumonia in California in 1962, but subsequent incidences have been rare and sporadic, according to the CDC.

"Identification of a large number of patients with HEV68 respiratory disease detected during a single season, such as described in this report, is a recent phenomenon," it added.

"Whether this increase in recognized cases is attributable to improved diagnostics or whether the clusters themselves represent an emergence of the pathogen is unknown."

The CDC said its report aimed to highlight HEV68 as "an increasingly recognized cause of respiratory illness" and urged clinicians to report cases of unexplained respiratory illness to public health authorities.

Human enterovirus is closely related to human rhinovirus, which causes the common cold.

CDC: Clusters of Acute Respiratory Illness Associated with Human Enterovirus 68 -- Asia, Europe, and United States, 2008-2010

United States

Georgia. In September 2009, a hospital in Atlanta started using a new, multipathogen testing system (Luminex xTAG Respiratory Viral Panel [RVP], Luminex Corporation, Austin, Texas) for respiratory viral testing in its laboratory. The system can detect several respiratory viruses, including HRVs and enteroviruses, which are identified by the system only as "entero-rhinovirus."

During the next respiratory illness season, September 2009 - April 2010, adult patients at the Atlanta hospital facility who were diagnosed with "entero-rhinovirus" appeared to be more ill than those diagnosed with HRV in previous seasons. Nucleic acid sequencing of 68 specimens from the 2009--2010 season revealed that 62 (91.2%) contained HRV and six (8.8%) contained HEV68.

Among the six patients with HEV68 (Table), three were aged >50 years and two were immunocompromised. Five patients had fever and four had cough. One patient had abnormal findings on chest radiography that were attributed to cryptococcosis. No other cases were associated with coinfections. Three patients were hospitalized for a median of 4 days. None of the patients required admission to an intensive-care unit (ICU), and none died.

Pennsylvania. In mid-September 2009, a pediatric hospital in Philadelphia noted more than twice the proportion of respiratory specimens testing positive for HRV by RT-PCR compared with those seen during previous fall HRV seasons. An investigation identified 390 children treated at the hospital during August - October 2009 from whom at least one respiratory specimen was positive for HRV. Respiratory specimens from 66 of these children were sent to CDC for further molecular characterization. HEV68 was identified in 28 (42%) of the specimens. Among the 28 patients with HEV68 infection, 15 (54%) were aged 0-4 years (Table), and 15 were admitted to the ICU. The median duration of hospitalization was 5 days, and none of the patients died.

Arizona. During August - September 2010, hospital officials at an isolated community hospital in rural Arizona noted an increase in pediatric admissions for lower respiratory tract illness. During this time, 43% of pediatric admissions were for respiratory illness, compared with a mean of 17% during the same period in the 3 previous years, a statistically significant difference. Similar illness, characterized by cough and tachypnea or hypoxemia, occurred in 18 patients. Abnormal lung examination result and wheezing, particularly new-onset wheezing, were noted. At least half of children with available chest radiographs had infiltrates. Hospitalization lasted a median of 1.5 days, and no deaths were reported. Despite viral testing and blood cultures performed at the Arizona Department of Health Services on patients with specimens available, no pathogen was detected. Nasopharyngeal specimens of seven patients were sent to CDC for further testing, and HEV68 was identified in five of the patients, one of whom also was positive by RT-PCR testing for Streptococcus pneumonia.