News Scan for Aug 07, 2014

News brief

Travel-related chikungunya cases in US rise to 484

This year's tally of US chikungunya cases related to foreign travel, mostly to the Caribbean, has risen to 484, an increase of 86 over the past week, the Centers for Disease Control and Prevention (CDC) says.

Forty states have reported cases, three more than a week ago, the agency said in an Aug 5 update. The number of locally acquired cases stayed at four, all of them in Florida.

Travel to the Caribbean region, which has had more than 500,000 cases in an epidemic that began last December, accounts for 472 of the 484 cases, the CDC said. The rest of the patients picked up the virus in the Pacific (five cases) or Asia (three).

Florida has reported by far the most travel-linked cases, 127, followed by New York, 72, New Jersey, 25, Tennessee, 23, and Massachusetts, 22. Before this year the nation averaged only 28 reported cases per year.

US territories in the Caribbean—Puerto Rico and the US Virgin Islands—have also been hit. The virus is spreading locally in Puerto Rico, which has reported 201 locally transmitted cases along with 16 travel-related ones, while the Virgin Islands has had 2 cases in each category.

The CDC's numbers represent cases voluntarily reported to ArboNet, the national network for reporting arthropod-borne diseases. Chikungunya is not a nationally notifiable disease in the United States.

In other developments, health officials in Harris County (Houston), Texas, said a mosquito has tested positive for the chikungunya virus, the first detection in the state, the Dallas Morning News reported yesterday. The finding raises the possibility of local spread of the virus.
Aug 5 CDC update
Aug 6 Dallas Morning News story
Related Jul 30 CIDRAP News item


Cyclospora illnesses rise, but no common source found

States reported more Cyclospora cases last week, but the increase was less than half as steep as the previous week, according to the latest update from the CDC. As of yesterday, 235 cases have been reported so far this year, 33 more than the previous week.

Most of them were reported to the CDC in July, and so far the federal and state investigators haven't identified a common source, though a portion of the illnesses appear to be travel-related. Texas and Michigan have launched outbreak investigations, while Maine and Massachusetts are exploring the increase in lab-confirmed cases.

Two more states, Arkansas and Pennsylvania, reported infections to the CDC, raising the number of affected states to 21. So far the largest portion (58%) of cases have been reported from Texas, where interviews that have so far been conducted with sick patients show that 88 patients had not traveled outside the country within 2 weeks of getting sick.

The Texas Department of State Health Services (TDSHS) said that as of Aug 5, 136 cases have been detected in 34 of the state's 254 counties, five more locations than the previous week. The department said its surge of cases began in the middle of June.

The CDC said of the other states reporting cases, at least 28 of 99 case-patients acquired their infections during travel outside the United States.

Last summer Texas was the hardest-hit state during a Cyclospora outbreak that sickened at least 631 people in 25 states and New York City. The national rise in illnesses was puzzling, because Nebraska and Iowa linked their restaurant-associated infections to a bagged salad mix produced in Mexico, while Texas officials said some of their cases were likely connected to fresh cilantro imported from Puebla, Mexico.

Past foodborne outbreaks have been linked to many kinds of imported fresh produce, including raspberries, basil, snow peas, and mesclun.
Aug 5 TDSHS update


Studies: Nasal brushings, urine test identify Creutzfeldt-Jacob disease

Two reports published today in the New England Journal of Medicine describe new tests that are described as advances in the diagnosis of Creutzfeldt-Jacob disease (CJD) and variant CJD (vCJD), the form of CJD linked to consumption of meat from cattle with bovine spongiform encephalopathy (BSE), or mad cow disease.

In one report, a quick and relatively noninvasive test for CJD using nasal brushings is described as an "exciting advance" in identifying a disease that formerly could be definitively diagnosed only after death or detected(though not as accurately) through cerebrospinal fluid (CSF) testing.

The nasal test is done by inserting a rigid fiberoptic rhinoscope into a patient's nasal cavity, then inserting a sterile brush alongside the scope, and gently rolling along the mucosal surface.

The researchers, from the National Institutes of Health (NIH) and the University of Verona, Italy, collected CSF samples as well as specimens obtained through the nasal-brushing technique from 31 CJD patients and 43 patients with other neurologic diseases or no disease.

The samples were tested using a real-time quaking (shaking)-induced conversion (RT-QuIC) assay, which the authors describe as "an ultrasensitive, multiwall plate–based fluorescence assay involving PrPCJD-seeded polymerization of recombinant PrP into amyloid fibrils."

Testing of the nasal samples yielded positive results in 30 of the 31 CJD patients, for a sensitivity of 97% (95% confidence interval [CI], 57%-89%). All 43 non-CJD samples were negative, for a specificity rate of 100% (95% CI, 90%-100%). Testing of the CSF samples showed a 100% specificity but a 77% sensitivity (95% CI, 57%-89%).

QuIC responses were stronger and faster from the nasal samples, and prion seeds were found at much higher levels in the nasal brushings than in the CSF.

Say the authors, "The high sensitivity and specificity of RT-QuIC testing of nasal brushings in identifying patients with Creutzfeldt–Jakob disease indicate that this procedure has the potential to be useful for establishing a definitive diagnosis of Creutzfeldt-Jakob disease in living patients."
Aug 6 NIH news release

In the other study, researchers found that prions of vCJD can be identified with high accuracy in the urine of infected patients.

The authors used the protein misfolding cyclic amplification (PMCA) method to amplify small quantities of PrPSc (abnormal prion protein). The marker was identified in 13 of 14 urine samples of vCJD patients and in none of 224 patients with other neurologic diseases or no disease, for an estimated sensitivity of 92.9% (95% CI, 66.1%-99.8%) and a specificity of 100% (CI, 98.4%-100%). PrPSc was detectable only after extensive amplification with PMCA, meaning the concentration of the protein was very small.
Aug 7 N Engl J Med table of contents (click on individual articles—Orru [nasal brushing], Moda [urine test], Masters [editorial])


Another new drug approved for bacterial skin infections

Oritavancin (Orbactiv), a new intravenous therapeutic agent for patients with acute bacterial skin infections, was approved by the Food and Drug Administration (FDA) yesterday after expedited review, said an FDA news release yesterday. It is the third such agent approved since May.

The drug was approved for treatment of acute bacterial skin and skin structure infections (ABSSSI) caused by susceptible bacteria, including methicillin-susceptible and methicillin-resistant Staphylococcus aureus, some Streptococcus species, and Enterococcus faecalis.

Clinical trials of oritavancin showed it to be as effective as vancomycin for ABSSSI. Side effects included headache, nausea, vomiting, skin and soft-tissue abscesses on arms and legs, and diarrhea.

The drug was designated as a Qualified Infectious Disease Product (QIDP) under the FDA Safety and Innovation Act of 2012 because it is "an antibacterial or antifungal human drug intended to treat a serious or life-threatening infection," the FDA said.

Dalbavancin (Dalvance) and tedizolid (Sivextro) were also given QIDP designation and approved for ABSSSI in May and June, respectively. QIDP drugs get priority review by the FDA as well as extended marketing advantages.
Aug 6 FDA news release
Jun 23 CIDRAP News scan regarding tedizolid approval
Jun 5 CIDRAP News scan regarding dalbavancin approval


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