News Scan for Aug 23, 2017

News brief

Cyclospora outbreak total continues steady rise; food source still elusive

In an ongoing multistate Cyclospora outbreak, 96 more patients without a history of international travel who were sick on or after May 1 have been reported to the US Centers for Disease Prevention and Control (CDC), boosting the national total to 347, according to the agency's latest update.

A rise in Cyclospora cases in international travelers is normal during the summer months, but spikes in illnesses in people who haven't traveled have been reported over the past several summers, with outbreaks tied to imported fresh produce such as basil, cilantro, and raspberries. On Aug 7 the CDC warned healthcare providers about an increasing number of cases.

The latest illness-onset date is Aug 10. Outbreak-related illnesses have been reported in 31 states, though Texas is the hardest hit. The Texas Department of State Health Services (TDSHS) said yesterday that 251 cases have been reported since the middle of June, reflecting an increase of 21 cases from the previous week.

In its latest update on Aug 18, the CDC said no specific food vehicle has been identified, and an investigation into the source of the outbreak is ongoing.

The hallmarks of cyclosporiasis, caused by the Cyclospora cayentanensis parasite, are watery, profuse diarrhea; fatigue; muscle pain; and low-grade fever.
Aug 18 CDC Cyclospora outbreak update


Study: Oral steroids do not shorten duration of respiratory illness

A new study yesterday in the Journal of the American Medical Association (JAMA) said that administering oral prednisolone to non-asthmatic adult patients with severe lower respiratory infections did not shorten the duration of their illness.

The randomized controlled trial included 401 adults with symptoms of acute lower respiratory tract infection, gathered from 54 family practices in England. The treatment group (199 patients) received oral prednisolone: 40 mg per day for 5 days.  The remaining 202 patients were treated with placebo. The steroid did not reduce the median duration of moderately bad or worsening cough (5 days for each group) or the mean severity of symptoms over the 5 days of treatment. None of the study participants were treated with antibiotics, and none had a history of chronic respiratory disease.

As more doctors become aware of the growing risks of antibiotic resistance and the misuse of antibiotics in respiratory infections, many are prescribing steroids to patients presenting with severe cough, wheezing, and shortness of breath. The study authors said there is no evidence this is a helpful practice.

"The trial also contributes to a growing body of evidence suggesting that systemic and topical corticosteroids have a limited role in the treatment of common infections and their postinfectious complications in primary care," the authors concluded.
Aug 22 JAMA study

 

Aedes aegypti found in Canada as firm reveals novel mosquito control steps

Aedes aegypti, the mosquito that transmits Zika, yellow fever, and dengue, has been found for the first time in Canada. According to a report from the Canadian Broadcasting Corporation, experts believe the bug is becoming established in southern Ontario.

The mosquito was caught in a trap just a week after the same area of Ontario announced the discovery of two Aedes albopictus mosquitoes, another type known to spread diseases to humans.

An official quoted in the story said none of the Aedes mosquitoes tested positive for dengue or Zika, and cited climate change as the likely reason the sub-tropical species were found so far north.
Aug 22 CBC report

In other mosquito news, a California-based biotech company unveiled novel ways to control mosquitos this week during an annual meeting of the American Chemical Society. The company said climate change has encouraged mosquitos to breed in new climates, resulting in the need for a rapid response to growing insect populations.

The company, ISCA Technologies, said more extreme storm events will increase flooding and pooling of water, excellent breeding ground for mosquito larvae. Three new techniques, including a formula that's used to treat floodplains before the rainy season, target mosquitos before they breed. According to ISCA, the formula relies on Bacillus thuringiensis israelensis, bacteria, also known as Bti, that kills mosquito larvae but is benign to the rest of the environment.
Aug 23 ICSA Technologies press release
Aug 22 TDSHS Cyclospora update

 

Diphtheria cases rising in crisis-hit Venezuela

So far this year, three countries in the Americas—Venezuela, Haiti, and Brazil—have reported 204 suspected or confirmed diphtheria infections, a number that has already exceeded the region's totals for 2015 and 2016, the Pan American Health Organization (PAHO) said yesterday in an epidemiologic update.

More than half of the cases (123) are in Venezuela, a country experiencing internal political and economic turmoil. The single case reported in Brazil probably involved exposure to the bacteria in Venezuela, PAHO said. Haiti has reported 80 cases.

Since the middle of July 2016, Venezuela has reported 447 suspected diphtheria cases, of which 51 were confirmed, along with 7 deaths. Cases have been reported in 17 of the country's 23 states. Of patients with lab-confirmed illnesses, 55% are women, 47% are young people ages 5 to 19 years old, 78% hadn't received the complete vaccination series, 15% were unvaccinated, and vaccination status was unknown for 7%.

In Haiti, 20 of 72 probable diphtheria infections this year were lab-confirmed, and 3 illnesses were fatal. The confirmed cases are in 4 of Haiti's 10 departments. Most (74%) involve children under age 10, and 60% are in girls or women. Vaccination status isn't known for 54.5% of the confirmed case-patients, 18.2% were vaccinated, and 27.3% were unvaccinated.
Aug 22 PAHO diphtheria epidemiologic update

This week's top reads