Experimental antiviral trial launches in male Ebola survivors

US health officials and their Liberian counterparts today announced the launch of a study to assess if a new antiviral drug can cut lingering Ebola virus RNA levels in the semen of men who survived the disease, a strategy that could decrease the risk of sexual spread.

The study is the fourth project of the Partnership for Research on Ebola Virus in Liberia (PREVAIL), according to a news release today from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

The trial involved GS-5734, a small-molecule antiviral compound that has already been tested for human safety in the United States. No serious side effects have been seen, but some volunteers experienced a temporary rise in liver enzyme levels.  In a rhesus monkey trial, the drug reduced blood viral levels and improved survival after a lethal dose of Ebola.

In the PREVAIL study, researchers will enroll 60 to 120 men who are already part of the PREVAIL Ebola natural history study. After kidney and liver function screening, participants in the new study will receive GS-5734 or placebo once a day for 5 days. Researchers will examine participants and their blood and semen samples 10 times during the first month and once a month for the next 5 months.

Anthony Fauci, MD, director of NIAID, said in the press release that traces of Ebola virus can remain in a survivor's body and be passed to others, posing the threat of new transmission chains. He said if the drug proves useful for dropping virus levels in semen, it has the potential to decrease the risk of sexual spread.

"If so, the drug would be another weapon in our arsenal against Ebola virus disease," he said.
Jul 5 NIAID press release

In other Ebola research developments, a genetic and epidemiologic analysis of Nigerian patients infected during West Africa's Ebola outbreak confirmed earlier evidence that transmission was triggered by a single introduction of the virus.

A sick airline passenger brought the virus to Nigeria in July 2014, and many of the patients exposed to the virus were healthcare workers. Scientists from Nigeria and their research partners from the Broad Institute at Massachusetts Institute of Technology and Harvard University published their findings yesterday in the Journal of Infectious Diseases.

They based their analysis on clinical data and contact information on 19 of the 20 reported cases in the cluster and genome sequences for 12 of the patients. Genetically, the virus in Nigeria was part of but distinct from a lineage seen in Liberia. Genetic findings are consistent with the transmission tree suggested by the epidemiologic data, the authors said, noting that the Nigerian illnesses didn't lead to any transmission outside of the country.
Jul 4 J Infect Dis abstract

 

4 new cases of MERS; 3 linked to camels

Saudi Arabia’s Ministry of Health (MOH) reported four new MERS cases over the past several days. Three of the patients had exposure to camels. None of the new cases are related to the current outbreak that began at the King Khalid University Hospital in Riyadh.

On Jul 3 the MOH reported two primary cases of MERS-CoV (Middle East respiratory syndrome coronavirus). The first patient is a 74-year-old Saudi woman from Al Duwadimi. She is in critical condition and is reported as having had indirect exposure to camels. A 24-year-old male expatriate from Riyadh is also in critical condition and had direct exposure to camels.

Yesterday the MOH said that a 67-year-old Saudi man from Riyadh is also infected. The agency lists his case as primary—meaning he did not contract the disease from another patient—and he is in stable condition.

Today the MOH reported another new case, as well as a death in a previously reported patient. A 74-year-old Saudi man from Najran is in stable condition after testing positive for MERS-CoV; he had direct exposure to camels. In addition, a 74-year-old woman Saudi woman from Al Kharj died recently from MERS, the agency said. She had preexisting illnesses.

As of today, Saudi Arabia's MERS-CoV total since 2012 is 1,411 cases, including 600 deaths. Contact with camels, including drinking camel milk, is a known risk factor for MERS, but researchers don't know exactly how the animal transmits the virus to humans.
Jul 3 MOH report
Jul 4 MOH report
Jul 5 MOH report

 

Reduced antibiotics for RTIs could lead to slight increase in pneumonia

A large new study out of the United Kingdom shows that a reduction in antibiotic prescribing for self-limiting respiratory tract infections (RTIs) might lead to a slight increase in some bacterial infections like pneumonia but not in several others.

According to the study, published yesterday in BMJ, about 50% of antibiotics prescribed in UK primary care practices are for RTIs such as common colds, sore throat, acute bronchitis, and sinusitis. This is despite the fact the antibiotics offer little benefit for such ailments, and UK health officials recommend a no-antibiotic-prescribing approach to RTIs as part of a strategy to reduce the inappropriate use of antibiotics and the risks of antibiotic resistance.

Some doctors, however, continue to prescribe antibiotics for RTIs over concerns about potential complications from those infections—including pneumonia, peritonsillar abscess, mastoiditis, empyema, bacterial meningitis, intracranial abscess, and Lemierre's syndrome.

To determine whether reducing unnecessary antibiotic prescribing for RTIs could increase the risk of these complications, researchers looked at electronic health records from more than 600 general practices in the United Kingdom from 2005 to 2014, a period that saw antibiotic prescriptions for RTIs decrease from 53.9% to 50.5% in men and from 54.5% to 51.5% in women. They then extrapolated the findings to determine the expected number of complications that might occur if a general practice with a population of 7,000 patients reduced antibiotic prescriptions for RTIs by 10% over a decade.

The study showed that while no increase is likely for mastoiditis, empyema, bacterial meningitis, intracranial abscess, or Lemierre's syndrome, general practitioners might see a slight increase in treatable cases of pneumonia (about one additional case a year) and peritonsillar abscess (about one additional case a decade). At the same time, the authors note, a 10% reduction in antibiotic prescribing for RTIs would likely reduce the risks of antibiotic resistance and the side effects of antibiotics.
Jul 4 BMJ study

Canadian study notes HPV vaccination success against cervical abnormalities

Administering the human papillomavirus (HPV) 16/18 vaccine to young girls prevents the cervical abnormalities that can lead to cervical cancer, according to a large population-based Canadian study yesterday in the Canadian Medical Association Journal (CMAJ).

The study took place 8 years after Alberta introduced a school-based vaccination program in Canada that aimed to give girls aged 10 to 11 three doses of the vaccine, with a catch-up program at age 14. In 2014, the school program was expanded to include boys.

Researchers collected data from the Pap smears of 10,204 women who were born from 1994 to 1997 (aged 18 to 21 years) and lived in Alberta before 2008. Forty-four percent of the women received at least one dose of the vaccine.

High-grade, or atypical squamous cells, found on a Pap smear can be a precursor to cervical cancer. The vaccine used in Canada protects against the two strains of HPV linked to 70% of cervical cancers.

Cervical abnormalities were detected in 1,481 women (14.5 %); among those women, 93.5% had low-grade abnormalities and 6.5% had high-grade abnormalities. Only 11.8% of fully vaccinated women had cervical abnormalities, compared with 16.1% in the unvaccinated group. Also, women in the vaccinated group were more likely to get regular screenings, meaning abnormal results were addressed earlier.
Jul 4 CMAJ study

Flu Scan for Jul 05, 2016

News brief

Flu vaccine more effective than thought in mismatched year

A new study in Clinical Infectious Diseases reports that the flu vaccine in 2014-15 was more effective than expected in hospitalized adults, including those 65 or older.

Influenza H3N2 strains were severe and circulated widely from November 2014 to March 2015, but they antigenically drifted from the viruses used in that year's flu vaccine. Previous studies showed that this led to less-than-optimal vaccine protection, especially in hospital settings. But researchers investigating patients at two hospitals in Michigan found that the vaccine was 43% effective against H3N2 in all adults, and 48% effective in those 65 or older.

Both numbers are higher than previous studies found for H3N2 protection that season.

Vaccine effectiveness was determined by contrasting the vaccination status of those who tested positive for H3N2 against those who tested negative for the virus. Of the 624 adults hospitalized for acute respiratory illness, 421 (68%) were vaccinated, and 98 patients (16%) tested positive for influenza A. Among 60 (61%) of influenza A virus samples, 53 (88%) had drifted to the 3C.2a genetic group.

"We can be encouraged by the current results which suggest that inactivated vaccines may perform better in preventing hospitalization than milder disease in a year with antigenic drift," the authors said.
Jul 1 Clin Infect Dis study

 

Study: Warmer winters may curtail flu-related deaths

Because of the association between cold winter temperatures and flu fatality rates in Europe, warmer winters might mean fewer influenza deaths, European researchers reported yesterday in Nature Climate Change.

The investigators analyzed daily regional mortality data from 1998 through 2005 for 16 European nations representing 405 million people. The countries used an identical method for collecting fatality data, which helped rule out confounding factors.

The team found a strong association in all countries but the United Kingdom, Netherlands, and Belgium between the year-to-year fluctuations in winter (December-to-March) mean temperatures and the number of flu deaths, with colder winters tied to higher fatality rates. For the 13 other countries, the correlation ranged from –0.60 in Denmark to –0.97 in Portugal, whereby –1.0 would be a perfect correlation.

The authors write, "Despite the lack of a strong year-to-year association between winter mean values in some countries, it can be concluded that warmer winters will contribute to the decrease in winter mortality everywhere in Europe."
Jun 4 Nat Clim Chang study

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