Tag Archives: medicine

New type of vaccine-resistant polio virus

Polio virus (Credit:  Sanofi Pasteur/Flickr)

Polio viruses in black and white (Credit: Sanofi Pasteur/Flickr)

Main Point:

Scientists have found a new strain of polio virus that is thought to be responsible for the major epidemics of polio cases in the recent times. This polio virus is not affected by polio vaccines. Continue reading

Safety lapses at government labs raise serious bioterror concerns

Gas Mask (Credit: User Surface Forces/Flickr)Main Points:

Recent safety lapses at the Centers for Disease Control (CDC) and National Institute of Health (NIH) facilities illustrate a new and grave bioterror threat: the risk for disease and death emanating from biocontainment laboratories themselves, according to a commentary being published in Annals of Internal Medicine. Continue reading

Rollout strategy for diagnostic test in India may impact TB

Tuberculosis (Credit: © Shutterstock)Main Points:

Xpert MTB/RIF, a recently implemented tuberculosis (TB) test, has the potential to control the TB epidemic in India, but only if the current, narrow, implementation strategy is replaced by a more ambitious one that is better funded, also includes the private sector, and better referral networks are developed between public and private sectors, according to new research published in this week’s PLOS Medicine. The study by David Dowdy, from Johns Hopkins University, United States, and colleagues is a mathematical model that suggests alternative strategies that include engagement with both the public and private sector may have a bigger population level impact on TB than the current implementation strategy of using Xpert for only those at risk of drug-resistance or HIV infection.

Published in:

PLOS Medicine

Study Further:

Xpert MTB/RIF is a new TB diagnostic that is more sensitive than other diagnostics in current widespread use and can detect resistance to certain antibiotics, but its cost is substantial, and the Indian health-care system is fragmented and heavily privatized with the majority of the population seeking private healthcare initially. Currently, due to resource constraints, the Indian Revised National Tuberculosis Control Programme is mainly implementing Xpert MTB/RIF as a rapid drug susceptibility test method among selected patients seeking care in the public sector.

The researchers explored the impact of six different rollout strategies on the incidence of tuberculosis (the number of new cases of tuberculosis in the population per year) by developing a mathematical model of tuberculosis transmission, care-seeking behavior, and diagnostic/treatment practices in India. A scenario that added access to Xpert MTB/RIF for 20% of all individuals with tuberculosis symptoms seeking diagnosis in the public sector and 20% of individuals seeking care from qualified private practitioners to the current national strategy was predicted to reduce the incidence of tuberculosis by 14.1% compared to the current national strategy which is only expected to reduce incidence by 0.2%. However, this scenario required more than 2,200 Xpert machines and reliable treatment referral. Notably, a scenario tested that encouraged informal providers to refer suspected tuberculosis cases to the public sector for diagnosis using currently available tests predicted a greater impact on the incidence of tuberculosis than Xpert scale-up within the public sector alone.

The authors acknowledge that their findings are subject to uncertainties in the assumptions made in their model but note, “Xpert [MTB/RIF] … could substantially reduce the burden of TB disease due to poor diagnosis in India; however, this impact depends not only on the accuracy of the test, but also on the behavior of both patients and providers, their level of access to new tools, and quality TB treatment following diagnosis.”

They conclude, “any Xpert [MTB/RIF] rollout strategy must also consider the complex health-care infrastructure into which the test is being rolled out. To achieve maximum impact of novel diagnostics, India should engage the private sector, improve quality of care across all sectors, and dramatically increase resources.”

Research Article:

Reference:

Salje H, Andrews JR, Deo S, Satyanarayana S, Sun AY, et al. (2014) The Importance of Implementation Strategy in Scaling Up Xpert MTB/RIF for Diagnosis of Tuberculosis in the Indian Health-Care System: A Transmission Model. PLoS Med 11(7): e1001674. doi:10.1371/journal.pmed.1001674, http://www.plosmedicine.org/article/info%3Adoi%2F10.1371%2Fjournal.pmed.1001674

Funding:

The project was funded by grants from the Bill & Melinda Gates Foundation (OPP1061487) and Canadian Institutes of Health Research (MOP 123291). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing Interests:

MP serves as a consultant to the Bill & Melinda Gates Foundation (BMGF). MP is also a member of the Editorial Board of PLOS Medicine.

Author Affiliations:

Johns Hopkins Bloomberg School of Public Health, United States

Massachusetts General Hospital, United States

Indian School of Business, India

McGill University, Canada

McGill University Health Centre, Canada

Johns Hopkins School of Medicine, United States

Johns Hopkins University, United States

Contact:

David Dowdy, Johns Hopkins Bloomberg School of Public Health, United States, +1 (410) 614-0902, ddowdy@jhsph.edu

Study Does Not Find Increased Risk of Blood Clot Following HPV Vaccination

Vaccination (Credit: Flickr)Main Point:

Although some data has suggested a potential association between receipt of the quadrivalent human papillomavirus (HPV) vaccination and subsequent venous thromboembolism (VTE; blood clot), an analysis that included more than 500,000 women who received the vaccine did not find an increased risk of VTE, according to a study in the July 9 issue of JAMA.

Published in:

JAMA

Study Further:

“Safety concerns can compromise immunization programs to the detriment of public health, and timely evaluations of such concerns are essential,” the authors write.

Nikolai Madrid Scheller, M.B., of Statens Serum Institut, Copenhagen, Denmark, and colleagues used data from Danish national registers to evaluate the potential link between quadrivalent HPV vaccination and VTE. Information on vaccination, use of oral contraceptives, use of anticoagulants (blood thinners), and the outcome of a first hospital diagnosis of VTE not related to pregnancy, surgery, or cancer was obtained from Danish registers.

The study included all Danish women, ages 10 through 44 years, from October 2006 through July 2013 (n = 1,613,798), including 500,345 (31 percent) who received the quadrivalent HPV vaccine; there were 4,375 incident cases of VTE. Of these, 889 women (20 percent) were vaccinated during the study period. Analysis of the data did not find an association between the quadrivalent HPV vaccine and VTE during the 42 days following vaccination (defined as the main risk period). Continue reading