Weekly Digest: Yellow Fever reemerging, spreads in Brazil; Is South Asia prepared for emerging infectious diseases?

14 Apr 2017

A weekly roundup of news on drug resistance and other topics in global health.

Is South Asia prepared for emerging infectious diseases? An analysis from CDDEP Director Ramanan Laxminarayan and colleagues finds that South Asia is highly vulnerable to growing infectious disease threats due to uneven health system capacity, against a backdrop of rapid urbanization and increasing populations. South Asia is home to a quarter of the world’s population and bears a significant proportion of the global burden of infectious disease, with longstanding battles against tuberculosis, HIV and malaria. Emerging and spreading infectious diseases such as Zika, Ebola, Middle East Respiratory Syndrome-coronavirus (MERS-CoV), and avian influenza, are adding to the already significant burden of disease, and may accelerate in the face of inadequate surveillance and uneven health system capacity. The analysis is part of a collection of twelve analyses on health in South Asia, published in The BMJ. [The BMJ]

Yellow Fever emerges again, spreads in Brazil. The reemergence of yellow fever in rural regions of Brazil has health officials concerned about epidemic potential if it is not contained before reaching Brazil’s urban areas. Since February 2017, health authorities in Brazil have reported 234 confirmed infections and 80 confirmed deaths. Large urban outbreaks had also occurred in Angola and spread to the Democratic Republic of Congo in December 2015, causing 961 confirmed cases and 137 deaths. Cases have even been noted in nonendemic areas, such as China. In a New England Journal of Medicine perspective, Catherine I. Paules M.D. and Anthony Fauci, M.D., suggest that to prevent an epidemic, “early identification of cases and rapid implementation of public health management and prevention strategies, such as mosquito control and appropriate vaccination, are critical.” [STAT, NEJM]

WHO report: Investment inadequate to meet clean water Sustainable Development Goals. A report from UN-Water, the UN interagency coordination mechanism for freshwater-related issues, finds that countries are not increasing spending fast enough to meet water and sanitation targets under the Sustainable Development Goals. While the global increase in spending for water, sanitation and hygiene (WASH) has been just under five percent per year for the last three years, more than 80 percent of countries report that financing is still insufficient to meet national targets. According to WHO’s Dr. Maria Neira, “almost two billion people use a source of drinking-water contaminated with faeces, putting them at risk of contracting cholera, dysentery, typhoid and polio." Contaminated drinking water is estimated to cause more than 500,000 diarrheal deaths each year. [WHO, Deutsche Welle]

Ebola epidemic explained through genomic analysis: The evolution and spread of the Ebola epidemic that began in 2013 and ended in 2016 in West and Central Africa is analyzed in the largest ever collaborative study of a viral epidemic, reported this week in Nature. Ninety-three scientists from 53 institutions in 16 countries, led by researchers from the Fred Hutchinson Cancer Research Center, contributed blood samples, genome analyses or other inputs, resulting in whole genome analysis of 1,610 virus samples.  The aim, beyond understanding the dynamics of this Ebola outbreak, was to "provide a framework for predicting the behavior of future outbreaks for Ebola virus" and other epidemics. From the gene sequences, they considered 25 geographic, demographic and climatic factors that could have affected the course of the epidemic, confirming that cities were major agents of disease spread. They also found that just a few travelers—3.5 percent of the sample—enlarged the spread of the disease disproportionately. Unaffected countries in the region were spared largely by chance as most of the countermeasures (e.g., border closings) were either too late or ineffective.  The study results are depicted in animated form on YouTube. [YouTube, Nature, CIDRAP]

New class of anti-TB drugs potential life-saver for millions with drug-resistant TB. A study published in Molecular Cell reports the discovery of a new class of drugs, effective against rifampin-resistant and multidrug-resistant tuberculosis (TB). TB infects one-third of the world's population and kills 1.8 million people annually, with increasing rates of drug resistance making it more difficult and more expensive to cure patients and control the spread of the disease. The work reported also represents an important step toward rational drug design for TB by its mapping of the structure of Mycobacterium tuberculosis RNA polymerase (Mtb RNAP), the enzyme inhibited by rifampin, the anchor drug for TB treatment for decades. Richard Ebright, lead investigator for the study at Rutgers University, calls Mtb RNAP mapping the “Holy Grail” for drug discovery in TB. The new class of drug compound—Na-aroyl-N-aryl-phenylalaninamides (AAPs)—binds to a different site on Mtb RNAP than rifampin, has shown no cross-resistance with rifampin, and has advantages when co-administered with rifampin over either compound given alone. Nader Fotouhi of the Global Alliance for TB Drug Development said, "The discovery of an alternative binding site and the AAPs represents a significant step towards the identification of a novel RNAP inhibitor that would behave like rifampin but be devoid of any pre-existing resistance.” [CIDRAP, Molecular Cell]

Rising carbapenem resistance in Enterobacter cloacae: Research published in Emerging Infectious Diseases examines the antimicrobial resistance of Klebsiella pneumoniae and E. cloacae in patients from the US Veterans Health Administration between 2006-2015, finding increasing resistance to carbapenems, particularly among E. cloacae complex (E. cloacae, E. asburiae, E. kobei, E. hormaechei, E. xiafangensis). Researchers tested the susceptibility to carbapenems of more than 128,400  K. pneumoniae isolates and more than 38,000 E. cloacae complex isolates from 140 VA facilities in 40 states. While carbapenem resistance and nonsusceptibility rates among K. pneumoniae remained steady over the study period, rates of resistance and nonsusceptibility increased in E. cloacae complex. In 2014-2015, more than 4 percent of isolates were nonsusceptible, and 2.5 percent were resistant, to carbapenems. According to the authors, the results of this study indicate that a second epidemic of carbapenem-resistant Enterobacteriaceae is taking place in E. cloacae complex. [CIDRAP, EID]

KFC commits to antibiotic-free meat by 2019. Kentucky Fried Chicken (KFC) has announced that starting in 2019, they will stop selling chicken that has been given antibiotics important in human healthcare in their 4,200 US restaurants. Antibiotics are often given to poultry and other food animals to prevent infections and to promote growth. KFC’s announcement follows similar policy changes implemented by McDonald’s, Subway and other food chains in recent years. According to Lena Brook of the Natural Resources Defense Council, “While federal antibiotics policy stagnates, the market is responding to consumer demand for better meat. This commitment from the nation’s most iconic fast food chicken chain will have a major impact on the way the birds are raised in the US and in the fight against the growing epidemic of drug-resistant infections.” [CIDRAP]