Goodbye Post!

I had a lot of fun writing these blog posts this semester. I really enjoyed researching topics to write up, and I feel like it was a good way to keep informed on what's going on the infectious diseases world. I also found out which topics I found interesting and which ones I did not. I was not surprised to learn that lab ops and policy was more interesting to me than current events. However, I did find that case studies were a lot more interesting than I had anticipated. My favorite post was about a new method for detecting antimicrobial resistance. I will probably not keep up with this blog, but I will probably archive it and leave it up for the world. I hope you all have a great fall semester!

Containing Ebola Virus

One of the most important issues hospitals and other healthcare providers face when treating highly infectious patients is keeping other patients in the facility safe. Highly infectious patients easily transmit disease to other people, and PPE (personal protective equipment) may not be enough to protect patients if a particular infection is spread through respiratory droplets or otherwise able to spread through the air. This concern is coming to the forefront now that an Ebola victim is being transported to Emory University Hospital for treatment after they were infected caring for other victims in the African outbreak.

The CDC recommendations which came out Friday afternoon recommend hospital workers in charge of Ebola patients should wear gloves, a fluid-resistant gown, eye protection, and a face mask. Double sets of gloves, shoe covers, or leg covers are recommended if there is a large amount of blood or bodily fluid present. The PPE is then removed when the healthcare worker exits the room, placed into specially marked waste bags, and burned. Emory University Hospital has a special wing that is separate from the rest of the hospital that was created to treat patients of pandemics or bioterrorism attacks. Additionally, the Ebola patient will likely be quarantined in a negative-pressure room with isolated air flow, even though Ebola is not spread through the air.

Dr. William Schaffner, infectious disease specialist and preventative medicine professor at Vanderbilt University, reminds us that "the system for keeping bad germs under control is simple...The trick will be to do it rigorously at all times." An important lesson was learned in 2003 during the SARS outbreak: hospital workers will shortcut PPE because they were busy, "or because familiarity breeds if not contempt then casualness". Hopefully, history will not repeat itself once the Ebola patient arrives at Emory.

Sources
Article: http://www.npr.org/blogs/health/2014/08/01/337140082/how-u-s-hospitals-contain-deadly-germs-like-ebola-virus
Picture: http://app1.unmc.edu/nursing/heroes/images/heroesDoffingYourHospitalPPE-Poster2012.jpg

Parasite Infection as a Treatment for Crohn's Disease

A new paper suggests that patients with intestinal disorders, such as Crohn's disease or inflammatory bowel disease (IBS), would gain from infection with intestinal parasites.Julius Lukes, one of the co-authors of the paper, and other scientists in the Canadian Institute for Advanced Research (CIFAR) Integrated Microbial Biodiversity program have begun to focus on eukaryotes which live within the human body in recent years - what they are calling the "eukaryome". Lukes asserts that most parasites are not harmful to otherwise healthy patients with low parasite loads. To prove his point, he ingested several eggs of Diphyllobothrium latum (picture below), a tapeworm commonly acquired by eating under-cooked fish. After a year, the parasites are estimated to be 12 feet in length, and Julius reports he is feeling fine.

The theory behind the deliberate infection of these patients with parasites is an extension of the "Old Friends Hypothesis", which is based on the idea that they evolved with us and have been inside humans for most of our history. These parasites, which include hookworms, tapeworms, and Blastocystis species, are thought to "distract" the immune system and prevent it from overreacting to normal stress and reducing inflammation in the intestines. These parasites are commonly thought to cause vitamin deficiency, anemia, and diarrhea, but Lukes says that a critical review of the evidence shows "no negative impact in well-nourished people with low overall parasite loads". The hypothesis is still in the early stages of testing, but similar strategies have worked for viral infections.

Sources

Article: http://www.medicalnewstoday.com/releases/280085.php

Picture: http://www.cdc.gov/parasites/images/diphyllobothrium/home_page_image_diphyllobothrium.jpg

Cryptococcus gattii in the Pacific Northwest

Cryptococcus gattii is a tropical fungus which causes severe neurological disease in those it infects. In 1999, C. gattii was isolated on Vancouver Island, British Columbia, Canada. In Canada, the fungus evolved into a virulent pulmonary form which has caused dozens of deaths. Since 1999, C. gattii has spread to mainland Canada, Washington state, and Oregon. In Oregon, a new strain of C. gattii was discovered which has increased lethality. This strain has spread through the Pacific Northwest.

These new strains of C. gattii  have been investigated by a team from the Translational Genomics Research Institute (TGen), led by David Engelthaler, Director of Programs and Operations. This team contained 24 researched from 13 institutions in 7 nations. They sequenced 115C. gattii genomes from 15 countries. Their results, published in the journal mBio, identify "several genes that may make the outbreak strains more capable of surviving colder environments and that make it more harmful in the lungs". These genes are also possible targets for new diagnostic tests, therapeutic drugs, or preventative vaccines. This study also "provide[s] evidence that the Pacific Northwest strains originated from South America", most likely originating from Brazil.

The study, "Cryptococcus gattii in North American Pacific Northwest: whole population genome analysis provides insights into species evolution and dispersal", warns that the virus is easily adaptable to new environments and warrants public heath vigilance, even in areas where C. gattii is not thought to be endemic.

Source: http://www.medicalnewstoday.com/releases/279696.php
Image: http://www.cdc.gov/fungal/images/cryptococcus-gattii-lifecycle.jpg

A New Rapid Test for Detecting Multi-Drug Resistance

One of the major complications of treating bacterial infections is the potential for multi-drug resistant (MDR), extensively drug-resistant (XDR), or pan-drug-resistant (PDR) organisms. Multi-drug resistance is defined as "non-susceptibility to at least one agent in three or more antimicrobial categories", XDR is defined as "non-susceptibility to at least one agent in two or fewer categories", and PDR is defined as non-susceptibility to all agents in all antimicrobial categories" (1). Fortunately, XDR and PDR organisms are much fewer in number than MDR organisms. However, antimicrobial resistance has increased dramatically over the past 20 years, particularly in regards to gram-negative rods, and broad-spectrum antibiotics such as cephalosporins and carbapenems (which used to be last-resort options) are now losing their efficacy.

A new rapid test, CarbAcineto NP, has been developed by Patrice Nordmann and Laurent Poirel which detects the presence of carbapenemase in Acinetobacter baumanii. This test detects "the acidification properties generated by the enzymatic hydrolysis of a carbapenem, imipenem, when it is cleaved by a carbapenemase". The acid produced by the breakdown of imipenem causes a pH indicator to turn from red to yellow. Either isolated bacteria or swabs of a site infection can be used in the test, which produces results in less than 2 hours, much faster than the 24-72 hours required for current methods. This new rapid test allows treatment decisions to be made much more quickly and effectively, as well as allowing for the identification of potential MDR organisms as a screening tool.

Article Sources
(1): http://www.ncbi.nlm.nih.gov/pubmed/21793988
Article: http://www.sciencedaily.com/releases/2014/06/140626095705.htm
Image: http://bacteriasactuaciencia.blogspot.com/2013/10/esperanza-en-la-lucha-contra.html

Biofilms and Catheters

Biofilms are formed by many bacteria, some that are harmful and some that are not. These films are slimy coatings that protect bacteria against antibiotics, our immune systems, cleaning agents, and other environmental dangers. In hospitals, biofilms that form inside catheters or around implanted medical devices can lead to infections, especially from Staphylococcus aureus. 

Researchers at Princeton University were able to observe how biofilms form within small tubes such as catheters. Typically, biofilms build up into thick layers on surfaces. In flowing liquids, biofilms for string-like filaments that float within the fluid. The researchers were first able to observe filament formation in a solution of Pseudomonas aeruginosa. Filaments formed by P. aeruginosa took around 50 hours to clog the tubing. When researchers repeated the experiment with S. aureus, the tubes clogged within a few hours. They then coated the tubes with plasma to imitate how the organism would act within an intravenous catheter. These tubes were clogged in a few minutes.

Howard Stone, a Princeton researcher, says he is unsure how the organism is able to form these filaments so quickly, but the knowledge will assist with designing medicals tools and devices that are more resistant to colonization. Stone also pointed out that the concentrations of bacteria used in the experiments was much higher than those typically found inside medical devices. Breaking up the biofilms and preventing them from forming could be the next step in treatment of these organisms.

Source: http://www.npr.org/blogs/health/2014/06/27/325502998/sticky-streamers-of-staph-bacteria-may-clog-up-medical-devices

MERS

MERS, or Middle Eastern Respiratory Syndrome, is a viral illness which appeared in Saudi Arabia in 2012. MERS is a coronavirus, similar in structure to rhinoviruses which cause the common cold and SARS. The first symptoms of MERS are fever, cough, and shortness of breath. Since 2012, MERS has spread across the Middle East, and has been found in camels in Qatar, Oman, and Egypt in addition to Saudi Arabia. The exact source of the infection is unknown, but camels are a strong suspect.  MERS cases outside the Middle East are associated with travel, and are not endemic. According to the World Health Organization (WHO), there have been 820 cases of MERS and 286 deaths. Saudi Arabia has reported 113 cases and 34 deaths. Currently, there is no vaccine available for MERS.

Reports of MERS cases began to increase in March of this year, but has begun to decrease again. However, some scientists at WHO are concerned that the annual pilgrimage (Hajj) to Saudi Arabia in October will further increase its spread. Currently, MERS does not easily spread from person-to-person (most cases are spread camel-to-person), but the increased number of people exposed to camels in the coming months could allow the virus to mutate. Saudi Arabian health officials say they have increased surveillance and infection control measures in anticipation of the Hajj.

Resources
http://www.nbcnews.com/storyline/mers-mystery/mers-outbreak-could-spread-annual-pilgrimage-officials-n132866
http://www.cdc.gov/coronavirus/mers/faq.html
http://www.bbc.com/news/health-28044151