What's Swimming in the Pool With You?

Over the last couple of weeks pools have been opening for the summer. I have a few friends with pools and live close to a large public pool. I know a lot of work goes into keeping the water as clean and clear as possible. Chlorine is a common additive to kill microbes and it does a pretty good job, but are there some out there that can survive? What kinds of bacteria are in public pools? How do I avoid getting an infection from something in the water? The CDC has the answers.

  by  Innisfree Hotels 

Swimmers

The CDC conducted a study of swimming pools in 2012. They sampled water filters in public pools to see what was potentially in the water. They found Escherichia coli in 58% of filters they tested. This indicates a lot of fecal matter enters the water. E. coli is common in the human gut and in feces, so it's presence in water is a marker for fecal contamination. People contaminate pools with feces when they have an "accident" in the pool or it washes off the body from people who haven't showered before entering the pool. On the bright side, no samples tested positive for O157:H7, a particularly virulent strain that produces a deadly toxin.

The CDC also found Pseudomonas aeruginosa in 59% of samples. P. aeruginosa is a bacteria that causes skin rashes and ear infections, and is the bacteria behind "Swimmer's ear". It is a natural contaminant, usually from inadequate chlorine and pH levels, and is also introduced from people. Cryptosporidium and Giardia were found in less than 2% of samples. Cryptosporidium is a bacteria that causes a bowel disease similar to dysentery. Giardia is a parasitic protozoan that causes diarrhea, vomiting, cramps, and dehydration. The study did not test water parks or residential pools, but believe the hygiene, sanitation, and contamination between pools is similar due to the most common microbes coming from swimmers themselves.

Prevention

The CDC recommends swimmers: 
Keep feces and other contaminants out of the water.
  -Do not swim when you have diarrhea.
  -Shower with soap before you start swimming.
  -Take a rinse shower before you get back into the water.
  -Take bathroom breaks every 60 minutes.
  -Wash your hands with soap after using the toilet or changing diapers.
Check the chlorine level and pH before getting into the water. 
Do not swallow the water you swim in.

Happy swimming this summer!

CDC Study 
CDC Healthy Swimming 

Fungal Infections

The last couple of weeks we have learned of a few infectious fungi like Cryptococcus sp. and Candida sp. We study bacteria and bacteria-related infections in depth, but very time is spent on fungal infections. A lot of people, including me, think it weird that something like yeast can cause a serious infection. The stuff you make bread with can make you sick? No way.

We talk about yeast and species of fungi, but I still associate it with the powder I mix into dough to get it to rise and the stuff in beer and wine that makes alcohol. I wanted to find out more about diseases caused from fungi, and what I did find was interesting. I didn't know there were so many species that had nothing to do with the carbon dioxide-producing baking aides. Here are some of the highlights.

Fungal Infections and HIV/AIDS

Fungal infections aren't something that happens often, and that's because our body does a great job of stopping infections and killing invaders. Fungi generally aren't protected by much and take a much longer time to grow and establish themselves than a bacterial infection would. But in a patient who was a weak or non-functioning immune system, opportunistic infectious agents have an easy time colonizing the body. That's why most fungal infections are seen in immunocompromized patients and why they are so serious. According to the paper linked below, around 50% of AIDS-related deaths are caused by fungal infections. Here are some of the most common fungal infections in HIV/AIDS patients.

Cryptococcosis

  by  Pulmonary Pathology 

Cryptococcosis is caused by Cryptococcus neoformans. The fungus is inhaled and enters the lungs. The lack of protection from alveolar macrophages allows the fungus to spread to the blood, and later to the brain and CSF. Encephalomeningitis causes increased cranial pressure that leads to death. Sub-Sahara Africa sees the majority of infections, but the infection can occur in all populated areas. This is considered one of the more dangerous fungal infections because without help from the bodies' immune system it is difficult to clear and once symptoms appear the disease progresses rapidly. However, once the fungus is detected, the mortality rate for developed countries is about 9% but 70% in developing countries. Drugs like Amphotericin B and flucytosine are used in treatment. The defining identification of cryptococcal meningitis is a positive India ink stain of CSF fluid, but the fungus can be found in other tissues, especially the lung and brain.

To Be Continued

A neglected epidemic: fungal infections in HIV/AIDS.

Colleges Using Unapproved Meningitis Vaccines

Princeton University and the University of California Santa Barbara recently experienced outbreaks of meningitis B. Meningitis B is a serologic group of bacterial meningitis. Meningitis in general is highly contagious in close quarters, such as college classrooms and dorms. There are FDA approved vaccines for other serologic groups, but no vaccine for type B.

There are 8 reported cases at Princeton and 4 at UCSB. The first case at Princeton was found in March 2013 and the first case at UCSB was found in November 2013. With no vaccines, Princeton was worried about the infection spreading. They were allowed to use an unapproved vaccine by the FDA under an "Investigational New Drug" tag to use the vaccine Bexsero, which is the only vaccine to protect against type B. The vaccine is approved in Europe, Australia, and Canada. About 5,000 students were vaccinated. Later that year, type B meningitis infections were found at UCSB. The same vaccine was allowed to prevent further outbreaks. A booster shot was offered at Princeton in February.

The CDC reports the FDA claims the vaccines are safe for use in specific situations, such as outbreaks in susceptible populations. There are no major side effects except a severe allergic reaction, which is extremely rare. The FDA uses the IND tag to approve use of a drug they feel is safe and the benefits are greater than the risks, and they applied it to Bexsero because they have not yet approved it for use for the general public in the US. The vaccine is a two-part intramuscular shot that requires a second booster 6 months after the initial vaccination to maximize protection.

Huffington Post

The Princeton Sun

CDC Type B Vaccine and Outbreaks

Welcome

My name is Zack and I'm a Clinical Laboratory Sciences (CLS) graduate student. I'll be posting interesting things from Infectious Diseases and Microbiology classes or outside sources I find that relate to the courses. So for an intro, I'll answer a few common questions.

What is a Clinical Laboratory Scientist?

Well, to start off I think it's best to say what we are not. We are not nurses or doctors. We work very closely with them, but we are definitely a separate field.  CLS and Medical Technologists are specialists in the clinical lab. We handle samples like blood, tissue, and other body fluids and analyze them to find out more about patient health and disease states. We are most commonly found in hospital labs, but also work in reference labs, private offices, and government facilities.

What's the difference of Microbiology and Infectious Diseases?

Microbiology is the study of microscopic organisms such as bacteria, yeasts, and parasites. Microbiology is all about the classification and characterization of the organism. We learn how to classify and identify bacteria based on growth patterns, staining, biochemical tests, antimicrobial susceptibility, and even physical senses like color and smell. Micro focuses on the just the organism.

Infectious Diseases looks at the associated diseases caused by the organisms.  It is about classifying organisms based on common disease traits to help pinpoint the organism or group of organisms most likely responsible so the best treatment and therapy can be given to a patient.

I hope this gives you some idea what this blog will be about!