Hiding In Your Meat: Sarcocystis Hominis
Sarcocystis hominis is a protozoan parasite that uses an intermediate-definite host relationship to be able to conduct its life cycle to survive. S. homins uses asexual stages to develop a life cycle inside it’s host to be able to survive causing infections in humans. There have been multiple researchers who conducted studies on S. homins where they tested slaughtered cattle or hamburger meat and used the Molecular method to be able to identify whether the meat has been contaminated or not. These methods were aimed to create an unbiased and creative method to identify whether there was a presence of the S. hominis in the meat that we consume. It also important to understand that the life cycle of this protozoa can be changed by simply following simple protocols like no eating raw meat period. This paper provides a summary of the life cycle of Sarcocystist, Epidemiology, some common signs and symptoms, treatments, medicines and some approaches to how to identify whether our meat is contaminated. Keywords: Molecular method, life cycle, signs and symptoms, treatments, epidemiology.
There are many types of Sarcocystis and some species are found in cattle (Sarcocystis hominis) while the ones found in pigs are Sarcosistis suihominis, the two being the most common humans are infected with. When humans ingest this parasite through eating undercooked meats, the parasite then uses the human as a definitive host causing intestinal disturbance and sometimes muscular sarcocystosis. This parasite can be found in skeletal muscle, cardiac muscle, larynx, pharynx and also the upper esophagus. They multiply asexually causing an inflammatory response which triggers some animals who are infected with it to die, abort, or even not being able to grow properly. It is highly important that we keep or livestock healthy and away from anything that can be contaminated by S. hominis. Some of these methods should be implemented fully by any company who distributes meats so that they can show their consumers that they care about their health and well-being after consuming their products. Even though some symptoms of the S. hominis are just like any other food poisoning that lasts a couple of days, it is still better to not deal with that kind of problem and be able enjoy the food you eat. As far as medication goes, there isn’t medication that could help getting rid of parasite, but more trying to alleviate some of the common symptoms. Even though it isn’t as common to get the parasite in the US, we can still use the same preventative measure to help other countries achieve that same prevention method.
Detection Methods
There was a study aimed to have a protocol to detect Sarcocystis hominis by using a molecular genetic analysis technique called the PCR-RFLP of the rRNA. The methods they used was to get 25 raw hamburger samples that were randomly selected from supermarkets in Yazd city, Iran and from each sample extract DNA to be able to perform the identification of Sarcocystis hominis through the molecular machine. Evidently, when they were able to get the results, among the 25 hamburger meat samples 68% of them showed that the PCR was able to detect Sarcocystis. This study was able to develop a technique to be able to detect the widespread of S. hominis in meat products like the hamburger meats used in this study, which could in turn help many countries and meat companies avoid selling contaminated meats and be distributed later and consumed by humans.
Another study similar to the hamburger meat was conducted to use the same molecular approach but to detect S. hominis in slaughterhouses. This approach was able to retrieve a genetic representation of meat by taking muscle samples of 15 cattle from the slaughterhouse of the Faculty of Veterinary Medicine of Turin University. DNA was extracted from 25mg of muscle from the diaphragm, heart, or masseter and then sent out to be analyzed to get the results. The result of this experiment was that there were able to detect the presence of Sarcocysitis in 91% of the samples. The research was able to prove that a Molecular approach can be a good unbiased method to be able to detect the S. hominis parasite and can potentially lead to further studies on contaminated meat so that there would be less people sick from this parasite. In Iran, there was study conducted to determine the invasion of thin and thick walled S. hominis in slaughtered cattle. The methods that were used in this study was getting the esophagus and diaphragm muscles of 100 cattle and were examined for the presence of Sarcocystis macroscopically and microscopically. The results were that macroscopically, there were no signs of Sarcocystis found in any of the samples they had. Microscopically, there were able to detect 89 out of the 100 cattle to have thin walled S. cruzi white the 21 had the thick-wall sarcocysts. Here in Iran, Sarcocystosis is not a very common disease in humans, but it does affect the cattle probably because of the lack of resources in which disable the care taker of these cattle to be more prone to getting infected by the parasite than humans. This comes to show that there are multiple studies and research that was made to show people that there are ways to prevent the infection to spread among animals, since they are the primary hosts, but it can also prevent humans getting infected because of the lack of care of their animals. These animals need to have a proper place to drink clean water, eating place, and a place where they can defecate and be able to have the place clean. These matters are important in slaughterhouses or any other place where we get our meat because we can easily solve this by simply testing the meat before we distribute it. We can also save our livestock from dying or aborting by keeping them clean, healthy and making sure that the other animals are in the same condition.
Life Cycle
Sarcocystis homins life cycle uses an intermediate to definitive host relationship usually starting with the cattle and the pig ingesting oocysts. Oocyst or sporocyst get eaten by an intermediate host, like the cattle or pig, and it ruptures inside them releasing sporozoites that enter the cell wall of the small intestine. This protozoan parasite develops asexually, releasing merozoites causing them to turn into bradyzoites. When the definitive host eats the meat (humans) containing the infectious sarcocysts, bradyzoites are released, causing an invasion of gut cells forming gametes that take form into oocysts causing the life cycle all over again after passed on by feces through the definite host. In order to prevent the intermediate host from getting infected with the parasite we need to prevent them from drinking water, and or eating feed that is contaminated by feces from a definitive host. If you look at table 1, there is a step by step chart that shows all the events that occur as someone ingests a Sarcocystis parasite.
Signs and Symptoms
After eating raw meat, people started showing symptoms between 3 to 6 hours, causing nausea, stomach ache, fever, chills, vomiting. Some people experienced abdominal pain, watery diarrhea 1 week after ingesting infected buffalo meat. Other symptoms are not only intestinal, there are some that affect the muscles, causing muscle cysts to form and creating muscle weakness and myalgia; this would be a more severe case if there was multiple Sarcocystis hominis that were ingested, invading the human body.
Some people experience little to no symptoms or discomfort but after their stool has been checked, there is positive signs of oocysts present. Treatments and Medicines There is no known treatment to get rid of the parasite intestinally since the duration of the symptoms are short and sometimes show no sign of symptoms. There had been cases where a person was diagnosed with Sarcocystis hominis and was given 37mg daily of Pyrimethamine (used to get rid of toxoplasmosis) and 3g of Sulfisoxazole (broad spectrum antibiotics) for 14 days but it didn’t do anything. Another person who got infected wih S. suihominis (parasite from eating pork) was given 0. 2g for four times a day of Acetylspiramycin (antibiotic that stops the growth of bacteria causing inflammation) for 15 days and the feces with oocysts did not stop till a month later. Every patient has a different case of the S. hominis because it all depends on how much of the parasite they actually ingested.
Epidemiology
Since S. hominis sometimes can be had with no symptoms at all, 10% of the people who had S. hominis got an actual infection. Getting Sarcocystis is to be estimated a 1. 1% but is more popular to be caught in places like in Europe where there is a percentage of 10. 4%. Since there are still trying to find out and do more research on this parasite, there was a study that was conducted on the popularity of Sarcocystis in Zango, abattoir, Zaria, Nigeria. This study’s method was to get samples of the esophagus and diaphragm of 200 slaughtered cattle and later analyze it with pepsin-hydrochloric acid digestion and stained with Giemsa. These researchers used the digestion method, simulating a way that our stomach and gastric juices digest the food, and later centrifuged to get a sample onto the microscope, to see whether there was a detection of bradyzoites whom are part of the Sarcocystis hominis cycle. Here, they were able to detect about 42. 5% who tested positive for bradyzoites with no association to what the cattle’s gender or age, it was all tested under the same category.
These studies were designed to further explain why most of the population is getting sick or obtaining foodborne related illnesses and to be able to comprehend that it can all be prevented. Much of the facts given in this summary was to bring a better understanding of why most of the time people are more prone at getting food poisoning from meat. S. hominis can be prevented if only people used a better hygiene system. Meat must be thoroughly cooked or frozen to kill any Sarcocystis left in the meat, if the meat is infected with any bradyzoites. Other options, like mentioned earlier, to examine the meat before it is distributed to the public by using a molecular approach in order to identify positive prevalence to the S. hominis gene and be able to deal with it so that we won’t infect the rest of the population.
