Continuation of scientific research is crucial to the understanding, treatment and prevention of diseases. With a greater understanding of disease pathology, it is reasonable to eliminate the fatalities from a specific disease in some cases. A major treatment and preventive method used for bacterial diseases is the implementation of antibiotics. Exposing the body to antigens, activates the production of specific antibodies that will eradicate the foreign bodies. Acute bacterial meningitis is an easily treatable and preventable disease but can be life threatening if not addressed.
This is a disease that is not extremely common, particularly in Australia. A specific type of this disease is named acute meningococcal meningitis refers to the particular bacteria at play, Neisseria meningitidis. The meningococcal bacteria causes an infection that results in the acute inflammation of the brain lining and spinal cord, called the meninges. A very severe and serious illness, this can lead to a number of complications or even death. With more research on the available antibiotics and treatment techniques there is the chance that the disease causing bacteria is eradicated.
Throughout this report there will be a discussion on the effectiveness of antibiotic treatment as a preventative measure to acute meningococcal meningitis. Assuming that the acute inflammation associated with the disease, is a direct result of the infection caused by Neisseria meningitidis bacteria.
The term Meningitis comes from the Greek word “m?ninges”, which refers to the layer of matter around the brain and spinal cord and “itis” is used medically associated with inflammation.
Hence “meningitis” is defined as the inflammation of the meninges. Meningitis can be caused by a number of reasons including bacterial infections, viruses, fungal infections, parasites or others. Acute meningococcal meningitis is a type of bacterial meningitis. The specific bacteria responsible for meningococcal meningitis is Neisseria meningitidis. It is most common in the “meningitis belt of sub-Saharan Africa” with still over 30 000 cases reported each year which is why the promotion of serogroup specific vaccines is so crucial to the prevention of acute meningococcal meningitis (World Health Organization, 2019).
In regards to the mechanisms involved and the pathogenesis, it starts with the bacteria entering the body via the nasopharynx and thrives in the mucus. However, it is hard to spread between people unless there is prolonged contact with the deep mucus. In some cases these bacteria adhere to epithelial cells in the body where they are absorbed into the bloodstream. This is where small vesicles may break off and encourages the production of inflammatory mediators and cytokines including neutrophils. When the bacteria begin to cross the blood brain barrier and enters the cerebrospinal fluid (CSF), this causes meningitis or inflammation. In more detail, the pathogen associated molecular patterns (PAMPs) are released by pattern recognition receptors (PRR) on resident mast cells. As a result, histamine and prostaglandin are released. This will encourage vasodilation and increased vascular permeability but prostaglandin will also induce pain. The extra blood flow due to the vasodilation can increase the levels of swelling and heat resulting in a fever. Exudate will then leak out in the area and in this case it will be purulent exudate commonly called pus. Pus may also contribute to the swelling of the meninges. Neutrophils then exit the cell into the extracellular space. Which can lead to the damage of other immune cells initiating the damage associated molecular patterns (DAMPs) to be released which maintains the immune response (Masouris et al, 2017). As a result, cytokine synthesis and chemotaxis is promoted.
Acute bacterial meningitis may also presents itself through a number of signs and symptoms that help diagnose the condition. These include a fever, fatigue, nausea, convulsions, sore throat, backache, general agitation, a stiff neck, sensitivity to light, dizziness and/or sensitivity to light. These signs and symptoms are quite conducive to acute meningococcal meningitis however there are other methods of diagnosis. Blood tests may be performed to evaluate the blood. With the blood tests there will be low glucose levels, high protein levels and inflammation markers will be present commonly called neutrophils. A blood culture may also be used and compared to determine the type of bacteria present. Magnetic Resonance Imaging (MRI) can also be used to identify abnormalities in the brain. A lumbar puncture may also be conducted. This is a procedure where the patient has a needle inserted into their dural sac in order to collect CSF. If the CSF is cloudy it usually means there is a large amount of proteins present as seen in bacterial meningitis. The CSF may also be cultured and with the use of gram staining an attempt to identify the bacteria will be conducted.
The inflammation that occurs around the brain and spinal cord is extremely dangerous and must be treated quickly. The increased intracranial pressure caused by the inflamed mengies can result in brain damage in the cranial cavity and/or spinal cord damage. A repercussion of such events include permanent disabilities such as hearing difficulties or other prolonged issues such as mental retardation. Hence, if diagnosed with acute meningococcal meningitis is crucial for the patient to seek advice from a medical professional and go to the hospital. The primary way to treat this disease is by intravenous antibiotics. This has been proven quite effective.
The left hemisphere of the brain of a 65 year old lady affected by bacterial meningitis can be seen. In the image, there are a number of key features that stand out which show how acute meningococcal meningitis has left its mark on the patient. As seen in the image, blood vessels ( appear large and dilated in the sulci of the brain and are dark blue in colour. Some areas the vessels appear irregular or more dense which may be indicative of haemorrhages. As discussed earlier purulent exudate or pus ( is a common product of acute meningococcal meningitis and the inflammatory response associated with this disease. Throughout the brain there are multiple diffuse areas of creamy colour, which is more than likely the result of this pus. The yellowish brown coloured parts of the brain are the parts of the brain that are not affected as badly by the disease ( However, due to the nature of this disease the whole brain may be affected as the meninges would have been inflamed and swollen, as a result, the brain may have been crammed inside the skull. For this reason, the sulci of the brain are slightly understated compared to a normal unaffected brain ( The inferior surface of the brain also seems to be a lesion of focused tissue that is rougher than the rest of the brain. This could mean there is some damage as a result of the increased intracranial pressure associated with meningitis.(
The disease causing bacteria in acute meningococcal meningitis is Neisseria meningitidis. Within the past couple of years the relative frequency of diseases caused by Neisseria meningitidis has increased and this is an area for concern. Although this can be accounted for by the widespread use of vaccines for Haemophilus influenzae B and Streptococcus pneumoniae (the other two main causes for bacterial meningitis), it is important that measures are taken to ensure there are no more outbreaks. In regards to acute meningococcal meningitis, there has been some research into the use of antibiotics as a prophylactic treatment regimen but also a preventative measure. Although, there could definitely be more comparative studies between the different drugs and antibiotics used and the adverse effects of drug resistance. Therefore, it is important to understand and uncover which antibiotics are the most effective and appropriate in the treatment of acute meningococcal meningitis. Hence, this will be a discussion about not only the effectiveness and appropriateness of antibiotics in the treatment of acute meningococcal meningitis but also the issues associated with antibiotics including drug resistance and adverse effects.
Three types of antibiotics used to treat acute meningococcal meningitis are Ceftriaxone, Ciprofloxacin and Rifampicin. “All of which have been proven effective in the treatment of acute meningococcal meningitis” (Trestioreanu et al, 2013). A randomised cluster trial on a group of people living in the same household of those suffering from meningococcal meningitis in Saudi Arabia in 1988 was conducted by B. Schwartz. A single dose of Ceftriaxone was used on one set of subjects and a single dose of Rifampicin was used on the other subjects. The study showed that carrying of the bacteria Neisseria meningitidis in the nasopharynx, was eradicated by 75% for patients taking Rifampin and 95% for patients receiving Ceftriaxone. Hence, the use of Ceftriaxone would be more effective in this case and arguable more appropriate due to the number of risk factors which also do not allow pregnant women to take this drug. Due to the limited amount of studies completed using Ceftriaxone the risks to the fetus of a pregnant individual, are not fully known. This is an area were the appropriateness of use is questionable but also hard to study due to ethical issues that are related to the research on unborn fetuses. However, this study was not extremely recent meaning the probability of adapting bacteria is extremely high. With regards to the antibiotic Ciprofloxacin, it has been proven quite effective in eradicating Neisseria meningitidis from carriers. A study was conducted on army recruits with 61 treated with this drug and 59 treated with a placebo drug. The results showed that carriers who took the placebo still had much higher carrier rates than those who took the Ciprofloxacin, 46 after treatment to 2 cases after treatment, respectively (Renkonen, Sivonen and Visakorpi, 1987).
Another subject to discuss is the drug resistance of antibiotics over a certain period of time. Rifampin has been the most common antibiotic used by doctors however there has been a noted resistance developed in many cases (Girgis et al., 1998, Guttier et al., 1971, Simmons, Jones and Calder, 2000). During an epidemic in New Zealand Simmons conducted a study on subjects who had shared a household with individuals affected by meningococcal meningitis. The method of this study involved individuals taking swabs of their throat before and after treatment to detect neisseria meningitidis. Half of the subjects were given Ceftriaxone and half Rifampicin. Much like B. Schwartz’s study, Ceftriaxone was more successful in eradicating Neisseria meningitidis from carriers systems then rifampicin (98.2%-7.6%). However, accessibility of subjects to Ceftriaxone was an issue and the cases of adverse events were greater in the Rifampicin treated group including nausea headaches etc (Simmons, Jones and Calder, 2000). It is clear to see the effectiveness of all three antibiotics, as well as their potential downfalls.
On going research will always have its challenges especially for bacterial meningitis. This is mainly due to the fact that bacteria are living organisms that will continue to adapt and evolve. It is crucial that antibiotics are not used too often as the bacteria will grow a tolerance however if it needs to be used and it is accessible it should be to prevent increased mortality rates. In turn, there is a constant struggle between researchers and staying on top of the constantly changing subject.
Another area which relates to the ongoing battle to fight the bacteria responsible for acute meningococcal meningitis is the cost. Running large scale research projects and providing vaccines and antibiotics to large amounts of people is always going to require lots of funding due to the associated costs of the products and staff required.
In order to complete this assignment it was crucial to create a research question that was valid and support this by scientific research articles. When deliberating on what I could write in the assignment I had to do further research into what is known about acute meningococcal meningitis in order to discover what was not yet known about the disease. After in depth research looking at articles, videos and visiting the museum of human diseases a number of key points stood out. Acute meningococcal meningitis had been researched quite a lot and hence there was an abundance of information and wealth of knowledge that has been shared. The way I then chose to approach formulating a research question about the disease was looking for improvements. Looking at treatments and why there were still multiple fatalities as a result of the presence of the disease. Finding current journal articles was quite difficult as there was much outdated research which may be irrelevant due to the ever changing and evolving nature of bacteria.