MENINGITIS_

CONTENTS_➤ INTRODUCTION

➤ PATHOGEN

➤ SYMPTOMS

➤ OUTBREAK

➤ DEFENCE

➤ IMMUNISATION

INTRODUCTION_ Meningitis is the inflammation of the meninges (Fig.1). They are the delicate membranes that surrounds the brain and the spinal cord.

The common causes of meningitis are viral and bacterial. In rare cases fungal and parasitic factors could also trigger meningitis.

Fig.1.THE MENINGES consists of three layers; Dura mater, Arachnoid and Pia mater.

Fig.2. An image of what infected meninges look like.

Fig.1

Fig.2

PATHOGEN_The interdependence between the host (us humans) and the pathogen could be categorised as parasitism as we are harmed when they enter our system.

There are different pathogens based on what type of meningitis it is. Some of the common pathogens for each of the meningitis types are listed below:

VIRAL MENINGITIS: ➤ Enteroviruses (Coxsackie or Echovirus) ➤ Herpes viruses (herpes simplex viruses

and varicella zoster virus)

BACTERIAL MENINGITIS: ➤ Meningococcal bacteria ➤ Haemophilus influenza type B (Hib) ➤ Pneumococcal bacteria ➤ Streptococcus pneumoniae

FUNGAL MENINGITIS: ➤ Candida albicans ➤ Cryptococcus neoformans ➤ Histoplasma

PARASITIC MENINGITIS: ➤ Naegleria fowleri

SYMPTOMS_Symptoms of meningitis varies based on the age group.

For BABIES and TODDLERS➤ Fever ➤ Cold feet and hands ➤ Rapid breathing ➤ Unusual high pitched crying ➤ Arching back and stiff neck ➤ Vomiting ➤ Refusing food intake ➤ Drowsiness ➤ Dislike of bright light ➤ Rashes (Fig.1) ➤ Seizures ➤ Unresponsive/blank expression/floppy

For CHILDREN and ADULTS➤ Fever ➤ Cold feet and hands ➤ Stiff neck ➤ Vomiting ➤ Difficulty to wake up ➤ Drowsiness ➤ Dislike of bright light ➤ Rashes (Fig.1) ➤ Seizures ➤ Muscle and joint pain ➤ Severe Headache ➤ Confusion/ irritability

SYMPTOMS_

Fig.1.THE TUMBLER TEST(also known as the glass test) is used to detect if the rash is a sign of meningitis. Usually the rash is one of the last symptoms to be displayed.

Fig.1

OUTBREAK_➤ Meningitis has been reported to appear in 1768 but it wasn’t recognised until 1805. It has

been suggested that Hippocrates may have known of its existence. ➤ It was after the development of vaccines that the death rates started decreasing. During 1990,

464,000 deaths were recorded. By 2013 the number of deaths were down to 303,000. ➤ Many countries are affected by the spread of meningitis (Fig.1). Population-wide studies have

shown that the rates of viral meningitis is higher. Except in Brazil, where bacterial meningitis is more common.

➤ 70% of the cases are of children under 5 years of age and people over the age of 60.

➤ Sub-Saharan Africa has been named the “meningitis belt” (Fig.1, in red) after the large outbreak of meningococcal meningitis for over a century.

Fig.1

Fig.1.The coloured areas of this world map shows which countries are affected by meningococcal meningitis.

DEFENCE_Meningitis is caused as the body responds to an invasion of a bacterial, viral, fungal or parasitic infection. The immune system's response leads to the inflammation of the meninges which then interferes with our sensory and motor responses throughout our body.

Before starting-off the treatment a lumbar puncture (Fig.1) is conducted to collect a sample of cerebrospinal fluid. This sample is tested to diagnose the infection. Later, depending on the infection, antibiotics, including penicillin, ampicillin, chloramphenicol and ceftriaxone, are prescribed as part of the treatment.

For bacterial meningitis, even after early diagnosis and treatment 5-10% of patients died. For this reason bacterial meningitis is considered to be one of the deadliest types of meningitis. Of the survivors, 10-20% of them had other complications like hearing loss, learning disability etc.

Fig.1.LUMBAR PUNCTURE (also known as spinal tap) is shown in the diagram. A needle is inserted into the spine to collect the fluid. The patient needs to be in the sitting or lying position (like shown) to derive the fluid.

Fig.1.

IMMUNISATION_Vaccinations have been developed to prevent only certain types of meningitis. There isn’t a vaccine to prevent all types. There are vaccinations available for Hib, meningococcal and pneumococcal pathogens.

PATHOGEN (Bacterial) VACCINES AGES

Haemophilus influenza type B

Hib There is a set routine. First dose at 2 months of age. Second dose at 4 months. Third Dose at 6 months (it is continued depending on the brand of vaccine). The final dose or booster dose is at 12-15 months of age.

Pneumococcal 1. Prevenar 2. Pneumovax

1. For children aged from 6 weeks to 9yrs of age. 2. Vaccine for adults aged 65yr and over.

Meningococcal

1. Meningtec 2. Menjugate 3. NeisVac-C 4. Mencevax 5. Menomune

1. Has a set routine vaccination schedule and is given to children at 12 months (sometimes even given to infants who are 6 weeks or older).

2. Same as 1. 3. Same as 1. 4. Given to children over the age of 2 and people who visit high risk areas

of contacting this infection. Every 3yrs a booster is required. 5. Same as 4.

These vaccinations only target some strains of the pathogen and their protection won’t last long thus boosters are needed after a time period.

➤ http://meningitis.com.au/about_meningitis/types_of_meningitis.phtml

➤ http://www.who.int/mediacentre/factsheets/fs141/en/

➤ https://en.wikipedia.org/wiki/Lumbar_puncture

➤ https://en.wikipedia.org/wiki/Meningitis

➤ http://www.mayoclinic.org/diseases-conditions/meningitis/basics/definition/con-20019713

BIBLIOGRAPHY_

THANK YOU FOR

WATCHING_Presentation by Nanditha MN