Bacterial Infections

Bacterial meningitis is a serious infection involving layers (meninges) covering the brain and spinal  cord. Causative bacteria differ among different age groups. 

Clinical presentation 

• Headache, high grade fever
• Altered mental status, convulsions, coma
• Photophobia
• Nausea and vomiting
• Signs of meningeal irritation

Investigations 

CBC, Blood C/S, Lumbar puncture for CSF analysis 

Pharmacological Treatment 

Where the organism is not known:

A: benzyl penicillin (IV) 5MU 6hourly for 14days. 

AND 

B: chloramphenicol (IV) 1000mg 6hourly for 14days 

Alternatively 

D: ceftriaxone + sulbactam (FDC) (IV) 1.5g 12hourly for 14days 

Alternatively 

A: ampicillin (IV) 2g 6hourly for 10–14days 

AND 

 S: cefepime (IV) 2g 8hourly for 10–14days 

Alternatively, and based on C/S results give 

S: meropenem (IV) 2g 8hourly for 10days 

Where the organism is known:

Meningococcal meningitis (Refer to notifiable diseases section: see 'Public Health Control Measures' under Bacterial Cerebro-Spinal Meningitis)

Haemophilus influenza meningitis 

B: chloramphenicol (IV) 1g 6hourly for 7–10days. 

OR 

D: ceftriaxone + sulbactam (FDC) (IV) 1.5g 12hourly for 14days 

Pneumococcal meningitis 

A: benzyl penicillin (IV) 5MU 6hourly for 14days 

OR 

D: ceftriaxone + salbactam (FDC) (IV) 1.5mg 12hourly for 14days

Tuberculous  meningitis  (TBM)  is  the  most  common  form  of  central  nervous  system  tuberculosis,  associated with high mortality and morbidity from neurological sequelae.  

Clinical presentation 

• Headache
• Low grade fever
• Altered mental status, coma
• Seizures
• Nausea and vomiting
• Cranial nerve palsies

Laboratory investigations

• CBC
• Blood C/S
• LP for CSF analysis
  • lymphocytic-predominant pleiocytosis usually between 100-500 cells/µL
  • elevated protein levels typically between 100 and 500 mg/dL
  • low glucose - usually less than 45 mg/dL or CSF:Plasma ratio <0.5
• CSF GeneXpert
• CSF for AFB
• HIV testing

Imaging Investigations 

• Contrast head CT scan - can demonstrate multiple ring-enhancing lesions, meningeal and basal cisterns enhancement
• Contrast brain MRI with diffusion weighted sequences (DWI)

Pharmacological management

Refer to TB and leprosy chapter  

Non-pharmacological management 

• Screen for post-infectious hydrocephalus as it is a common complication of all meningitis cases and can occur early during treatment — monitor for persistent headache, vomiting, papilledema on fundoscopy and Parinauds syndrome.
• Refer  all  patients  presenting  with  clinical  or  radiological  features  of  increased  ICP  from hydrocephalus for  neurosurgical evaluation  directed  at  treatment  of  the  associated hydrocephalus by external ventricular drainage (EVD) or VP shunt once CSF is sterile.
• Monitor urine output and serum sodium levels as syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a common complication

It  is  an  acute,  often  fatal  disease  caused  by  an  exotoxin  produced  by  the  anaerobic  bacterium  Clostridium tetani. It is acquired through wounds contaminated with spores of the bacteria and in the  case of neonates, through the umbilical stump, resulting in neonatal tetanus. 

Clinical presentation 

• Generalized spasms and rigidity of skeletal muscles
• Locked jaws
• Patients are usually fully conscious and aware
• Dysphagia
• Diaphoresis
• Local spasms may also occur

Non-pharmacological Treatment 

• Admit in intensive care unit (ICU)
• Nurse in dark, quiet room to avoid unnecessary external stimuli which can trigger spasms
• Protect the airway (evaluation for early tracheostomy is required)
• Thorough  cleaning  of  the  site of entry (e.g.,  wound),  leaving  it  exposed  without dressing
• Maintenance of fluid balance and nutrition (via NGT)
• Avoid giving medications via IV/IM route as injections can trigger spasms
• Sedation (see below) and care as for unconscious patient

Pharmacological Treatment 

Treatment is generally aimed at the following: 

Pain management as the spasms can be very painful 

A: paracetamol (PO/NGT) 1gm 8 hourly for 5 days 

For prevention of further absorption of toxin from the wound 

A: human tetanus immunoglobulin (IM) Adults give 3000IU stat 

AND 

A: amoxicillin (PO/NGT) 500mg 8hourly for 5days 

AND 

A: metronidazole (PO/NGT) 400mg 8hourly for 5days 

Control of spasms: Give a sedative cocktail of the following medications preferably via NGT: 

A: diazepam (PO/NGT) 10-30mg 4-6hourly for 7-14days 

AND 

A: chlorpromazine (PO/NGT)100–200mg 8hourly for 7-14days 

AND 

A: phenobarbitone (PO/NGT) 50–100mg 12hourly for 7-14days 

Table 8.1: Guidelines for Dosage Administration** 

Prevention: tetanus (toxoid) vaccine (IM) 0.5mL; repeat after 4 weeks and after 6-12 months, then boost every 10 years thereafter.

Brain abscess is a focal collection of purulent material within the brain parenchyma, which can arise  as a complication of a variety of local cranial or remote systemic infections, trauma, or surgery. The  manifestations of brain abscess depend on the site, size, and the immune status of the patient. 

Clinical presentation 

• Headache
• Fevers
• Seizures
• Focal neurological deficit
• Altered mental status that may progress to coma

Imaging Investigations 

• Contrast head CT scan - can demonstrate a ring enhancing lesion and possible source of
• infection e.g., from paranasal sinuses, ear infections
• Contrast brain MRI with diffusion weighted sequences (DWI)
• MR spectroscopy to distinguish from brain tumors where diagnosis is unclear
• CXR
• ECHO in suspected valvular heart disease

Lab Investigations 

• Gram stain, C/S of pus from possible sources
• Purulent aspirate from the abscess for C/S
• Ziehl Neelsen stain

Non-pharmacological Treatment 

• Follow the ABCD protocol
• If unconscious insert NGT for feeding
• Insert urethral catheter

Pharmacological Treatment: 

• Control fever and pain with IV Paracetamol
• Manage seizures with antiepileptic drugs
• Prompt initiation of intravenous antibiotics
• Steroids in selected case

Table 8.2: Pharmacological management of Brain abscess 

Note: If allergic to penicillin, chloramphenicol 500mg IV every 6hours can be used instead. In case antiepileptic drugs are used for prolonged durations 5mg daily Folic acid supplement should be added for the entire duration of anticonvulsants treatment especially in women of childbearing age.

Surgical management

• Refer all patients diagnosed with a brain abscess for neurosurgical evaluation.
• Surgical options include stereotactic abscess aspiration and craniotomy for abscess excision. In cases where the source of infection is paranasal sinuses or ear infection, involve concomitant ENT surgeon evaluation for primary source control interventions.