L18 Acute Respiratory Tract Infections

The common cold is a self ❌ illness (2 days - 2 weeks), characterised by nasal ❌ and a sore ❌. It is caused by ❌, predominantly rhinoviruses. No treatment is required, but ❌ relief is available. Complications in the elderly, young, and immunocompromised could be ❌.

A sore throat may be pharyngitis/tonsillitis. This can be viral or bacterial.
1. Viral: 80-90% of cases attribute to ❌. A mild, self-limiting infection presenting with a ❌ throat, and ❌ fever. No treatment required except for ❌ relief.
2. Bacterial: A more ❌ infection. The most common cause of bacterial throat infection is Group A ❌ (GAS). Presents with a sore throat, ❌, and aching, swollen ❌ nodes. Diagnosis is by throat ❌ and treatment is ❌. Common complications: abscess and ❌ fever.

Diphtheria is a serious throat infection caused by ❌. It presents with a sore throat, headache, greatly ❌ cervical lymph nodes, low grade ❌, and ❌ mucus on tonsils.
There is a gradual onset over ❌ days, and it is transmissible for up to ❌ weeks. It is ❌ producing which causes heart & kidney ❌. Prompt treatment with diphtheria ❌ is required & ❌ are given even before confirmation by culture. 1 in ❌ will still die from it. The last case in NZ was in 1998.
There has been a vaccine available since 1926, which has been on the NZ immunisation schedule since 1941. It is a ❌ vaccine given as an intramuscular injection, between 87-98% effective in generating anti-toxin ❌, though it declines with time, and boosters necessary & recommended at ❌. The vaccine is ❌ but not the administration. ❌ women are funded.

Whooping cough, also known as ❌, is caused by a highly infectious (via ❌), and ❌ producing bacteria, the gram negative bacilli Bordetella pertussis. It causes airway ❌, and airway ❌ death. The most at risk are ❌ too young to be immunised; Complications – pneumonia, convulsions, brain damage, death. 1 in 6 infants will ❌ or have ❌ damage.
For adults and children, ❌% of persistent coughs are pertussis.

There are ❌ yearly epidemics. The highest rates are in Pacific and Māori
infants, with ❌% hospitalized. There is a 4-fold increased risk of hospitalizations for children living in in ❌ conditions.

Stages of Whooping Cough:
After a ❌ day incubation -
• Stage 1 - (❌ week) malaise, low grade ❌, sneezing, runny ❌,
dry ❌. The ❌ infectious stage. Antibiotic treatment at this stage
can ❌ severity of stage 2. Contacts should also be ❌.
• Stage 2 - (❌ weeks) short burst of extreme paroxysmal coughing
(accumulation of ❌), vomiting, feeling of ❌, “whooping”
between coughing fits. Still infectious, and ❌ symptoms between
paroxysms. Treatment here will not effect the disease but reduces ❌.
• Stage 3 - (❌ weeks - months) recovery, cough less often.

Prevention:
- Vaccine available since 1945, on NZ immunisation schedule since 1960, i.m. injection
- Moved from a cell-based vaccine to an ❌ pertussis vaccine in
the 1990s – less ❌ but less effective. Boosters are required & funded.
- It is recommended, but not funded that contacts & carers of ❌ get boosters.

Influenza is an acute, self-limiting infection of the respiratory tract, causing fever, malaise, a sore throat, ❌ cough, and ❌.
It is caused by ❌ which has an RNA genome and 2 major surface ❌; ❌ (H) and ❌ (N).
There are 3 types of influenza viruses - A, B and C:
A - evolves ❌, causes ❌ epidemics & pandemics, ❌ disease, H/N subtypes
B - no H/N ❌, evolves more ❌ than A, causes disease in humans, usually ❌ severe
C - no H/N subtypes, no disease in ❌

Treatment for influenza is typically ❌ relief of fever and pain with ❌ meds.

We can also use:
1. ❌ Inhibitors (Cyclic Amines or Adamantanes) - amantadine, rimantadine: Inhibit viral ❌, which is symptomatic relief. Does not stop viral ❌. Has systemic ❌ and is associated with rapid induction of ❌ viruses.
2. ❌ inhibitors eg oseltamivir (Tamiflu) & zanamivir (Relenza): ❌ medicine in NZ. Symptomatic relief via ❌ of viral shedding, which reduces the ❌. May stop protective ❌ response developing. Has toxicities (especially ❌), and will induce viral resistance (especially ❌). There is ❌ evidence that it may reduce mortality, hospitalisation and duration of symptoms, compared with no treatment.

Seasonal influenza prevention:
- ❌ vaccines against 3 or 4 circulating strains available – the supplier varies from year to year
- Usually an intramuscular vaccine, which is ❌, effectiveness is ❌%?
- Funded in pharmacy for over ❌’s

Pandemic influenza prevention:
- H1N1 pandemic strain – now included in ❌ vaccine
- H5N1 vaccine – Focetria® (Novartis), etc
- H7N9 – pre-pandemic vaccines have been made by reverse genetics,
not publicly available but ❌ exist