Epidemiology of selected communicable diseases Flashcards
what is the minimal time period required for a country to receive a certificate of elimination ?
3 consecutive years
what two diseases have been eradicated globally ?
small pox
rinderpest
what is the causative agent of tetanus ?
clostridium tetani
anaerobic gram positive bacilli
what is the main reservoir of tetanus ?
soil
what are the toxins produced by tetanus ?
tetanospasmin and tetanolysin
which toxin of tetanus causes clinical manifestations of tetanus ?
tetanospasmin (neurotoxin)
what is the mode of transmission of tetanus ?
must pass through the skin barrier “ no wound no tetanus”
what are the presenting symptoms of tetanus ?
neurologic which start with headache, muscle stiffness in jaw and difficulty swallowing
what type of individuals are more prone to getting tetanus ?
disease almost exclusively happens in unvaccinated individuals
which countries have a higher rate of tetanus ?
developing and under developed countries
what prevention protocol is followed for infants and children for tetanus?
- infants at 2, 4, 6 months are given PENTA vaccine
- at 18 months a booster dose of DPT vaccine is given
- at school in the 4th year primary grade (Td)
- after 10 years a third dose of TT vaccine is given
what prevention protocol should be followed for prevention of tetanus during pregnancy if not previously immunized ?
- first dose at 6 months
- second dose at 7 months
must be at least 2 weeks before delivery - 3rd dose after 6-12 months or in subsequent pregnancy
- 4th and 5th dose each after one year
what is the prevention protocol that should be followed for a previously immunized pregnant woman for rabies ?
- 2 doses given after the first trimester
2. 3rd dose given after 6-12 months or in the next pregnancy
what is the prevention protocol in adults who are not immunized for tetanus ?
monovalent vaccine tetanus toxoid is given to :
soliders , sewage workers, farmers and gardeners
what does the monovalent vaccine tetanus toxoid include ?
primary course consists of two doses one month apart
the third dose is given after 6-12 months
if the adult is previously immunised for tetanus what is the best protocol ?
one booster dose is given every 10 years
what is the post exposure prophylaxis wound management for tetanus prevention if the patient is completely immunized ?
if it is an uninfected wound :
- less than 10 years from last dose then nothing should be done
- if more than 10 years from last dose then a booster dose should be given
when can we consider an individual to be immunized from tetanus ?
if 2 out of the 5 doses has been taken
if there is a tetanus prone contaminated wound in an immunized individual what is the best next step ?
less than 5 years from last dose , then nothing should be done
if it has been more than 5 years: Td vaccine should be taken
if a patient with a wound comes in with incomplete tetanus vaccination what is the next best step in management ?
- if it is a clean wound : give the age appropriate vaccine along with antibiotics
- if it is a contaminated wound then : age appropriate vaccination should be started along with passive immunization (TIG) along with antibiotics ( give immunoglobulins)
how do you immediately care for a case of tetanus ?
immediate treatment with human tetanus immune globulin (TIG)
how is the rabies virus transmitted ?
through direct contact with saliva or brain and NS tissue from an infected animal
what is the most common way to get rabies ?
bite of a rabid animal
what are the symptoms associated with rabies infection ?
excitement
excessive salivation
hydrophobia
which age group is highly associated with rabies ?
age group of under 15
what is the most cost effective strategy for preventing rabies in people ?
vaccinating dogs
what are the two vaccines for rabies ?
- human diploid cell vaccine (HDCV)
2. rabies vaccine adsorbed (RVA)
how many doses are meant to be taken for each vaccine ?
each vaccine is associated with 5 doses
what is the post exposure management of a human bitten by an animal ?
- cleansing the wound
- wound should not be sutured immediately
- tetanus prophylaxis and antibiotics may be indicated
- rabies immunoglobulin of human origin
- vaccination
how is the rabies immunoglobulin dose divided ?
half the dose is given through infiltration of the wound and the other half given IM
what is the protocol for post exposure prophylaxis for rabies for non immunised individuals?
the first dose is given as soon as possible after the bite day 0 day 3 day 14 day 28
what is the post exposure prophylaxis for those who have been previously vaccinated for rabies?
given 2 doses on days 0 and 3
what are the contraindications for post-exposure rabies vaccination ?
pregnancy and infancy are not contraindications
what are the different categories of contact with suspect rabid animals ?
category 1 - touching or feeding animals, licks on intact skin
category 2- nibbing of uncovered skin, minor scratches or abrasions without bleeding
category 3 - single or multiple transdermal bites or scratches , contact with bats
what is the best post exposure prophylaxis that should be applied for category 1 patients ?
none
what is the best post exposure prophylaxis for category II patients ?
immediate vaccination and local treatment of the wound
what is the best post exposure prophylaxis for category 3 patients ?
immediate vaccination n
administration of rabies immunoglobulins
local treatment of the wound
what is the reservoir of the polio virus ?
man is the only reservoir
how does the transmission of poliomyelitis occur ?
direct droplet infection n
faeco-oral infection
what are the three different presentations of polio virus ?
- inapparent infection
- clinical poliomyelitis abortive polio (minor illness)
- involvement of the CNS (major illness)
what are the two forms of polio which involves the CNS ?
non-paralytic
paralytic polio
which clinical presentation of polio is associated with acquired immunity ?
inapparent infection
what are the presenting symptoms of non paralytic polio ?
stiffness and pain in the neck and the back , recovery is rapid
what is the presentation of paralytic polio ?
involves destruction of the motor cells but not the sensory nerve cells
what is the cure for polio ?
there is no cure but it can only be prevented
when should polio vaccination be administered ?
IPV should be given at : 2 months 4 months 6 months 18 months 4 through 6 years
what is the minimum interval between doses of the polio vaccine ?
4 weeks
what is the minimum age for dose 1 of polio ?
6 weeks
when should OPV be given ?
at 2 months 4 months 6 months 9 months 12 months 18 months
why is it important to include OPV to IPV ?
OPV provides mucosal immunity and is required to stop person to person spread
what is the difference between the terms eradication and endgame ?
eradication refers to the wild virus
whilst
endgame refers to management of VDPVs and VAPP
