Biology
BiologyUnit I: Infectious DiseaseMeaslesPathogen: a species of
morbilivirusType of pathogen: VirusMethod of transmission: Droplet
infectionSigns & Symptoms: Cough, runny nose, inflamed eyes,
sore throat, fever and a red, blotchy skin rashPrevention:
Vaccination, however boosters are needed to develop
immunityMeaslesRarely affects infants under 8 months of age, as
they are protected by a mothers antibodiesUsed to be common
childhood disease in developed countries, but it is now rare as
most children are vaccinatedMajor disease in developing countries,
particularly in overcrowded, insanitary conditions where there is a
high birth rateInfects mainly malnourished infants suffering from
vitamin A deficiencyRise in Cases of MeaslesInfected
visitors/immigrants/returning residents from countries where
measles occursUnvaccinated people returning from travelling
abroadReduction in vaccination ratesPercentage cover too lowChange
in reporting patternExisting vaccine is no longer effectiveMutation
of virus produces new antigens, making the vaccines
ineffectiveIncrease in malnourished childrenNo immune response
towards vaccine
Why measles are still common in many parts of the world1 ref.
malnourishment / poor diet, vaccine ineffective / poor immune
response / insufficient protein for antibody production ; 2 some
(healthy) people do not respond to vaccines ; 3 one-dose not always
effective / problems administering boosters ; AW 4 ref. percentage
cover / herd immunity, insufficient ; A description A idea of
people in rural areas have less / no, access to vaccine A people
avoid vaccine, worry about side-effects / other reason 5 ref. cost
to authorities ; e.g. of, administering vaccination programme 6
people in some areas cannot afford to buy vaccine 7 vaccine may not
be thermostable ; AW8 high density of population / overcrowding,
increases chance of spread ; Tuberculosis (TB)poor / dense /
overcrowded, housing / accommodation ; low protein diets linked to
lowered immunity ;not, diagnosed / treated, early enough ;DOTS /
described, not used ; lack of vaccination / vaccinations
ineffective ;antibacterial drugs / antibiotics / AW, not available
/ too expensive ;medical services not available, qualified e.g. in
rural areas / AW ;idea of TB, linked to HIV/AIDS / opportunistic
disease ;MDR TB / XDR TB / not completing the course of antibiotic
treatment increases resistance ;no effective antibiotics to use ;no
facilities for isolating people ;lack of, testing / treatment of,
cattle / milk ; A unpasteurised milkdifficulty in obtaining
reliable data / AW ;Prevention of Tuberculosisref. (BCG) vaccine /
vaccination programme ;improvements in housing conditions / less
overcrowding (housing) / better ventilated homes ; R better
standards of living unqualifiedearlier detection / mass, chest
X-ray / screening ; i.e. in preventing spread improvements in diet
(leading to better immune system) / AW ;improved awareness of,
transmission / AW ; R better education unqualifiedcontact tracing /
explained ;ref. testing / treating, cattle / milk ;
Rise in Cases of Tuberculosis development of antibiotic
resistance (by organism) ; A drug resistance R immunityref. impact
of HIV infection ;higher rate of immigration from countries with
high incidence / AW ;increase in tourism to countries with high
incidence ;reduced surveillance leading to undetected cases (and
hence spread) ;(detected cases, MDR) unwillingness / AW, to
maintain drug regimen / AW ;ref. to vaccination programmes no
longer taking place ;ref. to poor / overcrowded, housing (in
cities) / AW ; must be in context of developed countriesProblem in
worldwide eradication of TBTB is found worldwide with the highest
incidence found in developing countriesThis may be due to the
overcrowded living conditions and remote areasIt is difficult to
identify infected people because of the symptomless
carriersDifficulty in conducting contact tracing as the some of the
contacts may not be able to be reachedSome cases of TB reported are
due to the fact that the patient have weakened immune systems
