2BrucellosisAlso known as undulant fever / malta fever / mediterranean fever.Bacterial zoonosis which is transmitted to man by direct / indirect contact with animals.Caused by different species of brucella- group of organisms and characterized by:Intermittent / irregular febrile attacksArthritis / enlarged spleen etc.
3Epidemiology Agent factors: Brucella abortus – in bovine – abortus feverB.Suis – Pigs – Swine – F or PorcineB.Canis – Canines – Canine feverB.Melitensis – Goats – Caprine feverHost factors: predominantly disease of males.FarmersShepherdsButchersSlaughter house menVeterinariansLab-workers – are at special risk because of occupational exposure.
4Environmental factors: Most prevalent under conditions of advanced domestication in the absence of corresponding advanced S.O. Hygiene (+) where there isOvercrowding of herdsIncreased rain fallLack of exposure to sunlightUnhygienic practice of milking/ heat production
5M.O.T:Ingestion – milk / milk products- meat even of camelContact – absorption from skinInhalationInoculation 02mm – throat or oral cavitySource / Reservoir:S – milk, lochial secretions, placenta, urine, feces & meat.R – farm animals e.g., cattle, goats, swine etc.I.P: highly variable usually 1-3 weeks.
7TetanusAn acute disease caused by exotoxins of clostridium tetani clinically characterized by :Muscular rigidityPainful paraoxysmal spasms of voluntary muscles esp.Masseters ( trismus / lock-jaw )Facial (risus sardonicus)Back / neck (opisthotonus)And those of lower limbs and abdomenMortality : 40-80%
8Agent factors:Clostridium tetaniReservoir of infectionSource – soil / dustExotoxinP.O.C – NoneHost factors:Age / sexOccupationRural / urban differencesImmunityEnvironmental factors:Tetanus is a positive environmental hazard.M.O.T: contamination of wounds with tetanus spores.
9I.P: 6 – 10 daysTypes:TraumaticPuerperalOtogenicIdopathicTetanus Neonatorum (8th day syndrome)Prevention:Active immunization – DPTPassive – ATSBothAntibioticsObserve tetanus schedule for pregnant women
10Plague (Black Death)Basically & primarily a zoonotic disease caused by Yersinia pestis involving rodents & fleas.It exists in natural foci & is transmitted by infected flea bites to humans living or intruding into the same ecological environment.Occurrence: many forms e.g.,EpizooticEnzooticSporadicAnd in epidemics of all forms including anthroporotic primarily pnemonic.
11History Epidemics of plague are mentioned in Bible Association of plague with rats is known to be ancient.1st out-break – 1320 B.C.1st Pandemic – 542 A.D. called Justinian plague, which lasted for 50 years & estimated mortality was 100 deaths.2nd Pandemic – 1346 B.C. lasted for 30 years & claimed one forth world mortality.In 1840 B.C. – Pandemic of pneumonic typeIn 1930 – 6 million deaths in India.In out-break in India, then subsided gradually.
12PlagueDef: Highly fatal disease characterized by high fever, progressive heart failure & nervous symptoms.Conjunctiva is injected with reddish appearance.Skin – hemorrhage & pustular eruptions.Clinical forms:BubonicPnemonicSepticemicsylvatic
13Bubonic plague Onset sudden, most common type High temperature, prostrationPainful buboosVesicular / pustular skin lesionsComplications:secondary terminal pneumonia
14Pneumonic plaguePrimary P. Plague is rare. Generally follows as a complication of bubonic - septicemic plague.Incidence decreased 1%Highly infectiousSymptoms – acute bacterial infectionSputum – hemorrhagicMost deadly form of plague
15Septicemic :RareBuboes absentFever – lowHemorrhages into skinSylvatic :Endemic in rodents in junglesMan is affected accidentally while doing activities like hunting etc.
16Source of infection:In bubonic plague : by bite of inf. Rat – fleasXenophsylla cheopisXenophsylla actiaXenophsylla braziliensisIn pneumonic plague:exhaled droplets of salivasputum of patientsReservoir : rats & wild rodents, out of 1700 species 200 associated with plague.
17I.P:Bubonic : 2-7 daysSepticemic : 2-7 daysPneumonic : 1-3 daysP.O.C: pneumonic is very communicable from person to person, bubonic if terminal inf. is there.M.O.T:Bubonic plague – bite of infected rat fleaPneumonic plague – droplets
18EpidemiologyAgent factors: yersinia pestis, occur in blood, buboes, spleen, liver, other viscera of infected persons.Host factors:Age / sex – all ages & both sexesActivities of man e.g., hunting, cultivation, grazing, harvesting, construction etc.Movements – ship, land, cargoImmunity – no natural immunityEnvironmental factors:Season : september – MayTemp : CHumidity less than 60%, Rain fallRural / urban, Human dwellings
19Population at risk:Geologists, BiologistsAnthropologistsHunters, agriculturists etc.Vector of plague: Pulex irritants (human fleas)Blocked / Partially blocked fleaFlea Indices:Total flea indexSpecific index – if >1Sp.% of fleasBurrow index
20Prevention & Control Control of cases: Early diagnosis Notification IsolationTreatmentDisinfectionControl of fleas/ rodents:Application of insecticides, rodenticides and other preventive measures to be adopted.Vaccination: ml SC after 7-10 days.