Brucellosis, Tetanus & Plague By Dr. Riaz Ahmed

Brucellosis Also 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 attacks Arthritis / enlarged spleen etc.

Epidemiology Agent factors: Brucella abortus – in bovine – abortus fever B.Suis – Pigs – Swine – F or Porcine B.Canis – Canines – Canine fever B.Melitensis – Goats – Caprine fever Host factors: predominantly disease of males. Farmers Shepherds Butchers Slaughter house men Veterinarians Lab-workers – are at special risk because of occupational exposure.

Environmental factors: Most prevalent under conditions of advanced domestication in the absence of corresponding advanced S.O. Hygiene (+) where there is Overcrowding of herds Increased rain fall Lack of exposure to sunlight Unhygienic practice of milking/ heat production

M.O.T: Ingestion – milk / milk products - meat even of camel Contact – absorption from skin Inhalation Inoculation 02mm – throat or oral cavity Source / 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.

Lab diagnosis: Bacteriological Serological / allergic test Control: in animals: Test / slaughter Vacc – B.Abortus strain – 19 Hygienic measures In humans: At individual level At community level

Tetanus An acute disease caused by exotoxins of clostridium tetani clinically characterized by : Muscular rigidity Painful paraoxysmal spasms of voluntary muscles esp. Masseters ( trismus / lock-jaw ) Facial (risus sardonicus) Back / neck (opisthotonus) And those of lower limbs and abdomen Mortality : 40-80%

Agent factors: Clostridium tetani Reservoir of infection Source – soil / dust Exotoxin P.O.C – None Host factors: Age / sex Occupation Rural / urban differences Immunity Environmental factors: Tetanus is a positive environmental hazard. M.O.T: contamination of wounds with tetanus spores.

I.P: 6 – 10 days Types: Traumatic Puerperal Otogenic Idopathic Tetanus Neonatorum (8th day syndrome) Prevention: Active immunization – DPT Passive – ATS Both Antibiotics Observe tetanus schedule for pregnant women

Plague (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., Epizootic Enzootic Sporadic And in epidemics of all forms including anthroporotic primarily pnemonic.

History 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 type In 1930 – 6 million deaths in India. In 1994 - out-break in India, then subsided gradually.

Plague Def: Highly fatal disease characterized by high fever, progressive heart failure & nervous symptoms. Conjunctiva is injected with reddish appearance. Skin – hemorrhage & pustular eruptions. Clinical forms: Bubonic Pnemonic Septicemic sylvatic

Bubonic plague Onset sudden, most common type High temperature, prostration Painful buboos Vesicular / pustular skin lesions Complications: secondary terminal pneumonia

Pneumonic plague Primary P. Plague is rare. Generally follows as a complication of bubonic - septicemic plague. Incidence decreased 1% Highly infectious Symptoms – acute bacterial infection Sputum – hemorrhagic Most deadly form of plague

Septicemic : Rare Buboes absent Fever – low Hemorrhages into skin Sylvatic : Endemic in rodents in jungles Man is affected accidentally while doing activities like hunting etc.

Source of infection: In bubonic plague : by bite of inf. Rat – fleas Xenophsylla cheopis Xenophsylla actia Xenophsylla braziliensis In pneumonic plague: exhaled droplets of saliva sputum of patients Reservoir : rats & wild rodents, out of 1700 species 200 associated with plague.

I.P: Bubonic : 2-7 days Septicemic : 2-7 days Pneumonic : 1-3 days P.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 flea Pneumonic plague – droplets

Epidemiology Agent factors: yersinia pestis, occur in blood, buboes, spleen, liver, other viscera of infected persons. Host factors: Age / sex – all ages & both sexes Activities of man e.g., hunting, cultivation, grazing, harvesting, construction etc. Movements – ship, land, cargo Immunity – no natural immunity Environmental factors: Season : september – May Temp : 20-25 C Humidity less than 60%, Rain fall Rural / urban, Human dwellings

Population at risk: Geologists, Biologists Anthropologists Hunters, agriculturists etc. Vector of plague: Pulex irritants (human fleas) Blocked / Partially blocked flea Flea Indices: Total flea index Specific index – if >1 Sp.% of fleas Burrow index

Prevention & Control Control of cases: Early diagnosis Notification Isolation Treatment Disinfection Control of fleas/ rodents: Application of insecticides, rodenticides and other preventive measures to be adopted. Vaccination: 0.5-1ml SC after 7-10 days.

Chemoprophylaxis: Surveillance Health education

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