Communicable Diseases😊

Varicella / Chickenpox:

Smallpox Rash	Chickenpox Rash
Deep seated	Superficial
No area of inflammation around the rash	Area of inflammation around rash
Centrifugal	Centripetal
Palms & Soles not spared	Palms & Soles Spared

Congenital Varicella

Teratogenic period:

• Infected in 1st trimester
• 0.4% of babies

• 2nd trimester → 12-20 weeks (after 3 months till 5 months end)
• 2% of babies
• Congenital / Fetal Varicella Syndrome
• Indication for MTP

Clinical features

• Cicatricial scarring in zoster like or
• Dermatomal distribution around umbilicus.

• Limb hypoplasia.

• Low birth weight.

• CNS involvement:
• Microcephaly,
• developmental delay,
• intellectual disability,
• seizures.

• Eye involvement:
• Chorioretinitis,
• cataract,
• microphthalmia (small eye).

• Renal involvement:
• Hydronephrosis.

• Autonomic dysfunction:
• Swallowing dysfunction,
• neurogenic bladder.

Diagnosis of congenital varicella infection

• history of varicella during pregnancy.

• clinical features in a baby.

• Anti-varicella IgM in a baby.

Neonatal Varicella Syndrome

• Pregnant female acquires infection 5 days before to 2 days after delivery

• Features
• Hepatitis
• Pneumonia
• Skin rash
• Meningoencephalitis

• Treatment :
• Give VZIG
• IV Acyclovir to child

• For mother :
• Oral Acyclovir

Case scenario

• An 18-month-old unimmunised girl had fever with rash (as shown in the given picture), cough and coryza.

• There is a history of similar complaints in 2 other children in the neighbourhood.

• The doctor also noticed few red spots with white central parts in the buccal cavity of this child.

• Which vitamin has a role in the management of this child?
ANS
Measles = Vitamin A deficiency

Buzzword: C’s

• Cough → Coryza → Koplik spots → Confluent rash = Measles
• K K sound

Incubation period

• 8-10 days.

• Infective:
• 4 days before to
• 5 days after the onset of rash

• Isolation
• Duration: 7 days after rash onset

• Disease progression:
• day 10 → Fever
• day 12 → Koplik spots near molars
• day 14 → Rash appears
• Starts behind ear/face/neck
• Other symptoms resolve after rash onset

Receptor for measles virus

• CD150 and PVRL4.

Pathognomonic feature

• Presence of multinucleated Warthin Finkeldey giant cells
• Intranuclear + intracytoplasmic inclusion

Measles Rash:

• Confluent maculopapular rash

• Retroauricular in origin

Koplik spot:

• Reddish spots with white centre

• Appears prior to the rash

• Occurs before 48 hours of eruption

• Formed on the buccal mucosa opposite the lower 2nd molar

Measles vaccine

• Strains used:
1. Edmonston Zagreb strain
• most common
2. Schwartz strain.
3. Moraten strain.

Measles vaccination during an outbreak:

• Post exposure Prophylaxis
• Susceptible Contacts with exposure
• Vaccine → within 72 hours of exposure
• Immunoglobulin (IVIG) → upto 6 days following exposure.

Indication	Prophylaxis
>1 yr old/ Immunocompetent/ Non pregnant	Live vaccine:  - Given <72h after exposure  - Effect starts in 11-12 days
<4 yr / Immunocompromised/ Pregnant	Immunoglobulin: • 0.25 ml/kg upto 15 ml • given <3-4 days of exposure  Vaccine only given after 8-10 weeks

• Measles vaccination can be given at 6-9 months age in:
• aka Measles 0 dose (Extra dose).
• During
• Outbreaks
• PEM (Protein-Energy Malnutrition)
• NIS schedule to be continued.
• Gap between NIS & outbreak dosing: >4 weeks.

Vaccine Seroconversion

• Faster than natural incubation

• Antibodies develop in 7–10 days

• NOT CHICKENPOX

WHO Measles Elimination Strategy

• “Catch up, Keep up, Follow up”
• → Again K K sound

Complications:

• Late → SSPE (Subacute Sclerosing Pan Encephalitis)
• Fatal after 7–10 years of infection

SSPE (Sub Acute Sclerosing Panencephalitis)

• Rare, fatal neurodegenerative complication of measles

• Appears 8 to 10 years after initial infection

• Virus crosses blood brain barrier and causes neurodegeneration.

CF:

• 8 years old unimmunized Previously child was completely normal
• Now presents with not able to understand things taught in school.
• Scholastic performance of child keeps on decreasing

• EEG shows burst suppression
• periods of high-voltage electrical activity
• alternating with periods of low-voltage activity
• Also seen in HIE stage 3

Investigation

• Diagnosis:
• CSF and Blood anti-measles antibody is done.

Neurological progression:

• Myoclonic jerks

• Sudden falls

• Choreoathetosis

• Dystonia

• Rigidity

• Course: Progressive downhill

Treatment

• No effective treatment currently available

• Mild and self-limiting illness that usually improves in 3-5 days.

• Classification: Matonaviridae (previously Togavirus)

Epidemiological & Clinical Features:

• AKA 3 day fever (Very mild illness).

• Mnemonic: Ruby → Threeyy

Age of Incidence:

• Developed countries: 3-10 years.

• Developing countries: >15 years.

Presentation: 

• Shows iceberg phenomenon

• 50-55% cases are subclinical

Incubation period: 

• 2 - 3 weeks.

Period of communicability: 

• 7 days before onset of rash,

• 7 days after.

Prodrome phase

• Low-grade fever, sore throat, malaise, and headache.
• URTI
• Posterior auricular lymphadenopathy (LAP)
• Rash lasting 3 days

• Rash begins on the face and spreads centrifugally - measles-like rash.

• Forsheimer spots on the soft palate and uvula.

Trend of infection: 

• Cyclic (Every 6-9 years).

Prevention:

Routine use:

• Strain: RA 27/3 winstar vaccine.
• Mnemonic: Win star → Vimal → German measles
• Fortunate baby (forchiemer spot)

• Type: Live vaccine.

• Schedule: Single dose after 12 months of age.

• Duration of protection: 14-16 years.

• C/I: Pregnancy.

In outbreaks:

• Strain: RA 27/3.

• Indication:
• Women of reproductive age (Non-pregnant):
• Advice to avoid pregnancy for 6-8 weeks post vaccination.
• Adolescents.
• Infants.

Post Exposure Prophylaxis

• Rubella Immunoglobulin:
• For pregnant females with known exposure to rubella virus.

Rubella Vaccination Strategy

• 1st Priority:
• Women of child-bearing age (15–34 or 15–39 years)
• Prevent Congenital Rubella Syndrome (CRS)

• 2nd Priority:
• All children aged 1–14 years
• Interrupt community transmission

• 3rd Priority:
• Routine immunization of all children under 1 year
• Use combined MR

Congenital rubella syndrome.

• Risk of transmission ↑↑↑ → if earliest before 11 weeks of gestation

• Least r/o perinatal transmission

• Virus excretion → saliva, urine

• Mnemonic : Rubee → Blue bee( Blueberry rash)
• Sitting in salt and pepper (Salt & Pepper Fundus)
• Shiny Pearly eyes → Nuclear pearly cataract
• Can't see (Small eyes) can't hear (SNHL) also had some heart disease.
• adich Padam (PDA) aakki

• Triad of Gregg
• PDA
• Cataract
• SNHL

Complications

1. Congenital heart diseases:
• Most common: Patent Ductus Arteriosus > PS
• Least common: Atrial Septal Defect.

2. Sensorineural hearing loss.

3. Blueberry muffin lesion:
• Bluish red nodular lesions
• characteristic of congenital rubella.

4. Microcephaly, IUGR.

5. Glaucoma.

6. Hepatosplenomegaly.

7. Jaundice.

8. Thrombocytopenia.

Key Ocular Manifestations:

• Congenital nuclear cataract
• Nuclear Pearly Cataract
• Most common cataract in CRS

• Micro-ophthalmos
• abnormally small eyes

• Salt & Pepper Retinopathy

NOTE:

• Salt & Pepper Fundus



• Mnemonic: Salt and pepper movie
• Ruby (Rubella) → a Star (Stargardts)
• Rough (Refsum) Labor (Lebers) who has Syphillis (CS) Raped (RP → Retinitis Pigmentosa) her → got Rid (Thioridazine) of body
• Thio Ridazine :
• Thio Ridazine → rid of
• Brown (Brown vision) Cuteee (QT prolongation) with colorful eyes (RP),
• like Salt and Pepper () movie
• but ejaculated retrograde ()

• Diagnosed by:
• Presence of IgM rubella antibodies in the infant shortly after birth
  (since IgM does not cross the placenta)
• Persistence of IgG antibodies for >6 months
  (maternally derived antibody would have disappeared)

• Serotypes causing epidemics: A and B

• Structure
• Outer proteins:
• Hemagglutinin (HA)
• → virus entry
• Neuraminidase (NA)
• → virus exit/release
• Destroys the cell receptors by hydrolytic cleavage
• M2 ion channel
• assists in virion uncoating inside host cell

Antigenic Variations

• Clinical Features
• Fever, headache, sore throat, cough, myalgia
• Running nose usually absent
• M/c complication → pneumonia

• Laboratory Diagnosis
• Specimen: Nasopharyngeal swab
• Hemagglutination inhibition test (HAI) → positive

Treatment

Case scenario

• A male child presents to you with swelling below the ear, but no systemic manifestations.

• There have been two other similar cases in the friends of the child in the same village.

• What will you do?

Clinical Features

• 30–40% are subclinical

• Pain and swelling of one or both parotid glands

• Earache on affected side before swelling

• Pain/stiffness in mouth opening before swelling

Features

• Agent:
• RNA virus
• Myxovirus family

• Period of Communicability:
• 4–6 days before rash
• 7 days after rash onset

• Incubation Period (IP):
• 2 – 4 weeks
• very infectious disease

• Mode of Transmission (MOT):
• Droplet

• Symptoms
• M/c → asymptomatic (inapparent)
• M/c symptomatic → bilateral parotitis
• Second M/c → unilateral orchitis

• Secondary Attack Rate (SAR):
• 86%

• Host Factor:
• Age group commonly affected: 5–9 years

• Self-limiting illness and no specific treatment is required.

Complications

• Children:
• Aseptic meningitis

• Adolescents:
• Orchitis (common in males)
• Oophoritis

Vaccine strain

• Jeryl Lynn

Case scenario

• An unimmunized 8 yr old girl presented with fever, sore throat and swelling of neck.

• The examination of throat revealed the lesion shown in image 1.

• The picture seen on Albert stain of the swab taken from the lesion is shown in image 2.

• What is the probable diagnosis?

Epidemiology

• Causative organism: 
• Corynebacterium diphtheriae.
• C. diphtheriae is also Klebs-Loeffler bacillus.
• Gram positive, non-motile, aerobe and facultative anaerobe
• Secretes exotoxin
• Diphtheria toxin production depends on iron levels.
• Toxoid vaccine is produced using acid and formalin solution.

• Incubation period: <1 week.

Presentation: 

• Asymptomatic > Symptomatic (3:1).

• H/o unimmunized child.

• Universal early symptom: Sore throat.

• Fever (only in 50%), malaise, headache.

• Dysphagia, hoarseness.

• Stridor & cough.

• Bull neck appearance.

• Drooling of saliva.

• Throat examination Pseudomembrane.
• Removal causes bleeding.
• Can extend to the tonsils, uvula, soft palate, and posterior oropharynx wall.

Isolation criteria: 

• Oropharyngeal/nasopharyngeal swabs

• Diphtheria → 2 culture negative

Notification & isolation:

• Typhoid → Till 3 negative stool cultures.

• Diphtheria → 2 culture negative

• Cholera → Isolate patient until 2–3 negative stool cultures

Period of communicability: 

• Up to 1 month after onset.

Stains:

Culture:

• McLeod agar

• Enriched media:
• Loeffler serum slope.
• Growth in 6-8 hours.
• Best medium for early diagnosis.
• Laugh (Loeffler) early (early) to become rich (Enriched)

• Selective media:
• Potassium tellurite agar/Tinsdale media.
• Produces black colonies.
• Grows in 48 hours.
• Best medium for C. diphtheriae.
• Best () story → selected (Selective)
• When pottan (Potassium tellurite) tells () a best () story of Tins dale ()

Toxigenicity/Susceptibility tests:

• Elek's gel precipitin test:
• Double diffusion in two dimensions.
• Uses filter paper with C. diphtheria antitoxin.
• Determines toxigenicity.
• A precipitin line indicates a toxigenic strain.

• Schick test:
• Intradermal test for susceptibility.
• Redness signifies susceptibility.
• Negative reaction indicates immunity (Mnemonic: SPIN).

Bio-typing of Corynebacterium species (Mnemonic: GIM)

• Gym buddies
• Minimal guy
• eat poached egg
• no effort → no infection
• Intermediate guy
• eat frog egg,
• but dont bleed for effort
• Great guy
• Daisy gives her head
• eat starch

• Gravis: Daisy head colonies, ferments starch.

• Intermedius: Frog egg colonies, non-hemolytic.

• Mitis: Poached egg colonies, least virulent, causes minimal infection.

Carriers stages:

• Most important source of infection is chronic carriers
• Nasal > Throat

• Immunization does not prevent carrier state

• Healthy.

• Incubatory.

• Convalescent.

Chemoprophylaxis

• Given regardless of the immunization status of contacts.

Complications of Diphtheria

• Early - Myocarditis, Airway obstruction.

• Long-term - Neurological (Multiple cranial nerve palsy, Quadriplegia).

Immunization, prevention and control :

Cases

• IM Procaine Penicillin G (DOC) x 14d OR Erythromycin +

• Serial cultures +

• DAT (Diphtheria anti toxin)
• Given Post skin sensitivity test
• Mild - Mod: IM
• Severe: IV

Cases	DAT dose
Pharyngeal/ laryngeal disease	30,000 - 40,000 IU
Nasopharyngeal disease	40,000 - 60,000 IU
Extensive disease (Bullneck/Hoarseness)	80,000 - 100,000 IU

Carrier stages: 

• Antibiotic (Oral Erythromycin x 10 days).

• Serial cultures → if negative, declare as non infective

Contacts:

• Assess for signs & symptoms of disease.
• Serial culture
• Oral Erythromycin/Penicillin G (DOC) x 7 days +
• Till 2 negative culture reports
• Note: Antibiotics can be stopped only after isolation criteria is met.
• Diphtheria toxoid (DT) vaccine if
• (<7 years: DPT and > 7 years: Tdap).
• 3 doses taken + last dose <5y
• No extra vaccine,
• continue NIS.
• 3 doses taken + last dose >5y
• Single dose DT booster
• Unknown status or <3 doses
• Give DT + Complete toxoid series
• 3 primary + 2 booster doses

• Family: Coronaviridae

• Genus: Beta coronavirus

• Morphology:
• Crown-like appearance under EM
• Petal-like peplomers help in attachment

• Structure:
• Spike protein (S1, S2)
• for attachment
• Long petal-shaped
• Nucleocapsid (N)
• Membrane (M)
• Envelope (E)

• Entry Mechanism:
• TMPRSS2 activates spike protein
• Spike attaches to ACE2 receptors

• Incubation Period: 2–14 days (median 5–6 days).

• Most common ocular manifestation of COVID-19 is follicular conjunctivitis

Diagnosis

• Sample:
• Nasopharyngeal swab + oropharyngeal swab
• Both placed in Viral Transport Media (VTM)

• RT-PCR (Real-time Reverse Transcriptase PCR):
• CT Value: lower = more infectivity
• Semi-confirmatory genes: E, N, S genes
• Confirmatory genes: RdRP, ORF1a

• Card test:
• Principle: Immunochromatography (ICT)
• Control line → ensures validity

Histopathology:

• Diffuse alveolar damage.

• Hyaline membrane deposition

Viral vector vaccines / Live vaccines

• Covishield: 
• Using CHAD-OX1 strain with chimpanzee adenovirus.
• Mnemonic: Shield for Chad from Ox and Chimpanzee

• INCOVACC (2022):
• Only nasal vaccine: BBV 154.
• Mnemonic: Cova → BBV
• CC → 154
• X → 152
• Recombinant replication deficient adenovirus, vector vaccine.
• Age: >18 years.
• Mnemonic: Inside Nose Covid Vaccination

• Killed vaccine: 
• Covaxin (BBV-152 strain).
• X → Killed

• Protein subunit vaccine: 
• Corbevax.
• Mnemonic: Corbe → Brotein

• mRNA vaccines.

• Vaccines:
• Pfizer-BioNTech (BNT162b2): 2 doses, 0.3 mL IM, 21 days apart.
• Moderna (mRNA-1273): 2 doses, 0.5 mL IM, 28 days apart.
• AstraZeneca (AZD1222): 2 doses, 0.5 mL IM, 4–12 weeks apart.

M/c HRCT finding:

• Bilateral Multifocal peripheral/ subpleural GGO
• Typical → CORADS 5 (highly suspicious).

• partial dsDNA

• Portal tract expansion

• ALT > AST

Classification

• Incubation period
• A & E → 15 - 50 days
• Both non enveloped
• B & D → 50 - 150 days
• C → 15 - 150

• Only cultivable
• Hep A

• No vaccine
• C (quasispecies) and E

• All RNA
• except Hep B → partial dsDNA

• Precore mutant → cannot produce HBeAg

Important facts

Hepatitis B:

• Dane Particle (Hepadna virus)

• DNA virus, partially double-stranded

• Susceptible to
• Hypochlorite
• Heat labile

• Reservoirs: Human.

• Mode of transmission:
• Parenteral: IV drug use.
• Vertical: Mother to child.

• Incubation period: 30-180 days.

• Period of communicability: 
• Till HBSAg +ve in blood.

• Clinical features:
• Low grade fever.
• Icterus.
• Malaise.
• Clay stools.

• Pathogenesis
• Ground glass hepatocytes (hazy cytoplasm)
• Surface antigen
• Orcein shikata

Prevention

HBV vaccine:

Accidental Needle Prick

• Timing: <2 h (up to 48h).

• Dose: 0.05 - 0.07 mL/Kg in 2-3 doses.

• Check HBSAg in the victim:
• + ve: Don't give vaccine.
• - ve:
• HB Vaccine (Recombinant) + HbIg → both can be given

WHO 5C's concept for prevention of Hepatitis B:

• Consent.

• Counselling.

• Confidentiality.

• Connection (For prevention, treatment and care services).

• Correct test results.

Note

Treatment

• LET → Lamivudine, Emtricitabine, Tenofovir

• Latest guidelines: TEA
• Tenofovir
• Entecavir
• Pegylated interferon-alpha (PEG-IFN-α)

Lab Diagnosis of HAV

• Shedding:
• Stool → 2 weeks before to 2 weeks after symptom onset

• Antibodies:
• IgM → with jaundice onset
• IgG → appears 2–4 weeks later

• TAD GH

• CADherins (A → Adherans, D → Desmosomes)

Vibrio Classification by Salt Requirement

V. Cholera classification - Classical vs. EL TOR

• Vibrio cholerae (Gram -ve comma shaped, motile bacilli).

• m/c type: O1 (serogroup) → El tor (biotype) → Ogawa (serotype)
• O → OG → group
• Ogawa → OGT

C/f: 

• Mostly asymptomatic.

• Fever → Uncommon

• Clinical history: Rice water stools (↑↑ cAMP)

Important Information

• Increased cAMP:
• Cholera
• Anthrax
• ETEC (liable)
• Pertussis

cAMP vs cGMP Mechanism

Important Information

• Vibrio cholera targets small intestine

• Cholera toxin increases cAMP

• Vibrio cholera disrupts zona occludens (Tight junction)

Epidemiology

• Cholera outbreak: 
• Indicates lack of social development.
• Note: lack of sanitation - typhoid

• Force of infection: 



• After controlling the source of outbreak
• the incidence of cholera cases still remains a plateu
• called force of infection / tail of outbreak
• D/t carrier stages.
• So no need for vaccination or any other interventions as half of people are carriers

• Reservoir of infection: Humans.

• Transmission: Water borne.

• Period of communicability:

Source	Period of communicability
Cases	7-10 days
Convalescent carriers	2-3 weeks
Chronic carriers	Weeks-months

Stool Collection & Transportation

• Container: McCartney bottle

• Transport media:
• Venkataraman Ramakrishna (VR) media
• Rectal swabs:
• Alkaline peptone water
• Cary Blair media
• Mnemonic: Venkata Raman Ramakrishnan () → Namamde Appi water (Alkaline peptone water) carry (Cary blair) cheyyum → Cartil (McCartney bottle)

• Culture media:
• TCBS (Thiosulphate citrate bile salt sucrose)
• Bromothymol blue (BTB) is the indicator.

• Culture Methods
• Hanging drop preparation:
• Shows scintillating (darting) motility
• Darkfield microscopy:
• "Darting/Shooting stars in dark sky" appearance
• Mnemonic: VR →
• appi thuukki idum (hanging drop) → apo aadum (dartling motility) OR
• Ratriyil starsine nokki eriyum ( Dark field → shooting star)

• Gelatin Stab:
• Turnip/Napiform Liquefaction

Biochemical tests:

• CCOINSS
• Cholera red reaction (nitroso indole compound)
• Catalase +ve
• Oxidase +ve
• Indole test +ve
• Nitrate reduction +ve
• Sucrose lysis +ve
• String test

• String test positive:
• Vibrio cholera
• Klebsiella
• Giardia lamblia
• when kleb ile guard vibe anel

• Oxidase positive
• Features
• vighnesh pseudo nyc vibe on camp helicopter micropenis
• Pseudomonas
• Vibrio cholera
• Neisseria
• Campylobacter
• Helicobacter

A child is brought to the PHC with acute diarrhoea. The doctor, based on history, suspects that the child may be suffering from an infection due to Shigella over cholera and proceeds to give ciprofloxacin as the antibiotic. Which of the following points on history, apart from bloody stools, favour the doctor’s suspicion?

Notification & isolation:

• Typhoid → Till 3 negative stool cultures.

• Diphtheria → 2 culture negative

• Cholera → Isolate patient until 2–3 negative stool cultures

Diagnosis

Treatment

• Isolation:
• Isolate patient until 2–3 negative stool cultures

• Rehydration:
• ORS + Zinc

• Antibiotics:
• Adults: Doxycycline
• Children: Erythromycin
• Pregnant women: Erythromycin or Azithromycin

Chemoprophylaxis

• Drug of choice: Tetracycline

• No use

Chemoprophylaxis cases isolation ??

• 3 days after starting Tetracycline till 48 hours of antibiotics

Disinfection

• Disinfectant: 5% cresol

Cholera Outbreak Management

1. Notifiable
• Single case is not notifiable
• Outbreak → Within 24 hours
• To WHO and Government of India

2. Most effective prophylactic measure:
• Health education

3. No use of chemoprophylaxis, vaccination in cholera
• Except for healthcare workers → vaccines given

4. Verification of diagnosis.

5. Early case finding.

6. Treatment

7. Epidemiological investigation.

8. Sanitation, health education.

Vaccines for healthcare workers :

• Etiology: Salmonella typhi (Gram -ve flagellate).

• Typhoid outbreak: Indicates poor sanitation.

• Reservoir: Humans.
• Age group: 5-19 y
• Sex:
• Cases: m > F
• Carriers: F > m.

• Mode of transmission: Feco oral > urine.

• Seasonal variation: Late summers & monsoon.

• Incubation period: 7-14 days (up to 4 weeks).

• Wilson/Salmonella → climbed with a Longitudinal (Longitudinal ulcers in GIT) Ladder (Step ladder pattern fever) → to drink pea soup (Pea soup diarrhea) → fell on a Spot with Rose flowers (Rose spots) with pressure (fade on pressure) → swelling in belly (Soft palpable spleen, liver) → he was then carried in a Sac (Sach's Buffered glycerol Saline)

• Clinical Features
• Enteric fever
• Step ladder pattern fever
• Longitudinal ulcers in GIT
• Pea soup diarrhea
• Fever with bradycardia - Faget's sign
• Soft palpable spleen, liver
• Rose spots
• 2nd /3rd week
• fade on pressure

• Transport – Sach's Buffered glycerol Saline

• Culture media
• Wilson blair media - jet black colonies
• (Only for salmonella, not shigella)

• Treatment - Ciprofloxacin

Diagnosis (mnemonic: BASU)

• Typhoid BASU prob (Probenecid with cholecystectomy)

• If started on antibiotics - most sensitive
• Bone marrow culture

Widal Test Table

• O (1st appears) – H (2nd to appears) – O (disappears 1st) – H (disappears last)

• Most immunogenic and earliest and highest Antibody appears - H

Slide Widal test

• Non specific test so serial testing needed

• Dot → Agglutination test occurred

New test

• Typhidot

• Dot blot

Notification & isolation:

• Typhoid → Till 3 negative stool cultures.

• Diphtheria → 2 culture negative

• Cholera → Isolate patient until 2–3 negative stool cultures

Treatment:

• Cases: Fluoroquinolone/3rd gen Cephalosporins.

• Carriers: Ampicillin/Amoxicillin + Probenecid with cholecystectomy.

Prevention

5 Fs in sanitation barrier: 

• Feces Enters Food via
• Fingers (unclean)
• Flies (Biological agent)
• Fluids (Contaminated water)

Deworming

• Albendazole is given
• On 10th February & 10th August (National Deworming day).

• Dose:
• 1 - 2 years of age: 200 mg.
• > 2 years of age: 400 mg.

Chandler's index: 

• Number of hookworm eggs per gram of stool.
• <200: Not a public health problem (PHP).
• 200-250: Potential danger of a PHP.
• 250-300: Minor PHP.
• > 300: Major PHP

• Mnemonic: Chandler Hooked (Hookworm) Monica

Taeniasis and Echinococcosis

Key Points

• Most common infestation: Ascariasis (roundworm)

• Worm causing IDA: Ancylostomiasis (hookworm)

• Worm related to step wells: Guinea worm

• National Deworming Days: 10th February, 10th August

Epidemiology

• Caused by: Lyssa virus (Rhabdoviridae family).



• SSRNA.
• Bullet shaped virus.

• Replication → initial in muscle tissue

• Spread:
• Binds acetylcholine receptors
• Retrograde axonal transport via peripheral nerves
• Reaches dorsal root ganglia → spinal cord → brain (centripetal spread)

• Further spread:
• Centrifugal spread → cornea, salivary glands, other nerves

• Disease progression:
• Axonal spread speed = 3 mm/hr
• Incubation shorter in children, upper limb bites, short stature

Rabies-Free Areas

• States in India:
• Goa
• Andaman & Nicobar Islands
• Lakshadweep Islands

• Countries:
• Australia
• U.K.

Types: