Midwife Licensure Exam Community & Public Health — Communicable Disease Control & ImmunizationRevision Notes

Exam Tips

• When the NLE stem asks 'what level of prevention is immunization?' — always answer PRIMARY prevention, specifically SPECIFIC PROTECTION.
• Contact tracing in TB = SECONDARY prevention (early case detection).
• Physiotherapy for post-polio = TERTIARY prevention (rehabilitation).
• Remember: Primary = Before disease; Secondary = Early in disease; Tertiary = After disability.

Key Points

• Primary prevention prevents disease BEFORE it occurs — this is the community nurse's most powerful tool.
• Primary prevention includes: health education, immunization, sanitation, safe water supply, vector control, and adequate nutrition.
• Immunization is the classic example of PRIMARY prevention under the category of SPECIFIC PROTECTION (Leavell and Clark model).
• Secondary prevention involves EARLY DETECTION and PROMPT TREATMENT — case-finding, screening programs, contact tracing, and early diagnosis.
• Tertiary prevention focuses on LIMITATION OF DISABILITY and REHABILITATION — managing complications and reintegrating recovered patients into the community.
• In Maslow's hierarchy, primary prevention safeguards physiological and safety needs before threats materialize.
• The nursing process aligns with levels of prevention: Assessment/Diagnosis drives secondary; Planning/Implementation spans all three levels.

Definitions

Section Title

Levels of Prevention in Communicable Disease

Common Mistakes

• Confusing immunization (primary prevention) with early diagnosis (secondary prevention) — immunization PREVENTS disease; it does not detect it.
• Placing DOTS/TB treatment under primary prevention — treatment is SECONDARY prevention (early diagnosis and prompt treatment).
• Forgetting that tertiary prevention includes rehabilitation, not just treatment of complications.
• Confusing 'specific protection' (immunization) with 'health promotion' — both are under primary prevention but are different sub-levels.

Exam Tips

• Vaccine/toxoid = ACTIVE immunity (artificial). Immunoglobulin/antiserum = PASSIVE immunity (artificial).
• Placenta/breast milk = PASSIVE immunity (natural).
• If an NLE question asks about 'immediate but temporary' protection — answer: PASSIVE immunity.
• If an NLE question asks about 'long-lasting' protection from a vaccine — answer: ACTIVE immunity.

Key Points

• Active immunity means the individual's own immune system produces antibodies — it is LONG-LASTING.
• Natural active immunity results from recovering from an actual infection (e.g., natural measles infection).
• Artificial active immunity results from vaccines and toxoids (e.g., BCG vaccine, MMR vaccine) — this is what EPI provides.
• Passive immunity means antibodies are RECEIVED from another source — it is IMMEDIATE but TEMPORARY.
• Natural passive immunity: maternal IgG antibodies cross the placenta; IgA from breast milk protects the newborn.
• Artificial passive immunity: immunoglobulins/antisera given to an exposed person (e.g., anti-rabies immunoglobulin, tetanus immunoglobulin).
• KEY DISTINCTION: Vaccines → active immunity (slow onset, long duration). Immunoglobulins → passive immunity (immediate onset, short duration).
• Toxoids are inactivated bacterial toxins that stimulate active immunity (e.g., tetanus toxoid, diphtheria toxoid in Td vaccine).

Definitions

Section Title

Immunity Types and Concepts

Common Mistakes

• Saying that breast milk gives the infant 'active' immunity — breast milk (IgA) gives NATURAL PASSIVE immunity.
• Confusing anti-rabies vaccine (active immunity) with anti-rabies immunoglobulin (passive immunity) — both are given post-exposure but they are different types.
• Thinking passive immunity is 'better' because it is immediate — passive immunity is TEMPORARY; active immunity is long-lasting.
• Forgetting that toxoids produce ACTIVE immunity — they are not passive just because they come from bacteria.

Exam Tips

• ROUTES MEMORY AID: BCG = Intradermal | OPV = Oral | MMR/Measles = Subcutaneous | Pentavalent/PCV/IPV/HepB = Intramuscular.
• 6-10-14 WEEKS vaccines: Pentavalent + OPV + PCV (all three, all together, all 3 doses).
• 9 MONTHS vaccines: MCV1 (measles/MMR) AND IPV 2nd dose.
• 12 MONTHS: MCV2 (MMR 2nd dose) — MMR given TWICE: at 9 months and 12 months.
• BIRTH vaccines: BCG (intradermal 0.05 mL) and Hepatitis B monovalent (IM 0.5 mL within 24 hours).
• EPI = 1976; RA 10152 = 2011 — memorize both years.
• Classic 6 EPI diseases: TB, Diphtheria, Pertussis, Tetanus, Polio, Measles — 'TDP-TPM'.
• Never withhold vaccines for minor illness (mild cough, low-grade fever, mild diarrhea) — missed opportunities lower coverage.

Key Points

• EPI was launched by DOH in 1976 to reduce morbidity and mortality from vaccine-preventable diseases.
• Legal basis: Presidential Decree 996 (compulsory immunization for children under 8) and RA 10152 — Mandatory Infants and Children Health Immunization Act of 2011 (mandates FREE routine immunization).
• Original 6 target diseases (memorize!): Tuberculosis, Diphtheria, Pertussis (whooping cough), Tetanus, Poliomyelitis, and Measles. Mnemonic: 'TD-PT-PM' or 'The Dirty Poor Town People Missed.'
• The program has EXPANDED to include Hepatitis B, Haemophilus influenzae type b (Hib), Pneumococcal disease, and others.
• BCG and Hepatitis B monovalent are given AT BIRTH.
• Pentavalent (DPT-HepB-Hib), OPV, and PCV follow the 6-10-14 WEEKS schedule (3 doses each).
• IPV (inactivated polio) is given at 14 WEEKS and 9 MONTHS (2 doses total).
• MCV1 (measles-containing vaccine or MMR) at 9 MONTHS; MCV2 (MMR) at 12 MONTHS.
• Fully Immunized Child (FIC): receives all antigens BEFORE 12 months of age.
• Completely Immunized Child (CIC): completes immunization at 12-23 months of age.
• Child Protected at Birth (CPAB): newborn protected from neonatal tetanus through maternal Td immunization.

Definitions

Section Title

Expanded Program on Immunization (EPI)

Common Mistakes

• Saying BCG is given IM — BCG is strictly INTRADERMAL (not IM, not SC).
• Confusing the dose: BCG for infants is 0.05 mL (NOT 0.1 mL — that is for older children).
• Saying MMR/measles is given IM — MCV1 and MMR (MCV2) are SUBCUTANEOUS.
• Forgetting that IPV has 2 doses in the current DOH schedule: at 14 WEEKS and 9 MONTHS.
• Saying FIC is completed by 18 months — FIC must be completed BEFORE 12 months. After 12 months = CIC.
• Confusing PD 996 (compulsory immunization) with RA 10152 (mandatory free immunization) — know both.
• Forgetting to include PCV in the FIC criteria — the current EPI schedule includes PCV at 6-10-14 weeks.
• Giving live vaccines (BCG, MMR, OPV) to severely immunocompromised children — this is a TRUE contraindication.

Exam Tips

• For NLE: When a question asks about the site of IM injection in an infant — always say VASTUS LATERALIS.
• Three vaccines at once at 6, 10, and 14 weeks: Pentavalent + OPV + PCV.
• Polio has BOTH OPV (oral, 3 doses) AND IPV (injectable, 2 doses) in the current schedule — a total of 5 polio vaccine doses.
• Vaccine given at the MOST visits from 6-14 weeks: Pentavalent, OPV, and PCV (3 vaccines at 3 visits).

Key Points

• BIRTH: BCG (intradermal, right upper arm, 0.05 mL) and Hepatitis B monovalent (IM, vastus lateralis, 0.5 mL, within 24 hours).
• 6 WEEKS: Pentavalent 1st dose (IM, 0.5 mL) + OPV 1st dose (oral, 2-3 drops) + PCV 1st dose (IM, 0.5 mL).
• 10 WEEKS: Pentavalent 2nd dose + OPV 2nd dose + PCV 2nd dose.
• 14 WEEKS: Pentavalent 3rd dose + OPV 3rd dose + PCV 3rd dose + IPV 1st dose (IM, 0.5 mL).
• 9 MONTHS: MCV1 — measles-containing vaccine or MMR (subcutaneous, 0.5 mL, outer upper arm) + IPV 2nd dose (IM).
• 12 MONTHS: MCV2 — MMR (subcutaneous, 0.5 mL).
• Minimum interval between doses in a series: 4 WEEKS (28 days) for Pentavalent, OPV, and PCV.
• SITE for IM injections in infants: VASTUS LATERALIS (anterolateral thigh) — not the deltoid (too small in infants).
• SITE for BCG: Right upper arm (deltoid region) — INTRADERMAL only.
• SITE for SC vaccines (MMR): Outer upper arm.

Definitions

Section Title

EPI Immunization Schedule (Detailed Reference Table)

Common Mistakes

• Giving IM injections to infants in the deltoid — use VASTUS LATERALIS for infants.
• Confusing the number of OPV doses (3 doses: 6-10-14 weeks) with the number of IPV doses (2 doses: 14 weeks and 9 months).
• Thinking the minimum interval between Pentavalent doses is 6 weeks — the MINIMUM is 4 WEEKS (28 days).
• Administering BCG subcutaneously or IM — BCG MUST be intradermal. If given SC/IM, a local abscess may form.

Exam Tips

• NLE MEMORY AID for Td duration: Td2 = 3 years, Td3 = 5 years, Td4 = 10 years, Td5 = Lifetime. Think: '3-5-10-Life'.
• Td2 = the magical dose — protects both mother and newborn from tetanus.
• CPAB indicator is achieved when mother has at least Td2 and baby is born.
• Td minimum intervals: Td1→Td2: 4 weeks | Td2→Td3: 6 months | Td3→Td4: 1 year | Td4→Td5: 1 year.

Key Points

• Goal: Eliminate MATERNAL AND NEONATAL TETANUS — a major cause of newborn deaths in developing countries.
• Td vaccine (Tetanus-Diphtheria toxoid) has replaced the older TT (Tetanus Toxoid) in the Philippine EPI.
• Td1: Given as early as possible in pregnancy or to women of childbearing age — gives NO immediate protection.
• Td2: At least 4 WEEKS after Td1 — gives approximately 3 YEARS of protection; PROTECTS THE NEWBORN FROM NEONATAL TETANUS.
• Td3: At least 6 MONTHS after Td2 — gives approximately 5 YEARS of protection.
• Td4: At least 1 YEAR after Td3 — gives approximately 10 YEARS of protection.
• Td5: At least 1 YEAR after Td4 — gives LIFETIME protection.
• A woman who has completed all 5 doses is considered permanently protected.
• Child Protected at Birth (CPAB): newborn whose mother has received at least Td2 during or before the pregnancy — protected from neonatal tetanus.
• Minimum interval for Td2 protection: 4 WEEKS after Td1 — and Td2 must be given at least 2-3 WEEKS BEFORE DELIVERY for maternal antibodies to transfer.

Definitions

Section Title

Tetanus (Td) Immunization for Women of Childbearing Age

Common Mistakes

• Saying Td1 gives protection — Td1 gives NO protection. Protection begins with Td2.
• Forgetting the minimum interval: Td1 to Td2 = at least 4 WEEKS (NOT just 'next visit').
• Confusing TT (tetanus toxoid) with Td (tetanus-diphtheria) — the current program uses Td, which also protects against diphtheria.
• Thinking 5 doses protect for only 10 years — Td5 gives LIFETIME protection.
• Forgetting that Td2 gives approximately 3 years of protection (not lifetime).

Exam Tips

• COLD CHAIN TEMPERATURE AID: Health center = +2°C to +8°C | Regional freezer = -15°C to -25°C.
• HEAT-SENSITIVE (store coldest): OPV > Measles > BCG. Think: 'OMB — store them coldest.'
• FREEZE-SENSITIVE (never freeze): DPT, Hep B, Td, Pentavalent. Think: 'Frozen DPT is dead.'
• VVM: Inner darker than outer = DISCARD. Inner lighter = SAFE to use.
• Shake test = for freeze-sensitive vaccines (to check if accidentally frozen).
• FEFO = first expiry, first out — always use the one expiring soonest first.

Key Points

• The COLD CHAIN is the system of storing and transporting vaccines within the safe temperature range from manufacturer to the child — any break in the cold chain can destroy vaccine potency.
• HEALTH CENTER/RHU refrigerator temperature: +2°C to +8°C (the standard working temperature for vaccine storage).
• REGIONAL/PROVINCIAL LEVEL freezers: -15°C to -25°C (for storing OPV and measles vaccine stocks longer-term).
• MOST HEAT-SENSITIVE vaccines (store where it is COLDEST): OPV (most sensitive) > Measles/MMR > BCG.
• FREEZE-SENSITIVE vaccines (must NEVER be frozen — store in the BODY of the refrigerator, NOT the freezer): DPT, Hepatitis B, Td, and Pentavalent. Freezing destroys their potency.
• The SHAKE TEST detects whether a freeze-sensitive vaccine has been frozen: shake the vial and observe — if a precipitate forms and does NOT redissolve (compared to a known good control), the vaccine has been damaged and must be discarded.
• FEFO principle: 'First Expiry, First Out' — always use the vaccine with the earliest expiry date first to prevent waste.
• Vaccine Vial Monitor (VVM): a heat-sensitive label on vaccine vials that changes color when the vaccine has been exposed to excessive heat, indicating it may no longer be potent.
• The inner square of the VVM changing color DARKER than the outer circle = vaccine should NOT be used.
• Cold chain equipment at the health center: refrigerators (for +2 to +8°C storage) and cold boxes/vaccine carriers with ice packs (for transport).

Definitions

Section Title

The Cold Chain System

Common Mistakes

• Putting DPT or Hepatitis B in the FREEZER — freeze-sensitive vaccines must NEVER be frozen; they belong in the refrigerator body at +2 to +8°C.
• Confusing the most heat-sensitive vaccine (OPV) with a freeze-sensitive vaccine — OPV is HEAT-sensitive (not freeze-sensitive; it IS stored in the freezer at regional level).
• Using the wrong VVM interpretation: a LIGHTER inner square means the vaccine is still good; a DARKER inner square means it is compromised.
• Forgetting FEFO — using vaccines closest to the front (not expiry date) is a common real-world mistake.
• Thinking the shake test is for all vaccines — it is specifically for FREEZE-SENSITIVE vaccines (DPT, Hep B, Td, Pentavalent).

Exam Tips

• DOTS mnemonic for 5 elements: 'P-C-S-U-R' — Political commitment, Case detection, Standardized treatment, Uninterrupted supply, Recording/Reporting.
• Drug side effects to MEMORIZE: Rifampicin = orange urine (NORMAL), hepatotoxicity | Isoniazid = peripheral neuropathy (give Vit B6), hepatotoxicity | Ethambutol = optic neuritis (color vision changes) | Streptomycin = ototoxicity (hearing loss), nephrotoxicity | Pyrazinamide = hyperuricemia (gout), hepatotoxicity.
• Category I = NEW cases = 2HRZE/4HR = 6 months total.
• Category II = PREVIOUSLY TREATED = longer regimen with Streptomycin added.
• GeneXpert is PRIMARY diagnostic; DSSM used for follow-up monitoring.
• Treatment partner in DOTS can be a family member, barangay health worker, or neighbor — someone the patient trusts and lives near.

Key Points

• TB remains a major public health problem in the Philippines — the NTP uses DOTS (Directly Observed Treatment, Short-course) as its cornerstone strategy.
• DOTS means a health worker or designated treatment partner PHYSICALLY WATCHES the patient SWALLOW EVERY DOSE of anti-TB medication — this is non-negotiable.
• The FIVE ELEMENTS of DOTS: 1) Political commitment with sustained financing, 2) Case detection through quality-assured bacteriology, 3) Standardized treatment with DIRECT OBSERVATION, 4) Uninterrupted supply of quality-assured anti-TB drugs, 5) Standardized recording and reporting system.
• PRIMARY DIAGNOSTIC TOOL: Xpert MTB/RIF (GeneXpert) — rapid, also detects rifampicin resistance. Direct Sputum Smear Microscopy (DSSM) is used for treatment monitoring/follow-up.
• First-line anti-TB drugs (HRZE-S mnemonic): H = Isoniazid, R = Rifampicin, Z = Pyrazinamide, E = Ethambutol, S = Streptomycin.
• Treatment has an INTENSIVE PHASE (~2 months) and a CONTINUATION PHASE (~4 months).
• Category I (NEW TB cases): 2HRZE / 4HR — 2 months HRZE (intensive) then 4 months HR (continuation).
• Category II (PREVIOUSLY TREATED cases — relapse, failure, after loss to follow-up): 2HRZES / 1HRZE / 5HRE.
• MDR-TB (Multi-Drug Resistant TB) is managed under PMDT (Programmatic Management of Drug-Resistant TB).
• BCG vaccine provides primary prevention against SEVERE FORMS of childhood TB (TB meningitis, miliary TB) but does NOT prevent adult pulmonary TB or TB infection.

Definitions

Section Title

National TB Control Program (NTP) and DOTS

Common Mistakes

• Thinking DOTS means giving the patient drugs to take at home — DOTS requires the health worker to WATCH the patient swallow each dose.
• Confusing Category I (new cases) with Category II (previously treated) — know the difference and the drug regimens.
• Thinking Rifampicin-induced orange-red urine is an adverse reaction requiring drug stoppage — it is NORMAL and expected; reassure the patient.
• Forgetting that Ethambutol can cause optic neuritis (visual changes) and Streptomycin causes ototoxicity — monitor accordingly.
• Confusing Isoniazid's side effect (peripheral neuropathy — prevented by Vitamin B6/pyridoxine) with other drug side effects.
• Thinking BCG prevents all forms of TB — BCG only prevents SEVERE childhood TB (meningitis, miliary TB), not adult pulmonary TB.

Exam Tips

• IMMEDIATE (24 hours): AFP, Measles, Neonatal Tetanus, Cholera, Meningococcal disease, Rabies.
• WEEKLY: Dengue, Typhoid, TB, Malaria.
• AFP = polio until proven otherwise — IMMEDIATE report within 24 hours.
• NLE question pattern: 'A nurse finds a child with sudden onset of leg weakness — what should the nurse do FIRST?' Answer: Report the case to the health authorities as AFP (within 24 hours).

Key Points

• The Philippine Integrated Disease Surveillance and Response (PIDSR) system mandates health workers to report certain communicable diseases to public health authorities.
• IMMEDIATELY NOTIFIABLE (within 24 hours): diseases of epidemic potential and eradication targets — Acute Flaccid Paralysis (AFP/polio), Measles, Neonatal Tetanus, Cholera, Meningococcal disease, Rabies.
• WEEKLY NOTIFIABLE: routinely reported conditions — Dengue, Typhoid fever, TB, Malaria, Leptospirosis, and others.
• Prompt and accurate reporting by the nurse triggers immediate investigation, contact tracing, and outbreak response.
• The community health nurse's role in disease surveillance: detect cases, report immediately, conduct contact tracing, implement control measures, and educate the community.
• Under RA 9173, nurses have the professional duty to report communicable diseases — failure to do so is negligence.
• Acute Flaccid Paralysis (AFP): any case of sudden onset of flaccid (floppy) weakness in a child under 15 years — must be reported IMMEDIATELY as a suspected polio case.

Definitions

Section Title

Notifiable Diseases and PIDSR

Common Mistakes

• Reporting dengue as immediately notifiable — dengue is WEEKLY notifiable (unless there is a suspected outbreak).
• Failing to recognize AFP as an immediate-report case — any sudden flaccid paralysis in a child under 15 = report immediately.
• Thinking only doctors can report notifiable diseases — nurses under RA 9173 have a legal duty to report.

Exam Tips

• VECTOR MEMORY: Aedes = Dengue (Day-biting) | Anopheles = Malaria (Night-biting) | Culex = Filariasis/Encephalitis.
• 4-S Strategy: Search and destroy | Self-protection | Seek early consultation | Support fogging (outbreaks only).
• Dengue breeds in CLEAN stagnant water — a classic NLE distractor.
• 4 serotypes = 4 chances to get dengue; 2nd infection with different serotype = more severe.
• Priority dengue nursing action: monitor for WARNING SIGNS and hydration status.
• NANDA nursing diagnosis for dengue: Risk for Deficient Fluid Volume; Risk for Bleeding.

Key Points

• Dengue is a viral disease transmitted by the AEDES AEGYPTI mosquito (also Aedes albopictus), a DAY-BITING mosquito that breeds in CLEAN, STAGNANT WATER (not dirty/stagnant water — this is a common misconception).
• There are FOUR DENGUE SEROTYPES (DENV 1, 2, 3, 4) — infection with one serotype gives immunity to THAT serotype ONLY.
• Secondary infection with a DIFFERENT serotype causes more severe dengue (Dengue Hemorrhagic Fever / Dengue Shock Syndrome) due to antibody-dependent enhancement.
• DOH 4-S STRATEGY: 1) Search and destroy mosquito breeding sites, 2) Self-protection measures, 3) Seek early consultation, 4) Support fogging/spraying only in hotspot areas.
• FOGGING is NOT the primary control measure — it kills adult mosquitoes but does NOT eliminate breeding sites. Fogging is used only during outbreaks in hotspot areas.
• DENGUE WARNING SIGNS (refer immediately): severe abdominal pain, persistent vomiting, bleeding (gums, nose, skin), restlessness/altered consciousness, difficulty breathing, rapid pulse.
• Dengue is NOT directly transmitted from person to person — a mosquito must bite an infected person and then bite another person.
• Nursing priority for dengue: assess for warning signs, monitor for plasma leakage (bleeding, rapid pulse, drop in blood pressure), ensure adequate hydration.
• The most common dengue nursing diagnosis: Risk for Deficient Fluid Volume related to plasma leakage and hemorrhage.

Definitions

Section Title

Dengue Control and the DOH 4-S Strategy

Common Mistakes

• Saying Aedes aegypti breeds in DIRTY stagnant water — Aedes breeds in CLEAN stagnant water (vases, drums, containers).
• Recommending fogging as the PRIMARY dengue control measure — fogging is supplementary, used only in outbreak hotspots.
• Confusing Aedes aegypti (dengue, day-biting) with Anopheles (malaria, night-biting).
• Thinking all dengue serotype infections give cross-immunity — each serotype gives immunity to THAT serotype ONLY; second infection with a different serotype = more severe disease.
• Forgetting that dengue is a NOTIFIABLE disease (weekly reporting to PIDSR).

Exam Tips

• Schistosomiasis in Philippines = Schistosoma japonicum + Oncomelania snail + freshwater exposure.
• Malaria = Anopheles (night); Dengue = Aedes (day); Filariasis = Culex.
• Rabies PEP Category III = vaccine + IMMUNOGLOBULIN (both needed).
• Leprosy MDT: Dapsone + Rifampicin + Clofazimine.
• RA 9482 = Anti-Rabies Act; RA 10152 = Mandatory Immunization Act; RA 9173 = Philippine Nursing Act.

Key Points

• MALARIA: transmitted by the ANOPHELES mosquito (night-biting). Endemic in parts of Palawan, Mindanao, and other provinces. Control: Long-Lasting Insecticidal Nets (LLINs), indoor residual spraying, case management with antimalarials.
• SCHISTOSOMIASIS: caused by Schistosoma japonicum (blood fluke). Intermediate host: ONCOMELANIA snail (freshwater snail). Endemic in parts of Leyte, Samar, Mindanao, and Sorsogon. Transmission through skin contact with infested freshwater.
• FILARIASIS: caused by Wuchereria bancrofti, transmitted by Culex mosquito. Causes lymphedema (elephantiasis). DOH has a national elimination program (Mass Drug Administration with DEC and Albendazole).
• LEPROSY (Hansen's Disease): caused by Mycobacterium leprae. DOH aims for elimination. Treatment: Multi-Drug Therapy (MDT) — Dapsone, Rifampicin, Clofazimine. Primary mode of transmission: prolonged close contact (droplet/nasal secretions).
• RABIES: caused by Rabies virus, transmitted through bites/scratches from infected animals (dogs most common in the Philippines). Post-exposure prophylaxis (PEP): wound wash, anti-rabies vaccine series, and anti-rabies immunoglobulin for Category III exposures. The Philippines has the Rabies Prevention and Control Act (RA 9482).
• The ONCOMELANIA snail is the specific intermediate host for Philippine schistosomiasis — NOT the Biomphalaria snail (which is for African schistosomiasis).

Definitions

Section Title

Other Endemic Diseases in the Philippine Context

Common Mistakes

• Saying the intermediate host of Philippine schistosomiasis is Biomphalaria — the Philippines uses ONCOMELANIA snail; Biomphalaria is for S. mansoni in Africa.
• Confusing Anopheles (malaria) with Culex (filariasis) mosquitoes.
• Giving anti-rabies immunoglobulin for Category II exposure — immunoglobulin is ONLY for Category III (deep bites, bites on face/neck, multiple bites).
• Saying leprosy is highly contagious — leprosy has LOW infectivity; prolonged close contact is required.