(a) (i) Describe the challenges of circulating Vaccine-Derived Poliovirus (VDPV). Add a note on the environmental surveillance…

(a)(i) VDPV

Circulating vaccine-derived poliovirus (cVDPV) emerges when oral polio vaccine (OPV) strains replicate in under-immunized populations and revert neurovirulently; it can spread person-to-person and cause paralysis. Immune-derived VDPV (iVDPV) arises in immunodeficient individuals, while ambiguous VDPV (aVDPV) is one of unclear origin, often detected in sewage or a single case. The challenges are that OPV remains essential for mucosal immunity yet low coverage creates reservoirs for reversion; that about 90% of cVDPV outbreaks are type 2, persisting after the global withdrawal of the type-2 component (the tOPV-to-bOPV switch of April 2016) left a cohort without type-2 mucosal immunity; that iVDPV excretion can continue for years in immunodeficient people; and that silent circulation (roughly one paralytic case per 200 type-1 infections) allows spread across borders before detection. Environmental surveillance under India’s polio eradication programme uses regular sewage sampling at fixed sites to detect poliovirus before paralysis, complementing AFP surveillance. Prevention requires high routine immunization coverage (≥90%) with OPV/nOPV for intestinal protection, introduction of IPV in the routine schedule to provide systemic humoral immunity and reduce VAPP; IPV does not prevent intestinal OPV replication or mucosal reversion, so OPV/nOPV remains needed for mucosal protection. India, polio-free since 2014, gives bOPV at birth, 6, 10 and 14 weeks and fractional IPV (fIPV) intradermally at 6 and 14 weeks, with a third fIPV dose at 9 months added in 2023. Outbreak response to cVDPV2 uses the genetically stabilised novel OPV2 (nOPV2), which is far less likely to revert, while type-1 or type-3 events use bOPV or mOPV, together with mop-up campaigns, strong AFP surveillance (non-polio AFP rate ≥2 per 100,000 children under 15 and adequate stool collection in ≥80%), and containment of poliovirus stocks under GAPIII.

(a)(ii) Cryptococcosis

Cryptococcus neoformans (from pigeon/bird droppings) and C. gattii (from eucalyptus and other trees) are acquired by inhaling desiccated yeasts or basidiospores; the primary focus is pulmonary (often subclinical or a nodule), followed by haematogenous spread with tropism for the CNS, where the polysaccharide capsule and melanin aid survival. C. gattii can infect immunocompetent hosts and cause cryptococcomas. In immunocompromised hosts, especially HIV with CD4 <100 cells/µL, it causes meningoencephalitis with headache, fever, altered sensorium, papilledema and “soap-bubble” lesions in basal ganglia. Conventional diagnosis includes India ink, culture and histopathology; India ink is quick but insensitive, while culture remains the reference standard. CSF CrAg is more sensitive than India ink. Rapid diagnostic tests detect cryptococcal antigen (CrAg) in serum or CSF; lateral flow assay gives point-of-care results in about 15 minutes, while ELISA is laboratory-based and more quantitative. The LFA has sensitivity and specificity above 95%, needs no electricity or special training, and detects antigenaemia weeks before meningitis; hence WHO recommends CrAg screening of people with advanced HIV (CD4 <100/µL, ideally <200) with pre-emptive fluconazole, which reduces mortality in resource-limited settings. Culture remains necessary for species identification and susceptibility testing, and CrAg titres do not reliably track treatment response.

(b)(i) Injury, hurt and grievous hurt

Under the Bharatiya Nyaya Sanhita, 2023 (in force from 1 July 2024), Section 2(14) BNS (formerly Section 44 IPC) defines injury as any harm illegally caused to a person in body, mind, reputation or property. Hurt, a narrower bodily form of injury, is defined in Section 114 BNS (formerly Section 319 IPC) as causing bodily pain, disease or infirmity. Section 116 BNS (formerly Section 320 IPC) defines grievous hurt as emasculation; permanent privation of sight of either eye, hearing of either ear, any joint, or the power of any joint; permanent disfiguration of head or face; fracture or dislocation of a bone or tooth; and any hurt which endangers life or causes severe bodily pain or inability to follow ordinary pursuits for 15 days (20 days under the old IPC). Contusion is subcutaneous haemorrhage from blunt trauma without breach of skin. Medicolegally, its shape, size and distribution can match the weapon, its colour changes (red-purple, blue-black, green, yellow) help estimate age, and it must be differentiated from post-mortem lividity by location, pressure blanching and tissue changes (on incision a bruise shows clotted blood infiltrating tissues that cannot be washed away, while lividity shows blood confined to vessels). Other medico-legal points: patterned bruises (tram-line from a rod, fingertip bruises in throttling) reflect the weapon; bruises may appear away from the site of impact (ectopic bruising, such as a black eye from a fracture of the anterior cranial fossa) or appear late in deep tissues; they are more easily produced in children, the elderly and in lax tissue; and a simple bruise is usually simple hurt unless it is associated with grievous features.

(b)(ii) Blood and seminal stains

Stains are first located visually and with ultraviolet light, then collected as swabs or cuttings and air-dried. Blood stains are screened by presumptive tests, phenolphthalein (Kastle–Meyer), leucomalachite green or the now-discarded benzidine (a carcinogen), which may give false positives with plant peroxidases and oxidants, so confirmation is essential by microchemical crystal tests: Takayama (haemochromogen) and Teichmann (haemin), or spectroscopy. Precipitin test determines human origin, and blood grouping helps link victim or assailant. Seminal stains are screened by ultraviolet fluorescence and the acid phosphatase test (presumptive), followed by Florence test (choline iodide crystals) and Barberio test (spermine picrate crystals), which are crystal tests of limited specificity; microscopy for spermatozoa (haematoxylin–eosin or Christmas-tree stain) is confirmatory; prostate-specific antigen (p30) detects semen even in azoospermic or vasectomised assailants; and STR/Y-STR DNA profiling identifies the assailant even when spermatozoa are absent. Samples are collected, sealed and sent to the forensic science laboratory with chain of custody, as required under Section 184 BNSS (formerly Section 164A CrPC). These tests establish sexual contact, identify the perpetrator through DNA, corroborate the victim’s account, and support medico-legal evidence collected during examination.

(c)(i) Hypertensive crisis

In a hypertensive emergency (severe hypertension with acute end-organ damage), parenteral drugs lower mean arterial pressure by no more than 25% in the first hour. Drugs include sodium nitroprusside (IV infusion; cyanide/thiocyanate toxicity), labetalol (IV bolus/infusion; bronchospasm, bradycardia), nicardipine (IV infusion; reflex tachycardia, flushing), esmolol (IV infusion; ultra-short acting, bradycardia), hydralazine (IM/IV; reflex tachycardia, headache), nitroglycerin (IV infusion; headache, tolerance), clevidipine (IV; reflex tachycardia, lipid load), fenoldopam (IV; reflex tachycardia, raised intraocular pressure), enalaprilat (IV; hypotension, renal impairment, contraindicated in pregnancy) and phentolamine (IV; for catecholamine crises such as phaeochromocytoma; tachycardia). In hypertensive urgency without organ damage, oral agents such as amlodipine, captopril or labetalol lower BP over 24–48 hours; sublingual immediate-release nifedipine is avoided because of precipitous falls in BP.

(c)(ii) HIV PEP

Post-exposure prophylaxis should start as early as possible, ideally within 2 hours and no later than 72 hours. The preferred regimen (NACO 2021, WHO) is tenofovir disoproxil fumarate 300 mg + lamivudine 300 mg (or emtricitabine 200 mg) + dolutegravir 50 mg, once daily for 28 days. Alternatives are raltegravir 400 mg twice daily in place of dolutegravir, or boosted protease inhibitors (atazanavir/ritonavir 300/100 mg once daily or lopinavir/ritonavir 400/100 mg twice daily); zidovudine can replace tenofovir if renal function is poor. For children, weight-based doses are used. A baseline HIV test is done (PEP is not given if the person is already positive), along with hepatitis B and C serology and renal function, and follow-up HIV testing at 6 weeks, 3 months and 6 months, with adherence counselling and safe-sex advice until then.