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FM13.20 | Drug Abuse, Mushroom & Food Poisoning — SDL Guide (Part 2)

Food Poisoning: Organisms, Mechanisms and Investigation

Food poisoning is defined as acute illness caused by consumption of food or drink contaminated with pathogenic organisms or their toxins. Mass food poisoning — particularly at community gatherings, school midday meals, and hospital canteens — is a frequent cause of medicolegal investigation, public health notification, and civil litigation in India.

Classification by mechanism and onset time:

SHORT INCUBATION (1–6 h) — pre-formed toxin in food:
- Staphylococcus aureus (1–6 h): toxin-mediated vomiting (emetic toxin — heat-stable). No fever. Source: contaminated dairy, sweets, cooked foods left at room temperature. Diagnosis: isolate Staph from food remnant.
- Bacillus cereus emetic type (1–6 h): same pattern as Staph; fried rice syndrome. Short onset, profuse vomiting, no fever.

INTERMEDIATE INCUBATION (6–24 h):
- Clostridium perfringens (8–24 h): large-volume watery diarrhoea, cramps, NO vomiting; enterotoxin. Source: improperly reheated meat.
- Bacillus cereus diarrhoeal type (6–15 h): watery diarrhoea; heat-labile enterotoxin; often vegetables/meat dishes.

LONG INCUBATION (>24 h) — invasive pathogens:
- Salmonella (12–72 h): fever + diarrhoea ± vomiting; systemic bacteraemia risk; Source: eggs, poultry.
- Vibrio cholerae (12–72 h): rice-water diarrhoea; massive fluid loss; dehydration is the cause of death.

BOTULISM (special case — neurological):
- Clostridium botulinum: pre-formed neurotoxin (or in-situ production in wounds/intestine). Toxin blocks ACh release at pre-synaptic NMJ AND autonomic junctions → descending flaccid paralysis (cranial nerve palsies first — diplopia, dysarthria, dysphagia) + autonomic dysfunction (dry mouth, constipation, urinary retention). Source: home-canned/preserved foods (anaerobic conditions allow C. botulinum growth). Treatment: antitoxin (trivalent A/B/E botulinum antitoxin); supportive ventilation.

Mass food poisoning investigation — forensic medicine role:

When a mass food poisoning outbreak occurs, the forensic medicine specialist participates in:
1. Clinical diagnosis and triage of victims
2. Collection of food samples, clinical specimens (stool, blood, vomitus) for microbiological and toxicological analysis
3. Estimation of the common food vehicle (attack rate analysis — epidemiological investigation)
4. Preparing reports for public health authorities (mandatory notification under the Epidemic Diseases Act)
5. Medicolegal opinion on whether negligence by the food preparer/vendor caused harm

Legal framework — food safety and food poisoning:
- Food Safety and Standards Act (FSSA) 2006: the central statute governing food safety in India; Food Safety and Standards Authority of India (FSSAI) is the regulatory body
- Prevention of Food Adulteration Act 1954: now largely replaced by FSSA 2006 but may still be cited in old cases
- IPC §272 (adulteration of food or drink), §273 (sale of noxious food or drink): criminal provisions for deliberate adulteration
- Consumer Protection Act 2019: civil claims for food poisoning negligence
- Epidemic Diseases Act 1897: may be invoked for large-scale outbreaks

Clinical Examination and Medicolegal Documentation

Drug abuse cases — examination and documentation:

For a living patient suspected of drug abuse or drug-facilitated assault:
- Detailed toxidrome identification (sympathomimetic/serotonergic vs cholinergic vs sedative-hypnotic vs hallucinogenic)
- Urine drug screen (immediately on presentation — many drugs have short detection windows, especially GHB which is undetectable in urine within 12 hours)
- Blood for quantitative drug levels (if toxidrome suggests specific agent)
- Document consent, chain of custody for all specimens
- For drug-facilitated assault: preserve urine/blood in sealed tubes with 4-fold witnessed labels before sending to forensic laboratory

For post-mortem drug-related death:
- Routine toxicological screen (blood + urine + vitreous + liver) for all unexplained deaths in persons aged 15–45
- Hair analysis for chronic use timeline reconstruction (drug deposited in growing hair — 1 cm/month of growth = 1 month's history)

Mushroom and food poisoning cases — documentation:

In a mass-poisoning event:
- Detailed attack-rate record (who ate what, who got sick — epidemiological table)
- Food samples (from the implicated dish, preserved at 4°C or frozen)
- Clinical specimens: stool (for organism culture), blood (for bacteraemia), vomitus
- Time of symptom onset relative to meal time (helps identify toxin type by incubation period)
- Photographs of the implicated food and its preparation site
- Witness statements

All specimens must be collected with documented chain of custody if criminal proceedings are anticipated (intentional food adulteration, negligent mass food poisoning).

Treatment summary for drug abuse:

Toxidrome	Treatment
Sympathomimetic (cocaine, amphetamine)	Benzodiazepines; cool; IV fluids; avoid beta-blockers (unopposed alpha in cocaine → worse hypertension)
Serotonin syndrome (MDMA)	Cyproheptadine (5-HT2A antagonist); benzodiazepines; active cooling; avoid paracetamol (high temp + paracetamol → hepatotoxicity)
Cannabis acute psychosis	Benzodiazepines; haloperidol if severe
Solvent inhalation	Avoid adrenaline (sensitised myocardium → VF); supportive
Botulism	Antitoxin; ventilatory support

Drug-Facilitated Assault Specimen Collection Flowchart