93  Insecticide Poisoning

93.1 Introduction

Insecticide poisoning remains a significant cause of childhood morbidity and mortality across many low- and middle-income countries. In Ghana and much of sub-Saharan Africa, the high burden of vector-borne diseases such as malaria, combined with widespread agricultural activity, has led to heavy reliance on insecticides in both domestic and farming environments. While these chemicals are essential for public health and crop protection, they pose substantial risks to children, who are naturally curious, physiologically vulnerable, and often exposed in poorly regulated environments.

Children may encounter insecticides through ingestion, inhalation, dermal absorption, or accidental spills in the household. Toddlers exploring their surroundings are particularly at risk, especially in homes where insecticides are stored in accessible places or transferred into beverage bottles. In agricultural regions, children may also be exposed indirectly through contaminated clothing or via residues carried into the home.

This chapter provides a comprehensive overview of insecticide poisoning in children, focusing on the insecticide types commonly used in Ghana, their mechanisms of toxicity, clinical features, and evidence-based management strategies adapted to resource-limited settings. The article-style narrative offers context relevant to paediatricians, residents, emergency clinicians, and general practitioners working in Ghana and similar environments.

93.2 Overview of Insecticide Use in Ghana and West Africa

Insecticides are deeply embedded in everyday life in Ghana. Urban households frequently use pyrethroid-based sprays, mosquito coils, and treated nets for mosquito control. Rural communities rely heavily on organophosphate pesticides (e.g., chlorpyrifos, diazinon) to protect crops such as cocoa, vegetables, and grains. Despite government regulations, many potent agricultural insecticides remain readily accessible in shops, markets, and roadside stalls.

Challenges contributing to paediatric exposure include:

• Improper storage: Chemicals kept within children’s reach or stored in food containers.
• Limited public awareness: Many caregivers underestimate the toxicity of insecticides.
• Poor ventilation: Spraying insecticides in closed rooms where children remain present.
• Agricultural exposures: Families living on or near farms may carry residues indoors.
• Weak regulatory enforcement: Persistent availability of highly hazardous pesticides.

In Ghanaian tertiary hospitals, insecticides consistently appear among the leading agents implicated in paediatric poisoning cases. Mortality remains highest with organophosphate poisoning, particularly in late presenters and settings with limited intensive care facilities.

93.3 Classification of Insecticides Relevant to Childhood Poisoning

A broad range of insecticides are implicated in paediatric exposures. The major classes encountered in Ghana and West Africa include:

93.3.1 Organophosphates (OPs)

Examples: Chlorpyrifos, diazinon, malathion.
Commonly used in agriculture and occasionally for home pest control.

93.3.2 Carbamates

Examples: Carbaryl, carbofuran.
Similar mechanism to organophosphates but reversible enzyme inhibition.

93.3.3 Pyrethroids

Examples: Permethrin, deltamethrin, cypermethrin.
Common in household sprays, mosquito coils, and treated nets.

93.3.4 Organochlorines

Examples: Lindane, endosulfan (now restricted but still encountered informally).
Persistent pollutants with potent CNS effects.

93.3.5 Miscellaneous household insecticides

Including repellents (DEET), ant poisons, and mixed formulations containing solvents or hydrocarbons.

Each class produces toxicity through distinct mechanisms, leading to characteristic clinical Syndromes.

93.4 Mechanisms of Toxicity

93.4.1 Organophosphates

OPs irreversibly inhibit acetylcholinesterase (AChE), resulting in excessive acetylcholine at synapses. Toxicity manifests through:

• Muscarinic effects: Bronchorrhoea, salivation, diarrhoea, vomiting, urination, bronchospasm.
• Nicotinic effects: Muscle fasciculations, weakness, tachycardia or bradycardia.
• CNS effects: Seizures, confusion, coma, respiratory failure.

93.4.2 Carbamates

Carbamates inhibit AChE reversibly, often resulting in shorter and less severe toxicity than OPs. However, in children, presentations may still be severe.

93.4.3 Pyrethroids

Pyrethroids prolong the opening of sodium channels, leading to neuronal hyperexcitability. Toxic effects include:

• Paraesthesias
• Tremors
• Irritability
• Hypersalivation
• Seizures (especially in infants)
• Respiratory irritation from aerosol inhalation

93.4.4 Organochlorines

These agents disrupt GABA-mediated inhibitory neurotransmission, leading to:

• Tremors
• Hyperreflexia
• Seizures
• Status epilepticus

Because organochlorines persist in the environment and accumulate in fat, toxicity may be prolonged.

93.5 Clinical Presentation

The clinical presentation depends on the agent, route of exposure, and child’s age. Common features include:

93.5.1 Ingestion

• Vomiting
• Drooling
• Diarrhoea
• Abdominal pain
• Altered consciousness

93.5.2 Inhalation

• Coughing
• Wheezing
• Respiratory distress
• Headache or dizziness

93.5.3 Dermal exposure

• Erythema
• Tingling or burning sensation
• Absorption leading to systemic symptoms (especially with organophosphates)

93.5.4 Organophosphate and Carbamate Poisoning: Cholinergic Syndrome

The hallmark of OP and carbamate poisoning is the cholinergic toxidrome, summarised by:

DUMBBELSS

• Diarrhoea
  
• Urination
  
• Miosis
  
• Bronchorrhoea
  
• Bradycardia
  
• Emesis
  
• Lacrimation
  
• Salivation
  
• Sweating

Respiratory failure results from bronchorrhoea, bronchospasm, fatigue, and CNS depression.

93.5.5 Pyrethroid Poisoning

Usually mild. Symptoms include:

• Paresthesias
• Headache
• Nausea
• Irritability
• Seizures at high doses
• Respiratory symptoms from aerosol inhalation

93.5.6 Organochlorine Poisoning

Predominantly neurological:

• Tremors
• Agitation
• Seizures (often recurrent)
• Potential arrhythmias

93.6 Evaluation and Investigations

Diagnosis is primarily clinical, especially in Ghana where laboratory confirmation may not be available.

Key investigations include:

• Blood glucose (hypoglycaemia is common)
• Electrolytes, urea, creatinine
• Full blood count
• Arterial or venous blood gas
• Chest X-ray if aspiration is suspected
• ECG to detect arrhythmias
• Serum cholinesterase levels, if available (confirmatory for OP poisoning)

Assess the airway, breathing, circulation, level of consciousness, and seizure activity on arrival.

93.7 Management

Management of insecticide poisoning in children focuses on stabilisation, decontamination, antidote administration (where applicable), and supportive care.

93.7.1 Stabilisation

• Airway: Suction secretions, position airway, intubate if GCS < 8 or severe respiratory distress.
• Breathing: Give high-flow oxygen; ventilatory support if necessary.
• Circulation: IV access, fluids for hypotension.
• Disability: Control seizures with benzodiazepines.
• Exposure: Remove contaminated clothing and wash skin thoroughly.

93.7.2 Decontamination

• Remove and bag contaminated clothing.
• Wash affected skin with soap and water.
• Activated charcoal may be used if ingestion occurred within 1 hour and airway reflexes are intact.

93.7.3 Antidotes for Organophosphate and Carbamate Poisoning

93.7.3.1 Atropine

Atropine is the cornerstone of treatment. The goal is to improve breathing and dry airway secretions.

• Initial dose: 0.02 mg/kg IV
  
• Double the dose every 3–5 minutes until atropinisation (drying of secretions, improved air entry).
• Continue with an infusion to maintain effect.

93.7.3.2 Pralidoxime (2-PAM)

Used in organophosphate poisoning to reactivate AChE before “aging” occurs.

• Dose: 20–50 mg/kg IV over 30 minutes
  
• Followed by continuous infusion if necessary
  
• Availability is inconsistent in Ghana; early use improves outcomes.

93.7.4 Management of Pyrethroid Poisoning

• Supportive care only
• Treat seizures with benzodiazepines
• Bronchodilators for wheezing
• Decontamination for dermal exposure

93.7.5 Management of Organochlorine Poisoning

• Aggressive seizure control
• Avoid phenytoin (may worsen dysrhythmias)
• Support ventilation
• Activated charcoal if early ingestion

93.8 Complications

Complications vary by insecticide type.

93.8.1 Organophosphate Poisoning

• Intermediate syndrome (1–4 days post-exposure): proximal muscle weakness, respiratory failure
• Delayed neuropathy (weeks later)
• Aspiration pneumonia
• ARDS
• Hypoxic brain injury

93.8.2 Pyrethroids

• Persistent paresthesias
• Rare seizures

93.8.3 Organochlorines

• Recurrent seizures
• Cardiac arrhythmias
• CNS depression

93.9 Prevention Strategies in Ghana

Prevention is the most impactful intervention. Strategies include:

• Educating caregivers about safe storage and handling
  
• Keeping chemicals in original containers
  
• Avoiding spraying insecticides in rooms where children are present
  
• Training farmers on proper use and protective equipment
  
• Strengthening regulatory enforcement of pesticide sales
  
• Establishing poison control centres
  
• Counselling adolescents on mental health and suicide prevention

93.10 Conclusion

Insecticide poisoning in children is both a medical emergency and a preventable public health issue in Ghana. The severity of toxicity varies widely across insecticide classes, with organophosphates remaining the most lethal. Early recognition, prompt resuscitation, and appropriate use of antidotes are key to improving outcomes. Paediatric clinicians must maintain a high index of suspicion, especially in agricultural regions. Ultimately, sustainable reduction in cases depends on improved public education, stronger regulation, and community-level safety practices.

93.11 Further Reading

1. World Health Organization. Clinical Management of Acute Pesticide Intoxication.
   
2. Nelson Textbook of Pediatrics. Chapter on Poisonings.
   
3. West African College of Physicians Paediatrics Residency Curriculum.
   
4. Ghana Poison Information and Management Guidelines (where available).
   
5. Roberts DM, Aaron CK. Management of acute organophosphate poisoning. BMJ.