The pathogen that cause smallpox is

Analyze the question: It asks which type of pathogen causes smallpox. The key is to link the disease name to its virus family.

Explain the concept: Smallpox is a viral disease. Viruses are classified into families, and many families are named after the diseases they cause or their features:

• Poxviridae (poxvirus): smallpox (variola), cowpox, monkeypox
• Picornaviridae (picornavirus): polio, common cold (rhinovirus), foot-and-mouth disease
• Paramyxoviridae (paramyxovirus): measles, mumps
• Herpesviridae (herpesvirus): chickenpox (varicella-zoster), cold sores, shingles

(Option B, "peramyxovirus", appears to be a misspelling of paramyxovirus.)

Step-by-step solution:

1. Smallpox is caused by the variola virus.
2. The variola virus belongs to the genus Orthopoxvirus in the family Poxviridae.
3. So the pathogen is a poxvirus.
4. Check the other options: • Picornavirus causes polio and colds, not smallpox. • Paramyxovirus causes measles and mumps. • Herpesvirus causes chickenpox, which is often confused with smallpox because of the similar name. They are different diseases with different viruses.

Answer: The correct option is D. poxvirus.

Exam tip: Match the name to the family: smallpox goes with poxvirus. Be careful not to confuse it with chickenpox, which is caused by a herpesvirus. Smallpox was declared eradicated by the WHO in 1980, which is a common fact in JAMB questions.