Case Definitions for Important Notifiable Diseases

There are 45 notifiable diseases of public health importance in Nigeria. There are many other diseases, events and conditions too that are considered of public health importance however. Below are some of the common ones that community informants and other health workers can use in doing their work.


Suspected case: Any individual presenting with one or more of the following: malaise, fever, headache, sore throat, cough, nausea, vomiting, diarrhoea, myalgia, chest pain, hearing loss and either a. History of contact with excreta or urine of rodents b. History of contact with a probable or confirmed Lassa fever case within a period of 21 days of onset of symptoms OR Any person with inexplicable bleeding/haemorrhage.


Suspected case: Any person with fever and maculopapular (non-vesicular) generalised rash and cough, coryza or conjunctivitis (red eyes) or any person in whom a clinician suspects measles.

Meningococcal Meningitis

Suspected case: Any person with sudden onset of fever (>38.5ºC rectal or 38.0ºC axillary) and one of the following signs: neck stiffness, altered consciousness or other meningeal signs.


Suspected case: An acute illness with fever > 38.3 C ( 101 F), intense headache, lymphadenopathy, back pain, myalgia, and intense asthenia followed one to three days later by a progressively developing rash often beginning on the face (most dense) and then spreading elsewhere on the body, including soles of feet and palms of hand.

Neonatal Tetanus

Any newborn with a normal ability to suck and cry during the first two days of life, and who, between the 3rd and 28th day of age, cannot suck normally, and becomes stiff or has spasms (jerking of the muscles) or both.

Or any neonatal death between 3 and 28 days of age in which the cause of death is unknown.


Suspected Case: Any person with illness of the upper respiratory tract with following: pharyngitis, nasopharyngitis, tonsillitis or laryngitis.

Polio (AFP)

Suspected case: Any child under 15 years of age with acute flaccid paralysis or any person with paralytic illness at any age in whom the clinician suspects poliomyelitis.


Suspected case: Any person with a cough of 3 weeks or more.

Yellow Fever

Suspected case: Any person with acute onset of fever, with jaundice appearing within 14 days of onset of the first symptoms.


Suspected case of COVID-19: A suspect case is defined as any person (including severely ill patients) presenting with fever, cough or difficulty in breathing AND who within 14 days before the onset of illness had any of the following exposures:

  • History of travel to any country with confirmed and ongoing community transmission of SARS-CoV-2
  • Close contact with a confirmed case of COVID-19
  • Exposure to a healthcare facility where COVID-19 case(s) have been reported.


A medical incident that takes place after immunisation, causes concern and is believed to be caused by the immunisation.


Suspected case: Any person with acute onset characterised by several clinical forms which are:

(a) Cutaneous form: Any person with skin lesion evolving over 1 to 6 days from a popular through a vesicular stage, to a depressed black eschar invariably accompanied by oedema that may be mild to extensive.

(b) Gastro-intestinal: Any person with abdominal distress characterised by nausea, vomiting, anorexia and followed by fever

(c) Pulmonary (inhalation): any person with brief prodrome resembling acute viral respiratory illness, followed by rapid onset of hypoxia, dyspnoea and high temperature, with X-ray evidence of mediastinal widening

(d) Meningeal: Any person with acute onset of high fever possibly with convulsions, loss of consciousness, meningeal signs and symptoms; commonly noted in all systemic infections, but may present without any other clinical symptoms of anthrax.


Suspected cholera case: In areas where a cholera outbreak has not been declared: Any patient aged two years and older presenting with acute watery diarrhoea and severe dehydration or dying from acute watery diarrhoea.

In areas where a cholera outbreak is declared: any person presenting with or dying from acute watery diarrhoea.

Dengue Fever

Suspected case: Any person with acute febrile illness of 2-7 days duration with 2 or more of the following: headache, retro-orbital pain, myalgia, arthralgia, rash, haemorrhagic manifestations, leucopenia.

Severe Pneumonia in Children Under 5 Years of Age

Clinical case definition (IMCI) for pneumonia: A child presenting with cough or difficult breathing and:

  • 50 or more breaths per minute for infant age 2 months up to 1 year
  • 40 or more breaths per minute for young child 1 year up to 5 years.

Note: A young infant age 0 up to 2 months with cough and fast breathing is classified in IMCI

as “serious bacterial infection” and is referred for further evaluation.

Clinical case definition (IMCI) for severe pneumonia: A child presenting with cough or difficult breathing and any general danger sign, or chest indrawing or stridor in a calm child. General danger signs for children 2 months to 5 years are: unable to drink or breast feed, vomits everything, convulsions, lethargy, or unconsciousness.

Acute Viral Hepatitis

Suspected case: Any person with discrete onset of an acute illness with signs/symptoms of; (i) Acute infectious illness (e.g. fever, malaise, fatigue) and (ii) Liver damage (e.g. anorexia, nausea, jaundice, dark coloured urine, right upper quadrant tenderness of body).


Suspected new case: Any person presenting with the following symptoms: Increasing thirst, Increased hunger, Frequent urination

Shigella (Bloody Diarrhoea)

Suspected case: A person with (abdominal pain) and diarrhoea with visible blood in stool.

Diarrhoea with Dehydration in Children Less than 5 Years of Age

Suspected case: Passage of 3 or more loose or watery stools in the past 24 hours with or without dehydration and:

Some dehydration – two or more of the following signs: restlessness, irritability; sunken eyes; thirsty; skin pinch goes back slowly, or

Severe dehydration – two or more of the following signs: lethargy or unconsciousness; sunken eyes; not able to drink or drinking poorly; skin pinch goes back very slowly.


Suspected case: A person presenting a skin lesion with itching or blister living in an endemic area or risk areas of Guinea worm, with the emergence of a worm.


Suspected case: Illness with onset of fever and no response to usual causes of fever in the area, and at least one of the following signs: bloody diarrhoea, bleeding from gums, bleeding into skin (purpura), bleeding into eyes and urine.

Crimean-Congo Haemorrhagic Fever

Suspected case of CCHF: Illness with sudden onset of fever, malaise, weakness, irritability, headache, severe pain in limbs and loins and marked anorexia. Early development of flush on face and chest and conjunctival infection, haemorrhagic enanthem of soft palate, uvula and pharynx, and often fine petechial rash spreading from the chest and abdomen to the rest of the body, sometimes with large purpuric areas.

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