| Generalities |
| Agents |
Several agents:
1) Bacteria:
- Neisseria meningitides (meningococcus): the serotypes responsible of invasive infection are A, B, C, W135, Y, X
- Haemophilus influenza: there are 6 serotypes from (a) to (f). The serotype (b) is responsible of invasive infection
- Streptococcus pneumonia (pneumococcus): there are more than 90 serotypes
- Other bacterial agents: listeria, staphylococcus, enteric bacteria, group B streptococci, tuberculosis …
2) Virus:
- Mumps
- Measles
- West Nile virus: a flavivirus
- Enterovirus: including Coxsackieviruses A (1-11, 14, 16-18, 22, 24), Coxsackieviruses B (1-6), Echoviruses (1-7, 9-23, 25, 27, 30-33), Enterovirus 71, Poliovirus (1-3)
- Herpes Simplex virus: with 2 types 1 and 2
- Varicella / Chicken-pox: Human (alpha) herpesvirus 3 (varicella-zoster) from the group Herpesvirus
- Adenovirus: Adenovirus, several types (1, 2, 3, 4, 5 and 7), genus Mastadenovirus, family Adenoviridae,
- Lymphocytic choriomeningitis: lymphocytic choriomeningitis virus (arenavirus)
- Sandfly fever viruses: genus phlebovirus, family Bunyaviridae. They include more than 60 antigenically distinct virus serotypes. Two main groups are identified: the sandfly fever group including the Naples serocomplex (Karimabad virus, Arabia virus, Massilia virus, Punique virus, Tehran virus, Toscana virus …) and Sicilian serocomplex; and the Uukuniemi group.
-Other virus: arboviruses…
3) Parasites and fungi:
- Leptospirosis: Spirochetes, Leptospira interrogans (25 serogroups)
- Other: Candida albicans, cryptococcal, syphilis … |
|
| Incubation |
The incubation varies with the agent.
| Agent |
Incubation |
| Bacteria |
|
| Neisseria meningitidis |
3-4 days (2-10 days) |
| Haemophilus influenza |
2-4 days |
| Streptococcus pneumoniae |
1-4 days |
| Listeria monocytogenes |
3-70 days (median of 3 weeks) |
| Virus |
|
| West Nile virus |
3-12 days |
| Enterovirus |
7-14 days (2-35 days) |
| Herpes |
2-12 days |
| Varicella / Chicken-pox |
2-3 weeks |
| Lymphocytic choriomeningitis virus |
8-13 days (15-21 days for meningitis) |
| Adenovirus |
1-10 days |
| Sandfly fever viruses |
3-4 days (up to 6 days) |
| Parasites and Mycoses |
|
| Leptospira |
2-30 days (10 days) |
|
| Period of communicability |
The period of communicability varies with the agent.
| Agent |
Period of communicability |
| Bacteria |
|
| Neisseria meningitidis |
From onset and up to 24 hours after starting antibiotherapy that has effective concentrations in nasopharynx. |
| Haemophilus influenza |
From onset and up to 24-48 hours of starting effective antibiotherapy. |
| Streptococcus pneumoniae |
As long as the bacteria is present in the upper respiratory tract. |
| Listeria monocytogenes |
- Mothers of infected newborns can shed the bacteria in vaginal discharges and urine 7-0 days after delivery
- Infected patients can shed the bacteria in stool for several months |
| Virus |
|
| West Nile virus |
No person-to-person transmission. |
| Enterovirus |
- Virus excreted in stools for several weeks
- Virus excreted in pharynx for the first 2 weeks post infection |
| Herpes |
2-7 weeks after skin lesions onset. |
| Varicella / Chicken-pox |
2 days before until the skin lesions are crusted (5 days). |
| Lymphocytic choriomeningitis virus |
No person to person transmission. |
| Adenovirus |
Shortly prior to and for the duration of the active disease |
| Sandfly fever viruses |
Virus present in blood of infected patients 1 day before and 1 day after onset of illness. |
| Parasites and Mycoses |
|
| Leptospira |
Excreted in urine for 1 month |
|
| Reservoir |
The reservoir varies with the agent.
| Agent |
Reservoir |
| Bacteria |
|
| Neisseria meningitidis |
Humans |
| Haemophilus influenza |
Humans |
| Streptococcus pneumoniae |
Humans, possible carriage. |
| Listeria monocytogenes |
Soil, forage, water, mud and silage. |
| Virus |
|
| West Nile virus |
Birds |
| Enterovirus |
Humans |
| Herpes |
Humans |
| Varicella / Chicken-pox |
Humans |
| Lymphocytic choriomeningitis virus |
House mouse (Mus musculus), hamster colonies. The mouse excretes the virus in saliva, feces and urine. |
| Adenovirus |
Humans |
| Sandfly fever viruses |
Humans, rodents. |
| Parasites and Mycoses |
|
| Leptospira |
Wild and domestic animals |
|
| Modes of transmission |
The modes of transmission vary with the agent.
| Agent |
Modes of transmission |
| Bacteria |
|
| Neisseria meningitidis |
Person to person transmission: direct contact with droplet, nasal and throat discharge |
| Haemophilus influenza |
Person to person transmission: direct contact with respiratory, nasal and throat discharge. |
| Streptococcus pneumoniae |
Person to person transmission: direct contact with respiratory discharge |
| Listeria monocytogenes |
- Food-borne: ingestion of raw or contaminated milk, soft cheese vegetables and ready-to-eat meats (Pate)
- Direct contact with infectious material
- Neonatal: from mother to fetus or from mother to newborn (through the infected birth canal)
- Nosocomial transmission in nursery: via contaminated equipment or material |
| Virus |
|
| West Nile virus |
Bite by infected mosquitoes (Culex sp, or Anophele sp) |
| Enterovirus |
- Person-to-person:
- Fecal-oral
- Contact with respiratory secretions
- Contact with conjunctival secretions
- Contaminated water / swimming pools
- Flies |
| Herpes |
- Person-to-person:
- Contact with saliva
- Sexual contact
- Soiled hands
- Neonatal (infected birth canal) |
| Varicella / Chicken-pox |
- Person-to-person:
- Contact with droplets
- Contact with vesicle fluid
- Indirect contact
- Airborne |
| Lymphocytic choriomeningitis virus |
- Airborne: contaminated dust
- Food-borne: ingestion of contaminated food
- Direct contact: skin contamination or cuts |
| Adenovirus |
- Person-to-person:
- Fecal-oral route
- Respiratory transmission
- Inoculation with conjunctival secretions
- Nosocomial
- Contaminated water and swimming pools |
| Sandfly fever viruses |
Bite of infective phlebotomine (Phlebotomus papatasi, P. perfiliewi , P. perniciosus, P. major sensu lato ) |
| Parasites and Mycoses |
|
| Leptospira |
- Contact with abraded skin or mucous membranes with soil, vegetation, contaminated with urine of infected animals or contaminated water
- Direct contact with urine or tissues of infected animals
- Ingestion of food or water contaminated with urine of infected animals |
|
| Clinical |
The symptoms vary with the agent.
| Agent |
Clinical picture |
| Bacteria |
|
| Neisseria meningitidis |
Meningitis, septicaemia |
| Haemophilus influenza |
Meningitis, epiglottitis, pneumonia … |
| Streptococcus pneumoniae |
Meningitis, pneumonia, septicaemia |
| Listeria monocytogenes |
|
| Virus |
|
| West Nile virus |
- Usually asymptomatic.
- Complication: meningitis and encephalitis |
| Enterovirus |
- Asymptomatic,
- Gastro-enteritis, flu-like illness, aseptic meningitis, paralysis |
| Herpes |
- Gingivostomatitis (type1), genital infection (type 2)
- Complications: meningoencephalitis
- Reactivation is possible |
| Varicella / Chicken-pox |
- Skin eruption: first maculo-papular then vesicular.
- Complications: pneumonia, hemorrhage, meningoencephalitis |
| Lymphocytic choriomeningitis virus |
- Influenza-like illness.
- Complications: meningitis, parotiditis, arthritis, myocarditis… |
| Adenovirus |
- Epidemic herato-conjunctivitis, gastro-enteritis, pharyngo-conjunctival fever, acute respiratory infection
- Complications: meningoencephalitis |
| Sandfly fever viruses |
- Usually self-limited disease: fever, myalgia, headache, photophobia …
- Complications: Aseptic meningitis and meningoencephalitis (Toscana), |
| Parasites and Mycoses |
|
| Leptospira |
Rash, hemolytic anemia, hemorrhage, hepato-renal failure, mental confusion, myocarditis… |
|
| Worldwide |
| Agent |
Profil |
| Bacteria |
|
| Neisseria meningitidis |
Endemic in the African meninigitis belt (from Senegal to Ethiopa) |
| Haemophilus influenza |
Worldwide under 5 years |
| Streptococcus pneumoniae |
Worldwide |
| Listeria monocytogenes |
Worldwide |
| Virus |
|
| West Nile virus |
Widespread in Africa, Middle East, North America, India.
|
| Enterovirus |
Worldwide |
| Herpes |
Worldwide |
| Varicella / Chicken-pox |
Worldwide |
| Lymphocytic choriomeningitis virus |
America, Europe. |
| Adenovirus |
Worldwide |
| Sandfly fever viruses |
In Mediterranean counties, Europe and Middle East |
| Parasites and Mycoses |
|
| Leptospirose |
Worldwide |
|
| Lebanon |
The annual average of reported cases of meningitis is 192.
Among them, meningitis due to Neisseria meningitis occurs with 6 (2-12) cases per year.
Among them, meningitis due to Haemophilus influenza occurs with 1 (0-2) cases per year.
Among them, meningitis due to Streptococcus pneumoniae occurs with 19 (16-21) cases per year.
|
| Control objective |
Control |
