Bacterial Droplet Infections

2. Bacterial Droplet Infections By Prof. Dr . Nadia Montasser Prof. Of Public Health & Preventive Medicine Mansoura Faculty Of Medicine

3. LEARNING OBJECTIVES • Identify the infectious cycle for each of the selected diseases • Define methods of prevention and control for each of these diseases • Identify routine, recommended, and potential vaccines • Describe the MOHP programs for prevention and control of selected diseases (e.g., tuberculosis) • Make a decision about the appropriate control measures related to specific situations

4. RATIONAL • Egypt is still suffering from a toll of bacterial droplet communicable diseases. Some are sporadic, but many are endemic or potentially epidemic. The physician working in the PHC presents the first line for prevention and control of such diseases on the individual, family, and community levels.

5. MEMNINGOCOCCAL MENINGITIS (CEREBROSPINAL FEVER)

6. Definitions • It is endemic acute bacterial • disease of the meningeal • membranes.

7. Public health significance and occurrence: • Worldwide distribution. • Epidemics occur irregularly (secular trend every 10 years), sporadic cases occur all over the year. • Up to 5-10% of population in endemic countries may be asymptomatic nasopharyngeal carriers.

8. Causative agent: • Neisseriameningitidis (the meningococcus :, a Gram-negative aerobic diplococcus, is the causative agent of meningococcal meningitis) • Various serogroups have been recognized including groups A, B, C, W135, X, Y and Z. • Group A; which is responsible for epidemics. • Group B and C; are responsible for sporadic cases, endemicity and sometimes outbreaks. • More recently W135 previously endemic but now emerging in epidemic forms.

9. Neisseriameningitidis A Gram-negative aerobic diplococcus, is the causative agent of meningococcal meningitis. There are 13 serotypes of N. meningitidis although only five serotypes, A, B, C, Y and W135, are clinically important. Serotypes A, B and C are the most common causes of illness worldwide, with serotypes B and C predominant in Europe, and A and C predominant throughout Africa and Asia. In recent years increasing emergence of serotype W135 in Africa and the Middle East has caused concern.

11. Global Epidemiology • Meningococcal disease occurs sporadically in small clusters all over the world with seasonal variations • N. meningitidis serogroups B and C are the most common cause of disease in Europe, the Americas, Australia, and New Zealand and tend to occur more frequently in winter and spring;

12. Epidemiolog:...........cont • The highest burden of meningococcal disease in the world occurs in the ‘African meningitis belt’, which extends across the dry, savannah parts of sub-Saharan Africa from Senegal in the west, to Ethiopia in the east. • Serogroup A is the main cause of disease in Africa and Asia.

15. Epidemiology …………….cont • During epidemics this region has a disease incidence rate of 10 percent of the population. • In 2002, countries further south of the Belt in the Great Lakes region, such as Tanzania, Rwanda, Burundi and the Democratic Republic of Congo reported over 2200 cases of meningococcal disease, including 200 deaths • Small villages and refugee camps were most affected

16. Epidemiology :……………cont. • The largest recorded outbreak of meningococcal disease in history occurred in Africa in 1996 where 250,000 cases including 25,000 deaths were reported to the WHO. • Between that crisis and 2002, 223,000 cases were reported, mainly from Burkina Faso, Chad, Ethiopia, and Niger.

18. Causative agent • Serogroup A was responsible for two pandemics in Asia throughout the 1960s, 70s and 80s. • It spread from China in the early 1980s to Nepal and India, and in 1987 serogroup A was responsible for an outbreak involving 2000 pilgrims to the Hajj in Mecca, Saudi Arabia.

19. Causative agent • The serogroups most commonly associated with the African meningitis belt are A and C . • however, serogroup W135 emerged in Burkina Faso in 2002 and has been isolated (along with A) from cases in 2002 and 2003 .

20. Season • Epidemics in the ‘meningitis belt’ countries occur in cycles . • Most epidemics occur during the winter-spring period in temperate areas and during the dry season in tropical areas. • The dry season in west Africa is usually between November and May/June, although it may vary from year to year; in east Africa the seasons are variable.

21. Reservoir: • Human, in the form of cases and carriers. • Cases :represent very minor role in transmission of infection. • Carriers:The most important source of infection in the endemic areas, they represent 5-10% of the normal population, having organisms in their nasopharynx during the inter-epidemic period. • When the carrier rate increase, it means threatened epidemics and during epidemics the carrier rate may increase to be to 70-80% of population.

22. Carrier rates • Carrier rates of meningococci can be increased to as high as 80% in situations of overcrowding such as during the Hajj. • Subsequent outbreaks occurred among pilgrims on return to their home countries. • This led to the introduction of a bivalent polysaccharide vaccine (against A and C serogroups) as an entry requirement for the Hajj and Umrah.

23. Mode of transmission: • Direct transmission: ( main mode) • Direct droplet, in case of direct contact with carriers or cases . • Indirect transmission: (minor role) • Vehicle-borne:contaminated articles act asvehicles • Rarely air born through droplet nuclei and dust.

24. Incubation period: • The incubation period is commonly three to four days, but can vary from two to seven days.

25. Susceptibility and resistance • Age:Occurs usually in children and young adults, during epidemics it may affect any age • Sex:More in males than females. • Immunity: • There is no maternal immunity. • Susceptibility to the clinical disease is low and decrease with age. • Presence of high ratio of carriers leads to repeated subclinical infection, with moderate or high level of immunity. • Patients deficient in certain complement components in the blood are prone to recurrent meningococcal infections. • Vaccination gives high level of immunity for the included strain in the vaccine for 3 years.

26. Environmental factors: • The greatest incidence occurs in winter and spring. Epidemics in adults commonly occur in confined communities under overcrowded living condition such as military camps, and institutes. • The risk in household contacts is 500 to 800 times higher than in the general population. • Epidemics usually having a secular trend every 10 years.

27. Clinical features: • The disease manifestation may be : • Clinical features of meningococcal infection include an acute onset of meningitis or septicaemia. • Typical features of meningitis include fever, intense headache, nausea, vomiting and neck stiffness. There may be a petechial or purpuric rash on the trunk and limbs that may sometimes cover large areas of the body. • In fulminating cases there is sudden prostration and shock associated with the characteristic rash and this condition has a high fatality rate. • Chronic meningococcal septicaemia : febrile episodes, skin rashes and fleeting joint pains.

33. Laboratory investigations: 1.Leucocytic count: marked polymorphnuclear (PMN ) leucocytosis (25.000- 50.000/cc ). 2. Blood: Meningococci may be cultured from blood in the 1 st 24 hours before the onset of meningitis. 3. C.S.F.: -Color: turbid. -Under tension. -Protein contents - clots on standing. -Glucose content. -Chloride content. -Presence of meningococci ( interacellular diplococci) in 90 -100% of cases.

34. Differential diagnosis • Other forms of acute meningitis: • 1. bacterial or septic meningitis • 2. Serous or aseptic meningitis • 3. Tuberculous meningitis • 4. Syphilitic meningitis • 5. Meningitic types of plague • 6. Acute lymphocytic chorimeningitis

35. Differential diagnosis…..cont • B.Toxemic diseases with cerebral symptoms as : • 1. Measles • 2.Influenza • 3.Pneumonia • 4. Malignant smallpox • 5. Typhoid fever • 6. Rheumatic fever • C.Meningism: • - Definition: meningeal irritation in acute infections as pneumonia due to increased warer content of the C.S.F as an attempt to dilute the toxins.

36. Complications: • A. Nervovus: 1. Hydrocephalus 2. Psychic disturbances 3. Hemiplegia 4. Flaccid paralysis • B. Eye: 1. Conjunctivitis 2. Keratitis 3. Iridocyclitis 4. Optic neuritis 5. Ocular nerve paresis 6. Blindness • C. Cardio –Respiratory : 1. Pneumonia &broncho-pneumonia 2. Myocarditis.

37. Fatality • With early diagnosis and treatment the case fatality rate varies between 5-15%. • Inpoorly treated cases the fatality may reach up to 50% . • In cases with septesemia fatality may be higher up to 80% .

38. Standard case definition A) Suspected case: Sudden onset of fever(>38.5°C) and one or more of the following: • Stiff neck • Altered consciousness • Other meningeal signs or petechial rash) N.B. Below I year suspect meningitis if there is fever and bulging fontanel) B) Confirmed Case: A suspected case with positive culture of CSF.

39. Prevention : • General Prevention : General Preventive measures for droplet infections . • Sanitary environment good ventilation and prevention of overcrowdings especially in work places, dormitories and hospitals. • Education of the public to reduce direct contact and exposure to droplet infection.

40. Specific prevention • Active immunization • Quadrivalent vaccinecontaining group A, C, Y and W 135: • Nature: capsular polysaccharides. • Dose: 0.5 ml S.C injection • Indications: • It is given to adult and older children, military troops and camps. • In Egypt it is given to school children at the age of 6 years and 9 years.

41. Vaccine containing group A: • for children 3 months - 2 years, 2 doses 0.5 ml S.C injection 3 months a parts (instead of one doses). • Vaccine containing group A and C: it is given to adult and old children. It is used in community control of group C disease in adult however group c is poor immunogenic and ineffective in children under 2 years. • Vaccination of meningitis does not include group B because its capsular polysaccharide is poorly immunogenic.

42. Vaccination Application • The quadrivalent (A, C, W135, Y) vaccine was recommended for pilgrims for the Hajj in 2001 but uptake was not 100%, and cases of W135 associated with the Hajj occurred again in 2001 • Therefore quadrivalent vaccine was made an entry requirement for all pilgrims to the Hajj and Umrah from 2002 and is now the only meningococcal vaccine available for travellers

43. Indications &Contraindications: Indications : • Mass vaccination of all children is not practical. • It is given only to the high risk groups to prevent epidemics and outbreaks as pilgrims, school children, military groups and groups with high carrier rate. • N.B., no vaccination for infants below 2 years. • Contraindications: • Pregnancy. • Hypersensitivity to the vaccine.

44. Chemoprophylaxis: • Rifampicin: 600mg every 12hours for 2 days. Children half the dose. • Ciftriaxone: 250mg IM given in a single dose • Ciprofloxacin: 500 orally once for adult.

45. Control: • Case • Early case finding • Notification to local health office • Isolation at fever hospital. • Treatment : • Concurrent disinfection for all articles in contact with patients discharges. • Release after 24 hours from starting treatment

46. Treatment : • Immediate Chemotherapy: • Treatment should be started immediately on clinical diagnosis and even before isolation of the organisms. • Penicillin is given parenterally in adequate dose it is the drug of choice. • Ampicillin and chloramphinicol are also effective. • Treatment should continue until after 5 days of termination of fever and CSF picture becomes normal.

47. Contacts • Enlistment age, sex, vaccination history. • Surveillance for early signs to start treatment without delay. • Contact should be given chemoprophylaxis .

48. Epidemic measures • When outbreak occurs careful surveillance should be done; early diagnosis and immediate treatment of suspected case. • Good ventilation and prevention of overcrowding congested living conditions • In case of epidemic mass chemoprophylaxis of small closed communities with rifampicin are given to reduce the carrier state and to limit spread of infection. • Using rifampicin in mass chemoprophylaxis may be associated with appearance or resistant strains, so it is recommend to be given only to close contacts .

49. Thank you