**3. Temporal and spatialdynamics of meningococcal infection in Ukraine**

#### **3.1. Place and time of meningococcal infection and other purulent meningitis**

Purulent bacterial meningitis (PBM) is a group of diseases of multi-bacterial etiology that determines the nature of the treatment, laboratory diagnostic approach and epidemiological characteristics for control and prevention. Indeed, PBM transmission and clinical presentation are fully dependent on the etiologic agent and concurrent risk factor. PBM etiology will ensure a successful causal treatment and important information regarding the whole nosology of the meningitis and epidemiology pattern. Bacteriological etiological diagnosis of PBM has been carried out for 24 years (1992–2015) in Ukraine (Ukrainian Centre for Disease Control and monitoring of the Ministry of Health): 37,843 cases were registered as PBM, among them, 18,878 were of purulent meningitis of meningococcal origin and other IMD. The ratio of meningococcal meningitis to non-meningococcal meningitis was about more or less of 1:1 (i.e., 49.89 to 50.11%) (**Figure 1**).

**Figure 1.** Incidence dynamics of different etiological forms of bacterial meningitis (Ukraine, 1992–2015). Legend: Abscissa = time (year); Ordinate = case of bacterial meningitis per 100,000 people; Empty diamond = Meningococcal Disease (MD); Empty square = Other Meningitis (caused by *Staphylococcus aureus, Streptococcus* groups A and B, *Klebsiella pneumoniae, Escherichia coli, Listeria monocytogenes* and PBM of unknown etiology); Empty circle = PBM pneumococcus (Purulent Bacterial Meningitis caused by *Streptococcus pneumonia*); Cross = Haemophilus influenzae type b (Hib).

The use of microbiological monitoring of PBM in Ukraine allowed to determine the etiological origin of 37,843 cases from 1992 to 2012. The basic etiological agents PBM included: Meningococci (49.89%); Pneumococci (6.34%); Staphylococci, Streptococci and others (*Escherichia* spp., *Listeria* spp., etc.) (17.30%); Hib-infection (0.71%), and pathogens of unknown etiology (25.77%). Among the 21,359 registered cases of MI, 9986 cases (46.75%) were confirmed to be of bacteriological origin. Bacteriological confirmation of MI ranges from 33.71% in 1993 to 55.95% 9 years after (2002) (**Figure 2**).

pneumococcal disease. As of 2013, an estimated of 68.9% of Ukrainians lives in urban areas

Since 2007, there is a Central Reference Laboratory for invasive bacterial diseases (IBD) characterizing and supervising the dynamic of IBD pathogens in order to forecast and reduce (preventive measures) the incidence of IBD. The State institution "Ukrainian Centre for Disease Control and monitoring of the Ministry of Health of Ukraine" is a reference as part of the IBD-laboratory WHO and UNICEF networks. A sentinel surveillance system included all patients younger than 5 years clinically suspected of meningitis and hospitalized as hospital

**3. Temporal and spatialdynamics of meningococcal infection in Ukraine**

Purulent bacterial meningitis (PBM) is a group of diseases of multi-bacterial etiology that determines the nature of the treatment, laboratory diagnostic approach and epidemiological characteristics for control and prevention. Indeed, PBM transmission and clinical presentation are fully dependent on the etiologic agent and concurrent risk factor. PBM etiology will ensure a successful causal treatment and important information regarding the whole nosology of the meningitis and epidemiology pattern. Bacteriological etiological diagnosis of PBM has been carried out for 24 years (1992–2015) in Ukraine (Ukrainian Centre for Disease Control and monitoring of the Ministry of Health): 37,843 cases were registered as PBM, among them, 18,878 were of purulent meningitis of meningococcal origin and other IMD. The ratio of meningococcal meningitis to non-meningococcal meningitis was about more or less of 1:1 (i.e., 49.89 to 50.11%) (**Figure 1**).

**Figure 1.** Incidence dynamics of different etiological forms of bacterial meningitis (Ukraine, 1992–2015). Legend: Abscissa = time (year); Ordinate = case of bacterial meningitis per 100,000 people; Empty diamond = Meningococcal Disease (MD); Empty square = Other Meningitis (caused by *Staphylococcus aureus, Streptococcus* groups A and B, *Klebsiella pneumoniae, Escherichia coli, Listeria monocytogenes* and PBM of unknown etiology); Empty circle = PBM pneumococcus (Purulent Bacterial Meningitis caused by *Streptococcus pneumonia*); Cross = Haemophilus influenzae type b (Hib).

in-patient of either the department of infectious disease or intensive care unit.

**3.1. Place and time of meningococcal infection and other purulent meningitis**

including the 68.2% of the population over 45 years old [8].

8 Meningoencephalitis - Disease Which Requires Optimal Approach in Emergency Manner

Meningococcal infection predominated among all bacterial meningitis during the whole period of observation. However, half of all non-meningococcal meningitis as well as IMD did not have bacteriological confirmation the bacteriological tests were done almost in all patients but were not positive for half of all meningococcal meningitis. Thus, the total sensitivity of bacteriological tests was inadequate (nearly 50%).
