THEME: EPIDEMIOLOGY DESCRIPTION OF GROUP OF INTESTINAL INFECTIONS AND GROUP OF RESPIRATORY INFECTIONS.

Department of infectious diseases with epidemiologyAssistant Mizyuk R.M.

EPIDEMIOLOGYLecture № 4

LECTURE PLAN• Actuality of the problem• General characteristics group of intestinal infections• Epidemiology of hepatitis A and E• Epidemiology of typhoid• Epidemiology of shigellosis• Epidemiology of salmonellosis• Epidemiology of botulism and poliomyelitis• General characteristics of respiratory infections• Epidemiology of diphtheria• Epidemiology of Influenza• Epidemiology of meningococcal disease• Epidemiology of measles• Conclusions

Actuality of themeProblem of morbidity of acute intestinal infections (AII)

takes on special urgency today. In the structure of infectious diseases AII occupy a leading position. According to WHO experts, annually in the world, recorded over 1 billion cases of diarrhea.

Scientists of our faculty have long engaged in the study of course of intestinal infections on the background of comorbidity. On this subject we have defended one doctor and several master’s dissertation. This particular professor Dykiy B.M., docents Nikiforova T.O., Pyuryk V.F., Hryzhak I.G., Kobryn T.Z., Boychuk O.P.

Diseases of the upper respiratory tract is also among the most common infectious diseases. Among the reasons for temporary disability they occupy the first place: even in the between epidemic period them has one sixth of the world population. WHO experts stress that it ARI occupy the leading position in the infectious diseases of man with a tendency toward continued growth.

The diseases with the faecal-oral mechanism of transmission belong to the group of intestinal infections.

TYPES OF INTESTINAL INFECTIONS

VIRAL INFECTIONS viral hepatitis A and E, enterovirus diseases,

poliomyelitis, rotavirus gastroenteritis

BACTERIAL INFECTIONS Typhoid fever,paratyphoids,

cholera,shigellosis (dysentery),

salmonellosis, yersiniosis,

esherihiosis, campylobacter infections

Epidemiological characteristics of viral hepatitis APathogen: Hepatitis A virus contains RNA, family

Pikornavirus (enterovirus 72), the size of virus 20-27 nm, one serotype, 7 genotypes. Replication - cytoplasm of hepatocytes.

Epidemiological characteristics of viral hepatitis AVirus is good survives in the environment:

- at 20 dg. C - 1 month - at 4 dg. C - some years - рН of a stomach from 3 up to 10 not influence a survival virus!!! - at рН is lower 3 - survives till 4 hours - at 60 dg. C - maintains 12 hours - desinfectants inactivate it for 15 minutes - resistance during

boiling - 5 minutes

GEOGRAPHIC DISTRIBUTION OF VIRAL HEPATITIS A

EPIDEMIOLOGY- antroponosis

The sourse - the patient with any form illnessesThe mechanism of transmission - fecal-oralThe factors of transmission: - personal contact to the patient or contaminated they by subjects (do not have seasonal prevalence!!!) - Contaminated nutrition and water Susceptibility general !!! Outbreaks in families, villages, in kindergartens, schools,

organized groups. The main risk group are children after 1 year of life .

Seasonality - Autumn and winter

FACTOR OF TRASMISSION :

Contaminated foodInfected waterObject of environment (tools, utensil, dishes)

Epidemiological characteristics of viral hepatitis E

Pathogen: Hepatitis E virus containing RNA, size 32-34 nm, 1 serotype, 3 genotypes.

Resistance during boiling - 3-5 minutes.Replication place - cytoplasm of hepatocytes.Virus is good survives at temperature (-) 20 dg.

C, but at temperature is higher 0 dg. C are fast inactivated. Are very sensitive to desinfection agents.

The disease is spread mainly in Asia, Africa and South America. Epidemics have an explosive character associated with water pollution during floods, rains.

EPIDEMIOLOGY- antroponosis

The preferred mechanism for transmission - fecal-oral, main transmission factor - water.

The main risk group - pregnant women, persons aged 18-20 years.• High lethality among the pregnant woman in

3rd trimester ( to 25 %) and children in neonatal period (Up to 77 %)

Chronic forms and carriers are not observed. The time of greatest infectivity - preicteric and

icteric periods.The virus is found in feces, blood in the acute

phase can detect IgM anti-HEV.

Antiepidemic measures

• Identify early (preicteric) period• Compulsory hospitalization of patients• Observation of contact persons for 35 days• Clinical convalescents 1-3 months.• The current epidemic foci conducted and the final disinfection• preseason immunoglobulin prophylaxis• Vaccination in epidemic foci (vaccine "HAVRIKS")

ETIOLOGY

The causative agent of typhoid fever - is Salmonella typhi from the family Enterobacteriacea, genus Salmonella, serogroup D, gram (-)

Salmonella typhi is not - spore-forming rod, has size 0.5 – 0.8 microns of width and 1.5 – 3 microns of lengh. Motile by them betray flagella

Salmonella typhi has 3 antigenes: - O- antigene (somatic, thermostable)

- Н-antigene (flagellar, thermolabile)

- Vi-antigene (somatic, thermolabile, is disposed more superficially, than O - antigine)

Salmonella typhi secrete only endotoxin at destroy of the bacterial cell. It is potent pyrogen (from it had received a medicinal preparation "Pyrogenalum") but enteropathogenic by operation has no

S. can longly be survived in an organism as filtered or L-

forms.

S. are survived by months in environment. S. not only are longly survived, but also are multiplied in

foodstuffs (milk, sour cream, cheese, jelly etc.) and not changing their gustatory qualities.

S. well endure low temperature, but at warming up to 60

dg.C destroy through 30 minutes and at boiling - instantly

S. are inactivated desinfectants in usual concentrations during 3 - 5 minutes.

Epidemiology: typhoid fever is anthroponosis

The source – sick person or the carrier which secrete of S . typhi with the feces and urine Path of transmission - fecal-oral

The factors of transmission: - contaminated water (more often) - contaminated foodstuffs - contact to the sick the person or subjects enclosing him

Age of the patients: - from 15 up to 45 years more often are sickSeasonal prevalence - in summer-autumn.

Regions with high risk infection by typhoid fever

The rules of discharing of the infectious patient from a

hospital - for 21 days of normal temperature - 3 negative coprocultures and 1 bileculture, which start

to take away from the patient after 2 days after cancellation of antibiotics

Prophylaxis: immunity after T.f. is often intensive but the

reinfections appear in 20 - 25 %

The vaccines do not create 100 % of protection, therefore them will using:

- at close family contact to the carrier S. - during flashouts T.f. - before visiting endemic areas on T.f.

- keeping of rules of personal hygiene; - control by preparation and storage of nutrition; - the registration, sanitation and discharge from

operation of carriers of the decree groups population;

- careful clearing of the drynking water; - desinfection of the sewers; - constant medical control for decree groups

population.

Antiepidemic measures

SHIGELLOSIS (DYSENTERY)DEFINITION – acute anthroponosis disease describing by sets

of symptoms an intoxications and a preferred damage distal of portions of a large intestine.

39 known serotypes Shigella are distributed on 4 groups:А. - Sh. Dysenteria (12 serovars) - Grigoriev-Shiga-Kruze, Schtucer - Schmitz, Lardj- Sachs В. - Sh. Flexneri (6 serovars) in subtype NewcastleС. - Sh. Boydii (18 serovars)В. - Sh. Sonne (1 serovar)

Main properties of causetive agents: - all shigellas are similar morphologically. They have a size 0.3 – 0.6 on 1.5 - 3 microns, spores and capsules will

not derivate, gram (-), well grow on simple mediums.

- outside of an organism of the man survive from several days - to several months,

- desiccation and low temperature transfer well, but at 60dg.C perish in 30 minutes, and at boiling is very quickly!!!

- all desinfectants in usual concentrations are inactivated of shigellas during 3 – 5 minutes.

- Sh. Sonei- will well be survive and is multiplied in nutrition

(milk)!!!

Antigenes: Sh. contain 2 thermostabile of an antigenes (typical and group) and 2 thermolabile antigenes (K - capsulated antigene – (in groups shigellas A and B) and fimbrial (in group В)

Toxinoformation - group A produces exotoxin, which breaks synthesis of protein in cells, has neurotoxity and enterotoxity by operation and hemolytic activity. Enterotoxical the operation of other groups shigellas in 100- 1000 times is less expressed.

At shigellas breakdown the endotoxin is freed which differs on operation from endotoxins gram- negative bacteria a little

EpidemiologySource of an infection the patients with the acute and chronic

forms of disease and bacteriocarriers.The mechanism of transmission - fecal-oral (main) and contact

The factors of transmission: - the water (is more often Flexneri) - nutrition (Sonnei), - the contacts (are more often the type А), - the carriers (fly, cockroaches), Seasonal prevalence summer-autumn, but not so legible as at a

salmonellosis!!! A sporadic case rate - the year round!!!- the children in the age of from 1 tо 4 years often are sick - meets often in prisons, psychiatric hospitals, barracrs, - as flashouts

(cause - lack of space and insanitary conditions)

- keeping personal, alimentary and hydrous hygiene, disinsection (fly, cockroaches);- registration of all patients and carriers and them sanitation; - planned inspection decree groups of the population and unplanned at any episode of a diarrhea;- regular current disinfection in the closed collectives of subjects of use (toy, pots etc.);- on all patients and carriers the emergency notice in SES ( sanitarno – epidemiologic station) and isolation (house or in a hospital) is referred.

Antiepidemic measures

BOTULISMBOTULISM - Acute severe food poisoning.

Characterized by lesion of CNS and autonomic nervous system.

Pathogen - Clostridium botulinum. Strict anaerobe. Exists in two forms - the vegetative and spore. 7 types of pathogens known botulinum-A, B, C, D, E, F, G, D.

Under anaerobic conditions, the spores germinate into vegetative forms and releases a lethal neurotoxin (lethal dose - 0.3 mg), it usually happens in canned foods. Dispute withstand boiling and killed only during autoclaving. The toxin is destroyed by boiling in 20 minutes.

EpidemiologyReservoir and source - soil, wild and domestic animals,

fish, birds, with bowel which allocated disputes. A sick man is not a source of infection.

Mechanism of transmission - fecal-oral, transfer factors - foods that contain toxins - canned food made at home (fungi spreads, stew), sausage, jerky and smoked fish.

Encountered - outbreaks, sporadic cases. Botulism is born before 26 weeks, the high mortality rate of 20-70%, very rare - wound botulism.

The incubation period of up to 5-7 days, more often - 12-16 hours.

Laboratory diagnosis - toxin neutralization reaction in mice. Investigations are taking gastric washings, food, vomit, blood.

Prevention - keeping technology of canned foods, removal of trade networks of infected products of their destruction.

Disease measures - obligatory hospitalization of patients, emergency notification

Disinfection of utensils and clothes patient - 1-3% chloramine 1 hour.

Emergency Prevention - antibotulinic serum for the contact persons, medical surveillance - 10 days.

PoliomyelitisAnthroponoses viral infection characterized by fever,

lesions of the spinal motor neurons and brain development flabby atrophic paralysis and paresis of extremities, and trunk.

Pathogen - RNA-containing enteroviruses, Picorno-virus, poliovirus I, II, III type. Polioviruses in feces, survive - 3-4 months., Killed by boiling, is not stable in the environment.

Source - a sick person or carrier. The virus is excreted in nasopharyngeal patient for 1 week, with excrement up to 3-6 weeks.

Transfer mechanism - fecal-oral, airborne, airborne dust, route of transmission - food, water, household.

Previously suffered children under 10 years. It was typical of summer-autumn seasonality.

The incubation period is 3-35 days.Laboratory diagnosis - the allocation of polioviruses from

stool, cerebrospinal fluid, swabs from the nasopharynx, blood for 3-7 day illness.

Serological - NT, CFT, UHAT in paired sera.Prevention - planned vaccination in childhood. Polio

vaccine IPV, OPV - 3-4-5 months., Revaccination - 18 months., 6 years, 14 years.

Events - hospitalization, urgent message. Discharge - not before 40 days from the onset of the disease.

Disinfection 2-3% by chloride lime, 1.5% hypochlorite Ca.To contact persons - children under 15 years and decreed

separated by 20 days, all of the contact re-vaccinated OPV, medical survilence for the contact person 20 days.

Poliomyelitis

The diseases with the airborne mechanism of transmission belong to the group of respiratory tracts infections.

TYPES OF RESPIRATORY TRACTS INFECTIONS

VIRAL INFECTIONS influenza, ARVI (acute

respiratory viral infections), measles, rubella, chickenpox,

epidemic parotitis, infectious mononucleosis,

enterovirus infection, herpesvirus infection etc.

BACTERIAL INFECTIONS meningococcal infection,

diphtheria, quinsy, whooping-cough,

scarlet fever, ornithosis, legyonelosis, respiratory

chlamidiosis and micoplazmosis.

Are most widespread is influenza and acute respiratory viral infections (ARVI): adenoviral infection, paragrippe, rhinoviral infection, coronaviral infection, respiratory-syncytial infection.

Lately often, there are the flashes of enterovirus infection, which is passing by both an airborne way, and fecal-oral.

From the bacterial diseases with the airborne mechanism of transmission most dangerous there is diphtheria that meningococcal infection.

influenzaF. Orthomyxoviridae, G. Mixovirus Influenza. A spherical cover virus by a size 80 - 120 nm. The core

contains one-filamentous RNA (-), divided on 8 fragments, (paired among themselves by common рrotein envelope derivating a nucleocapsid) which 10 virus protein encode derivation.

Covered bilayer by the lipide envelope, on a surface which 2 main antigenes of a virus are detected:

Hemagglutinin (Н) - 15 types (Н1, Н2, Н3 - for the man) provides affixion of a virus to a cell!!! Neuraminidase (N) - 9 types (N1, N2 - for the man) provides infiltration of a virus into a cell and facilitates escaping a cell of the viruses-descendants, preventing their aggregation!!

The nucleoprotein (s-antigenes) is constant on to structure also determines the type of a virus (A, B, C etc.)

Hemagglutinin and neuraminidase (v-antigenes) permanently chageable also determine appearance of the different strains one virus!!

The virus of an influenza A permanently varies (drift), causing epidemics everyone 2 - 4 years, but everyone 10-30 years there is a complete replacement of antigenes (shift) - that promotes by appearance of pandemics!! The virus B varies slowly (epidemic through 4 - 7

years) and it has not of the hemagglutitin but shift is not observed also pandemics do not arise!!

The virus of an influenza C does not change antigenes, contains only 7 fragments RNA (instead of 8) and one surface antigene (instead of 2) - supporting only sporadic case rate!!

Are unstable in the external environment, being inactivated: - at 20 dg.C - through 4 - 9 hours, - at 60 dg.C - 3-5 minutes - at boiling, effect of alcohol, bichloride of mercury, forma-

linum, disinfectants - is instantaneous. At fast freezing to (-) 70 dg.C - is survived by years!!!

EPIDEMIOLOGY

Source - the sick man 24 hours prior to illness and all acute periodPath of transmission - air-borneEpidemics of an influenza A - are retried everyone 2-3 years, duration 1 - 1,5 months with a damage up to 20 - 50 % of the populationThe pandemics - are retried everyone 10 - 40 yearsEpidemics of an influenza B- are retried through 3 - 4 years by duration 2,5 - 3 months with a damage 25 % of the population.At an influenza C an only sporadic case rate

Epidemics arise- - autumn and winter (Northern hemisphere) - spring and summer (Southern hemisphere) - the year round (along equators)The level of a case rate depends on number the population of

city: - 1 million and more - ARVD -29,7 % of an Influenza - 11,3 % - 500 т. - 1 million. - ARVD- 24,1 % of an Influenza - 10,3 % - It is less 500 т. - ARVD- 22,1 % of an Influenza - 9,7 % The village inhabitants are sick less often (less than density the population) Postinfectious immunity: - at an influenza A -1 - 3 years - at an influenza B - 3 - 6 years, - at an influenza C- all children have immunity to it to 10 to years of life.!!!

PROPHYLAXIS (common and special)

- Common - rise of stability of an organism to catarrhal diseases (walk, vitamin therapy etc.) - Specific - introduction of inactivated vaccines: - subunit (containing only H and N antigenes) Infuvac (Holland) - split- Fluarix (Holland), Vaxigrip (France)(At usage of split vaccines reduced in 2,6 times were sick by others ARVD less often!!!

Emergency prophylaxis usage of remantadinum, аrbidol, аdapromil in preventive doses, and intranose will be utillized by 0,25 % oxolinic and florenalic of unguentum!!

DIPHTHERIA - ETIOLOGYDefinition- acute, anthroponosis, infectious disease caused by the

toxicogenic strains corynobacterium diphteriae, which is characterized by an inflammation in a place of entry hiluses with derivation of a fibrinous film both toxic lesion of cardiovascular and nervous systems.

Corynobabacterium diphteriae (C.d.) Gram (+), - thin rods with rounded, widening ends which contein of a clump in them of grains of a volutin.

They are polymorphic and on cultural and enzymatic properties are divided into 3 biotypes:

GRAVIS, INTERMEDIUS, MITIS.Are steady against low temperatures.

At room temperature, in water, milk have survived 1 - 3 weeks. Desinfectants inactivate С.d by 1- 2 minutes At boiling were destroyed instantaneously.

EPIDEMIOLOGYSources of an infection: epidemiological danger Danger infectionThe sick 3 1Convalescent 2 2Bacteriocarrying 1 3

Sanitation of convalescents are completed through 15 - 20 days , but about 90 days can be delayed. The frequency of a carriage in a population makes 1-10 %Mechanism of transmission - aerogenic (main), less often contact and alimentary

Enlargement of a case rate - in autumn-winter period Periodicity of uprise of a case rate – 5 - 7 years.Controlled infection. The scheduled grafts in children's age have given increase of diseases among the adult now!!!

PROPHYLAXIS (common and special) Common: inspection of the contact persons, - Closing disinfection in the center, - Installation in the center of quarantine for 7 days

Special: introductions of a diphtherial anatoxin. - primary immunization on 3,4,5 months of life - revaccination per 18 months, and then in 6, 11, 14, 18 years - the adult population is subject to a revaccination everyone 10 years

Antiepidemic measures at meningococcal disease

• All cases of meningococcal disease shall be registered by sending an urgent message to the SES.• If there are 5 or more cases of generalized forms of meningococcal infection in a single cell serves special report on the country's Ministry of Health.• Mandatory immediate hospitalization of patients with generalized forms of meningococcal infection. Patients with nasopharyngitis detected in the cellscan be leave home if there are conditions for isolation (no preschool children, people who work in childcare).

Antiepidemic measures at meningococcal disease• Extract from the hospital with clinical recovery without bacteriological testing for carrier. Convalescents allowed in kindergartens, schools, orphanages, health centers after a negative result conducted 5 days after discharge from hospital.• Preventive vaccination convalescents could be done through 2-6 months after suffering nasopharyngitis, generalized forms of meningococcal infection carriers in 1 month.• All contact under review Otolaryngology - doctor, medical examination, hospitalization of those who are pathological changes in the nose, throat, fever, rash.• Quarantine in closed groups of 10 days from the date of the last patient isolation.

Antiepidemic measures at meningococcal disease• Bacteriological examination conducted: in children's institutions to children interacting with patients, support staff in schools - pupils and teachers of the class where found sick in boarding - students, teachers, educators, interacting with patients in vocational schools and universities -1 course, all students and teachers, senior courses - only those who communicate with patients.• The children's institutions bacteriological examination of contact persons hold not less than 2 times at intervals of 3-7 days, other groups - once. Carriers meningococcus identified by bacteriological examination in childcare in school - removed from the team and dignity, carriers adults not isolated.• Specific preventive vaccination provided. There monovaccines A and C, A bivalent C quart vaccine A C Y W135.

LITERATURE

1. Epidemiology. B.N. Dikiy, T.A. Niciforova, O.Y. Pryshlyak – Ivano-Frankivsk: Publishing house of the Ivano-Frankivsk State Medical University, 2008. – 142 p.

2. Epidemiology and fundamentals of infectious diseases. M.L. Volovskaya – Mir Publishers Moscow, 1990. – 308 p.

3. Materials from Internet sites and electronic libraries.