Infectious diseases

P. Babál, Dept. Pathology, FM CU Bratislava

Infectious diseases

= most frequent diseases of humans (look for medical help)

- world-wide most frequent cause of death

= transferable (contagious – transfer between people)

from natural reservoirs

virulence

immunity of the organism (also genetic disposition)

age (intrauterine, different course in children...)

behaviour of people

season of the year

Viruses

Bacteria

Moulds, Fungi

Parasites

Viral diseases

Respiratory infections

„bad cold“ – rhinoviruses, coronaviruses (resp. epithelium...bradykinin)

Influenza

Parainfluenza (children – laryngotracheitis with stridor)

RSV (dangerous for newborns), Adenovíruses (...interstic. pneumonia)

SARS (Severe Acute Respiratory Syndrome)

-etiology – for long uknown

... Corona virus:

source = palm cibet, China, Taiwan

transfer = medical personel

turists, business

Viral diseases

Respiratory infections - SARS

Exanthemas

Morbilli (measles) - in malnurished high mortality

- Indians – low natural resistence

mucositis + vasculitis (exantema)

Rubeola (rubella) - congenital rubella – serious defects

Variola - eradicated

Viral diseases

Intestinal infections

Rotaviruses - fecal-oral transfer, watery diarrhea (small intestine!)

Norwalk viruses – epidemic gastroenteritis

Hemorrhagic fewer

- transfered by moskito (yellow f., dengue)

- by tick (Krym´s f.)

- zoonotic (rodents; Bolivian f., Koreian f.)

- Ebola (transfer from bats?)

Yellow fewer - Afrika, S. America

= flavivirus, carrier Aedes moskito, reservoar monkeys.

endothelotropism (hemorrhagies)

hepatotropism (intermed. zone – necrosis, jaundice)

Viral diseases

Herpesvirus infections

Varicela - whole world; vesicular exanthema, latent

phase, herpes zoster.

Herpes simplex 1 - disease „above waist“ (>90% in childhood)

Herpes simplex 2 - disease „under waist“ (STD, neonatal herpes)

EBV infekcie - upto 3 y. asymptomatic,

later infectious mononucleosis

- endemic Burkitt lymphoma

- nazopharyngeal Ca

- Hodgkin lymphoma ?!!!

(CD3 R on B-Ly, on pharyngeal epit.)

Cytomegalovirus - only immunocompr.

- congenital infect

Human papiloma viruses

Bacterial infections

Staphylococcus aureus - furuncul, carbuncul, osteomyelitis,

(coagulase posit.) respiratory infects, toxic shock sy.

Streptococcus pyogenes - pharyngitis, scarlatina, erysipelas

impetigo (pyoderma) – contact, moist

environment

Streptococcus pneumoniae - pneumonia, otitis media, meningitis

Infections in children

Diphteria - C. diphteriae, toxin

Whooping-cough - B. pertussis, tracheobronchitis

Hemophilus i. - pharyngitis, meningitis

bronchopneumonia

Bacterial infections

Sexually transmited diseases

Gonorrhea

Syphilis

Ulcus mole - Hemophilus ducrei – genital ulceration,

lymphadenopaty = 3rd most frequent STD

- in less developed countries (transfer of HIV)

Granuloma ingvinale - tropic and subtropic clima

(ulcers of genitals and tissues around)

Calymmatobacterium granulomatosis

= Klepsialla granulomatis

Lymphogranuloma venereum - Chlamydia trachomatis, serovar L

- endemic in tropics, in Europe mostly homosex. male

Bacterial infections

Enteropathogenic infections

Enterotoxigenic E. coli - S. America, Africa, Asia

– carriers, children, foreigners

(+ enteropathogenic, enterohemorrhagic, enteroinvasive E. coli)

Shigelosis - low hygienic standard

- high child mortality in 3rd world

Cholera - epidemie or pandemies – Asia, Middle East,

India, Bangladesh

Bacterial infections

Enteropatogenic infections

Salmonella - enterocolitis

Salmonella typhi

-frequent in undeveloped countries

Clostridium infection

= sporulating anaerobic bacteria

C. perfringens

C. botulinum

C. difficile

C. tetani – especially where cattle

and horses

(! umbilical cord – soil)

Bacterial infections

-from animal reservoars:

Brucellosis - cattle

Pest (Yersinia pestis) - small rodents, rats (flea)

Tularemia - cattle, deer... (sucking insects)

Anthrax - cattle, dog, pig

Listeria - sporadic appearance (soil, animals)

- intrauterine/adult-meningitis

Cat-scratch - ...lymphadenopathy ( cat)

Bartonelosis - human (sand fly)

Peru, Ecuador, Columbia

1. hemolytic anemia (acute phase)

2. skin „verruca peruana“

Bacterial infections

Spirochete infections:

Syphylis

Lyme boreliosis

Leptospirosis - L. icterohaemorrhagica (rhodents)

Weil disease

Recurrent fewer - B. recurrentis (human) (lice)

high concentration of humans (work camp)

Ethiopia, Sudan, S. Amerika

Noma - T.vincentii + B. fusifomis

ulcerative-destructive necrotic process

- face tissues, extremities, genitals...

tropic climat, undernurishment+other infekct

Bacterial infections

Ricketsia infects:

Rocky mountain spotty fewer

- in Americas (tick)

R. ricketsii ...systemic vasculitis

Camp fewer (typhus)

- endemic in America, Asia

R. prowazekii (lice)

Q fewer

- domestic animals

C. burnetii

Bacterial infections

Mykobacteria:

Tuberculosis

natural resistence

different

Lepra

tropical Africa, Asia,

S.America

- contact transfer

Fungal infections

Candida

Aspergillus

Mucormycosis (bread, fruits)

Cryptococcosis

Histoplasmosis

Coccidiomycosis

Blastomycosis

Sporotrichosis

Mycetoma (Nocardia)

-Usually limited, spontaneously subside

-skin, lung, systemic infections

-unfavorable outcome in immunocompromised patients

Protozoal infections

Malaria

= major medical

problem

distribution

- eradicated in developed

countries

transfer moskito Anopheles

Plasmodium falciparum – malignant malaria

Inoculated sporosoits – asexual schizogonia

invade hepatocytes – divide to merozoits

after 2-3 weeks merozits from hepatocytes

erythrocytes

2-4 days consume hemoglobin and divide rupture eryt.

... some merozoits – gametocytes moskito

Malaria

Malaria

Malaria

Plasmodium falciparum

Protozoal infections

Amebiasis

Giardiasis

Leishmaniasis

source = various animals

(sand fly)

- tropics, subtropics, Orient

- skin form – ulcerations

- mucocutaneous form – after years ulcer at mucosal border

progression, destrucion

- visceral form (Kala-azar) – distribution to RES

...hepato-splenomegaly, lymphadenopathy, thrombocytopenia,

anemia, cachexia

Protozoal infections

Chagas disease

T. Cruzi

-central and south America

various animals bugs

nodular skin lesion

systemic spread

- damage is permanent

- myocardium

- ganglion cells of intestins

- meninges

Protozoal infections

African trypanosomiasis

T.gambiense, T. rhodesiensae

fly Glossina (tse-tse)

Patogenesis – vasculitis

- autoantibodies against Er Ag

- autoAb against brain, heart

Gmbian form – weeks/months

Rhodesian form – months/years

... meningoencephalitis, pancarditis

lung dysfunction, kidneys

Amebian meningoencephalitis

Naegleria fowleri

- bathing in warm sweet waters

Infections with worms

Filariasis

Various moskitos

...microfilaries into lymphatic vessels

adult worm = 80x0.3 mm, in lymphatic vessel

- surrounded – inflammatory reaction (repeated scarring)

-edema (elephantiasis)

S. Asia, Pacific, Africa, S. America

Onchocerciasis

„river blindness“ = one of the most frequent endemic diseases

black fly

Along rivers in tropical Africa, s.America, Guatemala, Mexico

female under skin microfilaries skin, LN, organs, eye

...after death evoke strong immunologic reaction

dermatitis (onchocercoma), blindness, edema

Infections with worms

Schistosomiasis

= bilharsia

After malaria the most spread (cca 10 % Earth citisens)

asexual genertion

- in snail

sexual generation

- in vertebrates

Eggs are diagnostic

Schistosoma mansoni Schistosoma haematobium

Askaridosis

Ascaris lumbricoides

Trichinellosis

Trichinella spiralis

Microfilariasis

Dirofilaria repens