INFECTIOUS DISEASE PART II
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Transcript INFECTIOUS DISEASE PART II
INFECTIOUS
DISEASE PART II
By Camille-Marie A. Go
PROTOZOA
SARCODINA (AMOEBAE)
ENTAMOEBA
histolytica
– 90% commensal strain – Amoebic
infection (asymptomatic)
10% invasive strain – Amoebic disease
– MOT – ingestion of mature cyst
SARCODINA (AMOEBAE)
ENTAMOEBA
histolytica
– Distribution
1. Inadequate sanitation
2. Poor personal hygiene
– Infective state – mature 4-nucleated
cyst
– Diagnostic stage – cyst and trophozoite
Different from E. coli
– DDx – bacillary dysentery
AMOEBIC
DYSENTERY
BACILLARY
DYSENTERY
Gradual onset
(-) Fever, vomiting
Bloody, mucoid
Offensive smell
Acid pH
Few pus cells
(+) Motile amoebae
Acute onset
(+) fever, vomiting
Watery, bloody
Odorless
Alkaline pH
Many pus cells
(-) Amoebae
SARCODINA (AMOEBAE)
Extraintestinal Amoebiasis
Liver – most common site (post ®
lobe)
Adults; men (3:1)
Skin, CNS, Lungs
SARCODINA (AMOEBAE)
DIAGNOSIS
– Fecalysis – cyst – formed and
semiformed
-troph.–dysenteric (w/in15”)
- Rectal smear (Prostoscopy)
– Rectal biopsy
– Liver (Abscess wall) biopsy
– Serological (Extraintestinal)
SARCODINA (AMOEBAE)
Treatment
– Metronidazole
– Iodoquinol
*NAEGLERIA fowleri–Primary Amoebic
Meningoencephalitis
(PAM)
CILIOPHORA (CILIATES)
BALANTIDIUM coli
– Only ciliate that parasitizes man
– NH-pigs; MOT- ingestion of cyst
– Infective stage – cyst (No incubation)
– Diagnostic stage – cyst (formed and
semiformed stool)
- Trophozoite (dysenteric
stools)
CILIOPHORA (CILIATES)
BALANTIDIUM coli
– Causes bloody mucoid diarrhea
– Diagnosis by Rt. Fecalysis
– Treatmnent – drug of choice –
Iodoquinol
MASTIGOPHORA
(FLAGELLATES)
GIARDIA lamblia
Humans as only reservoir infection
– MOT – ingestion of cyst
– Infective stage – cyst (no incutation)
– Diagnostic stage – cyst (formed and
semiformed stool)
- Trophozoite (in diarrheic
stools)
MASTIGOPHORA
(FLAGELLATES)
GIARDIA lamblia
– Duodenum, jejunum
– Prevalent among children
– Causes Villous Atrophy – Malabsorption
and lactose intolerance; steatorrhea
– Predisposition: GIT disorders, bacterial
infection of intestine; hypochloridia,
pancreatic disease
MASTIGOPHORA
(FLAGELLATES)
GIARDIA lamblia
– Diagnosis: Routine Fecalysis
Duodenal aspirate
Enterotest capsule
– Treatment: Metronidazole
Quinacrine HCl – drug of
choice
TRICHOMONAS vaginalis
MOT -sexually transmitted
common cause of acute vaginitis
with yellow–green purulent discharge
in females (urinary frequency)
Causes urethritis and purulent
discharge in males
Infective stage: Flagellates (No cyst
stage)
TRICHOMONAS vaginalis
Treatment: Metronidazole
Both partners
* T. hominis
* T. intestinalis
TRYPANOSOMA b. rhodesiense
(zoonosis)
TRYPANOSOMA b. gambiense
(humans mostly)
Cause
African sleeping sickness
M.O.T. – bite of tsetse fly (Glossina)
and blood transfusion
Infective stage – Metacyclic
trypomastigote
Diagnostic stage – Trypomastigote
(peripheral blood)
DIAGNOSIS
– Peripheral Blood Smear
– Aspirate of lymph node
– Chancre fluid
– CSF Morula (MOTT) cells
– TP (IgM)
TREATMENT
– Pentamidine
Drug of Choice:
– Suramine (Early hemolymphatic stage)
– Metarsoprol (Late stage) – CNS Involvement
TRYPANOSOMA cruzi (Zoonosis)
Endemic in S. America
Causes Chaga’s disease
MOT- Bite wound made by kissing
bug (Triatoma or Rhodnius) is
contaminated by rubbing bug’s feces
containing metacyclic trypomastigote
- Via blood transfusion
- Transplacental route
TRYPANOSOMA cruzi (Zoonosis)
Infective stage – Metacyclic
trypomastigote
Diagnostic stage – Trypomastigote
(C-shaped)
SSx: Early – Chagoma (Romana’s
sign)
– Late – Cardiomegaly
Mega-esophagus
Mega-colon
TRYPANOSOMA cruzi (Zoonosis)
DIAGNOSIS
– Peripheral blood smear
– Xenodiagnosis
– Blood culture
– IgM determination
TREATMENT
– Nifurtimox, Bezuidazole
LEISHMANIA donovani (Zoonosis)
Endemic in S. and C. America, Europe,
Africa, Asia (esp. India); Local cases
(OCW’s)
Causes visceral Leishmaniasis/Kalaazar
MOT – bite of sandfly (Phetobotomus or
Lutzomyia)
– Congenital/transplacental
– Sexual contact
– Blood transfusion
LEISHMANIA donovani (Zoonosis)
Infective
stage: Promastigotes
Diagnostic stage: Amastigotes in
macrophages
Pathology: Blockage and destruction
of R.E.S.
LEISHMANIA donovani (Zoonosis)
DIAGNOSIS
– Peripheral blood monocytes
– Aspirate of bone marrow, lymph node,
spleen
– Formol get test (non-specific; increased
IgG (+)
– Gelling and Whitening of serum
LEISHMANIA donovani (Zoonosis)
TREATMENT
– Antimony compounds
e.g.
Sodium Stibogluconate – drug of
choice
N. methyl – Glucamine
Pentamidine isothionate
PLASMODIUM
PLASMODIUM falciparum
Causes malignant tertian malaria
Most prevalent in the world, in the Phil.
Most pathogenic- Cytoadherence
MOT – bite of Anopheles mosquito
– 1° vector- A.minimus flavirostris
– 2° vector- A. balabacencis
A. littoralis
A. mangyanus
*Potential vector: A. maculatus
PLASMODIUM falciparum
Parasitizes
red cells of all ages
Schizogony, sporogony
Severe Falciparum Malaria
– Cerebral malaria
– Anemia
– Blackwater fever
– Diarrhea/Vomiting (GIT)
– Pulmonary edema ± renal failure
– Hypoglycemia
PLASMODIUM falciparum
In
pregnancy – abortion, premature
labor, stillbirth, neonatal death, lowbirth weight infants
Hyperactive malaria splenomegaly
Recrudescence
Vaccine production fails because of
antigenic variation
PLASMODIUM falciparum
Diagnosis:
– Clinical: History of travel, SSx
– Laboratory:
Thick
and thin blood smears
– Maurer’s dots
– Ring forms (young trophozoites), Accoele forms
– Crescent/Banana-shaped gametocytes
Immunofluorescent (Q.B.C.)
Serological
PLASMODIUM falciparum
Treatment:
– Quinine, Quinidine
– Quinhaosu derivatives: Artemisin,
Artesunate, Artemether
PLASMODIUM vivax
Causes
benign tertian malaria
Parasitizes young red cells
(reticulocytes)
Rarely found in E. Africa (-) Duffy
blood group antigen Fya and Fyb
Relapses due to hypnozoites
Common etiology of transfusion
malaria
PLASMODIUM vivax
DIAGNOSIS: Enlarged red cells
Schuffner’s dots
TREATMENT: Chloroquine + Primaquine
* Plasmodium malariae
Quartan
malaria, nephrotic syndrome
Older red cells; Ziemann’s stippling, daisy schizont;
band form; bird’s eye form
Recrudescence
* Plasmodium ovale
Causes
Ovale Tertian Malaria
Relapses
Young cells; red cells become slightly
enlarged, oval-shaped with fimbriated
(ragged) ends; James dots
CRYPTOSPORIDIUM sp.
(Zoonosis)
Common
among AIDS patients
Common cause of diarrhea in
children <5 y/o and non-breast fed
infants
Habitat: small intestine
MOT – ingestion of oocyst
Infective and Diagnostic stage:
oocyst
CRYPTOSPORIDIUM sp.
(Zoonosis)
DIAGNOSIS:
Rt. Fecalysis
- Sugar floatation technique
– Fecal smear stained with:
Modified
(Kinyoun’s) Acid
Fast staining technique
Safranin-Methylene Blue
TREATMENT:
Spiramycin
TOXOPLASMA gondii (Zoonosis)
Nat.
host/Def. host – cat
Humans. Other mammals – Int. host
Common among
immunocompromised individuals,
e.g. AIDS patients
MOT – ingestion of oocyst
– Eating uncooked meat of IH
– Blood transfusion
TOXOPLASMA gondii(Zoonosis)
Transplacental/Congenital:
serious form
Pathology
Most
– Acute stage: Tachyzoites – phagocytes
– Late stage: Bradyzoites – visceral
organs (pseudocyts)
TOXOPLASMA gondii (Zoonosis)
Clinical
forms
– Lymphadenopathy
– Ocular toxoplasmosis
– Myocarditis
– Meningoencephalitis
– Atypical pneumonia
– Congenital toxoplasmosis
Increased
IgM
Cerebral calcification
TOXOPLASMA gondii (Zoonosis)
DIAGNOSIS:
– Aspirate of lymph node, bone marrow,
spleen
– CSF, pleural or peritoneal fluid, sputum
– Serological: IgM
Sabin-feldman
dye test
– (Live toxoplasms)
TOXOPLASMA gondii (Zoonosis)
TREATMENT
– Pyrimethamine
– Sulfadiazine
PNEUMOCYSTIS carinii
Common
cause of death in AIDS
patients
Common among malnourished
children
MOT – droplet infection
Infective and Diagnostic stage:
Cyst/Trophozoite
Pathology: Interstitial (viral-like)
pneumonia
PNEUMOCYSTIS carinii
DIAGNOSIS:
– Transbronchial Lung Biopsy;
Cell Imprint
– Stains: Methenamine Silver or
Gram–Weigert
Giemsa
PNEUMOCYSTIS carinii
TREATMENT
– Pentamidine
TMP-SMZ
– drug of choice
HELMINTHS
PLATYHELMINTHES
(Flat worms)
TREMATODA (Digenetic flukes)
FASCIOLOPSIS buski
Largest
intestinal fluke
MOT – ingestion of metacercaria
Infective stage: Metacercaria
Diagnostic stage: Immature egg
DH – man, pigs, buffalo
IH 1 – Segmentina, Hippeutis
IH 2 – Water caltrop, water chestnut
FASCIOLOPSIS buski
DIAGNOSIS
– Rt. Fecalysis
TREATMENT – Praziquantel
ECHINOSTOMA ilocanum
Garrison’s
fluke
Endemic in the Phil. (N. Luzon,
Leyte, Samar, Mindanao)
Adult Habitat – Small intestine
DH – man
IH 1 – Gyraulus, Hippeutis
IH 2 – Pila luzonica
ECHINOSTOMA ilocanum
Diagnosis:
Eggs in feces
Treatment: Praziquantel,
Hexylresprcinol
PARAGONIMUS westermani
Oriental
lung fluke
MOT – ingestion of metacercaria
Infective stage: Metacercaria
Diagnostic stage: Immature egg
DH – man, rodents, domesticated
animal
IH 1 – Semisulcospira, Thiara
IH 2 – Crab, crayfish, shrimps
PARAGONIMUS westermani
Habitat
– Bronchioles
– Causes PTB–like SSx
Cough,
night sweats , chest pains,
hemoptysis
DIAGNOSIS:
Eggs in sputum, feces
Treatment: Praziquantel
PARAGONIMUS westermani
Clonorchis
sinensis –
Chinese Liver Fluke
Cholangiocarcinoma
Metagonimus yokogawai – smallest
fluke that parasitizes man
Heterophyes heterophyes – causes
cardiac beriberi
Dicrocoelium dendriticum – IH2 is an
ant
SCHISTOSOMES
CLASSIFICATION
– Superfamily schistosomatoidea
S.
haematobium
S. mansoni
S. japonicum
S. mekongi
SCHISTOSOMES
FEATURES
– Adult habitat – venous plexuses
– Sexes- separate
– Shape – cylindrical
– Definitive host – humans only
– 1st I.H. – snails; NO 2nd I.H.
– Transmission – skin penetration
– Lab. diagnosis – eggs in urine, feces,
rectal scrapings
SCHISTOSOMA hematobium
Endemic
in Africa, Middle East
Causes urinary Schistosomiasis
Spread and construction of irrigation
channels and dams for hydroelectric
power and flood control
MOT – skin/mucosal penetration by
cercariae
SCHISTOSOMA hematobium
Infective
stage: cercaria
Diagnostic stage: mature egg
D.H. – man
Adult habitat – Urinary bladder
I.H. – Bulinus
Pathology: Granulomata formation
– Hematuria
– Squamous cell carcinoma
SCHISTOSOMA hematobium
Diagnostic
stage: urine – egg with
terminal spine
Treatment: Praziquantel
SCHISTOSOMA mansoni
Causes
intestinal schistosomiasis
MOT – skin penetration by cercariae
Infective stage: cercariae
Diagnostic stage: mature egg
D.H. – Man
I.H. - Biomphalaria
SCHISTOSOMA mansoni
Adult
habitat – Inf. mes. veins
Pathology: Granulomata formation
– Bloody mucoid diarrhea
– Rectal polyps
– Claypipe-stem fibrosis
– Portal HPN; Esophageal varices,
Splenomegaly
SCHISTOSOMA mansoni
Diagnosis:
Fecalysis- egg with
prominent lateral spine
Treatment: Praziquantel
SCHISTOSOMA japonicum
Causes
intestinal schistosomiasis
MOT – skin penetration by cercaria
Infective stage – cercaria
Diagnostic stage – mature egg
DH – man, rodents,etc.
IH – Oncomelania quadrasi
Adult habitat – sup. mes. veins
SCHISTOSOMA japonicum
Pathology – similar to S. mansoni
Katayama reaction
Egg output – 1500 – 3500 eggs/day
Diagnosis: Feces – egg w/ vestigial
lateral spine
Serum – C.O.P.T.
Treatment: Praziquantel
• S. mekongi – Mekong River Basin (Laos, Kampuchea,
Thailand
• Swimmers’ itch
CESTODA (Tapeworms)
TAENIA solium
Taeniasis
– ingestion of measly pork
containing cysticerci
Cysticercosis – ingestion of eggs
– Regurgitation of gravid proglottid into
the stomach
TAENIA solium
Diagnosis:
Scolex with 4 suckers and
2 rows of hooks
Taeniasis – finding of adult segments
or eggs in the stool
Cysticercosis – radiological
(radiolucent or radio-opaque cysts
along limb soft tissue parts
- serological
TAENIA saginata
More
prevalent worldwide; in R.P.
MOT – ingestion of cysticerci in
undercooked, infected beef
Cysticercosis bovis not seen
Scolex with 4 suckers and no hooks
Diagnosis: Fecalysis
– Adult proglottid - >13 main
lateral uterine branches
– Cellophane (Scotch) tape swab
ECHINOCOCCUS granulosis
(Zoonosis)
Endemic
in sheep-raising countries
Causes hydatid disease/hydatidosis
MOT – ingestion of eggs
Infective stage – eggs
Diagnostic stage – eggs and adult
DH – dogs
Accidental host – man
IH - sheep
ECHINOCOCCUS granulosis
(Zoonosis)
Pathology:
– Hydatid cyst: 60% in ® liver, others in lungs,
bone, brain, kidney, spleen
– Rupture of cyst – Anaphylactic shock
Diagnosis:
–
–
–
–
X-ray
Cyst fluid
Serological
Casoni skin test – intradermal test
– Mx: Surgical removal/extirpation
DIPHYLOBOTHRIUM latum
Largest
fish tapeworm
MOT – ingestion of plerocercoid
Infective stage: Plerocercoid in
undercooked or raw freshwater fish
DH – humans and fish–eating
animals
IH 1 – crustaceans (procercoid)
cyclops Diaptomus
IH 2 – freshwater fish
DIPHYLOBOTHRIUM latum
Pathology:
– Mechanical intestinal obstruction
– Megaloblastic/Pernicious anemia
Treatment:
Praziquantel
*Sparganosis (Spirometra)
NEMATHELMINTHES
(Round worms)
ASCARIS lumbricoides
Large
intestinal roundworm
MOT – ingestion of embryonated ova
Distn inadequate sanitation; use of
night soil
ASCARIS lumbricoides
Pathology:
–
–
–
–
Loffler’s syndrome (Heart–lung migration)
Malnutrition
Intestinal obstruction
Erratic behavior or adult
Diagnosis: Eggs and adult worm in feces
Treatment: Pyrantel pamoate,
Mebendazole
ENTEROBIUS vermicularis
Pinworm,
Seatworm, Threadworm
MOT
– Ingestion of D-shaped embryonated
eggs/fecal-oral route
– Airborne/Inhalation of embryonated
eggs
– Autoinfection via mouth and/or anus
(retroinfection)
Adult
Habitat – caecum, appendix
ENTEROBIUS vermicularis
Cepahalic
alae
Pathology: Nocturnal anal pruritus in
children
Diagnosis: Cellophane(Scotch)tape
swab
Urinalysis (occasionally)
Treatment: Pyrantel pamoate
Mebendazole
STRONGYLOIDES stercoralis
Dwarf
threadworm
MOT – skin penetration by filariform
larva, transmammary route, internal
autoinfection
Infective stage – Filariform larva
Diagnostic stage – Rhabditiform
larva
STRONGYLOIDES stercoralis
Pathology:
Heavy infection
malabsorption with steatorrhea,
Larva currens; free-living phase
Diagnosis: Fecalysis
Harada-Mori culture tech.
Enterotest
Treatment: Albendazole
Thiabendazole
TRICHURIS trichiura
Whipworm
MOT
– ingestion of bipolar-plugged
ova
Pathology: Chronic cases rectal
prolapse; prone to 2ndy E. histolytica
infection
Diagnosis: Fecalysis, Proctoscopy
Treatment: Albendazone,
Mebendazole, O. pyrantel
HOOKWORMS
MOT – skin penetration by filariform larva;
mucosal; transmammary; transplacental
Hookworm infection vs. Hookworm
disease
Pathology:
–
–
–
–
A. duodenale – more blood loss (0.15 ml/day)
Ground itch
Respiratory problems – petechial hemorrhages
Hookworm anemia – iron deficiency,
hypochromic, microcytic; hypoalbuminemia
* Creeping Eruption by non-human hookworms
HOOKWORMS
Diagnosis:
Fecalysis
Harada Mori culture tech
Treatment: Mebendazole
Pyrantel pamoate
CAPILLARIA philippinensis
Small
whipworm, Pudoc worm
Nat. host – fish-eating birds
Endemic in N. Luzon, Bohol, Leyte,
Mindanao
M.O.T. – ingestion of infective eggs
in undercooked or raw fish (Bacto,
Bagsit, Bagsan)
CAPILLARIA philippinensis
Pathology:
Internal autoinfection
Intestinal gurgling
(Borborygmi)
Chronic watery diarrhea;
F/E IMB
Diagnosis: Eggs in feces
Treatment: Mebendazole
WUCHERERIA bancrofti
Causes
Bancroftian lymphatic
filariasis
Most prevalent worldwide, in the
Phil.
Microfilaremia and periodicity
Mosquito vectors: Anopheles, Aedes,
Culex
MOT – mosquito bite
WUCHERERIA bancrofti
Pathology:
–
–
–
–
–
Recurrent lymphangitis, fever
Elephantiasis (Whole lower limb)
Hydrocoele
Chyluria
Tropical pulmonary eosinophilia
Diagnosis: Thick & Thin Smears (12 MN)
Treatment: Diethylcarbamazine (DEC)
BRUGIA malayi
Causes
Malayan lymphatic filariasis
Mosquito vectors- Anopheles,Aedes,
Culex, Mansonia
MOT – mosquito bite
More seen in children
– More rapid course
– Elephantiasis – below knee
BRUGIA malayi
Diagnosis:
Thick& Thin smears (12
MN)
Treatment: DEC
* Loa loa – Calabar swellings
* Onchocerca volvulus – River
blindness and hanging groin
DRACUNCULUS medinensis
Guinea
worm
Cyclops contain the infective larvae
No reservoir host
Mx: Manual extraction
Rx: Steroid, Antibiotic, Anti-tetanus
TRICHINELLA spiralis (Zoonosis)
Nat.Hosts
– pigs, wild boar
MOT – ingestion of undercooked
pork, sausage meat containing
larvae
Man – accidental IH
TRICHINELLA spiralis (Zoonosis)
Pathology:
GIT (Diarrhea, nausea,
vomiting, abdominal pain)
Migration – fever allergic reaction,
myalgia, headache
Diagnosis: Muscle biopsy
Serological
Treatment: Steroids
ANISAKIS sp.
fondness for raw fish (Japanese
restaurants)
Present as gastritis, gastric ulcer,
gastric cancer
Mx: Fiberoptic gastroscopy with
forceps extraction of mass containing
the worm
CUTANEOUS LARVA MIGRANS
Ancylostoma
brasiliense – Dog/Cat
hookworm larva
Ancylostoma caninum – Dog
hookworm
larvae
Larva migrate to superficial layers of
the skin
– Feet, legs, hands, thigh, and back
CUTANEOUS LARVA MIGRANS
Clinical
Features: Allergic reaction
Irritation
Inflammation
Secondary infection
VISCERAL LARVA MIGRANS
Toxocara
canis/cati- larvae of dog
and cat roundworms cause
granuloma formation
- Common in
children up to 3 years
VISCERAL LARVA MIGRANS
ORAL
INGESTION OF OVA
Ova carried by blood to:
– liver, brain, lungs, heart, and eyes
VISCERAL LARVA MIGRANS
Clinical
Features:
– Eosinophilic granuloma
– Hyperglobulinemia
Antihelminthic
Agents
Mebendazole and Albendazole
(Benzimidazoles)
MOA: inhibit microtubule polymerization by binding to betatubulin → immobilization → death
Mebendazole and Albendazole
(Benzimidazoles)
Indications:
both drugs effective for
Enterobius,
Ascaris,
Trichiuris,
and hookworms
*albendazole is more
effective against
hydatid cysts
Adverse Effects:
allergic reactions
alopecia
reversible neutropenia
agranulocytosis
hypospermia
teratogenic in experimental
animals
*Albendazole has lesser ADRs
Contraindications
pregnant patients
children below 2 years old
* Albendazole is
contraindicated in
hepatic cirrhosis
Pyrantel pamoate
MOA:
depolarizing neuromuscular blocking agent
releases acetylcholine and inhibits
cholinesterase
induces marked, persistent activation of
nicotinic receptors
spastic paralysis of worms
Indications:
hookworms
pinworms
Ascaris
*Ineffective against Trichiuris
Adverse effects:
transient and mild GIT upset
headache
dizziness
rash
fever
Drug interaction:
pyrantel + piperazine = antagonism
Contraindications:
pregnancy
children less than 2 years old
Oxantel pamoate
effective against Trichiuris
Oxantel-pyrantel
combination (Quantrel)
is available in a fixed
dose of each drug
Piperazine citrate
MOA:
blocks the response of Ascaris muscle to acetylcholine
causes flaccid paralysis of Nematodes
Piperazine
Piperazine
Pharmacokinetics:
absorbed rapidly from
the GIT
20% excreted
unchanged in the urine
Indications:
Enterobius
Ascaris
Piperazine
Adverse Effects:
GIT upset
neurotoxicity
urticaria
Drug interaction with pyrantel: antagonism
Piperazine
Contraindications:
pregnancy
seizures
renal disorders
Praziquantel
MOA:
increases cell membrane
permeability to calcium
resulting in marked
contraction, followed by
paralysis of worm
musculature
Praziquantel
Pharmacokinetics:
rapidly and almost completely absorbed from the GIT
peak serum concentration is reached in 1-2 hours
penetrates the BBB
first pass metabolism in liver
excretion: renal
Praziquantel
Adverse effects:
most common – malaise, headache, dizziness, anorexia
others – drowsiness, nausea, vomiting, abdominal pain,
low grade fever, pruritus
Contraindication:
ocular cysticercosis
children under 4 years old
pregnant and lactating mothers
Niclosamide
MOA:
inhibits oxidative phosphorylation
Pharmacokinetics:
minimally absorbed following oral administration
Niclosamide
Adverse effects:
mild and transient nausea, vomiting, diarrhea, abdominal
discomfort;
Contraindications/precautions:
consumption of alcohol
children below 2 years old
pregnancy
Niridazole
MOA:
not established
Pharmacokinetics:
absorbed slowly
peak serum concentration attained in 6 hours
mainly excreted in the urine, some in feces
Niridazole
Adverse effects:
GIT – nausea, vomiting,
diarrhea, abdominal pain
headache, dizziness
myalgia
hematologic and neuropsychiatric effect
*Updated from: Handbook
of Pediatric Infectious
Diseases, 2004, a PPS
Publication
DRUGS OF CHOICE & ALTERNATE
DRUGS
Ascaris lumbricoides
Pyrantel pamoate, Mebendazole
Piperazine citrate
Trichiuris trichiura (whipworm)
Mebendazole
DRUGS OF CHOICE & ALTERNATE
DRUGS
*Updated from: Handbook of
Pediatric Infectious Diseases, 2004,
a PPS Publication
Necator americanus & Ancylostoma
duodenale
Mebendazole
Pyrantel pamoate
Enterobius vermicularis (pinworm)
Pyrantel pamoate
Mebendazole
*Updated from: Handbook of
Pediatric Infectious Diseases, 2004,
a PPS Publication
DRUGS OF CHOICE & ALTERNATE
DRUGS
Strongyloides stercoralis
Albendazole
Thiabendazole
Schistosoma japonicum
Praziquantel
DRUGS OF CHOICE & ALTERNATE
DRUGS
*Updated from: Handbook of
Pediatric Infectious Diseases, 2004,
a PPS Publication
Taenia saginata & Taenia solium
Niclosamide
Praziquantel
Paromomycin
Cysticercosis
Praziquantel
DRUGS OF CHOICE & ALTERNATE
DRUGS
*Updated from: Handbook of
Pediatric Infectious Diseases, 2004,
a PPS Publication
Wuchereria bancrofti & Brugia malayi
Diethylcarbamazine citrate
Capillaria philippinensis
Mebendazole
Paragonimus westermani
Praziquantel
Bithionol
CHLAMYDIAL INFECTION
Chlamydophila pneumoniae
ETIOLOGY
obligate intracellular pathogens
established a unique niche in host cells
gram-negative envelope without detectable
peptidoglycan
share a group-specific lipopolysaccharide antigen
use host ATP for the synthesis of chlamydial proteins
encode an abundant surface exposed protein called the
major outer membrane protein (MOMP, or OmpA)
The most significant human pathogens are:
C. pneumoniae ; C. trachomatis ; C. psittaci
Clinical Manifestations
classic atypical (or nonbacterial) pneumonia
characterized by mild to moderate constitutional
symptoms, including
fever, malaise, headache, cough, pharyngitis
Asymptomatic respiratory infection has been
documented in 2-5% of adults and children and can
persist for ≥1 yr
Diagnosis
Auscultation: rales,wheezing
Chest radiograph:
appears worse than the patient's clinical status
mild, diffuse involvement or lobar infiltrates with small
pleural effusions.
CBC: may be elevated with a left shift but is usually
unremarkable
Specific diagnosis:
isolation of the organism in tissue culture
grows best in cycloheximide-treated HEp-2 and HL cells
optimum site for culture is the posterior nasopharynx
Treatment
effective for eradication of C. pneumoniae from the
nasopharynx of children with pneumonia in
approximately 80% of cases
erythromycin (40 mg/kg/day PO divided twice a day
for 10 days),
clarithromycin (15 mg/kg/day PO divided twice a day
for 10 days), and
azithromycin (10 mg/kg PO on day 1, and then
5 mg/kg/day PO on days 2-5)
Chlamydia Trachomatis
Genital Tract Infections
Etiology
C. trachomatis is a major cause of epididymitis and is
the cause of 23-55% of all cases of nongonococcal
urethritis,
50% of men with gonorrhea may be co-infected with C.
trachomatis
prevalence of chlamydial cervicitis among sexually active
women is 2-35%
Rates of infection among girls 15-19 yr of age exceed
20% in many urban populations but can be as high as
15% in suburban populations as well
Clinical Manifestations
Up to 75% of women asymptomatic
discharge that is usually mucoid rather than purulent
can cause urethritis (acute urethral syndrome),
epididymitis, cervicitis, salpingitis, proctitis, and pelvic
inflammatory disease
Asymptomatic urethral infection is common in sexually
active men.
Autoinoculation from the genital tract to the eyes can
lead to conjunctivitis
Diagnosis
Definitive diagnosis: isolation of the organism in
tissue culture and as confirmation of the characteristic
intracytoplasmic inclusions by fluorescent antibody
staining
C. trachomatis can be cultured in cycloheximide-treated
HeLa, McCoy, and HEp-2 cells.
Treatment
uncomplicated C. trachomatis genital infection in men
and nonpregnant women
azithromycin (1 g PO as a single dose)
doxycycline (100 mg PO twice a day for 7 days)
erythromycin base (500 mg PO 4 times a day for 7 days),
erythromycin ethylsuccinate (800 mg PO 4 times a day for
7 days),
ofloxacin (300 mg PO twice a day for 7 days),
levofloxacin (500 mg PO once daily for 7 days).
Treatment
For pregnant women
erythromycin base (500 mg PO twice a day for 7 days)
amoxicillin (500 mg PO 3 times a day for 7 days)
erythromycin base (250 mg PO 4 times a day for 14 days),
erythromycin ethylsuccinate (800 mg PO 4 times a day for
7 days or 400 mg PO 4 times a day for 14 days),
azithromycin (1 g PO in a single dose)
Amoxicillin at a dosage of 500 mg PO 3 times a day for 7
days is as effective as any of the erythromycin regimens
Treatment
Empirical treatment
only for patients at high risk for infection who are unlikely
to return for follow-up evaluation,
including adolescents with multiple sex partners
treated empirically for both C. trachomatis and gonorrhea
Sex partners of patients with nongonococcal urethritis
should be treated
Especially if they have had sexual contact with the patient
during the 60 days preceding the onset of symptoms
The most recent sexual partner should be treated even if
the last sexual contact was more than 60 days from onset
of symptoms
Complications
perihepatitis (Fitz-Hugh-Curtis syndrome) and salpingitis
up to 40% will have significant sequelae:
17% will suffer from chronic pelvic pain,
17% will become infertile
9% will have an ectopic (tubal) pregnancy
Adolescent girls at higher risk for complications:
tubal scarring,
subsequent obstruction with secondary infertility,
increased risk for ectopic pregnancy
Complications
50% of neonates born to pregnant women with
untreated chlamydial infection will acquire C.
trachomatis infection
Women with C. trachomatis infection have a 3-5-fold
increased risk for acquiring HIV infection
Prevention
Timely treatment
Sex partners should be evaluated and treated if they had
sexual contact during the 60 days preceding onset of
symptoms in the patient
The most recent sex partner should be treated even if
the last sexual contact was >60 days
Complications
Patients and partners:
abstain from sexual intercourse until 7 days after a singledose regimen or after completion of a 7-day regimen
Annual routine screening for C. trachomatis for
sexually active female adolescents,
women 20-25 years of age,
older women with risk factors such as new or multiple
partners or inconsistent use of barrier contraceptives
Chlamydia Trachomatis
Conjunctivitis and Pneumonia in Newborns
Epidemiology
5-30% of pregnant women
50% risk for vertical transmission at parturition to
newborn infants
infected at 1 or more sites, (conjunctivae, nasopharynx,
rectum, and vagina)
Transmission is rare following cesarean section with intact
membranes
systematic prenatal screening and treatment of pregnant
women decreased the incidence
Inclusion Conjunctivitis
30-50% of infants born to mothers with active,
untreated chlamydial infection
develop 5-14 days after delivery,
from mild conjunctival injection with scant mucoid
discharge to severe conjunctivitis with copious purulent
discharge,
chemosis,
pseudomembrane formation
conjunctiva may be very friable and miight bleed when
stroked with a swab
50% of infants with chlamydial conjunctivitis also have
nasopharyngeal infection
Pneumonia
10-20% of infants born to women with active, untreated
chlamydial infection
25% of infants with nasopharyngeal chlamydial infection
develop pneumonia
Onset:1 and 3 mo of age
Presentation: insidious, with persistent cough,
tachypnea, and absence of fever
Auscultation: rales
Laboratory finding: peripheral eosinophilia (>400
cells/mm3)
Chest radiograph: hyperinflation accompanied by
minimal interstitial or alveolar infiltrates.
Diagnosis
Definitive diagnosis: isolation of C. trachomatis in
cultures of specimens obtained from the conjunctiva or
nasopharynx.
Nonculture methods including direct fluorescent antibody
(DFA)
sensitivities of ≥90% and
specificities of ≥95% for conjunctival specimens compared
with culture.
Treatment: C. trachomatis
conjunctivitis or pneumonia in
infants
erythromycin (base or ethylsuccinate, 50 mg/kg/day
divided 4 times a day PO for 14 days).
results of 1 small study:
short course of azithromycin (20 mg/kg/day once daily PO
for 3 days) is as effective as 14 days of erythromycin.
An association between treatment with oral
erythromycin and infantile hypertrophic pyloric
stenosis has been reported in infants <6 wk of age
who were given the drug for prophylaxis after nursery
exposure to pertussis
Prevention
screening and treatment of pregnant women
Reasons for failure of maternal treatment:
poor compliance
re-infection from an untreated sexual partner
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