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
THANK YOU :D