[DISCUSSION] MODULE 2 UNIT 3 Flashcards
INTESTINAL FLAGELLATES
- Giardia lamblia
- Dientamoeba fragilis
- Chilomastix mesnili
- Pentatrichomonas hominis
ATRIAL FLAGELLATES
- Trichomonas vaginalis
- Trichomonas tenax
HEMOFLAGELLATES
- Leishmania spp.
- Trypanosoma spp.
Giardia lamblia Also known as
Giardia duodenalis, or Giardia intestinalis
manifests as a significant but not life-threatening gastrointestinal
disease
Giardia lamblia
resistant forms and are responsible for transmission of giardiasis
Giardia lamblia Cysts
infective stage
Giardia lamblia Cysts
hardy and
can survive several months in
cold water
Giardia lamblia mature cysts
occurs in the small
intestine.
Excystation Giardia lamblia
multiply by longitudinal binary fission, and remain in the duodenum and upper jejenum
Giardia lamblia Trophozoites
occurs when the trophozoite transits to the colon
Giardia lamblia Encystation
occurs when the host ingests food or water contaminated with the mature cysts
Infection with G. duodenalis
Depending on the strain involved, infection can occur with one ingesting as few as 10 cysts.
Giardia lamblia
Giardiasis in about half of the infected patients may be
Asymptomatic
- occurs in 1 to 4 weeks (average of 9 days)
Giardiasis
Symptomatic infection. Acute phase
- patients experience abdominal pain, described as cramping, associated with diarrhea.
Giardiasis
Symptomatic infection. Acute phase
- There is also excessive flatus with an odor of “rotten eggs” due to hydrogen sulfide.
Giardiasis
Symptomatic infection. Acute phase
- Other clinical features include abdominal bloating, nausea, and anorexia. Spontaneous recovery occurs within 6 weeks in mild to moderate cases.
Giardiasis
Symptomatic infection. Acute phase
- In untreated cases, patients may experience diarrhea with varying intensities, for weeks or months. The acute phase is often followed by chronic phase.
Giardiasis
Symptomatic infection. Chronic phase
- Characterized by steatorrhea
Giardiasis
Symptomatic infection. Chronic phase
- In some cases, periods of diarrhea have been observed to alternate with normal or even constipated bowel periods. There may be weight loss, profound malaise, and low-grade fever.
Giardiasis
Symptomatic infection. Chronic phase
Giardia lamblia trophozoite does not invade the tissue, but remains adhered to intestinal epithelium by means of the sucking disc.
Cytoadherence
It is able to cause alterations in the villi such as villous flattening and crypt hypertrophy.
Cytoadherence
These alterations lead to decreased electrolyte, glucose, and fluid absorption, and cause deficiency enzymes such as disaccharidases.
Cytoadherence
This results in the entire surface of the parasite being covered with (?) which help the parasite in evasion of host immune system.
variant-specific surface proteins (VSSPs)
Giardia lamblia Transmission
Fecal-oral route.
Transmission depends on the swallowing of mature cysts in fecally-contaminated food or water or by direct contact related to poor personal hygiene or sexual practices.
Giardia lamblia
The risk factors that favor survival and transmission are the same as those affecting amoebiasis
Giardia lamblia
Geographical distribution: Cosmopolitan. Endemicity is very high in areas with low sanitation, especially tropics and subtropics.
Giardia lamblia
Prevalence: Approximately 1.6 to 22% in the Philippines.
Giardia lamblia
Reservoir: Human, beavers, dogs, cats, and sheep serve as reservoirs
Giardia lamblia
was previously considered as an amoeba but has now been reclassified as an amoeboflagellate, based on electron microscopic study and antigenic similarity to Trichomonas
Dientamoeba fragilis
does not invade tissues, but its presence in the intestines produces irritation of the mucosa with secretion of excess mucus and hypermotility of the bowel
Dientamoeba fragilis
In 25% of the disease, the most common symptoms are diarrhea and abdominal pain
dientamoebiasis
Symptoms also can include loss of appetite, weight loss, nausea, and fatigue.
Dientamoeba fragilis
The infection does not spread from the intestine to other parts of the body.
Dientamoeba fragilis
transmissionoccurs when infective cysts are ingested
Chilomastix mesnili
It normally lives in the cecal region of the large intestine, where the organisms feed on bacteria and debris.
Chilomastix mesnili
The trophozoites live in the cecal area of the large intestine and feed on bacteria.
Pentatrichomonas hominis
cannot be transplanted into the urogenital tract or the mouth
Pentatrichomonas hominis
Transmission probably occurs by ingesting the trophozoite form.
Pentatrichomonas hominis
If ingested in a protective substance such as milk, these organisms can apparently survive passage through the stomach and small intestine in patients with achlorhydria.
Pentatrichomonas hominis
causes a sexually transmitted disease called trichomoniasis
Trichomonas vaginalis
It is now often described as the most prevalent non-viral sexually transmitted infection
Trichomonas vaginalis
The parasite is found in the urogenital tract.
Trichomonas vaginalis
In women, it is found in the vagina but may ascend as far as the renal pelvis.
Trichomonas vaginalis
The parasite can be isolated from the urethra, prostate, and less frequently, in the epididymis in men.
Trichomonas vaginalis
The trophozoites multiply by binary fission in the host and are transferred passively from person to person
Trichomonas vaginalis
generally asymptomatic
Trichomoniasis in males
Although, some may develop urethritis, epididymitis and prostatitis.
Trichomoniasis in males
There is no strong evidence that males infected with trichomoniasis are more likely to develop
prostate cancer
Trichomoniasis in females, after an incubation period of 4 days to 4 weeks, the following symptoms of vaginitis or cervicitis are common:
greenish-yellow, frothy, foul-smelling vaginal discharge
vaginal or vulval pruritis
dysuria
dyspareunia
Itching in the vaginal area
vaginal or vulval pruritis
painful and burning sensation on urination
dysuria
pain during sexual intercourse
dyspareunia
Females infected with trichomoniasis have a higher risk of (?), especially when co-infected with HPV.
cervical cancer
Speculum examination reveals small punctate
hemorrhagic spots on the vaginal and cervical
mucosa; this has been called
Strawberry appearance
The trophozoites feed on the mucosal surface of the vagina, where bacteria and leukocytes are found.
strawberry appearance
Normal vaginal pH
3.8 – 5.0
Preferred pH of T. vaginalis
6.0-6.3
Complications in women include
secondary bacterial infection of the urogenital tract
are infrequent complications
Endometritis and pyosalpingitis
Geographical distribution: Cosmopolitan.
T. vaginalis
T. vaginalis
About (?) of women and (?) of men in developed countries are infected.
5 to 20%
2 to 12%
Humans are the only natural host for
T. vaginalis
is frequently seen concomitantly with other STDs, particularly gonorrhea
Trichomoniasis
The majority of women with trichomoniasis also have
bacterial vaginosis
Unlike other STDs, which have a higher prevalence among adolescents and young adults, the rates of trichomoniasis are more evenly distributed among (?), further strengthening its potential utility as a marker for risky sexual behavior
sexually active women of all age groups
T. vaginalis Infection is acquired primarily through
sexual intercourse
Higher prevalence is associated with greater frequency of sexual intercourse with multiple partners and with commercial sex workers.
Trichomoniasis
Hence, there is the need to diagnose and treat
asymptomatic males
Simultaneous treatment of both partners is recommended to prevent (?), i.e., a reinfection from the same sexual partner.
“ping-pong infection”
T. vaginalis is known to be transferred by means of fomites such as toilet articles, towels, or underclothes
Indirect contact transmission
However, this mode of transmission is thought to be very rare.
Indirect contact transmission
T. vaginalis can survive for one to few hours in (?), and longer in a (?).
dry fomites
moist environment
are considered as the most resistant among the protozoan trophozoites.
Trophozoites of T. vaginalis
Trichomoniasis in pregnant women may cause premature rupture of the membranes that protect the baby, and early delivery.
Congenital transmission
The trophozoites may also migrate through a mother’s birth canal and infect the unborn child.
Congenital transmission
can only live in the mouth, in the periodontal pockets, carious tooth cavities and, less often, in tonsillar crypts
trophozoite of T. tenax
The mode of transmission is by direct contact (by kissing or through salivary droplets) or by use of contaminated dishes and glasses.
Trichomonas tenax
considered to be a nonpathogen
Trichomonas tenax
Treatment, therefore, is not indicated.
Trichomonas tenax
