Parasitology - Mansonella ozzardi

1. MANSONELLA
OZZARDI

2. OUTLINE
Introduction
Taxonomic Classification
Morphology
Epidemiology
Life Cycle
Transmission
Manifestation
Laboratory Diagnosis
Treatment and Prevention

3. INTRODUCTION
Mansonella ozzardi is a New
World filaroid parasite
Adults live in the body cavity,
within the mesenteries,
peritoneum, and in
subcutaneous tissues
Infected with Wolbachia
Intermediate hosts are midges
and blackflies

4. TAXONOMIC
CLASSIFICATION
 Kingdom: Animalia
 Phylum: Nematoda
 Class: Secernentea
 Order: Spirurida
 Family: Filariidae
 Genus: Mansonella
 Species: Mansonella
ozzardi

5. MORPHOLOGY
M. ozzardi is a cylindrical and bilaterally symmetrical worm, with
a pseudocoel.
Its exterior, the cuticle, is a protective layer that can withstand
the harsh environment in the digestive tracts of the human hosts.
M. ozzardi and other nematodes have longitudinal muscles that
run along the body wall. They also have dorsal, ventral, and
longitudinal nerve cords connected to these longitudinal muscles.
Adult M. ozzardi are long and slender with reduced lips. Females
are larger than males, and produce thousands of offspring called
microfilariae.

6. MORPHOLOGY
M. ozzardi microfilariae are
170-240 um long, unsheathed,
and have a slender, clear, tapered
tail called a "button hook."
The nuclei do not extend to the
end of the tail.
When stained, the presence or
absence of a sheath, internal
nuclei and organs can all be seen,
with the organization of these
aiding in identification and
classification of the different
filarial worm species.

7. MORPHOLOGY

8. EPIDEMIOLOGY
It is prominent in the subtropical, tropical, and
temperate regions of Central and South America (Mexico,
Panama, Brazil, Colombia, and Argentina), and the
Caribbean
Its prevalence rate varies from a few percent to 96% in
endemic areas such as Trinidad, Guyana, and Columbia

9. LIFE CYCLE

10. TRANSMISSION
M. ozzardi is transmitted by two types of arthropods that feed
on the blood of humans: biting midges (genus Culicoides) and
blackflies (genus Simulium).
Biting midges are small
flies that breed on sandy
beaches near the sea
Blackflies are larger
blood-sucking flies that
breed in fast-flowing
streams and rivers.

11. MANIFESTATION
The pathogenicity of M. ozzardi needs further research.
Although the adult worms live in the body cavities and the
mesentery, they seem to cause little or no harm to their human
hosts.
Infected people rarely present any symptoms. However, a few
clinical manifestations have been reported:1. Moderate fever
2. Coldness in the legs
3. Joint pains, like articular pain or
arthralgias
4. Headaches
5. Pruritus (itchiness)
6. Skin eruptions
7. Pulmonary symptoms
8. Lymphadenitis - inflammation of the
lymph nodes
9. Adenopathy - enlargement of the
lymph nodes
10. Hepatomegaly - enlargement of the
liver

12. LABORATORY DIAGNOSIS
Microscopic examination is the most
practical diagnostic tool used to identify
the M. ozzardi microfilariae in blood
samples from infected patients.
Since the microfilariae are not periodic,
periodicity is not a factor in taking the
blood sample.
Blood smears are usually stained with
haematoxylin and eosin or Giemsa to
visualize the worms under the
microscope.

13. TREATMENT AND
PREVENTIONIvermectin is the treatment of choice for M. ozzardi infections.
Diethylcarbamazine (DEC) also has been used in treating filarial
infections but is not effective in treating M. ozzardi microfilarial
infections.
Individuals living in endemic areas such as the Caribbean should
wear long-sleeved shirts and pants to decrease the exposed body
parts.
Insect repellents could also be used to cover body parts not
protected by clothing.
Communities should also maintain the natural vegetation around
them to decrease the possible breeding grounds for the biting
midges.