Filariases

Question 1

Common name for a group of diseases caused by ————-

Answer 1

filarial worms

Question 2

Pathogenic spp include:

Non-pathogenic spp include:

Answer 2

Pathogenic spp.:
✓ Wuchereria bancrofti; W. bancrofti var. pacifica
✓ Brugia malayi; B. timori
✓ Loa loa
✓ Onchocerca volvulus
Non-pathogenic spp:
✓ Mansonella perstans
✓ Mansonella streptocerca
✓ Mansonella ozzardi

Question 3

Widely distributed in trop./subtrop such as:

Answer 3

Widely distributed in trop./subtrop. Africa, America, Asia

Question 4

Transmitted by ——— vectors: non-pathogenic sp. mainly by ——— sp.

Answer 4

Transmitted by dipteran vectors: non-pathogenic sp. mainly by Culicoides sp.

Question 5

Loa loa transmitted by

Answer 5

Deer fly-chrysops

Question 6

Onchocerca volvulus is transmitted by

Answer 6

Black fly

Question 7

Periodicity is seen only in?

Answer 7

Microfilariae

Question 8

Periodicity
▪ nocturnal include
▪ diurnal include

Answer 8

:
▪ nocturnal: W. bancrofti (save sub-periodic W. bancrofti var. pacifica)
• B. malayi (save sub-periodic strains); B. timori
▪ diurnal: L. loa

Question 9

▪ nocturnal: W. bancrofti (except ———- W. bancrofti var. ——-)
• B. malayi (save ——-strains); B. timori
▪ diurnal: L. loa

Answer 9

:
▪ nocturnal: W. bancrofti (save sub-periodic W. bancrofti var. pacifica) • B. malayi (save sub-periodic strains); B. timori
▪ diurnal: L. loa

Question 10

———- can also be found outside the time period

Answer 10

Sub periodic

Question 11

Microfilariae of pathogenic group are sheathed. T or F

Answer 11

T

Question 12

Microfilariae of pathogenic group are sheathed; except

Answer 12

Onchocerca volvulus

Question 13

microfilariae of ———- are not sheathed & do not exhibit periodicity

Answer 13

microfilariae of Onchocerca

Question 14

Microfilariae (mf) of pathogenic spp have nuclear arrangement at ——— & ——— ends taxonomic; helps you tell the ——— of microfilariae

Answer 14

Microfilariae (mf) of pathogenic spp have nuclear arrangement at cephalic & caudal ends taxonomic; helps you tell the specie of microfilariae

Question 15

Distinguishing features of microfilariae (mf) based on no. & position of ——— in cephalic & caudal end

Answer 15

nuclei

Question 16

LYMPHATIC FILARIASIS
Aetiologic agents:
➢ it is one of the 21 ———
➢ Global estimates:
✓ ———- at risk in — countries (≈ —% live in ———-, Cameroon, Côte d’Ivoire, DR Congo, India, ———, Mozambique, ———, Nigeria [> —- million], Tanzania)
✓ > ——— infected (——— LF-related morbidity)
✓ elimination (which countries )

Answer 16

LYMPHATIC FILARIASIS
Aetiologic agents: W. bancrofti; B. malayi; B. timori
➢ it is one of the 21 Neglected Tropical Diseases
➢ Global estimates:
✓ 856 million @ risk in 52 countries (≈ 80% live in Angola, Cameroon, Côte d’Ivoire, DR Congo, India, Indonesia, Mozambique, Myanmar, Nigeria [> 100 million], Tanzania)
✓ > 120 million infected (40 million LF-related morbidity)
✓ elimination (China; Korea; Maldives; Sri Lanka; Cambodia; Cook Islands; Niue, Vanuatu; Togo; Egypt)

Question 17

LYMPHATIC FILARIASIS
➢ Transmission ensured by ———
➢ Residents of ——— areas @ greatest risk
➢ Causes ———-; leading cause of permanent disability

Answer 17

➢ Transmission ensured by mf periodicity
➢ Residents of endemic areas @ greatest risk
➢ Causes disfiguration; leading cause of permanent disability

Question 18

microfilarial periodicity = ——— time

Answer 18

vector feeding time

Question 19

Morphology & Development
➢ the microfilariae is ——- & ———
➢ male and female inhabit ——,——— (≈ — to —yr)
➢ female shed mf ———- which finds its way to the ——-
➢——- ingest mf; → then through the ——- → to the ——— muscles ( L3 develops — to —days after infection .) haemocoel → proboscis
➢Human infection: mf →goes through ———

Answer 19

Morphology & Development
➢ the microfilariae is whitish& filamentous
➢ male and female inhabit lymphatic vessels, l/nodes (≈ 5 to 7yr)
➢ female shed mf nocturnally which finds its way to the blood
➢mosquitoes ingest mf; → then through the gut wall → to the thoracic muscles ( L3 develops 9-13 days after infection .) haemocoel → proboscis
➢Human infection: mf →goes through skin

Question 20

Pathology/Clinical Features
➢ Most, asymptomatic; subclinical lymphatic dilatation & dysfunction
➢ Pathogenicity: ——filariae> ——filariae
➢ Incubation period usually ≤ — - — months
➢ Onset of symptoms: y/adults → l/nodes: symptoms begin when ——- get to lymph nodes
✓————-
✓ acute attack; — - — days (——spp)
▪ can recur severally in the course of a year T or F
▪ induration around ———»» whole limb

Answer 20

Pathology/Clinical Features
➢ Most, asymptomatic; subclinical lymphatic dilatation & dysfunction
➢ Pathogenicity: macrofilariae>microfilariae
➢ Incubation period usually ≤ 8 - 16 months
➢ Broad range of symptoms vary considerably regionally
➢ Onset of symptoms: y/adults → l/nodes: symptoms begin when adults get to lymph nodes
✓ lymphadenitis (inguinal &/or axillary »» deep abdominal): mild headache, fever & malaise
✓ acute attack; — - — days (——spp)
▪ can recur severally in the course of a year T
▪ induration around l/nodes »» whole limb

Question 21

➢ Death of adult worms:(death will lead to ——-)
Death of worm causes:
✓ ————
✓————
✓————

Answer 21

➢ Death of adult worms:
✓ lymphadenitis & lymphangitis
✓ funiculitis/epididymitis/orchitis (W. bancrofti): 25 million ♂ suffer genital dis. globally
funiculitis = inflammation of spermatic cord
✓ lymphadenitis @ intervals (B. malayi): shivers, fever, other general symptoms

Question 22

funiculitis/epididymitis/orchitis (——spo): — million male suffer genital dis. globally
funiculitis = inflammation of ———
✓ lymphadenitis @ intervals (———spp): presents with:

Answer 22

✓ funiculitis/epididymitis/orchitis (W. bancrofti): 25 million ♂ suffer genital dis. globally
funiculitis = inflammation of spermatic cord
✓ lymphadenitis @ intervals (B. malayi): shivers, fever, other general symptoms

Question 23

➢ Chronicity (— to —15 yr):
✓———-

hydrocele is a fluid-filled sac around a ——-

chyluria = lymphatic fluid leaks into the ——- & turns the urine ——- colour

✓ lymphedema (> — million) leads to ——- (≈ —%); microhaematuria & proteinuria
➢ TPES may occur:

TPES occurs more in ——— sp in Asia than ———

✓ diffuse lung infiltrations
✓ ↑ ——— + ↑ levels of —— &antifilarial——(hence can be diagnosed ———-)
✓ no peripheral ———(they are in the ———)
✓ symptoms include:

Answer 23

➢ Chronicity (10 - 15 yr):
✓ hydrocele & chyluria (W. bancrofti)

hydrocele is a fluid-filled sac around a testicle

chyluria = lymphatic fluid leaks into the kidneys & turns the urine milky white

✓ lymphedema (> 15 million) »» elephantiasis (≈ 30%); microhaematuria & proteinuria
➢ TPES may occur:

TOESoccurs more in brugia sp in Asia than wuchereria

✓ diffuse lung infiltrations
✓ ↑ eosinophilia + ↑ levels of IgE & antifilarial Abs(hence can be diagnosed serologically)
✓ no peripheral microfilaraemia(they are in the lungs)
✓ cough, fever, dyspnoea & wheezing (can be worse at night )

Question 24

➢Brugia filariasis:
✓ typified by lower leg & lower arm ——
✓chronic cases: frequent ——-
—% of elephantiasis patients amicrofilaraemic in the Pacific & Indonesia

Answer 24

➢Brugia filariasis:
✓ typified by lower leg & lower arm elephantiasis
✓chronic cases: frequent amicrofilaraemia (40% of elephantiasis patients amicrofilaraemic in the Pacific & Indonesia)

Question 25

Diagnosis > Microscopy (for mf): - fresh —— samples -———-- or haematoxylin-eosin stained (thick/thin?)smears —Provocation test: used to diagnose infections in areas where microfilariae exhibit ———- periodicity - oral — mg —- leads to increased microfilaraemia (30 - 60 min) -& severe ——— rxn in areas with mixed filariasis life threatening reaction that occurs within — days of treatment of microfilariasis > QBC technique - also called————— technique; examine ———after ————

Answer 25

Diagnosis > Microscopy (for mf): - fresh blood samples -Giemsa- or haematoxylin-eosin stained thick smears —Provocation test: used to diagnose infections in areas where microfilariae exhibit nocturnal periodicity - oral 100 mg DEC »» ^ microfilaraemia (30 - 60 min) -& severe Mazzotti rxn in areas with mixed filariasis life threatening reaction that occurs within 7 days of treatment of microfilariasis > QBC technique - Quantitative buffy coat technique; examine buffy coat after centrifugation

Question 26

Diagnosis Biopsy of palpable ———-;you see the adults (L—) • Membrane/Nucleopore filtration (pore size, — um) microfilariae are >—um in size - Serological: Point of Care - Rapid Diagnostic tests POC-RDTs (bancroftian filariasis)examples: - • - increased levels of antifilarial ———, ———, ———, ———, -Ultrasonography - Lab tests generally -ve in patients with ————

Answer 26

Diagnosis Biopsy of palpable I/nodes;you see the adults (L5) • Membrane/Nucleopore filtration (pore size, 3 um) microfilariae are >3um in size - Serological: Point of Care - Rapid Diagnostic tests POC-RDTs (bancroftian filariasis)examples: -BinaxNOW® Filariasis(detecting antigens) •Filariasis Test Strip (FTS) - increased levels of antifilarial IgG4: CFT, IHAT, IIFT, ELISA (complement fixation test, indirect hemagluttinin test, indirect immunofluorescent test, ELISA respectively) -Ultrasonography - Lab tests generally -ve in patients with lymphedema

Question 27

Treatment &/or Management;include . . . .

Answer 27

Treatment &/or Management ➢ **DEC: 6 mg/kg (/d x 7 - 12 d) or (/wk x 6 wk) > Ivermectin or DEC + Albendazole > Doxycycline (200 mg/d × 6 wk) • Hydrocelectomy surgery

Question 28

Treatment &/or Management > *** DEC: —mg/kg (/d x 7 - 12 d) or (/wk × 6 wk); micro and macrofilaricidal.T or F > Ivermectin or DEC + Albendazole ——— preferred to ——- due to its toxicity > Doxycycline (——mg/d × 6 wk) kills ——- • Hydrocelectomy surgery to remove ——-

Answer 28

Treatment &/or Management > *** DEC: 6 mg/kg (/d x 7 - 12 d) or (/wk × 6 wk); micro- and macrofilaricidal > Ivermectin or DEC + Albendazole ivermectin preferred to DEC due to is toxicity > Doxycycline (200 mg/d × 6 wk) kills Wolbachia • Hydrocelectomy surgery to remove hydrocele

Question 29

Prevention & Control • PC: MDA; (Preventive chemotherapy: Mass Drug Administration) I/annual ————- (400 mg) +: rx of onchocerca is ———— . Ivermectin (— mg/kg) in areas co-endemic for ——— DEC (6 mg/kg) +/- Ivermectin (200 g/kg) in some areas (no ———) 2/annual —— mg albendazole in areas co-endemic for ——— Treatment for loa is ——- & ——— • Vector control: - ————- - ————- bio-control: biological larvicides include

Answer 29

Prevention & Control • PC: MDA; (Preventive chemotherapy: Mass Drug Administration) I/annual albendazole (400 mg) +: rx of onchocerca is IVERMECTIN . Ivermectin (200 mg/kg) in areas co-endemic for oncho DEC (6 mg/kg) +/- Ivermectin (200 g/kg) in some areas (no oncho) 2/annual 400 mg albendazole in areas co-endemic for loiasis Tx for loa is DEC & ALBENDAZOLE • Vector control: V eliminate breeding sites V insecticiding +/or larviciding bio-control: Bacillus thuringiensis var. israelensis (Bti); B. sphaericus biological larvicides

Question 30

• Avoid vector bites: - - — "Integrated approach: annual MDA (decreases ————; decreases ———) + ——- control = Basis of global campaign for elimination • Elimination: —— (2020)

Answer 30

• Avoid vector bites: - repellents (DEET) DIETHYLTOLUAMIDE - mechanical prev. measures — "Integrated approach: annual MDA (decreases microfilaraemia; decreases transmission) + vector control = Basis of global campaign for elimination • Elimination: Togo (2020)