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144 Parasitic Infestations of Surgical Importance in Children

• Resection: The affected bowel segment is surgically removed with
the contained worms and an end-to-end anastomosis is performed.
This is indicated in those cases for which the mass of worms is very
tightly packed, causing partial necrosis of the gut, and stretching
the gut wall may threaten its viability.
Prevention
• Mass treatments with single-dose mebendazole or albendazole for
all preschool and school-age children every three to four months
have been used in some communities.
• Encourage proper and safe methods of sewage disposal.
• Protect food from dirt and soil.
• Thoroughly washing raw food materials is good practice.
• Encourage proper hand-washing habits and other sanitary measures.
Dracontiasis
Dracontiasis is a disease caused by the adult female Dracunculus Figure 23.2: Dracontiasis in a child (note the worm emerging from the ankle).
medinensis, the oldest human parasite. It is more commonly known as
guinea worm disease (GWD), after the Europeans who first saw the body, including the trunk, arms and hands, buttocks, thigh, knee joint,
disease on the Guinea Coast of West Africa in the 17th century. genital area, and, rarely, the neck. At this stage, the female body is mostly
Currently, transmission occurs in only 10 countries of the world, occupied by a distended uterus containing millions of larvae. A substance
all in sub-Saharan Africa. Other countries are either certified free of secreted by the gravid female causes a blister to form in the skin of the
transmission or are presently in the precertification period. The goal is host around the anterior extremity of the female worm. When in contact
for dracontiasis to be the first parasitic disease to be eradicated and the with water, as occurs during swimming, washing, bathing, or wading, the
first disease in history eradicated through behaviour change, without blister ruptures; the worm protrudes and discharges hundreds of thousands
use of vaccines or cure. of larvae into the water. The larvae are then ingested by the cyclops and
Demographics mature in about 3 weeks, thus completing the life cycle of the parasite.
Dracontiasis is essentially a disease affecting rural communities. Whilst Generally, two types of lesions are produced in man: vesicles, which
the occurrence of cases is possible in urban environments, such cases ulcerate, and subcutaneous or deep abscesses around dead adult worms.
usually have been “imported” and were contracted elsewhere. At pres- Calcification of worms, which sometimes occurs in tissues, may induce
ent, the disease is endemic mainly in West Africa, the site of 9 of the local manifestations: pulmonary, cardiovascular, abdominal, urogenital,
10 countries where transmission occurs: Benin, Burkina Faso, Cộte or gyn-obstetrical.
d’Ivoire, Ghana, Niger, Nigeria, Mali, Mauritania, and Togo. The tenth Secondary bacterial superinfection at the point of emergence of
country is Ethiopia in East Africa. the worm is rather common when nursing is not available, and may
Dracontiasis rarely occurs in children younger than the age of 3 lead to an aggravation of the condition and complications such as
years because the babies are generally breast-fed, and the long period septicaemia and tetanus. Severe arthritis and ankylosis may be due to
of incubation delays the first emergence of the worm to one year after either the release of D. medinensis embryos inside the joint (aseptic
weaning. The incidence of the disease increases significantly after 5 arthritis) or the bacterial infection of the tunnel of the worm (septic
years and is maximal between 15 and 45 years of age. The incidence arthritis). Such complications may lead to physical deformity and
is high in active adults who, because of their farming activities, drink limitation of mobility.
larger quantities of water and use water from unsafe sources such as Clinical Presentation
nontreated ponds far from the village and close to the farming field.
• GWD is rare in children <3 years old, but increases significantly
The disease usually shows no significant gender difference in
after 5 years of age. Both sexes are equally affected.
prevalence of infection. However, in some communities, such as in
northern Nigeria, the rate of infection appears to be higher in males. • Symptoms arise when a live worm reaches the skin at the site of
This is observed in populations in which women do not participate in emergence.
farming activities, and thus are less exposed to drinking water from
• A cutaneous blister erupts with an intense burning sensation
unsafe sources.
locally. A few hours before the development of the local lesion, the
Aetiology/Pathophysiology symptoms are exacerbated and may include erythema, urticarial
GWD is acquired by the ingestion of the water flea, cyclops, in drinking rash, intense pruritus, nausea and vomiting, diarrhoea, dyspnoea,
water. It is the only disease transmitted exclusively through drinking giddiness, and syncope.
water. The guinea worm requires a host (man) and an intermediate host • The lesion develops within a few hours in the form of a papule
(cyclops) for its full development. The larvae mature in the cyclops centred by a veside and surrounded by a local induration. On con-
found in standing dirty water (e.g., puddles, ponds, and dams). When tact with water, the blister bursts and the anterior part of the worm
such water is consumed, the infected cyclops is digested in the gastric emerges and discharges larvae and internal fluids. At this stage, the
hydrochloric acid, thus liberating the larvae. The larvae, male and pain and the burning sensation are reduced and the other symptoms
female, burrow through the intestine to enter the circulation. The males, also tend to decrease.
only 2–3 cm long, die after fertilising the females.
The female then matures in the connective tissue to measure 550–800 • The worm can emerge at any place of the body, but most com-
cm long by 1.7–2.00 mm in diameter at 10–14 months after infection, monly at the lower part of the leg around the ankles.
before it emerges from the subcutaneous tissue, mainly of the lower leg • Calcified worms, which remain asymptomatic, have been discov-
around the ankle (Figure 23.2). However, it can emerge at any part of the ered by chance on x-ray or during a surgical intervention.