A comprehensive overview of roundworm covering subjects like cure, treatment, symptoms, diagnostics, research, causes and pictures


     The disease, caused by roundworms is considered the most common parasitosis in the world, and it is produced by a cylindrical worm, having clinical events and general digestive disorders - sometimes severe, especially in children - and which can lead to complications if the parasites are in large numbers (occlusion bowel, appendicitis).


  • The roundworm is the biggest human intestinal nematode parasite;
  • It is a cylindrical worm, white-yellow, pointed to the extremities;
  • Sexes are separated, the female is larger;
  • Female: 30 cm, straight and sharp extremities;
  • Male: 15 cm the posterior extremity being ventral curved, with two genital spiculi;
  • The inlet mouth is located at the front end and is provided with three chitin lips with shaped teeth in form of Y;
  • The digestive system is complete;
  • The anal-hole is located under terminal, ventral.

Fertilized roundworm egg at the time of submission

  • Is yellow-brown in the feces
  • Is spherical or slightly oval
  • Is oblong, the surface shows a loose substance, whitish.
  • The fertilized egg: 70.75. It has two membranes (external and internal). Inside there is the egg cell and the bubble show and yolk.
  • The embryos eggs: found only in the external environment, not in the stool.

Roundworm structure

     An exterior shell-albumin is the auxiliary protective membrane. Beneath it there is another colorless layer, relatively thick, smooth- then a thin inner membrane, inside is the roundworm egg cell which is not completely fill the egg, leaving a space at the extremities

Roundworm evolutionary cycle

     Transmission does not require an intermediate host, and the egg needs a period in the external environment for embryo.

     Man ingest larvae which passes through the liver, grow, shed, reaches the portal circulation, heart and lungs, then increases, it breaks the alveoli and is out by the sputum. Sputum may be expectorated or swallowed (adult parasite in the intestine is formed). Basically, the disease is not transmitted from human to human. After 30-60 days, from larvae are forming adults and female lays eggs.

Roundworm epidemiology

     The disease is cosmopolitan, spread everywhere except the poles and desert areas; is considered that approximately one billion people are infected with roundworms. The definitive hosts and the unique source of infection is the man, the worm being specifically a human parasite.

     The clinical picture varies depending on the stage and intensity of infection and the host reactivity to parasite attack. Incubation is 60-70 days.

     The events vary in relation to the number of parasites (100, commonly severe clinical events), but also with their location (especially in cases of extra intestinal disease). Such events can meet the location in lung, liver, but the general roundworm symptoms (so-called "vermin syndrome"), evidenced by fatigue, headache, fatigue, low grade fever, loss of appetite, impaired general condition. Complications of the disease can be intestinal (under occlusions, occlusions), by engaging in the digestive annexes tube or in the peritoneal cavity, or extra intestinal, roundworms can enter the trachea, bronchi, in the Eustachian tube, and in rare cases, quoted in literature in the pulmonary artery, right ventricle, nasal sinuses.

     Roundworm allergen exposure may cause hypersensitivity reactions, manifested by urticarial rash, abdominal pain, conjunctivitis, edema face.

     The diagnosis is made by the method of Willis-Hung: 1-2 g homogenized feces with saturated NaCl solution. Apply to surface a plate solution. After 30 minutes, slide with a forceps, is placed on a slide and examined with targets 10 and 40. Pathogenic treatment with corticosteroids is used for hypersensitivity reactions.

     The prophylaxis of the infection is through prevention measures of general order and through specific measures, in countries with high levels of sanitation even mass chemotherapy is recommended (specific treatment with albendazole in a single dose at 4 to 6 months).

     Adult roundworms live in the lumen of small intestine of the host. Female deposits here its numerous eggs. In the absence of male, female lays unfertilized eggs, which have a non infesting capacity. Eggs resulting from sexual reproduction containing a single egg cell, undivided (are unicellular). They have a durable protective coating. They are eliminated with feces by the host in the environment. Are very resistant to external environment and can remain viable in soil for more than a year. They are not infesting when they are ingested in the non fertilized stage. When encountered favorable conditions (wet ground, shaded, ambient temperature of 22-24 degrees C), the egg cell which they contain starts to divide, and the eggs become infected within a period which can vary from 18 days to three weeks.

     The embryonated roundworm eggs contaminate soil, water and plants that have come into contact. They can be ingested by humans or animals once with them (through consumption of contaminated water, unwashed fruits and vegetables, dirty hands).

     Once the roundworms reach the small intestine, the embryonated eggs hatch, releasing larvae, that invade the intestinal mucosa and reaches, via portal and lymphatic circulation, in the liver. Here they suffer a first cycle of larval maturation, lasting four days. Then, via the systemic circulation, reach the lungs. Follows a cycle of larval maturation, a period of 10-14 days, after which the larvae pass through the alveolar wall and climbs up the tree trachea bronchitis in pharynx, where they are swallowed. Arriving back in the small intestine, the larvae are developing in adult worms and the cycle repeats.

     Once ingested, the infected roundworm eggs need 2-3 months to develop to adult stage worms, in which the female deposits her eggs in her first series. The life of an adult worm is 1-2 years.