Schistosomiasis

Schistosomiasis (bilharziasis, blood fluke, snail fever, Katayama fever) – the neglected tropical disease

 By Dr S V Bulatov – registered homeopath

Schistosomiasis is a disease caused by parasitic flatworms called schistosomes that live in rivers, dams, lakes, canals, lagoons, fish ponds, wells, water reservoirs, etc.

Schistosomiasis is named for the genus of parasitic flatworm Schistosoma, whose name means 'split body'.

The name Bilharzia comes from Theodor Bilharz, a German pathologist working in Egypt in 1851 who first discovered these worms.

The first physician who described the entire disease cycle was the Brazilian parasitologist Pirajá da Silva in 1908.

The earliest known case of infection was discovered in 2014, belonging to a child who lived 6,200 years ago.

The disease is found in tropical countries in Africa, the Caribbean, eastern South America, Southeast Asia and the Middle East. S. mansoni is found in parts of South America and the Caribbean, Africa and the Middle East; S. haematobium in Africa and the Middle East; and S. japonicum in the Far East. S. mekongi and S. intercalatum are found locally in Southeast Asia and central West Africa, respectively.

1. haematobium, the infectious agent responsible for urogenital schistosomiasis, infects over 112 million people annually in Sub-Saharan Africa alone. It is responsible for 32 million cases of dysuria, 10 million cases of hydronephrosis and 150,000 deaths from renal failure annually, making S. haematobium the world’s deadliest Schistosoma.

Estimates regarding the number of deaths vary. Worldwide, the Global Burden of Disease Study issued in 2010 estimated 12,000 direct deaths while the WHO in 2014 estimated more than 200,000 annual deaths related to schistosomiasis. Another 20 million have severe consequences from the disease. It is the deadliest of the neglected tropical diseases.

Schistosomiasis affected about 252 million people worldwide in 2015. An estimated 4,400 to 200,000 people die from it each year. The disease is most commonly found in Africa, Asia and South America. Around 700 million people, in more than 78 countries, live in areas where the disease is common. In tropical countries, schistosomiasis is second only to malaria among parasitic diseases with the greatest economic impact. Schistosomiasis is listed as a neglected tropical disease.

People are infected during routine agricultural, domestic, occupational and recreational activities, which expose them to infested water.

Infected individuals release Schistosoma eggs into water via their stool or urine. After larvae hatch from these eggs, the larvae infect a very specific type of freshwater snail. For example, in S. haematobium and S. intercalatum it is snails of the genus Bulinus, in S. mansoni it is Biomphalaria, and in S. japonicum it is Oncomelania. The Schistosoma larvae undergo the next phase of their lifecycles in these snails, spending their time reproducing and developing. Once this step has been completed, the parasite leaves the snail and enters the water column. The parasite can live in the water for only 48 hours without a mammalian host. Once a host has been found, the worm enters its blood vessels. For several weeks, the worm remains in the vessels, continuing its development into its adult phase. When maturity is reached, mating occurs and eggs are produced. Eggs enter the bladder/intestine and are excreted through urine and stool. The process repeats itself. If the eggs do not get excreted, they can become engrained in the body tissues and cause a variety of problems such as immune reactions and organ damage.

Humans encounter larvae of the Schistosoma parasite when they enter contaminated water while bathing, playing, swimming, canoeing, washing, fishing or walking through the water.

There are a few other ways of transmission:

1. Neglected sanitization of water reservoirs, wells, pools and fish ponds.
2. Bilharzia eggs in pre-washed salads from infested farm water.
3. Bilharzia eggs in salads and meals prepared from infected restaurant or domestic workers.
4. Infested municipal water for drinking and showering.
5. School and caravan camping.
6. Visiting farms, game lodges/reserves.
7. Living in a squatter camp.

The urogenital tract or the intestines may be infected. Symptoms include abdominal pain, diarrhea, bloody stool or blood in the urine. Those who have been infected for a long time may experience liver damage, kidney failure, infertility or bladder/prostate cancer. In children, it may cause poor growth and learning difficulty.

The disease is spread by contact with fresh water contaminated with the parasites. These parasites are released from infected freshwater snails. The disease is especially common among children in developing countries, as they are more likely to play in contaminated water. Other high-risk groups include farmers, fishermen and people using unclean water during daily living. It belongs to the group of helminth infections. Diagnosis is by finding eggs of the parasite in a person's urine or stool. It can also be confirmed by finding antibodies against the disease in the blood.

Methods to prevent the disease include improving access to clean water and reducing the number of snails. In areas where the disease is common, the medication praziquantel/biltricide 600mg may be given according to the body weight once a year to the entire group. This is done to decrease the number of people infected, and consequently, the spread of the disease. Praziquantel/biltricide 600mg is also the treatment recommended by the World Health Organization for those who are known to be infected.

Many individuals do not experience symptoms. If symptoms do appear, they usually take 4–6 weeks from the time of infection. The first symptom of the disease may be a general feeling of illness. Within 12 hours of infection, an individual may complain of a tingling sensation or light rash, commonly referred to as "swimmer's itch", due to irritation at the point of entrance. The rash that may develop can mimic scabies and other types of rashes. Other symptoms can occur 2–10 weeks later and can include fever, aching, cough, diarrhea, chills or gland enlargement. These symptoms can also be related to avian schistosomiasis, which does not cause any further symptoms in humans.

The manifestations of schistosomal infection vary over time as the cercariae and later adult worms and their eggs, migrate through the body. If eggs migrate to the brain or spinal cord, seizures, paralysis or spinal-cord inflammation are possible.

There are 2 major forms of schistosomiasis – intestinal and urogenital – caused by 5 main species of blood fluke.

 Species’ geographical distribution:

 Intestinal schistosomiasis Schistosoma mansoni - Africa, the Middle East, the Caribbean, Brazil, Venezuela and Suriname;

Schistosoma japonicum - China, Indonesia, the Philippines;

Schistosoma mekongi - several districts of Cambodia and the Lao People’s Democratic Republic;

Schistosoma guineensis and related S. intercalatum - rainforest areas of central Africa;

Urogenital schistosomiasis Schistosoma haematobium - Africa, the Middle East, Corsica (since 2014);

 In intestinal schistosomiasis, eggs become lodged in the intestinal wall and cause an immune system reaction called a granulomatous reaction. This immune response can lead to obstruction of the colon and blood loss. The infected individual may have what appears to be a potbelly. Eggs can also become lodged in the liver, leading to high blood pressure through the liver, enlarged spleen, the buildup of fluid in the abdomen and potentially life-threatening dilations or swollen areas in the oesophagus or gastrointestinal tract that can tear and bleed profusely (oesophageal varices). In rare instances, the central nervous system is affected. Individuals with chronic active schistosomiasis may not complain of typical symptoms.

In urogenital schistosomiasis the worms of S. haematobium migrate to the veins around the bladder and ureters. This can lead to blood in the urine 10 to 12 weeks after infection. Over time, fibrosis can lead to obstruction of the urinary tract, hydronephrosis and kidney failure. Bladder cancer diagnosis and mortality are generally elevated in affected areas; efforts to control schistosomiasis in Egypt have led to decreases in the bladder cancer rate. The risk of bladder cancer appears to be especially high in male smokers, perhaps due to chronic irritation of the bladder lining allowing it to be exposed to carcinogens from smoking.

In women, urogenital disease can also include genital lesions that may lead to increased rates of HIV and HPV transmission.

In women, urogenital schistosomiasis may present with genital itching/burning, genital lesions, grainy or yellow sandy patches, abnormal blood vessels, rubbery papules, vaginal bleeding, pelvic pain, pain during/after sexual intercourse, nodules in the vulva, contact bleeding, infertility, abortion, ectopic pregnancy, involuntary urination when sneezing/coughing/jumping.

In men, urogenital schistosomiasis can induce pathology of the seminal vesicles, epididymis, prostate, bladder and other organs. This disease may also have other long-term irreversible consequences, including infertility.

Both intestinal and urogenital schistosomiasis could cause fibrosis in various organs within 5 to 15 years of the primary infection.

The first potential reaction is an itchy, papular rash that results from cercariae penetrating the skin, often in a person's first infection. The round bumps are usually one to three centimetres across. Because people living in affected areas have often been repeatedly exposed, acute reactions are more common in tourists and migrants. The rash can occur between the first few hours and a week after exposure and lasts for several days. A similar, more severe reaction called "swimmer's itch" reaction can also be caused by cercariae from animal trematodes that often infect birds.

Another primary condition, called Katayama fever, may also develop from infection with these worms, and it can be very difficult to recognize. Symptoms include fever, lethargy, muscle pains, abdominal pain, eruption of pale temporary bumps associated with severe itching (urticarial) rash, liver/spleen enlargement, bronchospasm with dry cough and changes on chest x-rays.

Acute schistosomiasis (Katayama fever) may occur weeks or months after the initial infection as a systemic reaction against migrating schistosomuli as they pass through the bloodstream through the lungs to the liver. Similarly to swimmer's itch, Katayama fever is more commonly seen in people with their first infection such as migrants and tourists. It is seen, however, in native residents of China infected with S. japonicum.

The symptoms usually get better on their own but a small proportion of people have persistent weight loss, diarrhea, diffuse abdominal pain and rash.

In long-established disease, adult worms lay eggs that can cause inflammatory reactions. The eggs secrete proteolytic enzymes that help them migrate to the bladder and intestines to be shed. The enzymes also cause an eosinophilic inflammatory reaction when eggs get trapped in tissues or embolize to the liver, spleen, lungs or brain. The long-term manifestations are dependent on the species of schistosomae, as the adult worms of different species migrate to different areas. Many infections are mildly symptomatic, with anaemia and malnutrition being common in endemic areas.

Central nervous system lesions occur occasionally. Cerebral granulomatous disease may be caused by S. japonicum eggs in the brain. Communities in China affected by S. japonicum have rates of seizures eight times higher than baseline. Similarly, granulomatous lesions from S. mansoni and S. haematobium eggs in the spinal cord can lead to transverse myelitis with flaccid paraplegia. Eggs are thought to travel to the central nervous system via embolization.

Diagnosis of infection is confirmed by the identification of eggs in stools. Eggs of S. mansoni are about 140 by 60 µm in size and have a lateral spine. The diagnosis is improved through the use of the Kato technique, a semi quantitative stool examination technique. Other methods that can be used are enzyme-linked immunosorbent assay, circumoval precipitation test and alkaline phosphatase immunoassay.

Microscopic identification of eggs in stool or urine is the most practical method for diagnosis. Stool examination should be performed when infection with S. mansoni or S. japonicum is suspected and urine examination should be performed if S. haematobium is suspected. Eggs can be present in the stool in infections with all Schistosoma species. The examination can be performed on a simple smear (1 to 2 mg of stool). Because eggs may be passed intermittently or in small numbers, their detection is enhanced by repeated examinations or concentration procedures, or both. In addition, for field surveys and investigational purposes, the egg output can be quantified by using the Kato-Katz technique (20 to 50 mg of stool) or the Ritchie technique. Eggs can be found in the urine in infections with S. haematobium (recommended time for collection: between noon and 3 PM) and with S. japonicum. Quantification is possible by using filtration through a nucleopore filter membrane of a standard volume of urine followed by egg counts on the membrane. Tissue biopsy (rectal biopsy for all species and biopsy of the bladder for S. haematobium) may demonstrate eggs when stool or urine examinations are negative.

IgM, IgG and IgE antibody detection can be useful to indicate schistosomal infection in people who have travelled to areas where schistosomiasis is common and in whom eggs cannot be demonstrated in stool or urine specimens. Test sensitivity and specificity vary widely among the many tests reported for the serologic diagnosis of schistosomiasis and are dependent on both the type of antigen preparations used (crude, purified, adult worm, egg, cercarial) and the test procedure.

Many countries are working towards eradicating the disease. The World Health Organization is promoting these efforts. In some cases, urbanization, pollution and the consequent destruction of snail habitat have reduced exposure, with a subsequent decrease in new infections. The drug praziquantel/biltricide 600mg is used for prevention in high-risk populations living in areas where the disease is common.

Two drugs, praziquantel/biltricide 600mg and oxamniquine, are available for the treatment of schistosomiasis. They are considered equivalent in relation to efficacy against S. mansoni and safety. Because of praziquantel/biltricide's lower cost per treatment and oxaminiquine's lack of efficacy against the urogenital form of the disease caused by S. haematobium, in general praziquantel/biltricide 600mg is considered the first option for treatment. The treatment objective is to cure the disease and to prevent the evolution of the acute to the chronic form of the disease.

N.B. All cases of suspected schistosomiasis should be treated regardless of presentation because the adult parasite can live in the host for 3 to 40 years!!!

Adult male and female worms live much of this time in copula, the slender female fitted into the gynaecophoric canal of the male, where she produces eggs and he fertilises them (appendix).

Eggs—whether excreted or retained in the body—die within 1–2 weeks after being released by the female worm.

All evidence suggests that schistosome eggs, and not adult worms, induce the morbidity caused by schistosome infections. Many eggs are not excreted and become permanently lodged in the intestines or liver (for S mansoni, S japonicum, and S mekongi) or in the bladder and urogenital system (for S haematobium). There, the eggs induce a granulomatous host immune response largely characterised by lymphocytes (which mainly produce T-helper-2 cytokines; eg, interleukins 4, 5 and 13), eosinophils, and, alternatively, activated macrophages. These granulomas contain egg proteolytic enzymes to prevent tissue necrosis, but the process of granuloma formation induces chronic inflammation that leads to the disease manifestations of schistosomiasis.

Adult worms digest erythrocytes and although most of their energy is obtained by glucose metabolism, egg production is dependent on fatty acid oxidation - both glucose and fatty acids being derived from the host. They live within either the peri-vesicular (S haematobium) or mesenteric (S mansoni, S japonicum, and others) venules.

Schistosomes have no anus and cannot excrete waste products, so they regurgitate waste into the bloodstream. Some of these expelled products are useful for blood-based and urine-based diagnostic assays.

N.B. Eosinophilia is often a symptom of an acute or chronic schistosomiasis!!!

Schistosomiasis is treatable by taking a single dose of the drug praziquantel/biltricide 600 mg for one day a month for a few months according to the lab reading and body weight.

The recommended dosage is 40-60 mg per kg.

The optimal dosage is 60 mg per kg in order to eradicate the infection.

Here is a simple rule for the correct dosage:

1 tab per 10 kg.

10 kg – 1 tab – 0.3+0.3+0.4 tabs

15 kg – 1.5 tabs - 0.5+0.5+0.5 tabs

20 kg – 2 tabs – 1+0.5+0.5 tabs

25 kg – 2.5 tabs – 1+1+0.5 tabs

30 kg – 3 tabs – 1+1+1 tabs

35 kg – 3.5 tabs – 1.5+1+1 tabs

40 kg – 4 tabs – 1.5+1.5+1 tabs

45 kg – 4.5 tabs – 1.5+1.5+1.5 tabs

50 kg – 5 tabs – 2+1.5+1.5 tabs

55 kg – 5.5 tabs – 2+2+1.5 tabs

60 kg – 6 tabs – 2+2+2 tabs

65 kg – 6.5 tabs – 2.5+2+2 tabs

70 kg – 7 tabs – 2.5+2.5+2 tabs

75 kg – 7.5 tabs – 2.5+2.5+2.5 tabs

80 kg – 8 tabs – 3+2.5+2.5 tabs

85 kg – 8.5 tabs – 3+3+2.5 tabs

90 kg – 9 tabs – 3+3+3 tabs

95 kg – 9.5 tabs – 3.5+3+3 tabs

100 kg – 10 tabs – 3.5+3.5+3 tabs

105 kg – 10.5 tabs – 3.5+3.5+3.5

110 kg – 11 tabs – 4+3.5+3.5 tabs

115 kg – 11.5 tabs – 4+4+3.5 tabs

120 kg – 12 tabs – 4+4+4 tabs

125 kg – 12.5 tabs – 4.5+4+4 tabs

130 kg – 13 tabs – 4.5+4.5+4 tabs

135 kg – 13.5 tabs – 4.5+4.5+4.5 tabs

140 kg – 14 tabs – 5+4.5+4.5 tabs

145 kg – 14.5 tabs – 5+5+4.5 tabs

150 kg – 15 tabs – 5+5+5 tabs

155 kg – 15.5 tabs – 5.5+5+5 tabs

160 kg – 16 tabs – 6+5+5 tabs

In order to be effective, a high concentration of the drug should be maintained in the blood for 12-14 hours.

This is achieved by taking it with a glass of water after breakfast, lunch and dinner (every 5 hours), (8:00-13:00-18:00 or 9:00-14:00-19:00 or 10:00-15:00-20:00) for one day only.

No other drugs and supplements should be taken on that day.

Praziquantel/biltricide 600mg works by causing severe spasms and paralysis of the worms' muscles. Most schistosomes are killed within 24 hours. Some of the worms are then passed in the stool.

The excretion of praziquantel/biltricide 600mg occurs mainly through urine (60-80%) as well as bile and stool (15-35%) and is completed within 24 hours. The elimination half-life of praziquantel/biltricide 600mg in the human body is 1-2 hours and after 24 hours, only a trace amount remains in the human body.

Side effects: headache, dizziness, stomach pain, nausea, tiredness, weakness, joint/muscle pain, loss of appetite, vomiting, diarrhea and sweating may occur.

These side effects are usually rare, mild and short lasting (1-2 days) and may be symptoms of parasite infection and/or the dying parasites.

Drinking fresh ginger tea with lemon juice eases the side effects.

However, praziquantel/biltricide 600mg is not effective for the deeply lodged eggs and juvenile schistosomes.

The following homeopathic remedies are also very helpful: ant-t., sec., zinc., zinc-pic., zinc-val.

Citricidal plus, Viroban, artemisia (lengana, umhlonyane), cryptolepis, panxent, RV1166/1187/1188/2231/2410 formula or bilharzeo should be taken for 3-6 months to eradicate completely all schistosoma forms, especially eggs and juvenile schistosomes.

I.V. vit C 50 000mg for 2-3 weeks is very effective for persistent/resistant chronic schistosomal infection.

Alomo bitters 25ml a day could also be used as an effective treatment in some cases.

Other possible treatments include a combination of praziquantel/biltricide 600mg with metrifonate, artesunate or mefloquine. A Cochrane review found tentative evidence that when used alone, metrifonate was as effective as praziquantel/biltricide 600mg.

Another agent, mefloquine, which has previously been used to treat and prevent malaria, was recognised in 2008–2009 to be effective against schistosoma.

Historically, antimony potassium tartrate remained the treatment of choice for schistosomiasis until the development of praziquantel in the 1980s.

According to my own experience in South Africa, about 60-70% of my patients’ results show an acute or chronic schistosomiasis together with intracellular bacterial and viral infections.

Most of them have remained undiagnosed for many years due to lack of awareness, common sense, clinical thinking and specialized tests to identify the above infections.

Please, go for bilharzia Ab test every 3-6 months as South Africa, Swaziland, Lesotho and Africa are endemic areas.

I hope this article is enlightening for the readers to recognize many mysterious, long-lasting symptoms in themselves, their families, friends and colleagues.