Cochrane Evidence Aid: resources for flooding and poor water sanitation

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Free accessThe Cochrane Reviews in this Evidence Aid Special Collection are freely available; please click on the links below to access the reviews.

In times of natural disaster, having access to safe and clean water is essential. Water polluted by faecal matter can lead to the spread of diarrhoeal diseases such as cholera, and water polluted by animal waste can spread other diseases, such as leptospirosis. Natural disasters can also result in an increase in water-based insect vectors that can spread disease (such as malaria), and a lack of clean water for personal hygiene can result in an increase in diseases such as conjunctivitis and scabies. These outcomes are outlined in the World Health Organization's Communicable Disease Control in Emergencies field manual,1 and have informed the preparation of this Special Collection.

The burden caused by natural disasters adds to the existing burden of morbidity and mortality from diarrhoeal diseases. According to the World Health Organization (WHO), diarrhoeal disease is the second leading cause of death in children under five years old and kills 1.5 million children each year.2

Cochrane systematic reviews can contribute to the use of effective interventions to prevent and treat water-related diseases, and they have also examined interventions to improve sanitation and promote hand washing. This Special Collection presents the Cochrane Reviews that summarize the available evidence around water safety and water-related diseases. Where available, links to Evidence Update summaries are provided.

This Special Collection concludes with a list of additional resources and guidelines, recommended by the contributors to this Special Collection, likely to be of relevance and interest to those working in disaster relief.

A Japanese translation is maintained by Kyoto University School of Public Health.

Water-related diseases caused by faecal pollution: general diarrhoea prevention, management, and treatment

Diarrhoea prevention: water quality and hand washing

Diarrhoea is a common cause of morbidity and a leading cause of death among children aged less than five years, particularly in low- and middle-income countries. Persistent diarrhoea can also contribute to malnutrition, reduced resistance to infections, and sometimes impaired growth and development. Many of the infectious agents are transmitted by ingesting contaminated food or drink, by direct person-to-person contact, or from contaminated hands.

Interventions to improve water quality for preventing diarrhoea

Interventions to improve water quality are generally effective in preventing diarrhoea, and interventions to improve water quality at the household level are more effective than those at the source.

Diarrhoeal diseases are a leading cause of mortality and morbidity, especially among young children in developing countries. While many of the infectious agents associated with diarrhoeal disease are potentially waterborne, the evidence for reducing diarrhoea in settings where it is endemic by improving the microbiological quality of drinking water has been equivocal. This review assesses the effectiveness of interventions to improve water quality for preventing diarrhoea. These include conventional improvements at the water source (eg protected wells, bore holes, and stand posts) and point-of-use interventions at the household level (eg chlorination, filtration, solar disinfection, and combined flocculation and disinfection). [Evidence Update summary]

Interventions to improve disposal of human excreta for preventing diarrhoea

This review provides some evidence that interventions to improve excreta disposal are effective in preventing diarrhoeal disease.

Over a third of the world's population lacks access to improved facilities for the disposal of human excreta, such as a basic pit latrine, a toilet connected to a septic tank or piped sewer system, or a composting toilet. This puts many people at risk of exposure to human excreta, which can lead to the transmission of diarrhoeal diseases. This review assesses the effectiveness of interventions to improve the disposal of human excreta for preventing diarrhoeal diseases.

Hand washing for preventing diarrhoea

Interventions that promote hand washing can reduce diarrhoea episodes by about one-third. This significant reduction is comparable to the effect of providing clean water in low-income areas.

Hand washing after defecation and handling faeces, and before preparing and eating food, is one of a range of hygiene promotion interventions that can interrupt the transmission of diarrhoea-causing pathogens. This review evaluates the effects of interventions to promote hand washing on diarrhoeal episodes in children and adults. [Evidence Update summary]

Diarrhoea management: oral rehydration solution (ORS)

Reduced osmolarity oral rehydration solution for treating dehydration caused by acute diarrhoea in children

In children admitted to hospital with diarrhoea, reduced osmolarity ORS [total osmolarity ≤ 250 mmol/L with reduced sodium] when compared to WHO standard ORS [90 mmol/L sodium, 111 mmol/L glucose, total osmolarity 311 mmol/L] is associated with fewer unscheduled intravenous fluid infusions, lower stool volume post randomization, and less vomiting. No additional risk of developing hyponatraemia when compared with WHO standard ORS was detected.

Note: Since the publication of this review, the WHO standard has changed to a reduced osmolarity ORS.

Children with diarrhoea lose body water and sometimes become dehydrated. ORS (sugar and salt dissolved in water) is widely used to treat dehydration caused by diarrhoea. This review compares two formulations of ORS with different osmolarities in children with acute diarrhoea. [Evidence Update summary]

Oral rehydration salt solution for treating cholera: ≤ 270 mOsm/L solutions vs ≥ 310 mOsm/L solutions

In people with cholera, ORS ≤ 270 is associated with biochemical hyponatraemia when compared with ORS ≥ 310 [90 mmol/L of sodium, 20 mmol/L of potassium, 80 mmol/L of chloride, 10 mmol/L of citrate, and 111 mmol/L of glucose, with a total osmolarity of 311 mmol/L], but there are no differences in terms of other outcomes. Although this risk does not appear to be associated with any serious consequences, the total patient experience in existing trials is small. Under wider practice conditions, especially where patient monitoring is difficult, caution is warranted.

ORS is used to treat the dehydration caused by diarrhoeal diseases, including cholera. ORS formulations with an osmolarity (a measure of solute concentration) of ≤ 270 mOsm/L (ORS ≤ 270) are safe and more effective than ORS formulations with an osmolarity of ≥ 310 mOsm/L (ORS ≥ 310) for treating non-cholera diarrhoea. As cholera causes rapid electrolyte loss, it is important to know if these benefits are similar for people suffering from cholera. This review compares the safety and efficacy of ORS ≤270 with ORS ≥ 310 for treating dehydration due to cholera.

Polymer-based oral rehydration solution for treating acute watery diarrhoea

Polymer-based ORS shows some advantages compared to ORS ≥ 310 [the original ORS was based on glucose and had an osmolarity of ≥ 310 mOsm/L] for treating all-cause diarrhoea, and in diarrhoea caused by cholera. Comparisons favoured the polymer-based ORS over ORS ≤ 270 [the currently agreed best formula with ≤ 270 mOsm/L], but the analysis was underpowered.

ORS has had a massive impact worldwide in reducing the number of deaths related to diarrhoea. Most ORS is in the form of a sugar–salt solution, but over the years people have tried adding a variety of compounds (glucose polymers) such as whole rice, wheat, sorghum, and maize. The aim is to slowly release glucose into the gut and improve the absorption of the water and salt in the solution. This review compares polymer-based ORS with glucose-based ORS for treating acute watery diarrhoea. [Resumen en español]

Oral versus intravenous rehydration for treating dehydration due to gastroenteritis in children

There were no important clinical differences between oral rehydration therapy and intravenous rehydration therapy for rehydration secondary to acute gastroenteritis in children.

Dehydration associated with gastroenteritis is a serious complication. Dehydration occurs when body water content is reduced causing dry skin, headaches, sunken eyes, dizziness, confusion, and sometimes death. Children with dehydration due to gastroenteritis need rehydrating either by liquids given by mouth or a tube through the nose, or intravenously. This review compares oral with intravenous therapy for treating dehydration due to acute gastroenteritis in children. [Resumen en español]

Diarrhoea treatment: zinc and probiotics

Oral zinc for treating diarrhoea in children

In areas where the prevalence of zinc deficiency or the prevalence of moderate malnutrition is high, zinc may be of benefit in children aged six months or more.The current evidence does not support the use of zinc supplementation in children below six months of age.

Zinc supplementation is recommended by WHO and UNICEF. In areas where the prevalence of zinc deficiency or the prevalence of moderate malnutrition is high, zinc may be of benefit in children aged six months or more. But the current evidence does not support the use of zinc supplementation in children below six months of age.

There is currently not enough evidence to confirm that whether zinc supplementation during acute diarrhoea reduces death or hospitalization. But in children aged more than six months with acute diarrhoea, zinc supplementation may shorten the duration of diarrhoea. In children over six months with malnutrition zinc appears to reduce the duration of moderate diarrhoea. In children aged less than six months, the available evidence suggests zinc supplementation may have no effect on mean diarrhoea duration. In children aged over six months with persistent diarrhoea, zinc supplementation may shorten the duration of diarrhoea. The majority of the data included in the 24 included trials are from Asia, from countries at high risk of zinc deficiency, and may not be applicable elsewhere.

Probiotics for treating infectious diarrhoea

Used alongside rehydration therapy, probiotics appear to be safe and have clear beneficial effects in shortening the duration and reducing stool frequency in acute infectious diarrhoea. However, more research is needed to guide the use of particular probiotic regimens in specific patient groups.

Probiotics are microbial cell preparations or components of microbial cells that have a beneficial effect on the health and well-being of the host. Probiotics may offer a safe intervention in acute infectious diarrhoea to reduce the duration and severity of the illness. This review assesses the effects of probiotics in proven or presumed acute infectious diarrhoea.

Probiotics for treating persistent diarrhoea in children

There is limited evidence suggesting probiotics may be effective in treating persistent diarrhoea in children.

Persistent diarrhoea (diarrhoea lasting more than 14 days) accounts for one third of all diarrhoea-related deaths in developing countries in some studies, and probiotics may help treatment. This review evaluates probiotics for treating persistent diarrhoea in children.

Water-related diseases caused by faecal pollution: sorted by disease

Amoebiasis

Amoebic colitis is caused by the parasite Entamoeba histolytica. This protozoan is distributed throughout the world and is commonly acquired by ingestion of contaminated food or water. It is estimated that about 40 to 50 million people infected with E. histolytica develop amoebic colitis or extraintestinal abscesses, which result in up to 100,000 deaths per year. Adequate therapy for amoebic colitis is necessary to reduce the severity of illness, prevent development of complicated disease and extraintestinal spread, and decrease transmission.

Antiamoebic drugs for treating amoebic colitis

Tinidazole is more effective in reducing clinical failure compared with metronidazole and has fewer associated adverse events. Combination drug therapy is more effective in reducing parasitological failure compared with metronidazole alone. However, these results are based on trials with poor methodological quality so there is uncertainty in these conclusions.

Metronidazole is currently the drug of choice for treating invasive amoebiasis in adults and children, but it may not be sufficient to eliminate parasite cysts in the intestine. Combinations with other drugs are therefore also used. Also, some unpleasant adverse effects associated with metronidazole in some patients, and the possibility of parasite resistance to metronidazole have to be considered. This review evaluates antiamoebic drugs for treating amoebic colitis.

Image-guided percutaneous procedure plus metronidazole versus metronidazole alone for uncomplicated amoebic liver abscess

Therapeutic aspiration in addition to metronidazole to hasten clinical or radiologic resolution of uncomplicated amoebic liver abscesses cannot be supported or refuted by the present evidence.

The most common complication of amoebiasis is the formation of a pus-filled mass inside the liver (liver abscess). Metronidazole is the drug of choice for treatment of amoebic liver abscesses, and this is followed by a luminal agent to eradicate the asymptomatic carrier state. However, a subset of patients with amoebic liver abscesses remains symptomatic, with a significant risk of rupture of the abscess into the peritoneum. The role of image-guided percutaneous therapeutic aspiration in these patients remains controversial. This review assesses the beneficial and harmful effects of image-guided percutaneous procedure plus metronidazole versus metronidazole alone in patients with uncomplicated amoebic liver abscess.

Cholera

Cholera is caused by bacteria (Vibrio cholerae) ingested through contaminated food or water, and is commonly found where sanitation measures are poor. It causes severe diarrhoea and vomiting, which can lead to profound dehydration and potentially death.

Polymer-based oral rehydration solution for treating acute watery diarrhoea

Polymer-based ORS shows some advantages compared to ORS ≥ 310 [the original ORS was based on glucose and had an osmolarity of ≥ 310 mOsm/L] for treating all-cause diarrhoea, and in diarrhoea caused by cholera. Comparisons favoured the polymer-based ORS over ORS ≤ 270 [the currently agreed best formula with ≤ 270 mOsm/L], but the analysis was underpowered.

ORS has had a massive impact worldwide in reducing the number of deaths related to diarrhoea. Most ORS is in the form of a sugar-salt solution, but over the years people have tried adding a variety of compounds (glucose polymers) such as whole rice, wheat, sorghum, and maize. The aim is to slowly release glucose into the gut and improve the absorption of the water and salt in the solution. This review compares polymer-based ORS with glucose-based ORS for treating acute watery diarrhoea. [Resumen en español]

Oral rehydration salt solution for treating cholera: ≤ 270 mOsm/L solutions vs ≥ 310 mOsm/L solutions

In people with cholera, ORS ≤ 270 is associated with biochemical hyponatraemia when compared with ORS ≥ 310 [90 mmol/L of sodium, 20 mmol/L of potassium, 80 mmol/L of chloride, 10 mmol/L of citrate, and 111 mmol/L of glucose, with a total osmolarity of 311 mmol/L], but there are no differences in terms of other outcomes. Although this risk does not appear to be associated with any serious consequences, the total patient experience in existing trials is small. Under wider practice conditions, especially where patient monitoring is difficult, caution is warranted.

ORS is used to treat the dehydration caused by diarrhoeal diseases, including cholera. ORS formulations with an osmolarity (a measure of solute concentration) of ≤ 270 mOsm/L (ORS ≤ 270) are safe and more effective than ORS formulations with an osmolarity of ≥ 310 mOsm/L (ORS ≥ 310) for treating non-cholera diarrhoea. As cholera causes rapid electrolyte loss, it is important to know if these benefits are similar for people suffering from cholera. This review compares the safety and efficacy of ORS ≤270 with ORS ≥ 310 for treating dehydration due to cholera.

Vaccines for preventing cholera: killed whole cell or other subunit vaccines (injected)

Injected cholera vaccines appear to be safe and relatively more effective than usually realized. Protection against cholera persists for up to two years following a single dose of vaccine, and for three years with an annual booster. However, they have been superseded by oral vaccines.

Vaccination against cholera was first tested in the nineteenth century and may play a role in controlling epidemics. Injected (parenteral) whole cell vaccines were used in the 1960s and 1970s, but they went out of favour as their efficacy was thought to be low and short-lived, and associated with a high rate of adverse effects. This review evaluates killed whole cell (KWC) cholera vaccines and other inactive subunit vaccines (administered by injection) for preventing cholera and death, and aims to evaluate the adverse effects. A separate Cochrane Review about oral cholera vaccines, which were introduced more recently and are used currently, is in progress.

Hepatitis A

Immunoglobulins for preventing hepatitis A

Immunoglobulins seem effective for preventing hepatitis A in both children and adults. However, the evidence, on which the conclusion is based, is not strong as the included trials appear to have risk of bias and their number is insufficient.

Hepatitis A is a common, contagious viral disease in low-income countries. Hepatitis A is transmitted primarily by faecal-oral spread from person to person. Passive immunoprophylaxis for hepatitis A using immunoglobulin preparations was essential for prevention before the development of a specific hepatitis A vaccine (active immunization). This review assesses the beneficial and harmful effects of the pre- and post-exposure prophylaxis with immunoglobulins for preventing hepatitis A.

Salmonellosis

Antibiotics for treating salmonella gut infections

There appears to be no evidence of a clinical benefit of antibiotic therapy in otherwise healthy children and adults with non-severe salmonella diarrhoea. Antibiotics appear to increase adverse effects and they also tend to prolong salmonella detection in stools.

Non-typhoidal salmonellosis appears to be an important cause of acute diarrhoea in some developing countries. Antibiotic treatment of salmonellosis aims to shorten illness and prevent serious complications. There are also concerns about increasing antibiotic drug resistance. This review assesses the effects of antibiotics in adults and children with diarrhoea who have salmonellosis.

Vaccines for preventing invasive salmonella infections in people with sickle cell disease

It is expected that salmonella vaccines may be useful in people with sickle cell disease, especially in resource-poor settings where the majority of those who suffer from the condition are found. Unfortunately, there are no randomized controlled trials on the efficacy and safety of the different types of salmonella vaccines in people with sickle cell disease.

Salmonella infections are a common bacterial cause of invasive disease in people with sickle cell disease, especially children, and are associated with high morbidity and mortality rates. Although available in some centres, people with sickle cell anaemia are not routinely immunized with salmonella vaccines. This review determines whether routine administration of salmonella vaccines to people with sickle cell disease reduces the morbidity and mortality associated with infection.

Schistosomiasis

Drugs for treating urinary schistosomiasis

Praziquantel and metrifonate are effective treatments for urinary schistosomiasis and have few adverse events. Metrifonate requires multiple administrations and is therefore operationally less convenient in community-based control programmes. Evidence on the artemisinin derivatives is currently inconclusive, and further research is warranted on combination therapies.

Urinary schistosomiasis is caused by the blood fluke, Schistosoma haematobium, which is transmitted upon contact with contaminated water. The worms reside in blood vessels of the bladder and cause urinary schistosomiasis, which can lead to long-term ill-health. The disease is commonly found in African and eastern Mediterranean countries, especially in poor, rural areas. This review evaluates antischistosomal drugs, used alone or in combination, for treating urinary schistosomiasis.

Drugs for treating Schistosoma mansoni infection

The available evidence supports single dose praziquantel at 40 mg/kg as standard treatment for S. mansoni infection as recommended by the WHO. Oxamniquine, a largely discarded alternative, appears efficacious and production and distribution should continue to ease selective pressure on praziquantel. However, its use should be limited to areas without S. haematobium co-endemicity.

Schistosoma mansoni is a parasitic infection common in the tropics and sub-tropics. Chronic and advanced disease includes abdominal pain, diarrhoea, blood in the stool, liver cirrhosis, portal hypertension, and premature death. This review evaluates the effects of antischistosomal drugs, used alone or in combination, for treating S. mansoni infection.

Shigellosis

Antibiotic therapy for Shigella dysentery

We recommend the use of antibiotics for moderate to severe Shigella dysentery. The choice of antibiotic to use as first line against Shigella dysentery should be governed by periodically updated local antibiotic sensitivity patterns of Shigella isolates. Other supportive and preventive measures recommended by the WHO should also be instituted along with antibiotics (eg health education and hand washing).

Shigellosis is a bacterial infection of the colon that can cause diarrhoea and dysentery (diarrhoea with blood and/or mucus), and may lead to death. It occurs mainly in low- and middle-income countries where overcrowding and poor sanitation exist, and may lead to around 1.1 million deaths per year globally, mostly in children aged less than five years. Mild symptoms are self-limiting, but in more severe cases, antibiotics are recommended for cure and preventing relapse. The antibiotics recommended are diverse, have regional differences in sensitivity, and have adverse effects. This review evaluates the efficacy and safety of antibiotics for treating Shigella dysentery.

Typhoid and paratyphoid fever (enteric fever)

Fluoroquinolones for treating typhoid and paratyphoid fever (enteric fever)

Trials were small and methodological quality varied. In adults, fluoroquinolones may be better for reducing clinical relapse rates compared to chloramphenicol. Data are limited for other comparisons, particularly in children.

Fluoroquinolones are recommended as first-line therapy for typhoid and paratyphoid fever (enteric fever), but how they compare with other antibiotics and different fluoroquinolones is unclear. This review evaluates fluoroquinolone antibiotics for treating enteric fever in children and adults compared with other antibiotics, different fluoroquinolones, and different durations of fluoroquinolone treatment. [Evidence Update summary]

Vaccines for preventing typhoid fever

The licensed Ty21a and Vi polysaccharide vaccines are efficacious. The new and unlicensed Vi-rEPA vaccine is as efficacious and may confer longer immunity.

Two typhoid vaccines are commercially available, Ty21a (oral) and Vi polysaccharide (parenteral), but neither is used routinely. Other vaccines, such as a new modified, conjugated Vi vaccine called Vi-rEPA, are in development. This review evaluates vaccines for preventing typhoid fever.

Water-related diseases caused by water-based insect vectors

Dengue fever

Corticosteroids for treating dengue shock syndrome

There is insufficient evidence to justify the use of corticosteroids in managing dengue shock syndrome. As corticosteroids can potentially do harm, clinicians should not use them unless they are participating in a randomized controlled trial comparing corticosteroids with placebo.

Dengue virus is an arbovirus transmitted to humans by two species of mosquito, Aedes aegypti and A. albopictus. The four serotypes of dengue virus can cause a wide range of symptoms from mild febrile illness to dengue haemorrhagic fever (severe illness with fever and bleeding), which leads to dengue shock syndrome (shock, collapse, and sometimes death). It is currently estimated that most of the 100 million cases of dengue infection occurring annually are in South-East Asia, although many also occur in the Americas. Dengue shock syndrome is the most severe form of dengue haemorrhagic fever. The current treatment for dengue shock syndrome is to give fluids directly into the bloodstream, but corticosteroids have been suggested as drugs that may help due to their anti-inflammatory properties. This review compares corticosteroids with placebo or no corticosteroids for treating dengue shock syndrome. [Evidence Update summary]

Malaria

See the World Malaria Day Special Collection.

Onchocerciasis (river blindness)

Ivermectin for onchocercal eye disease (river blindness)

Ivermectin can prevent damage to the front of the eye but its effectiveness in preventing blindness remains uncertain.

Onchocerciasis causes severe itching and thickening of the skin, and damages structures at the front and back of the eye. It also affects the nerve that connects the eye with the brain. Onchocerciasis is caused by tiny worms that are transmitted from person to person by a small biting fly. The fly breeds in fast-flowing rivers and streams mainly in West Africa, although it is also endemic in some countries in the Americas and eastern Mediterranean. It is believed that ivermectin (a microfilaricide) could prevent blindness due to onchocerciasis. This review assesses the effectiveness of ivermectin in preventing visual impairment and visual field loss in onchocercal eye disease.

Japanese encephalitis

Vaccines for preventing Japanese encephalitis

It is not possible to compare the effectiveness of currently used vaccines in preventing clinical disease as only one of three vaccines has been directly investigated for effectiveness in an RCT.

Japanese encephalitis is a viral disease of the central nervous system with general symptoms of headache, fever, vomiting, and diarrhoea. Most people recover within a week without further complications, but approximately 1 in 300 suffers additional and severe symptoms such as disorientation, seizures, paralysis, and coma. Around 30% of the severe cases are fatal, and most survivors are left with serious and often chronic disabilities such as mental impairment, limb paralysis, and blindness. Vaccination is recognized as the only practical measure for preventing Japanese encephalitis, but production shortage, costs, and issues of licensure impair vaccination programmes in many affected countries. Concerns over vaccine effectiveness and safety also have a negative impact on acceptance and uptake. This review evaluates vaccines for preventing Japanese encephalitis in terms of effectiveness, adverse events, and immunogenicity.

Skin, eye, and louse-borne diseases that can occur when there is a lack of water for personal hygiene

Skin infections: scabies

Interventions for treating scabies

On the basis of the available evidence from randomized controlled trials, topical permethrin appears to be the most effective treatment for scabies. Ivermectin appears to be an effective oral treatment, but in many countries it is not licensed for this indication.

Scabies is an intensely itchy parasitic infection of the skin caused by the Sarcoptes scabiei mite. The female mite burrows into the skin to lay eggs, which then hatch out and multiply. The infection can spread from person to person via direct skin contact, including sexual contact. Scabies occurs throughout the world, but it is particularly problematic in areas of poor sanitation, overcrowding, and social disruption, and is endemic in many resource-poor countries. Various drugs have been developed to treat scabies, and herbal and traditional medicines are also used. This review evaluates topical and systemic drugs for treating scabies.

Skin infections: impetigo

Interventions for impetigo

There is good evidence that topical mupirocin and topical fusidic acid are equally, or more, effective than oral treatment. Due to the lack of studies in people with extensive impetigo, it is unclear if oral antibiotics are superior to topical antibiotics in this group. Fusidic acid and mupirocin are of similar efficacy. Penicillin was not as effective as most other antibiotics. There is a lack of evidence to support disinfection measures to manage impetigo.

Impetigo is a common superficial bacterial skin infection that is contagious and usually occurs in young children. Impetigo causes blister-like sores, which can fill with pus and form scabs; scratching can spread the infection. There is no generally agreed standard therapy, and guidelines for treatment differ widely. Treatment options include many different oral and topical antibiotics as well as disinfectants. This review assesses the effects of treatments for impetigo, including non-pharmacological interventions and 'waiting for natural resolution'. Penicillin is not as effective as most other antibiotics for impetigo. Topical mupirocin and topical fusidic acid are equally, or more, effective than oral treatment. Due to the lack of studies in people with extensive impetigo, it is unclear if oral antibiotics are superior to topical antibiotics. Fusidic acid, mupirocin and retapamulin are of similar efficacy; other topical treatments seem less effective. There is little evidence to support disinfection measures to manage impetigo.

Ophthalmic infections: conjunctivitis

Antibiotics versus placebo for acute bacterial conjunctivitis

Acute bacterial conjunctivitis is frequently a self-limiting condition, but the use of antibiotics is associated with modestly improved rates of clinical and microbiological remission compared to placebo.

Acute bacterial conjunctivitis is an infective condition in which the eyes become red and inflamed. The condition is not normally serious and usually recedes spontaneously within about a week. People with acute conjunctivitis are often given antibiotics, usually as eye drops or ointment, to speed recovery. The benefits of antibiotics to the sufferer of conjunctivitis have been questioned. This review assesses the benefit and harm of antibiotic therapy in the management of acute bacterial conjunctivitis and findings suggest that the use of antibiotic eye drops is associated with modestly improved rates of clinical and microbiological remission in comparison to the use of placebo. Use of antibiotic eye drops should therefore be considered in order to speed the resolution of symptoms and infection.

Ophthalmic infections: trachoma

Trachoma is the world's leading cause of preventable blindness. It is a bacterial infection in the eye caused by Chlamydia trachomatis and is common in underprivileged children living in the poor communities of low-income countries, mainly in Africa, Asia, and the Middle East. Through repeated infections, the eyelashes turn in and brush against the cornea. The contact between the lashes and the surface of the eye results in blindness.

Antibiotics for trachoma

The review found some evidence that antibiotics reduce trachoma. Ointment is neither better nor worse than tablets.

In 1997, WHO launched an initiative on trachoma control based on the SAFE strategy (surgery, antibiotics, facial cleanliness, and environmental improvement). This review aims to assess the evidence supporting the antibiotic arm of the SAFE strategy by assessing the effects of antibiotics on both active trachoma and on Chlamydia trachomatis infection of the conjunctiva.

Environmental sanitary interventions for preventing active trachoma

The role of insecticide spray as a fly control measure in reducing trachoma remains unclear. There is some evidence from two trials that insecticides are effective in reducing transmission of trachoma, but not demonstrated in another trial that also used insecticides. Health education may be effective in reducing the transmission of trachoma.

Trachoma is a major cause of avoidable blindness. It is responsible for about six million blind people worldwide, mostly in the poor communities of developing countries. One of the major strategies advocated for the control of trachoma is the application of various environmental sanitary measures to such communities. Environmental sanitation is a package of measures aimed at eliminating factors that encourage proliferation of flies and the spread of the disease. Some of these interventions include provision of water and latrines as well insecticide spray to control flies. This review assesses the evidence for the effectiveness of environmental sanitary measures on the prevalence of active trachoma in endemic areas.

Face washing promotion for preventing active trachoma

Evidence from one trial suggests that face washing can be effective in increasing facial cleanliness and in reducing severe trachoma, but its effect in reducing active trachoma is inconclusive. In another trial, there was no evidence of effect of face washing alone or in combination with tetracycline in reducing active trachoma in children with already established disease.

Face washing is part of the 'SAFE' strategy (surgery, antibiotics, facial cleanliness, and environmental improvement) promoted by the WHO programme for the global elimination of trachoma. Face washing should reduce the number of eye-seeking flies and transmission of the trachoma organism from person-to-person. This review assesses the effects of face washing on the prevalence of active trachoma in endemic communities.

Interventions for trachoma trichiasis

No trials show interventions for trichiasis prevent blindness. Certain interventions have been shown to be more effective at eliminating trichiasis.

Repeated infections cause scarring of the conjunctiva of the upper eyelid, which causes the eyelid to turn in (entropion) so that the eyelashes touch the cornea at the front of the eye. This is known as trachoma trichiasis. Every movement of the eye or eyelids causes trauma to the corneal surface so that it eventually turns opaque and the person becomes blind. This review assesses the effects of different interventions for trachoma trichiasis (both surgical and non-surgical) to identify the most effective means of eliminating trichiasis and the most acceptable way of delivering these. [Evidence Update summary]

Louse-borne disease: scrub typhus

Antibiotics for treating scrub typhus

There are no obvious differences between tetracycline, doxycycline, telithromycin, or azithromycin; rifampicin may be better than tetracycline in areas where scrub typhus appears to respond poorly to standard anti-rickettsial drugs.

Scrub typhus is a bacterial infection transmitted by chiggers (mites). The infection causes fever and a typical sore on the skin. Scrub typhus is common in the western Pacific region and many parts of Asia, particularly in agricultural workers and travellers in areas where the disease is common, particularly people camping, rafting, or trekking. Antibiotics (chloramphenicol, tetracycline, and doxycycline) have been used to treat the disease. Resistance to these antibiotics has been reported. This review evaluates antibiotic regimens for treating scrub typhus.

Skin diseases caused by long-term exposure to water

Skin infections: fungal infections of the skin of the foot (including tinea pedis or athlete's foot)

Topical treatments for fungal infections of the skin and nails of the foot

Placebo-controlled trials of allylamines and azoles for athlete's foot consistently produce much higher percentages of cure than placebo. Allylamines cure slightly more infections than azoles and are now available OTC [over the counter]. Further research into the effectiveness of antifungal agents for nail infections is required.

The skin between the toes is a frequent site of fungal infection (athlete's foot or tinea pedis), and this can cause pain and itchiness. The skin may become white and macerated, and vesicles (small blisters) may form. These can erupt and spread to other areas of the foot, especially the soles where the area becomes reddened and raw. Also, patches of hard, thickened skin occur on the soles, heels, and side of the feet. This can lead to splits (fissures) in the skin. Fungal infections of the toenail can affect the entire nail plate, and one, several, or all toenails can be infected simultaneously. This review assesses the effects of topical treatments in successfully treating fungal infections of the skin of the feet and toenails, and in preventing recurrence.

Oral treatments for fungal infections of the skin of the foot

The evidence suggests that terbinafine is more effective than griseofulvin and that terbinafine and itraconazole are more effective than no treatment.

About 15% of the population have fungal infections of the feet (tinea pedis or athlete's foot). While there are many clinical presentations of tinea pedis, the most common are between the toes and on the soles, heels, and sides of the foot, which is known as moccasin foot. Once acquired the infection can spread to other sites including the nails, which can be a source of reinfection. Oral therapy is usually used for chronic conditions or when topical treatment has failed. This review assesses the effects and costs of oral treatments for fungal infections of the skin of the foot (tinea pedis).

Water-related diseases caused by urine of certain mammals

Leptospirosis

Antibiotic prophylaxis for leptospirosis

Regular use of weekly doxycycline 200 mg oral therapy has increased odds for nausea and vomiting with unclear benefit in reducing Leptospira seroconversion or clinical consequences of infection. If it is efficacious in reducing disease, it may be more so in travellers rather than in residents of an endemic area.

Leptospira infection is a global zoonosis caused by spirochetes of the genus Leptospira. It causes endemic disease among agricultural workers and others regularly exposed to flooded fields and livestock, or other sources of animal urine. Outbreaks of leptospirosis also occur among immune-naive individuals who may be exposed because of changing environmental conditions, travel, or occupational or recreational activities, for example. This review assesses the evidence for or against use of antibiotic prophylaxis against Leptospira infection.

Additional resources and guidelines

Acknowledgements

Thank you to Prof Zulfiqar Bhutta, Dr Anita Zaidi, Dr Saeed Farooq, Prof Paul Garner, Ms Bridget Jones, Dr Prathap Tharyan, and Prof Mike Clarke for their input and support in preparing this Special Collection.

References

1. Connolly MA (editor). Communicable Disease Control in Emergencies: A Field Manual. Geneva: World Health Organization, 2005. Available at http://www.who.int/infectious-disease-news/IDdocs/whocds200527/ISBN_9241546166.pdf (accessed 20 November 2012).

2. World Health Organization. Diarrhoeal disease: key facts. August 2009. http://www.who.int/mediacentre/factsheets/fs330/en/index.html (accessed 20 November 2012).

Image credit: Paolo Koch/Science Photo Library

Date published: 18 August 2010; updated 25 August 2010, 10 November 2010, 21 December 2010 and 20 November 2012.  Last updated 08 August 2013 to update one review.

Contact: Cochrane Editorial Unit (editorial-unit@cochrane.org)

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