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For decades, guinea worm disease, caused by the parasitic worm Dracunculus medinensis, has been a major public health concern, impacting vulnerable populations in Africa and Asia. This review gives an in-depth examination of the various therapeutic approaches used to combat guinea worm disease. This study seeks to provide a current and evidence-based summary of available treatment techniques by conducting an exhaustive examination of peer-reviewed literature, medical databases, and official health organisation publications. The current review intends to contribute to the knowledge base and influence plans for guinea worm disease control and eradication by critically evaluating the success and obstacles associated with various treatment approaches through standard heterocyclic medications, herbal sources, phytochemicals, and nanomedicines. The importance of integrating community engagement and collaboration among national and international stakeholders is emphasised to foster sustainable solutions and ensure a collective effort towards a guinea worm-free world., (© 2024 Wiley-VHCA AG, Zurich, Switzerland.)

Guinea worm (GW) disease, caused by Dracunculus medinensis, is an almost eradicated waterborne zoonotic disease. The World Health Organization (WHO) currently lists GW as endemic in only five African countries. In July 2020, the Vietnamese public health surveillance system detected a hanging worm in a 23-year-old male patient, who did not report any travel to Africa or any country previously endemic for GW. The patient was hospitalized with symptoms of fatigue, anorexia, muscle aches, and abscesses, with worms hanging out of the skin in the lower limbs. The worms were retrieved from the lesions and microscopically examined in Vietnam, identifying structures compatible with Dracunculus spp. and L1-type larvae. A section of this parasite was sent to the Centers for Disease Control and Prevention (CDC) in Atlanta, United States, for confirmatory diagnosis of GW. The adult worm had cuticle structures compatible with Dracunculus parasites, although the length of L1 larvae was about 339 μm, substantially shorter than D. medinensis. DNA sequence analysis of the 18S small subunit rRNA gene confirmed that this parasite was not GW, and determined that the sample belonged to a Dracunculus sp. not previously reported in GenBank that clustered with the animal-infective Dracunculus insignis and Dracunculus lutrae, located in a different clade than D. medinensis. This study highlights the importance of effective public health surveillance systems and the collaborative work of local public health authorities from Vietnam with the WHO and CDC in efforts to achieve the eradication of GW., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Of the three diseases targeted for eradication by WHO, two are so-called Neglected Tropical Diseases (NTDs)-guinea worm disease (GWD) and yaws. The Guinea Worm Eradication Programme (GWEP) is in its final stages, with only 25 reported in 2016. However, global eradication still requires certification by WHO of the absence of transmission in all countries. We analyze the cost-effectiveness of the GWEP in the end game, when the number of cases is lower and the cost per case is higher than at any other time. Ours is the first economic evaluation of the GWEP since a World Bank study in 1997., Methods: Using data from the GWEP, we estimate the cost of the implementation, pre-certification and certification stages. We model cost-effectiveness in the period 1986-2030. We compare the GWEP to two alternative scenarios: doing nothing (no intervention since 1986) and control (only surveillance and outbreak response during 2016-2030). We report the cost per case averted, cost per disability adjusted life year (DALY) averted and cost per at-risk life year averted. We assess cost-effectiveness against a threshold of about one half GDP per capita (less than US$ 500 in low income countries). All costs are expressed in US$ of 2015., Results: The GWEP cost an estimated US$ 11 (95% uncertainty interval, 4.70-12.49) per case averted in the period 1986-2030. The pre-certification and certification phases can cost as much as US$ 0.0041 and US$ 0.0015 per capita per year. The cost per DALY averted by the GWEP relative to doing nothing is estimated at US$ 222 (118-372) in 1986-2030. The GWEP is probably more cost-effective than control by the year 2030. The GWEP is certainly more cost-effective than control if willingness to pay for one year of life lived without the risk of GWD exceeds US$ 0.10., Discussion: Even if economic costs are two times as high as the financial costs estimated for the period to 2020, the GWEP will still be cost-effective relative to doing nothing. Whether the GWEP turns out to be the most cost-effective alternative in the period beyond 2015 depends on the time horizon. When framed in terms of the number of years of life lived without the risk of GWD, a case can be made more easily for finishing the end game, including certification of the absence of transmission.

Dracunculiasis is rarely reported in cats, yet over the last few years we have identified two cats with filarioid-like spirurid infections. Case 1 was a 9-year-old cat with pituitary-dependent hyperadrenocorticism from New York tate from which four adult dracunculoid nematodes were isolated from its torso. Based on morphometric characteristics and parasite geographic distribution, the specimens were identified as Dracunculus insignis females; at least one of the females was gravid, suggestive of patent infection. Species identification was confirmed through amplification and sequence analysis of nuclear and mitochondrial loci. Case 2 was a 14-year-old diabetic cat from Massachusetts. Formalin-fixed sections were obtained from a subcutaneous mass excised from the left foreleg. Histopathological examination revealed a large nematode with morphometrical characteristics of Dracunculus, surrounded by lymphocytes and sheets of eosinophils. These two cases appear to be the first published reports of dracunculiasis in domestic cats in the USA, and based on the findings from case 1, D insignis may be the species associated with both infections.

Objective: To assess the quantity and distribution of evidence from randomised controlled trials for the treatment of the major neglected tropical diseases and to identify gaps in the evidence with network analysis., Design: Systematic review and network analysis., Data Sources: Cochrane Central Register of Controlled Trials and PubMed from inception to 31 August 2011., Study Selection: Randomised controlled trials that examined treatment of 16 neglected tropical diseases or complications thereof published in English, French, Spanish, Portuguese, German, or Dutch., Results: We identified 971 eligible randomised trials. Leishmaniasis (184 trials, 23,039 participants) and geohelminth infections; 160 trials, 46,887 participants) were the most studied, while dracunculiasis (nine trials, 798 participants) and Buruli ulcer (five trials, 337 participants) were least studied. Relative to its global burden of disease, lymphatic filariasis had the fewest trials and participants. Only 11% of trials were industry funded. Either a single trial or trials with fewer than 100 participants comprised the randomised evidence for first or second line treatments for Buruli ulcer, human African trypanosomiasis, American trypanosomiasis, cysticercosis, rabies, echinococcosis, New World cutaneous leishmaniasis, and each of the foodborne trematode infections. Among the 10 disease categories with more than 40 trials, five lacked sufficient head to head comparisons between first or second line treatments., Conclusions: There is considerable variation in the amount of evidence from randomised controlled trials for each of the 16 major neglected tropical diseases. Even in diseases with substantial evidence, such as leishmaniasis and geohelminth infections, some recommended treatments have limited supporting data and lack head to head comparisons.

Neglected helminthic diseases cause many social, economic and health care challenges in developing countries. The high number of patients suffering from these parasitic infections and the lack of sufficient treatment options represent severe problems. Research on new drugs and therapies to meet this urgent requirement has to be intensified. This review focuses on infections caused by four helminthic parasites, which have been declared as neglected diseases by the World Health Organization: namely drancunculiasis, lymphatic filariasis, onchoceriasis, and schistosomiasis. They show a considerable overlap in their world-wide prevalence and treatment strategies. Nevertheless, treatment is not without complications. The most efficient lymphatic filariasis drug, diethylcarbamazine, causes severe adverse effects in onchocerciasis patients and completely fails in the treatment of drancunculiasis. In this review, we discuss these incongruities at the molecular and cellular level. Furthermore, established or investigational drug combination regimens are highlighted. In the past years, progress has been made in the area of schistosomiasis and onchocerciasis. The molecular biology of underlying mechanisms, signalling pathways and related targets affected by drug therapy are discussed in detail. Finally, successful treatment strategies and remaining future challenges are summarized.

This report describes how Nigeria, a country that at one time had the highest number of cases of dracunculiasis (Guinea worm disease) in the world, reduced the number of cases from more than 653,000 in 1988 to zero in 2009, despite numerous challenges. Village-based volunteers formed the foundation of the program, which used health education, cloth filters, vector control, advocacy for safe water, voluntary isolation of patients, and monitored program interventions and cases reported monthly. Other factors in the program's success were strong governmental support, advocacy by a former head of state of Nigeria, technical and financial assistance by The Carter Center, the U.S. Centers for Disease Control and Prevention, the United Nations Children's Fund, the World Health Organization, and many other partners and donors. The estimated cost of the Nigerian program during 1988-2009 is $37.5 million, not including funding for water supply projects or salaries of Nigerian governmental workers.

Africa's populous country, Nigeria, contains or contained more cases of dracunculiasis, onchocerciasis, lymphatic filariasis, and schistosomiasis than any other African nation and ranks or ranked first (dracunculiasis, onchocerciasis, schistosomiasis) or third (lymphatic filariasis) in the world for the same diseases. After beginning village-based interventions against dracunculiasis 20 years ago and confronting onchocerciasis a few years later, Nigeria has nearly eliminated dracunculiasis and has provided annual mass drug administration for onchocerciasis to over three quarters of that at-risk population for 7 years. With assistance from The Carter Center, Nigeria began treating lymphatic filariasis and schistosomiasis in two and three states, respectively, over the past decade, while conducting pioneering operational research as a basis for scaling up interventions against those diseases, for which much more remains to be done. This paper describes the status of Nigeria's struggles against these four neglected tropical diseases and discusses challenges and plans for the future.

Gold standard diagnosis using blood films or skin snips has dimished relevance as mass drug distribution programmes for control of filaria infections expand. The view of 'diagnosis' and its relevance at the individual level has changed, as it has been recognised that the spectrum of programmatic processes (mapping, mass drug interventions, monitoring and evaluation, and surveillance) require different approaches as different questions are asked at each stage. The feasibility and relevance of skin biopsy or blood film examination is challenged when mass drug distribution seeks to treat all eligibles in communities. The need to expand programmes rapidly by identifying the highest risk communities has seen the development of rapid assessment methods, such as rapid epidemiological mapping of onchocerciasis (REMO) and rapid epidemiological assessment (REA) for onchocerciasis, immunochromatographic test (ICT)-based mapping for lymphatic filariasis (LF), and Rapid Assessment Procedure for Loiasis (RAPLOA) for Loa, to reduce the risk of serious adverse events and to guide projects in high-risk communities. As programmes reduce the prevalence through mass drug distribution, more sensitive techniques are required to define endpoints, for LF in particular where the programmatic goal is elimination; for onchocerciasis, sensitive surveillance tools are required particularly in those areas where such risks of recrudescence are high. Whilst much progress has been made in the development and deployment of rapid methods, there are still specific needs for antigen detection in onchocerciasis, whilst standardisation of a panel of tools for LF will allow the definition of endpoint parameters so that countries can decide when mass drug administration (MDA) can be stopped and have a sensitive post-MDA surveillance system.

The four diseases discussed in this chapter (dracunculiasis, onchocerciasis, schistosomiasis, and trachoma) are among the officially designated "Neglected Tropical Diseases," and each is also both the result of and a contributor to the poverty of many rural populations. To various degrees, they all have adverse effects on health, agricultural productivity, and education. The Carter Center decided to work on these health problems because of their adverse effect on the lives of poor people and the opportunity to help implement effective interventions. As a result of the global campaign spearheaded by the Carter Center since 1986, the extent of dracunculiasis has been reduced from 20 to five endemic countries and the number of cases reduced by more than 99%. We have helped administer nearly 20% of the 530 million Mectizan (ivermectin) doses for onchocerciasis, which is now being controlled throughout most of Africa, and is progressing toward elimination in the Americas. Since 1999, two Nigerian states have been using village-based health workers originally recruited to work on onchocerciasis to also deliver mass treatment and health education for schistosomiasis and lymphatic filariasis. They now also distribute vitamin A supplements and bed nets to prevent malaria and lymphatic filariasis. Ethiopia aims to eliminate blinding trachoma in the Amhara Region of that highest-endemicity country by 2012, already constructing more than 300,000 latrines and other complementary interventions. Because of the synergy between these diseases and poverty, controlling or eliminating the disease also reduces poverty and increases self-reliance.

Context: The neglected tropical diseases include 13 conditions that occur in areas of extreme poverty and are poverty promoting. The neglected tropical diseases produce a disease burden almost as great as that associated with human immunodeficiency virus/AIDS, tuberculosis, or malaria, yet are virtually unknown by health care workers in North America, because they occur almost exclusively in the poorest regions of the world. Seven of the most prevalent diseases have existing oral drug treatments. Identifying treatments that are effective against more than 1 disease could facilitate efficient and inexpensive treatment., Objectives: To systematically review the evidence for drug treatments and to increase awareness that neglected tropical diseases exist and that treatments are available., Data Sources and Study Selection: Using a MEDLINE search (1966 through June 2007), randomized controlled trials (RCTs) were reviewed that examined simultaneous treatment of 2 or more of the 7 most prevalent neglected tropical diseases using oral drug therapy., Data Synthesis: Twenty-nine RCTs were identified, of which 3 targeted 4 diseases simultaneously, 20 targeted 3 diseases, and 6 targeted 2 diseases. Trials were published between 1972 and 2005 and baseline prevalence of individual diseases varied among RCTs. Albendazole plus diethylcarbamazine significantly reduced prevalence of elephantiasis (16.7% to 5.3%), hookworm (10.3% to 1.9%), roundworm (34.5% to 2.3%), and whipworm (55.5% to 40.3%). Albendazole plus ivermectin significantly reduced prevalence of elephantiasis (12.6% to 4.6%), hookworm (7.8% to 0%), roundworm (33.5% to 6.1%), and whipworm (42.7% to 8.9%). Levamisole plus mebendazole significantly reduced prevalence of hookworm (94.0% to 71.8%), roundworm (62.0% to 1.4%), and whipworm (93.1% to 74.5%). Pyrantel-oxantel significantly reduced hookworm (93.4% to 85.2%), roundworm (22.8% to 1.4%), and whipworm (86.8% to 59.5%), while albendazole alone significantly reduced prevalence of hookworm (8.1% to 1.3%), roundworm (28.4% to 0.9%), and whipworm (51.9% to 31.9%). No RCT examined treatment of river blindness or trachoma as part of an intervention to target 2 or more neglected tropical diseases. Adverse events were generally inadequately reported., Conclusions: At least 2 of the most prevalent neglected tropical diseases can be treated simultaneously with existing oral drug treatments, facilitating effective and efficient treatment. Increasing awareness about neglected tropical diseases, their global impact, and the availability of oral drug treatments is an essential step in controlling these diseases.

The effectiveness of trichlorophenol (TCP), chlorhexidine gluconate plus cetrimide (Savlon) and Izal in inhibiting the growth of bacterial isolates from guinea worm ulcers was investigated. Using an adaptation of the method of Russell and Furr (Russell, A.D., Furr, J.R., 1977. The antibacterial activity of a new chloroxylenol preparation containing ethylenediamine tetraacetic acid. J. Appl. Bacteriol. 43, 253-260) the minimum inhibitory concentration (MIC) values of the three anti-microbial agents for each of the isolated bacteria was determined. Water drawn from the rural guinea worm endemic sites was autoclaved and used for the various dilutions of the anti-microbial agents. At the manufactures' recommended use-dilutions in cases of wounds/cuts/sores, Savlon showed greater effectiveness than Izal and TCP in this order. Probable organic and inorganic inhibitors in water that is usually employed in diluting anti-microbial agents in the rural areas for the dressing of guinea worm ulcers very likely had greatest effect(s) on TCP and least effect(s) on Savlon.

A randomized, single-blind, controlled study comparing the efficacy of an ointment containing two antibiotics, one containing one antibiotic plus hydrocortisone, and no treatment in reducing secondary infections in patients with patent Guinea worm was undertaken in the northern region of Ghana. Seventy-seven patients were included. Time to complete healing was significantly shorter in the treatment groups compared with the controls (P = 0.044 and P = 0.003, respectively). Secondary infections occurred more often in the controls (P = 0.00014). Ointments containing antibiotics are recommended for application at the early stage of patent Guinea worm infection.

The effect of ivermectin on prepatent guinea-worm was tested in a single-blind placebo-controlled trial; 400 adults were randomly allocated to a single dose of ivermectin (150 micrograms/kg) or placebo. Fifty-four of the 385 participants who were followed for 15 months developed a total of 69 emergent guinea-worms. There was no significant difference in the proportion of persons with emergent guinea-worms between the 2 treatment groups; 58% appeared in males. 80% of emergent guinea-worms were located below the knee. Migration of guinea-worms in the tissues was not affected. It is concluded that ivermectin has no effect on prepatent guinea-worms nor does it disturb their migration pattern. No adverse reaction to treatment was seen. It appears that ivermectin can be used safely as mass chemotherapy against onchocerciasis and lymphatic filariasis in areas where guinea-worm is also endemic.

Traditional medicinal treatments of guinea worm being applied in various parts of Bauchi State were investigated. Extracts of leaves of a number of plants were universally applied topically. Users perceived relief of pain and accelerated expulsion of worms and healing process. In particular, Tamarindus indica, Adansonia digitata, Calotropis procera, Ziziphus jaozeiro and Moringa olifera are known in nature to have relevant medicinal properties especially lessening of inflammation, relief of pain, or promoting healing or reducing secondary bacterial infections. The possibility was expressed that some of the herbs might be exerting useful effects and could be exploited for the effective treatment of guinea worm.

Twenty patients with Guinea worm disease having a total of 29 emerging worms in a rural village of North West Frontier Province, were put on a 5-day course of antibiotics and antiinflammatory drugs and compared with age-matched control patients. The ulcer sites of emerging worms were kept continuously moist, and 18 worms were extracted from 14 patients during the above mentioned period. The average time taken for the entire worm to be expelled in these patients was considerably shorter (13.6 days) than in controls (89 days). Seven (39%) of these worms were expelled spontaneously whereas the remaining 11 (61%) were pulled out manually with relative ease. Fifteen (75%) patients in this study had a single emerging worm, three (15%) had two emerging worms and two (10%) patients had four or more emerging worms.

400 cases of dracunculosis were treated with Thiabendazole and the results reported. Thiabendazole appears to be highly effective and its pleasant taste and lack of adverse effects account for its acceptability by the patients. The drug is cheap and can be recommended even for poor patients. The adverse reactions are minimal and do not necessitate stoppage of therapy. We conclude the Mintezol is highly efficacious and should prove a useful weapon against Guinea worm disease.

In 6 differnet animal assays in the laboratory, thiabendazole had clear anti-inflammatory effect, though it was less potent than aspirin in all assays. These findings add support to clinical suggestions that the drug may have anti-inflammatory properties in man. Such properties may contribute to the clinical response observed following the use of thiabendazole in cases of trichinosis, cutaneous larva migrans, visceral larva migrans, dracunculosis and scabies. In parasitic infections in which corticosteroids are commonly used in clinical management, notably trichinosis, the fact that thiabendazole does not appear to have immunosuppressive activity may confer an added clinical advantage.

In a clinical trial of metronidazole for dracunculiasis (75 cases), the drug was effective in giving symptomatic relief but had no preventive or vermicidal action. It was well tolerated. No difference was observed in the results of two dose schedules (200 mg or 400 mg three times daily for 10 days).

In a placebo-controlled field trial involving 111 cases of dracontiasis, thiabendazole (at 50 mg kg-1 daily for two days or 100 mg kg-1 daily for two days) was compared with metronidazole (at 30-40 mg kg-1 t.d.s. for three days) for effectiveness against the guinea-worm, Dracunculus medinensis. All three regimens gave similar results and were significantly more effective than the placebo in bringing relief from symptoms of the disease and in the healing of guinea-worm ulcers. Elimination of adult worms was more rapid, but not significantly so, in patients treated with anthelmintic than in the control group. Clinical and parasitological relapses were less frequent in the treated patients. Metronidazole was generally well tolerated but transient dose-related side-effects, mostly gastrointestinal, occurred in about 50% of patients treated with thiabendazole. Nevertheless, it is concluded that both anthelmintics are clinically significantly effective in the treatment of dracontiasis.

Guinea worm disease is endemic in West Africa. In 1973 a field drug trial was conducted to compare effectiveness, cost, and side-effects of thiabendazole and metronidazole in treating active guinea worm disease and preventing latent worms from emerging. A mass chemotherapy campaign was planned to follow the drug trial. Only 15.5% of the treated patients expelled the worm completely, and in 28.4% of the cases worms continued to appear. Both drugs were equally unsatisfactory in their anti-helminthic effect. Consequently, our efforts to control guinea worm have shifted from chemotherapy to chemical control of cyclops and improvement of rural water supplies.

Between 1971 and 1974 a series of drug trials was conducted in 17 rural communities in western Nigeria where guinea-worm is endemic. During these trials and in subsequent years treatment, in the form of chemotherapy and/or dressing of ulcers, was given to all infected persons. A longitudinal study of infection in these villages showed a marked fall in the annual incidence over an 8-year period. The aggregate reduction in incidence in the three sectors surveyed was from 15.5% to 0.5% in sector 1, 29.8% to 0.4% in sector 2, and 20.3% to 0.0% in sector 3. The change appeared to be partly due to the treatment, which reduced the reservoir of infection and the rate of pollution of the water supply. Most of the sources of water continued to harbour Cyclops, none of which was found to be infected with Dracunculus, but which were shown experimentally to be capable of sustaining infection. The study demonstrates the potential role of therapeutic measures in controlling guinea-worm infection. It is suggested that the satisfactory measure of control that has been achieved could be increased by elimination of the Cyclops, with a view to total eradication of the disease from affected communities. Attention is drawn to the relevance of the findings for the International Drinking Water Supply and Sanitation Decade.

We studied 18 cases of dracunculosis treated in our department of Internal Medicine in Paris. The mean duration of the hospital stay is 38 days (15 to 90). The cost of this stay, calculated on the basis of the daily charge, accounts for 93.3 % of the total cost. The longest stays are due to serious subcutaneous infections at the site of the worm and to multiple or complex associated diseases. Average charge for laboratory test, roentgenograms or other investigations amounts to 4.4 % of the cost of the hospital stay. A significant part of these investigations is warranted by cellulitis and the diagnosis of associated conditions. Antibodies prescribed for subcutaneous infections account for almost all of the drug expense (2.3 % of the total cost). Thus, investigations and treatment together amount to only 6.7 % of the daily charge. Traditional treatment of dracunculosis is based on manual extraction of the worm. Thiabendazole was added in 12 of the 18 patients. The average duration of hospitalization (34 days) and average charge for investigations and drug treatment (FF 611) were less in these 12 patients than in the 6 others (47 days, FF 1286). However, this result is to be considered with caution as the number of patients in each group is small, treatments were assigned without any statistical rule, subcutaneous infections were more or less serious and associated diseases may have had a bearing on results.

Genital involvement of Dracunculus medinensis is uncommon, and when it does occur, it usually involves the scrotum. A case has been described in which the inguinal gland was involved producing a bubo simulating that caused by other commoner conditions. It is suggested that the microscopical examination of a wet preparation of bubo aspirates should routinely be practised, especially in tropical countries.

In a controlled field trial of treatment for dracontiasis, mebendazole (Vermox) was found to be effective in eliminating the adult worm and preventing clinical relapses, but it did not achieve significant amelioration of symptoms, subsidence of inflammation, or healing of ulcers. The failure is attributed to poor absorption and lack of anti-inflammatory action of the drug. Mebendazole was well tolerated and although two patients reported mild gastrointestinal disturbances, which may be attributed to the drug, the study confirms that mebendazole is one of the safest anthelmintics in current use and is in that respect ideal for mass therapy.

The purpose of the present work is the study of the epidemiological aspects of dracontiasis in an endemic area in Cameroon. The study was undertaken in the central Podokwo settlement in Mora subdivision. It is a mountainous area with a climate characterized by a long dry season, from October to mid-May, and a short rainy season. Two seasonal, streams run across the settlement. The water supply of the community is ensured throughout the year by two well built wells. During the rainy season, shallow unprotected wells are the water sources of about 80% of the inhabitants. Among the 944 subjects studied in our sample, 251 had the disease, corresponding to a prevalence of 26 6%. There is no significant difference between both sexes in the prevalence of the disease in our study. The age group 13-26 years is most affected. The worm load varies from 1 to 5, averagely 1.5. As to the localization of the worms in the body, in 92.7% of cases the worms is located in the lower limbs, the feet alone representing up to 46.8%. Less common sites of localization are the head, the breast, the external genitalia. The maximum rate of infestation is observed between August and September. Desinfection of wells with chemicals would be recommended during this period of time.

Two-hundred and twenty-nine cases dracunculiasis were selected for a double-blind trial of metronidazole against placebo. A cure rate of 85% was observed with metronidazole. A dosage of 400 mg metronidazole three times daily for 10-20 days appears suitable. Even with secondarily infected lesions, it was unnecessary to administer any other chemotherapeutic agent. In most cases symptomatic relief, especially of pain and pruritus, was obtained within two weeks. In patients with only subcutaneous worms, metronidazole did not apparently prevent the development of lesions and seemed to stimulate the worm to emerge quickly, with resultant less severe lesions. Complete cure was delayed in patients with multiple lesions, where worms reached the emergence state at different times. There did not appear to be any direct relationship between severity of the disease and response to metronidazole. If the worm was broken during treatment with metronidazole, no abscess formed nor was there any local inflammation. Metronidazole was very well tolerated even when administered for 20 to 25 days. No serious side-effects or toxic effects were observed.

Onchocerciasis is a disease of Africa and Central and South America. It produces severe skin disease and is a leading cause of blindness worldwide. Dracunculosis infection, caused by the guinea worm Dracunculosis medinensis, occurs in tropical Africa. Included in this article are discussions of the vector and transmission, pathology, immunology, diagnosis, and treatment of these two diseases.

Guinea worm infection is one of the most easily prevented parasitic diseases, but it is nevertheless a common cause of disability in rural areas of Africa, south-west Asia, and India. Infection occurs when drinking water is infested with infected Cyclops, a microcrustacean. Worms up to 70-80 cm in length develop in the subcutaneous tissues of the feet or legs and larvae are liberated to renew the cycle when an infected individual steps into a well or pond from which others draw drinking water. Infection is markedly seasonal because of (a) the influence of the climate on the types of water source used and (b) the developmental cycle of the parasite. The disability may be economically very important if the period of infection coincides with busy periods in the agricultural year. Sieving water through a cloth is sufficient to remove the Cyclops, but on a public health scale improved water supplies are required for control. Once the cycle of reinfection can be broken in any district the disease disappears. Chemical treatment of water bodies with temephos is also an effective and safe way of controlling transmission. Treatment consists of rolling out each emerging worm onto a small stick, a few centimetres each day, and certain drugs reduce the pain and pruritus and enable the worm to be removed more quickly.

Mebendazole was found to be effective in the treatment of patients infected with adult guinea worms. The patients consistently reported a rapid relief of pain, tenderness and swelling. The worms emerge from the ulcers in a degenerated, fragmented form. No extraction of worms is needed as the fragments are expelled spontaneously. Some cases need repetition of treatment when fresh lesions appear but healing is as rapid as in original lesions. No side-effects were encountered in spite of repetition of the course in some cases. The drug was well tolerated by all the patients included in the present study.