Diagnostics for schistosomiasis in Africa and Arabia: a review of present options in control and future needs for elimination.

Within the World Health Organization 2012-2020 roadmap for control and elimination of schistosomiasis, the scale-up of mass drug administration with praziquantel is set to change the epidemiological landscape across Africa and Arabia. Central in measuring progress is renewed emphasis upon diagnostics which operate at individual, community and environmental levels by assessing reductions in disease, infections and parasite transmission. However, a fundamental tension is revealed between levels for present diagnostic tools, and methods applied in control settings are not necessarily adequate for application in elimination scenarios. Indeed navigating the transition from control to elimination needs careful consideration and planning. In the present context of control, we review current options for diagnosis of schistosomiasis at different levels, highlighting several strengths and weaknesses therein. Future challenges in elimination are raised and we propose that more cost-effective diagnostics and clinical staging algorithms are needed. Using the Kingdom of Saudi Arabia as a contemporary example, embedding new diagnostic methods within the primary care health system is discussed with reference to both urogenital and intestinal schistosomiasis.

[Diagnostic image (391). A man with fever and urticaria after a trip to Uganda]. / Diagnose in beeld (391). Een man met koorts en urticaria na een reis door Uganda.

A 35-year-old man presented with fever and severe urticaria after visiting Uganda. His symptoms were caused by acute invasive schistosomiasis, also known as Katayama fever.

Human schistosomiasis in the post mass drug administration era.

Profound changes are occurring in the epidemiology of schistosomiasis, a neglected tropical disease caused by a chronic infection with parasitic helminths of the genus Schistosoma. Schistosomiasis currently affects 240 million people worldwide, mostly in sub-Saharan Africa. The advent and proliferation of mass drug administration (MDA) programmes using the drug praziquantel is resulting in substantial increases in the number of people, mainly children aged 6-14 years, being effectively treated, approaching the point where most people in endemic areas will receive one or more treatments during their lifetimes. Praziquantel treatment not only cures infection but also frees the host from the powerful immunomodulatory action of the parasites. The treatment simultaneously enhances exposure to key parasite antigens, accelerating the development of protective acquired immunity, which would take many years to develop naturally. At a population level, these changes constitute a substantial alteration to schistosome ecology in that the parasites are more likely to be exposed not only to praziquantel directly but also to hosts with altered immune phenotypes. Here, we consider the consequences of this for schistosome biology, immunoepidemiology, and public health. We anticipate that there could be substantial effects on chronic pathology, natural immunity, vaccine development strategies, immune disorders, and drug efficacy. This makes for a complex picture that will only become apparent over decades. We recommend careful monitoring and assessment to accompany the roll-out of MDA programmes to ensure that the considerable health benefits to populations are achieved and sustained.

[Impact of implementation of Three Gorges Project on schistosomiasis endemic situation and control in Nanjing City].

OBJECTIVE: To understand the changes of hydrological regime in the Yangtze River and schistosomiasis endemic situation in Nanjing City after the implementation of Three Gorges Project. METHODS: The data of hydrological regime of the Yangtze River, schistosomiasis epidemic situation, and Oncomelania hupensis snail status were collected and analyzed in Nanjing City from 2002 to 2012. RESULTS: After the implementation of the Three Gorges Project in 2003, the water level of the Yangtze River slightly rose from January to April, the average water levels in May and August both reduced compared with those in 2002, and the time of water withdrawal was moved up. The water level of the Yangtze River slightly reduced from November to December. The endemic situation of schistosomiasis showed a decline tendency in the areas along the Yangtze River in Nanjing City. In 2012, the rates of human and bovine infected with Schistosoma japonicum both reduced by 100% as compared with those in 2002, and the snail area, infected snail area and snail density were reduced by 48.45%, 100% and 95.76% respectively as compared with those in 2002. CONCLUSION: After the implementation of the Three Gorges Project, the schistosomiasis endemic situation shows a decline tendency in the areas along the Yangtze River in Nanjing City, but the long-term monitoring still need to be carried out.

[Analysis of epidemic situation and control strategy of schistosomiasis in Jiu- jiang City from 2008 to 2014].

OBJECTIVE: To understand the epidemic situation of schistosomiasis in Jiujiang City, so as to provide the evidence for formulating further control strategy. METHODS: The data of schistosomiasis control were collected in Jiujiang City from 2008 to 2014. and the indicators including the annual schistosome infections of human and cattle, acute schistosome infection, outbreak of schistosomiasis endemic, schistosome infected Oncomelania hupensis snails were analyzed statistically. RESULTS: Compared with 2008, in 2014, the infection rates of schistosomiasis declined by 98.40% and 92.54% in human and cattle respectively. The area of schistosome infected snails decreased from 103.24 hm² to zero. The occurrence rate of frames with snails and density of living snails declined from 14.86% and 0.334 5/0.1 m² to 6.89% and 0.126 5/0.1 m², respectively. The acute schistosomiasis infection cases occurred except 2011 and 2014. CONCLUSION: The control strategy emphasizing on infection sources control is effective in Jiujiang City, but the risk of schistosomiasis still exists, and the risk control and schistosomiasis control strategy should be strengthened.

Multiple parasitic infections in a cardiac transplant recipient.

Infectious complications represent an important cause of morbidity and death in patients with transplant. Parasitic infections are less frequent than viral and bacterial agents, and are often overlooked. We describe the case of a 13-year-old adolescent, born in São Tomé Island, who was under immunosuppressive therapy after a cardiac transplant. The patient had an intermittent course of diarrhoea, abdominal pain and vomiting. She was admitted dehydrated, and Strongyloides stercoralis, Schistosoma intercalatum and Cystoisospora belli were isolated in her stools. The patient was treated with ivermectin, albendazole, praziquantel and ciprofloxacin with clinical and microbiological resolution. Her immunosuppressive therapy was reduced during hospitalisation. We believe that the parasitic infection was a result of a recrudescence of dormant infections acquired in her homeland. To the best of our knowledge, there are no reports of cystoisosporiasis or schistosomiasis in heart transplant recipients.

[Measures and effectiveness of comprehensive schistosomiasis control along Xinglong River in Qianjiang City].

OBJECTIVE: To evaluate the effect of comprehensive control of schistosomiasis along the Xinglong River in Qianjiang City, so as to provide the evidence for improving schistosomiasis control. METHODS: The comprehensive control measures including infection source control and Oncomelania hupensis snail eradication were surveyed along the Xinglong River in Qianjiang City. RESULTS: The prevalence of schistosomiasis was under control, that was the human and cattle infection rates decreased by 53.77% and 100% respectively, the snail area decreased by 26.9%, the mean density of living snails decreased by 25.5%, and no infected snails was found. CONCLUSIONS: The comprehensive control measures along the Xinglong River are effective, and the management and surveillance of snail environments still should be strengthened.

A safe, effective, herbal antischistosomal therapy derived from myrrh.

Schistosomiasis is a widespread helminthic disease. Treatment of schistosomiasis is based on chemotherapy with praziquantel, which is the drug of choice. Since resistance to praziquantel has been demonstrated, alternative drugs must be considered. Myrrh is an oleo-gum resin from the stem of the plant Commiphora molmol. This study was carried out on 204 patients with schistosomiasis. The drug was given at a dose of 10 mg/kg of body weight/day for three days, and induced a cure rate of 91.7%. Re-treatment of cases who did not respond with a dose of 10 mg/kg of body weight/day for six days gave a cure rate of 76.5%, increasing the overall cure rate to 98.09%. The drug was well tolerated, and side effects were mild and transient. Twenty cases provided biopsy specimens six months after treatment and none of them showed living ova.

Agro-engineering and sanitation improvement in the control of schistosomiasis japonica in the Philippines: a review.

Measures that would change the habitat of the snails were found to prevent its breeding. Among these are clearing and drainage of waterlogged areas; filling of depressions where filling materials are available; ponding of areas which cannot be drained, and improved rice culture. The degree of success in snail control depends to a large extent on the amount of change brought about in the habitat. The more radical the change, the greater the reduction in snail density. It can be expected that improvement in sanitation in the form of toilet construction and use, provision of safe water supply, building of footbridges and the control of stray animals will bring a further decline in the transmission of the disease. Studies have shown that perfect sanitation in the form of toilet construction and use will reduce transmission by about 75%, the other 25% being contributed by lower mammals. Agro-engineering control measures are presently being carried out intensively in 7 town of Leyte, with food assistance from the UN/FAO World Food Program being given to volunteer workers as incentives for them to work. Snail evaluation after 2 years has shown a snail reduction by 72% in the areas covered. It may be mentioned here that sanitation improvement, especially latrine construction, is an ongoing program of the Department of Health in all rural areas.

Control of Schistosoma japonicum infection in Lindu Valley, Central Sulawesi, Indonesia.

In Indonesia, schistosomiasis is presently confined to two endemic areas in Central Sulawesi; Lindu (1,500) and Napu (5,000 inhabitants) valleys. Because of various development schemes now underway, it is feared that the natural balance which existed for many years between the parasite, the snail intermediate hosts and man, will be upset and will place some 70,000 people of the adjoining Palu and Palolo areas at risk. Measures are being taken to control and prevent the spread of the disease. A pilot control programme is planned for two years in the village of Anca in Lindu with a population of 391 and a prevalence rate of 70.5%. Langko village with a population of 464 and a prevalence rate of 53.7% will be utilized as the comparison area. Baseline data on human, malacological and animal reservoir hosts are being collected and control operations are anticipated to commence in July 1975. Measures to be applied to control schistosomiasis in the order of priorities are: (a) agro-engineering or modification of the environment; (b) environmental sanitation through the provision of adequate water supply and construction of latrines; (c) mollusciciding of remaining snail infested areas; (d) chemotherapy, and (e) health education campaign. At the end of the two-year control programme, the following activities will be carried out to determine the degree of intervention achieved; (a) human data: calculation of prevalence rates, incidence rates, and changes in the intensity of infection based on quantitative egg counts; (b) malacological data: changes in the number and extent of snail foci; snail density, and snail infection rates; (c) reservoir hosts: changes in the prevalence rates among domestic and wild animals. Calculation of reclaimed areas and increase in agricultural production will also be assessed together with the overall cost/benefit analysis of the project undertaking.

[Schistosomiasis control effect of measures of replacing cattle with machine for cultivation and forbidding depasturage of livestock on marshlands in marshland and lake regions].

OBJECTIVE: To evaluate the schistosomiasis control effect of the measures of replacing cattle with machine for cultivation and forbidding depasturage of livestock on marshlands in marshland and lake regions. METHODS: The retrospective review and field survey were implemented in the Jiangling and Gongan counties of Hubei Province where were implemented with the measure of replacing cattle with machine for cultivation, and Yuanjiang and Huarong counties of Hunan Province where were implemented with the measure of forbidding the depasturage of livestock on marshlands. The schistosome infection status of human, cattle, and Oncomelania hupensis snails, and schistosome-infested field excreta were surveyed from 2007 to 2013. The effects of the interventions were compared before and after their implementations. RESULTS: The 6 villages of Hubei Province were implemented with the measure of replacing cattle with machine for cultivation, and 7 villages of Hunan Province were implemented with the measure of forbidding the depasturage of livestock on marshlands. From 2007 to 2013, the schistosome infection rates of residents declined from 3.95% to 0.70% (χ2 = 128.376, P < 0.05), with the descend range of 82.53%. The descend ranges of the measures of replacing cattle with machine for cultivation and forbidding the depasturage of livestock on marshlands were 83.081% and 81.62% respectively, and there was no significant difference between the two measures (χ2 = 0.132, P > 0.05). The infection rate of cattle decreased from 3.66% in 2007 to 0.65% in 2013, and the descend range was 82.24% (χ2 = 13.692, P < 0.05). The field excreta was surveyed in the snail breeding place in 2013. The investigated area was 157.435 hm2, and 625 samples of field feces of cattle were collected with the density of field excreta of 3.97/hm2, and the positive rate was 1.12% (7/625). The schistosome infection rate of snails and the density of infected snails decreased successively from 2007, and no infected snails were detected from 2011 to 2013. CONCLUSIONS: The schistosomiasis endemic situation are decreased significantly after the interventions of replacing cattle with machine for cultivation and forbidding the depasturage of livestock on marshlands. Therefore, schistosomiasis control effect of these measures is notable in the marshland and lake regions.

[Evaluation of comprehensive measures of schistosomiasis control in Caidian District, Wuhan City].

OBJECTIVE: To evaluate the implementation and effectiveness of comprehensive control measures of schistosomiasis in Caidian District, Wuhan City. METHODS: The data of implementation of the schistosomiasis control measures in Caidian District was collected and analyzed statistically. RESULTS: The number of Oncomelania hupensis snail environments and snail area decreased from 213 sites and 223.47 hm2 in 2003 to 59 sites and 51.20 hm2 in 2013, with the decreasing rate of 72.30% and 77.09%, respectively. The infection rate of schistosomiasis of human decreased from 1.58% in 2006 to 0.24% in 2013, with the decreasing rate of 84.81%. The positive rate of stool tests of cattle was 2.19% in 2006 while it was 0 in 2013. CONCLUSION: The comprehensive control measures of schistosomiasis are effective.

[Analysis of schistosomiasis endemic situation in Jiangling County from 2004 to 2013].

OBJECTIVE: To analyze the schistosomiasis endemic situation and understand its transmission trend in Jiangling County from 2004 to 2013, so as to improving the schistosomiasis control. METHODS: The relevant data of schistosomiasis were collected and analyzed statistically in Jiangling county from 2004-2013. RESULTS: The human prevalence of schistosomiasis was decreased from 10.22% in 2004 to 0.63% in 2013 with the descend rate of 93.84%, and the notable descend rate was 76.92% from 2009-2013. The cattle infection rate was decreased yearly from 7.59% in 2004 to 0 in 2013. The appearance rate of frames with living Oncomelania hupensis snails and the infection rate of snails reduce by 17.53% and 100% respectively. CONCLUSIONS: After 10-year control, the endemic situation of schistosomiasis in Jiangling County decreases and is at a low level. However, the risk factors of transmission still exist. Therefore, the comprehensive control measures still should be enhanced continuously.

[Effect of comprehensive schistosomiasis control strategy based on infection source control in Hanchuan City].

OBJECTIVE: To evaluate the effect of comprehensive schistosomiasis control measures based on infection source control in Hanchuan City (marshland and lake endemic regions). METHODS: The data of comprehensive schistosomiasis control in Hanchuan City from 2004 to 2013 were collected, and the change trends of the Oncomelania hupensis snail status and the infection situation of human and livestock were analyzed to evaluate the control effect. RESULTS: After the implementation of the comprehensive measures, the infection rates of residents and cattle decreased from 6.38% and 8.11% in 2004 to 0.16% and 0 in 2013 respectively. There were no acute schistosomiasis patients since 2007, no new infection cases since 2011, and no infected snails since 2012. Compared with 2004, the occurrence rate of frames with living snails and the average density of living snails decreased by 56.78% and 68.35%, respectively, but the snail area and susceptible area increased by 0.62% and 7.10%, respectively. In 2013, all the 367 endemic villages in 26 townships reached the criteria of transmission controlled. CONCLUSIONS: The comprehensive schistosomiasis control measures based on infection source control can control the schistosomiasis transmission effectively in marshland and lake endemic regions. When consolidating the achievement, the snail area in inner embankment should be compressed to prevent the schistosome re-infection in human and livestock.

[Effect of schistosomiasis comprehensive control in Linxiang City, 2004-2012].

OBJECTIVE: To evaluate the effect of schistosomiasis comprehensive control in Linxiang City. METHODS: The data of the endemic situation and control measures of schistosomiasis in Linxiang City from 2004 to 2012 were collected and analyzed, so as to assess the effect of schistosomiasis comprehensive control. RESULTS: Since 2005, a total of 14 610 household latrines improved, 9 782 biogas pools were built, 40.65 km river and river banks were protected, 809 cattle were eliminated, 23.30 hm2 pond were dug, 15.18 km ditches were hardened, 18.10 hm2 land were polished, more than 20 safe drinking water projects were constructed, and the beneficiary population reached 68 400 people. The human and cattle infection rate reduced from 2.07% and 3.95% in 2004 to 0.46% and 1.35% in 2012, with reduction rates of 77.78% and 65.82%, respectively. The living Oncomelania snail density and snail infection rate showed an overall decline tendency, which reduced from 0.114 4 snails/0.1 m2 and 0.19% in 2004 to 0.0 056 snails/0.1 m2 and 0 in 2012, with reduction rates of 95.10% and 100%, respectively. CONCLUSION: The promotion and implementation of the schistosomiasis comprehensive control measures with emphasis on control of the source of infection control is the key to further expand the achievements of schistosomiasis control in Linxiang City.

[Effect of comprehensive schistosomiasis control measures with focus on buffalo and sheep removal in Anxiang County].

OBJECTIVE: To understand the effect of comprehensive schistosomiasis control measures with focus on buffalo and sheep removal in Anxiang City, Dongting Lake area. METHODS: The data of buffalo and sheep removal, routine schistosomiasis control measures such as disease detection and treatment, Oncomelania snail survey and control, as well as health education were collected and analyzed in Anxiang County, Hunan Province from 2004 to 2012. RESULTS: The schistosome infection rates of people, domestic animals and snails decreased from 11.23%, 17.06% and 1.07% in 2004 when the comprehensive measures had not been implemented to 0.58%, 0 and 0 in 2012, respectively. The average density of infected snails decreased from 0.003 4 snails/0.1 m2 to 0. CONCLUSION: The comprehensive control measures with focus on buffalo and sheep removal are significantly effective, and can control the transmission of schistosomiasis in marshland and lake regions.

[Preventive effect of plant cercaricide Fangyouling for schistosome infection].

OBJECTIVE: To evaluate the preventive effect of Fangyouling (a plant cercaricide) for schistosome infection in the field. METHODS: Villagers contacting schistosome infested water in 3 administrative villages in Hubei Province were randomly selected, and the villagers rubbing Fangyouling before they contacted with the infested water were divided into Group I (159 cases) and those not rubbing Fangyouling before they contacted with the infested water were divided into Group II (172 persons). All the villagers were investigated by questionnaire, and their infections of schistosome were tested by sera and fecal examinations. RESULTS: There were no differences of constituent ratios of gender, age, occupation, time and type of infested water contact between the two groups (all P values > 0.05). The positive rates of sera and fecal examinations were 3.14% and 1.87%, respectively in Group I , and the positive rates of sera and fecal examinations were 9.30% and 6.40%, respectively in Group II, and there were significant differences between both the results of sera and fecal examinations of Group I and Group II (both P values < 0.05). In Group I , there were 110 people who completely embrocated Fangyouling, and their positive rates of sera and fecal examinations were 0.91% and 0, respectively. There are 42 people who incompletely embrocated Fangyouling, and their positive rates of sera and fecal examinations were 8.16% and 6.12%, respectively, and there were significant differences (both P values < 0.05). CONCLUSIONS: The preventive effect of schistosome infection of Fangyouling is significant. Incomplete embrocating may be one of the possible reasons for people still being infected with schistosome after rubbing the protective agent.

[Analysis of trend of Oncomelania snail status in Yangtze River valley of Anhui Province, 1998-2009].

OBJECTIVE: To understand the trend of Oncomelania hupensis snail distribution in Yangtze River valley of Anhui Province so as to provide an evidence for making out schistosomiasis prevention and control strategies in the future. METHODS: The snail data from 1998 to 2009 of the Yangtze River valley in Anhui Province were collected including the snail area, newly occurred and re-occurred snail areas, densities of snails and infected snails, etc., and the trend and influence factors were analyzed. RESULTS: With several fluctuations, the snail area showed a trend of declining in general after the devastating summer flooding in 1998. From 1998 to 2009, 3 peaks of newly occurred snail areas appeared in 1998, 2004 and 2006 and 2 peaks of reoccurred snail areas appeared in 1998 and 2004. The densities of living snails and infected snails were more severe in banks of the Yangtze River than in islets of the Yangtze River. During 12 years, 1 peak of living snail density appeared in 2003, and 3 peaks of infected snail density appeared in 1999, 2003-2004 and 2006 in the islets of the Yangtze River. The densities of living snails and infected snails in banks of the Yangtze both appeared 1 peak in 1998. CONCLUSIONS: The distribution of snails in the Yangtze River valley is related to nature, society and financial circumstances, and it is hard to completely perform the snail control in a short-term. Therefore, at the same time of strengthening snail control, we should also strengthen infectious source control.

[Distribution of Oncomelania snail in Liyang City, 2000-2010].

The distribution of Oncomelania snails showed an irregular point pattern, and new snail habitats were found in Liyang City, 2000 - 2010. It is suggested that the surveillance of snails should be considered from various aspects to ensure the quality of snail survey and control.