Ascaris lumbricoides is the most common helminth of human health importance, and the most resilient helminth found in faecal sludge. There are numerous types of sludge treatments; however, heating and drying are most commonly used for pathogen inactivation. Ascaris suum eggs were heated in a water bath at 40–55 °C for 10 seconds to 60 minutes in water, as well as heated in both urine diversion dry toilet and ventilated improved pit latrine sludge at 40 °C, 60 °C and 80 °C for times ranging from 5 seconds to 120 minutes. Eggs were also spiked into sludges of different moisture contents and incubated over 12 weeks at 25 °C, with samples analysed weekly. Overall, we concluded that eggs were inactivated at temperatures >50 °C, that the temperature–time relationship directly impacted the efficacy of heat treatment, that suspension medium had no effect, and that eggs survived better in wet rather than dry sludges.

This dataset contains the digitized treatments in Plazi based on the original journal article Appleton, C. C., Miranda, N. A. F. (2015): Two Asian freshwater snails newly introduced into South Africa and an analysis of alien species reported to date. African Invertebrates 56 (1): 1, DOI: 10.5733/afin.056.0102, URL: http://www.bioone.org/doi/10.5733/afin.056.0102

Bilharzia surveillance at local authority level in South Africa relies on public health personnel being able to locate transmission sites. Although several methods have been tried, the method of choice is collecting snails, identifying those that serve as intermediate hosts for bilharzia, and examining them for evidence of infection. Unfortunately, public health personnel are seldom trained to recognise these snails or the parasites' larval stages, and few laboratories are able to assist. Therefore, the intention is that these guidelines will help to equip personnel with the basic information needed to collect and identify the bilharzia-carrying snails, and then examine them for infection. The intramolluscan or larval stages of trematode parasites likely to be encountered in dissected snails are described. However, emphasis is placed on the furcocercariae, a group which includes the infective stage of bilharzia flukes. A family key to furcocercariae is presented.

Two Asian freshwater gastropods, Radix rubiginosa (Michelin, 1831) (Lymnaeidae) and Gyraulus chinensis (Dunker, 1848) (Planorbidae) are reported from a facility supplying fish and plants to the aquarium trade in KwaZulu-Natal, South Africa. Neither species has been found in South Africa previously. Both are considered potentially invasive. Updated keys for Lymnaeidae and Gyraulus spp. in South Africa are presented. An analysis of data on the dates of first collection and regions of origin for all 14 freshwater snails known to have been introduced into the country, regardless of whether or not they have survived, shows three phases of introduction. These are (i) from North America between the 1940s and 1960s, (ii) from South America during the 1970s and 1980s and (iii) from Asia between the 1990s and the present. Further research may show two species long regarded as indigenous to also be introductions.

Nine cases of paragonimiasis have been reported from cats (4), dogs (2) and children (3) in South Africa, with an additional suspected case in an adult female patient. Details of these cases are reviewed. All nine cases, and perhaps the adult case as well, were from the province of KwaZulu-Natal but locality data are only available for six of them. These six cases represent four localities which all lie below 100m above sea level in the province's lowlands, suggesting that there may be a focus of transmission here. The molluscan first intermediate host must be one of the two prosobranch snail species present in the area, Melanoides tuberculata or Tomichia natalensis, and the decapod second intermediate host the common river crab Potamonautes sidneyi. All infected cats and dogs had pulmonary infections, while two human cases for which there is sufficient information had extrapulmonary infections. Transmission appears to be ongoing but the invasive snail Tarebia granifera may be competing with both M. tuberculata and T. natalensis. If so, this may bring transmission to an end.

This review describes the types of habitats in which human schistosomiasis is transmitted in wetlands across southern Africa. The snails that serve as the parasites' intermediate hosts are tolerant of water with a wide range of chemical composition but are restricted by current velocity, temperature and habitat permanence. Human contact with the water in snail habitats is crucial to the establishment of transmission and children are more frequently and more severely infected than adults. Swimming is the contact activity that contributes most to transmission. Case studies illustrating the roles of high temperatures, hydrology and over-fishing in the epidemiology of the disease in the region are also reviewed.

The prevalences and intensities of Ascaris lumbricoides, Trichuris trichiura and hookworm (probably Necator americanus) infection were measured in the young children (aged 2-10 years) living in 10 urban slums in Durban, South Africa. Re-infection was assessed at 4-6 and 12 months post-treatment. The baseline prevalences of A. lumbricoides and T. trichiura were 81.7%-96.3% and 54.5%-86.2%, respectively, and the corresponding geometric mean intensities were 960 and 91 eggs/g faeces. Most (85%) of the children found infected with A. lumbricoides and 23% of those found infected with T. trichiura had moderate-heavy infections. A few of the children investigated had intensities of Ascaris and Trichuris infection that were considerably higher than those previously recorded in South Africa. The baseline prevalences of hookworm infection (0%-20% in individual slums, with a mean of 4.7%) and intensities of such infection (geometric mean = 17 eggs/g) were relatively low. Albendazole proved very effective against A. lumbricoides and hookworm but less so against T. trichiura. Re-infection by A. lumbricoides and T. trichiura reached pre-treatment prevalences by 4-6 months post-treatment in some of the slums and by 12 months in all the other slums. By 12 months post-treatment, the intensities of A. lumbricoides infection had reached their pretreatment levels while those of T. trichiura infection were higher than at baseline. Approximately 50% of children had moderate-heavy T. trichiura infections at 12 months post-treatment compared with approximately 23% at baseline. Hookworm infections did not re-appear after treatment. The results show clearly that urban slums should be included in any future helminth-control programmes in South Africa.

SUMMARY Beginning in 1970, the potential of remote sensing (RS) techniques, coupled with geographical information systems (GIS), to improve our understanding of the epidemiology and control of schistosomiasis in Africa, has steadily grown. In our current review, working definitions of RS, GIS and spatial analysis are given, and applications made to date with RS and GIS for the epidemiology and ecology of schistosomiasis in Africa are summarised. Progress has been made in mapping the prevalence of infection in humans and the distribution of intermediate host snails. More recently, Bayesian geostatistical modelling approaches have been utilized for predicting the prevalence and intensity of infection at different scales. However, a number of challenges remain; hence new research is needed to overcome these limitations. First, greater spatial and temporal resolution seems important to improve risk mapping and understanding of transmission dynamics at the local scale. Second, more realistic risk profiling can be achieved by taking into account information on people's socio-economic status; furthermore, future efforts should incorporate data on domestic access to clean water and adequate sanitation, as well as behavioural and educational issues. Third, high-quality data on intermediate host snail distribution should facilitate validation of infection risk maps and modelling transmission dynamics. Finally, more emphasis should be placed on risk mapping and prediction of multiple species parasitic infections in an effort to integrate disease risk mapping and to enhance the cost-effectiveness of their control.

Wetlands provide a range of benefits to society, and yet in South Africa wetlands continue to be affected by human activities. Considerable effort is now being directed towards rehabilitation of degraded wetlands and the construction of artificial systems to treat effluent and stormwater. At the same time, wetlands provide potential habitat for vectors or intermediate hosts (collectively referred to in this document as 'invertebrate disease hosts': IDHs), of parasites implicated in the transmission of such important diseases as malaria and schistosomiasis (bilharzia). The present review considers, for the 2 major IDHs (mosquitoes and schistosome-transmitting snails), the type of habitat required by the water-dependent life stage and the ways in which wetland degradation, rehabilitation and creation may affect the availability of suitable habitat. General practical measures for minimising pest species, particularly mosquitoes, are included. This review also highlights other issues that require research and testing in the South African context, including: the IDHs implicated in less well-known diseases (both of humans and animals) and the control of mosquitoes and schistosome-transmitting snails through biomanipulation. We Conclude that in regions of the country where the diseases are prevalent there is the likelihood that wetland rehabilitation and creation could inadvertently encourage the IDHs responsible for transmitting malaria and schistosomiasis. Assessment of the potential risks and benefits of a proposed wetland modification needs to be undertaken in a holistic manner using an adaptive framework that recognises the critical need to balance human and environmental health. Possible ways of controlling IDHs both in an environmentally- and socio-friendly manner need to be investigated using a multi-disciplinary approach engaging invertebrate biologists, health care officials, wetland scientists and also sociologists and economists.

The basommatophoran family Physidae possesses a remarkable but little known set of muscles called the "physid musculature". Using Physa acuta as a model, this musculature was shown to be anatomically complex and associated in places with the columellar muscle. The physid musculature has two main components, the physid muscle sensu stricto and the fan muscle, both of which have previously been named but not examined in detail. The physid muscle s.s. is branched with the larger branches running to the neck, head and foot, and the smaller ones to the lung floor and mantle. The fan muscle is not branched. We propose that the physid musculature is responsible for a unique ability of physids to rapidly flick their shells from side to side-a reaction that frequently enables them to escape predation. We suggest that during this movement the lung floor, which is strengthenec by several bands of muscle from both the physid musculature and the columellar muscle, serves as a pivot for the rotating visceral hump and shell, while the main trunk of the physid muscle s.s. and its main branches provide a broad anchorage in the foot.

The Asian prosobranch snail Tarebia granifera was reported from South Africa (and Africa) for the first time in 1999 in northern KwaZulu-Natal though it was probably introduced sometime prior to 1996. In the 10 years since its discovery it has spread rapidly, particularly northwards, into Mpumalanga province, the Kruger National Park and Swaziland. The snail has colonized different types of habitat, from rivers, lakes and irrigation canals to concrete lined reservoirs and ornamental ponds. It reaches very high densities, up to 21 000 m-2, and is likely to impact on the entire indigenous benthos of the natural waterbodies of the region – more so than any other invasive freshwater invertebrate known from the country. The indigenous thiarids Thiara amarula, Melanoides tuberculata, and Cleopatra ferruginea are considered particularly vulnerable. Preliminary accounts of the reproductive biology and population fluctuations of T. granifera in KwaZulu-Natal are also presented.

A well documented epidemic of human intestinal schistosomiasis caused by Schistosoma mansoni occurred at Maun in the seasonal part of the Okavango Delta, Botswana, building from very few cases in the 1950s and early 1960s to a peak prevalence of >80% in the 1980s. A retrospective analysis was performed on all available records of the prevalence of S. mansoni in the Maun area and the corresponding flow records of the Thamalakane River. These revealed a statistically significant correlation between prevalence and flow, but only when a lag period was introduced. The correlation was greatest with a lag period of 5-6 years between the rise and fall of discharge and the rise and fall of transmission. Since the hydrological events in the delta follow a cyclical pattern, another epidemic around 2020 appears likely.

Afrotropical sciomyzids are predators of freshwater pulmonate snails. Studies have indicated that these flies may play a role in controlling medically important (target) snail populations, especially snail intermediate hosts of schistosomes. This study investigated the preferential feeding of Sepedon scapularis and S. neavei on four commonly-occurring molluscs in South Africa. The feeding behaviour of these flies was observed on a polyphagous diet consisting of Bulinus tropicus, Bu. forskalii, Bu. africanus and Biomphalaria pfeifferi. Laboratory experiments were set up with a constant number of 12 live snails per petri dish. Snail mortality was recorded daily for the duration of the larval period. Preliminary results show that both fly species fed preferentially upon Bu. africanus and Bi. pfeifferi. Overall, S. neavei killed more target snails than S. scapularis did. The preference of both fly species was Bi. pfeifferi, followed by Bu. africanus, Bu. tropicus and Bu. forskalii. These sciomyzid species are, therefore, potential candidates as biological control agents of medically-important snails. Whilst these findings are based on laboratory studies, they need to be validated by field trials.

Information on hookworm infection and re-infection in a cohort of primary school children and interview data on their socioeconomic background and behavior were combined with environmental data using a geographic information system (GIS). Multivariate models served to explore the covariation of environmental and infection patterns adjusted for possible confounders. Our aim was to identify environmental factors that might serve to predict infection and thus guide control efforts when epidemiologic information is insufficient. Furthermore, we wanted to establish whether soil type has a genuine influence on hookworm infection. Prevalence maps and spatial statistics showed considerable spatial clustering of infection in the small ( approximately 28 x 16 km) study area. The multivariate logistic regression models showed strong positive associations of infection at baseline (baseline prevalence = 83.2%) with settlement density (odds ratio [OR] = 1.24, 95% confidence interval [CI] = 1.10-1.38) and vegetation density (OR = 1.66, 95% CI = 1.25-2.22) and a strong negative association with the clay content of the soil (OR = 0.67, 95% CI = 0.62-0.73). Similar but weaker correlations were found after re-infection. Socioeconomic status and behavior did not seem to confound these associations. Spatial analysis of the model residuals suggested that because the models accounted for most of the spatial pattern, the model standard errors were not affected by spatial clustering. Our study shows that the pattern of hookworm infection is strongly influenced by several environmental factors. The GIS-aided prediction of areas in need of treatment is therefore a promising tool to guide control efforts when epidemiologic information is insufficient.

Physa mosambiquensis Clessin, 1886 (Physidae) has long been an anomaly in the freshwater malacology of southern Africa. The type specimens and all available literature records are examined and used to propose an area of origin for the species and a mode of translocation to Africa. It is concluded that P. mosambiquensis is conspecific with P. marmorata from South Africa and P. waterloti from several west African countries (both were previously assigned to Aplexa by some authors), and that all these African Aplexinae conform to the South American P. marmorata (sometimes ascribed to Stenophysa). The spread of P. marmorata in eastern South Africa is updated.

Schistosomiasis is endemic in South Africa and continues to pose public health challenges especiallyindynamicallychangingareas, eg. informal settlements. Asurvey was conductedin the central Pieter maritzburg area, KwaZulu-Natal, to determine the prevalence, distribution and intensity of urinary schistosomiasis (Schistosoma haematobium) amongst occupants of informal settlements and to establish the distribution of snail hosts in relation to the settlements. Results revealed urinary schistosomiasis to be present amongst settlement dwellersatlowprevalence(7.2%)and intensity levels (mostly < 200eggs/10ml.) Transmission was patchy. Infected snail hosts (Bulmm africanus) were found in nearby rivers and dams and an active focus ofS. haematobium transmission was discovered in a city park - the first example of urban schistosomiasis from South Africa. A structured interview questionnaire was administered to settlement occupants to provide ancillary data. The public health implications of schistosomiasis control for South Africa are discussed.

OBJECTIVES To identify environmental factors that could serve to predict Ascaris lumbricoides infection patterns and thus guide control efforts in the absence of epidemiological information; to assess whether A. lumbricoides infection is positively associated with the soil clay content.METHODS Information on A. lumbricoides infection and re-infection in a cohort of primary schoolchildren and interview data on their socioeconomic background and behaviour were combined with environmental data using a geographical information system (GIS). Multivariate models served to explore the covariation of environmental and infection patterns adjusted for possible confounders.RESULTS Prevalence maps and spatial statistics revealed considerable spatial clustering of infection in the small study area. Logistic multivariate regression models showed strong positive associations of infection with vegetation density measured as the normalized difference vegetation index (NDVI) at baseline [odds ratio (OR) for a 10% increase: 1.82; 95% confidence interval (95% CI): 1.24-2.68; P = 0.002] and after re-infection (OR: 2.22; 95% CI: 1.71-2.87; P < 0.001). We also found a strong negative association of re-infection with the sun exposure of the soil surface as estimated from digital elevation models (OR: 0.78; 95% CI: 0.88; P < 0.001). The soil clay content was only moderately positively associated with infection and re-infection. Socioeconomic and behavioural variables, although correlated with A. lumbricoides infection, did not appear to confound the above associations in the demographically homogeneous study area. Spatial analysis of the model residuals suggested that as the models accounted for most of the spatial pattern, the model standard errors should not be affected by spatial clustering.CONCLUSION NDVI seems to have a high potential for the prediction of A. lumbricoides infection as it was strongly associated with infection patterns in the study area. Further advantages are that NDVI information is easy to use, affordable and available with global coverage.