Investigations on the biology, epidemiology, pathology and control of Tunga penetrans in Brazil: I. Natural history of tungiasis in man

Tungiasis among children in Kenya is associated with poor nutrition status, absenteeism, poor school performance and high impact on quality of life

Tungiasis is a highly neglected tropical skin disease caused by the sand flea, Tunga penetrans. The flea burrows into the skin inducing a strong inflammatory response, leading to pain and mobility restrictions with potential impacts on quality of life. Few countries implement control efforts and there are few data on the impact of the disease to support policy decisions. We conducted a survey to determine the impact of tungiasis among primary school children across nine counties of Kenya. A total of 10,600 pupils aged 8 to 14 years were randomly selected from 97 primary schools and examined for tungiasis. For 81 cases and 578 randomly selected controls, anthropometric measurements were made, and school attendance and exam scores were collected from school records. Of those with tungiasis, 73 were interviewed regarding their quality of life using a tungiasis-specific instrument. Mixed effect ordered logistic and linear models were used to assess associations between disease status and impact variables. Compared to uninfected pupils, those with tungiasis had lower weight-for-age z-scores (adjusted β -0.41, 95% CI: -0.75-0.06, p = 0.020), missed more days of school the previous term (adjusted Incidence Rate Ratio: 1.49, 95% CI: 1.01-2.21, p = 0.046) and were less likely to receive a high score in mathematics (aOR 0.18, 95% CI: 0.08-0.40, p<0.001) and other subjects. Pupils with severe disease (clinical score >10) were four times more likely to experience severe pain than those with mild disease (OR 3.96, 95% CI: 1.35-11.64, p = 0.012) and a higher impact on their quality of life than those with mild disease (aOR 3.57, 95% CI: 1.17-10.8, p = 0.025) when adjusted for covariates. This study has demonstrated tungiasis has a considerable impact on children's lives and academic achievement. This indicates the need for integrated disease management for school-aged children to protect their physical and cognitive development and their future prospects.

Management of very severe tungiasis cases through repeated community-based treatment with a dimeticone oil formula: A longitudinal study in a hyperendemic region in Uganda

Tungiasis (sand flea disease) is a neglected tropical disease that is endemic in Sub-Saharan Africa and Latin America. Tungiasis causes pain, mobility restrictions, stigmatisation and reduced quality of life. Very severe cases with hundreds of sand fleas have been described, but treatment of such cases has never been studied systematically. During a larger community-based tungiasis control programme in a hyperendemic region in Karamoja, northeastern Uganda, 96 very severe tungiasis cases were identified and treated with the dimeticone formula NYDA®. They were repeatedly followed-up and treated again when necessary. The present study traces tungiasis frequency, intensity and morbidity among these 96 individuals over 2 years. At baseline, very severe tungiasis occurred in all age groups, including young children. Throughout the intervention, tungiasis frequency decreased from 100% to 25.8% among the 96 individuals. The overall number of embedded sand fleas in this group dropped from 15,648 to 158, and the median number of embedded sand fleas among the tungiasis cases decreased from 141 to four. Walking difficulties were reported in 96.9% at the beginning and in 4.5% at the end of the intervention. Repeated treatment with the dimeticone formula over 2 years was a successful strategy to manage very severe cases in a hyperendemic community. Treatment of very severe cases is essential to control the spread and burden of tungiasis in endemic communities.

Use of sarolaner in the treatment of tungiasis in naturally infested dogs

Tungiasis is an endemic dermatological parasitic zoonosis in Latin America, caused by the sand flea Tunga spp. (Siphonaptera, Tungidae), which promotes intense discomfort, swelling, erythema, itching, pain, secondary bacterial infection, cellulitis and necrosis. Sarolaner has been used to control different ectoparasites, but there is no record of its use for the treatment of tungiasis in dogs. The objective of this study was to evaluate the effectiveness of sarolaner for the treatment dogs naturally infested by Tunga spp. kept in the same infested environment. Three of four animals were medicated with sarolaner orally with a single dose of 2 mg/kg, as recommended by the manufacturer, and one animal remained without medication. After 24 hours, the fleas from all four dogs were mechanically removed. The animals were reevaluated on days +15 and +30 to assess possible reinfestation. The medicated animals remained free of fleas, while the untreated animal had fleas on the days previously defined for reevaluation. We can thus conclude that the use of sarolaner is an effective choice for tungiasis treatment.

Developing low-cost house floors to control tungiasis in Kenya - a feasibility study

CONTEXT

Tungiasis is a neglected tropical skin disease endemic in resource-poor communities. It is caused by the penetration of the female sand flea, Tunga penetrans, into the skin causing immense pain, itching, difficulty walking, sleeping and concentrating on school or work. Infection is associated with living in a house with unsealed earthen house floors.

METHODS

This feasibility study used a community-based co-creation approach to develop and test simple, locally appropriate, and affordable flooring solutions to create a sealed, washable floor for the prevention of tungiasis. Locally used techniques were explored and compared in small slab trials. The floor with best strength and lowest cost was pilot trialed in 12 households with tungiasis cases to assess its durability and costs, feasibility of installation in existing local houses using local masons and explore community perceptions. Disease outcomes were measured to estimate potential impact.

RESULTS

It was feasible to build the capacity of a community-based organization to conduct research, develop a low-cost floor and conduct a pilot trial. The optimal low-cost floor was stabilized local subsoil with cement at a 1:9 ratio, installed as a 5 cm depth slab. A sealed floor was associated with a lower mean infection intensity among infected children than in control households (aIRR 0.53, 95%CI 0.29-0.97) when adjusted for covariates. The cost of the new floor was US$3/m2 compared to $10 for a concrete floor. Beneficiaries reported the floor made their lives much easier, enabled them to keep clean and children to do their schoolwork and eat while sitting on the floor. Challenges encountered indicate future studies would need intensive mentoring of masons to ensure the floor is properly installed and households supervised to ensure the floor is properly cured.

CONCLUSION

This study provided promising evidence that retrofitting simple cement-stabilised soil floors with locally available materials is a feasible option for tungiasis control and can be implemented through training of community-based organisations. Disease outcome data is promising and suggests that a definitive trial is warranted. Data generated will inform the design of a fully powered randomized trial combined with behaviour change communications.

TRIAL REGISTRATION

ISRCTN 62801024 (retrospective 07.07.2023).

Efficacy of an oral formulation of afoxolaner and milbemycin oxime against Tunga penetrans in naturally infected dogs

BACKGROUND

The sand flea Tunga penetrans is one of the agents of tungiasis, an important parasitic skin disease affecting humans and several mammalian species. Tungiasis is mainly observed in disadvantaged rural and peripheral urban communities in Latin America and sub-Saharan Africa. The dog is a major reservoir of Tunga fleas. Hematophagous adult female Tunga spp. embed and grow in their host's epidermis and cause cutaneous inflammatory disorders. NexGard Spectra® is an orally administered endectocide for dogs, a co-formulation of the isoxazoline afoxolaner and the macrocyclic lactone milbemycin oxime. The objective of this study was to assess the efficacy of this product against canine tungiasis.

METHODS

A blinded, negative-controlled field trial was conducted in a Brazilian community known to be highly endemic for tungiasis. Sixty-six dogs naturally infected with live T. penetrans were randomly allocated to a treated group (44 dogs) and an untreated control group (22 dogs). In a first phase, dogs from the treated group were treated on days 0, 30, and 60. Efficacy was evaluated on the basis of the macroscopic parasitic skin lesions (Fortaleza classification) on days 7, 14, 21, 30, 45, 60, 75, and 90. In a second phase, to evaluate natural reinfections, all dogs were treated on day 90 and evaluated every 2 weeks thereafter until at least 30% of dogs were infected with live sand fleas.

RESULTS

During the first phase, efficacy (reduction in live sand fleas) of 92.4% was demonstrated on day 7. From day 14 until day 90, the efficacy of NexGard Spectra® was 100%. In the second phase, all dogs were free of live T. penetrans from 15 until 45 days after the day 90 treatment; 60 days post-treatment, 11% of dogs were reinfected, and 75 days post-treatment, 40% of dogs were reinfected.

CONCLUSIONS

NexGard Spectra® was demonstrated to be highly effective against canine tungiasis. In addition to an obvious beneficial effect on the health and welfare of the treated dog, the use of this product may have a one-health benefit on human cases by controlling the main reservoir of sand fleas.

Tungiasis: Participation of Cats and Chickens in the Dispersion and Maintenance of the Disease in an Endemic Tourist Area in Brazil

Tunga spp. are fleas commonly found in impoverished tropical regions. In Vila Juerana, a tourist community in Ilheus, Bahia, Brazil, where tungiasis is endemic, dogs are the main host of fleas during their life cycle. However, there is no information about the role of cats and chickens in tungiasis in the village. Of the 272 households investigated, 112 had domestic animals, 48 had only dogs, 28 had only cats, and nine had only chickens. Of the 27 households with cohabitation among species, 16 had cats and dogs, eight had chickens and dogs, and three had dogs, cats, and chickens. The injuries due to tungiasis were ranked according to the Fortaleza classification, considering stages I, II, and III as viable lesions. The paws/feet of 71/111 (63.9%) cats and 173/439 (39.4%) chickens were inspected. Dogs that lived with positive cats and chickens also were inspected. Among the 38% (27/7; 95% IC 26.74-49.32) positive cats, 16 cohabited houses with infected dogs but none lived with positive chickens. Of the chickens, 2.3% (4/173; 95% IC 0.07-4.5) had lesions caused by tungiasis. In each household where a cat was infected, the dog was also positive. Two chickens cohabited with an infected dog and the other two did not coexist with other species. Cohabitation with infected dogs and the absence of house confinement restrictions in Vila Juerana make cats important carriers that spread tungiasis in this community. Chickens had a low frequency of tungiasis lesions despite living in proximity to infected dogs and cats.

High Level of Knowledge about Tungiasis but Little Translation into Control Practices in Karamoja, Northeastern Uganda

Tungiasis is a neglected tropical disease (NTD) that can cause significant suffering and disability. Health promotion is an important pillar in NTD control programs, assuming that better knowledge contributes to reduced risk behavior and reduced risk of infection. The study objective was to assess tungiasis-related knowledge and its translation into control practices in a rural and highly endemic setting in Karamoja, Northeastern Uganda. We applied a mixed-methods design on household and community level. A semi-quantitative questionnaire on knowledge, practices, and attitudes (KAP) regarding tungiasis was administered to 1329 individuals with the main caring responsibilities in the household. Additionally, eight community dialogue meetings were held and analyzed. Overall, knowledge of tungiasis in humans was high but knowledge of tungiasis in animals was low. Most questionnaire respondents knew the causative agent and clinical presentations of tungiasis in humans, risk factors, and preventive measures. This tungiasis-related knowledge was translated into simple prevention measures. However, adequate tungiasis control was impeded due to a lack of resources, such as access to water and effective medical treatment. In conclusion, health promotion campaigns should be integrated with support towards adequate tungiasis control measures, such as provision of safe treatment, hardening of non-solid floors in the houses, and improved access to water.

Tungiasis in the Sanumás Amerindians in the Amazon Rainforest, Brazil: Prevalence, Intensity and Morbidity

BACKGROUND

Tungiasis is a disease associated with extreme poverty. We aimed to evaluate the prevalence of tungiasis in six different settlements of the Sanumás indigenous community in a remote area in the Auaris region, Yanomami territory, Brazil.

METHODS

We conducted an observational study to detect clinical and epidemiological factors associated with tungiasis using a cross-sectional strategy and multivariate logistic regression. Soil analysis was performed by visual and microscopic methods.

RESULTS

We examined 555 persons, 45 of whom had active tungiasis; 18 cases were classified as mild, 16 as moderate and 11 as severe. The disease was significantly more prevalent in children than in adults (odds ratio (OR) 15.77; 95% confidence interval (CI) = 5.34-67.91; p < 0.001). Soil infestation was significantly related to the occurrence of human tungiasis (OR = 12.29; 95% CI = 3.75-45.88). The sex and GPS location of the houses were not related to the occurrence of tungiasis.

CONCLUSIONS

We conclude that tungiasis is an important problem in the Sanumás community, especially for children. We suggest that interruption of the off-host transmission cycle, together with regular treatment [human and animal interventions], must be prioritized to achieve control of tungiasis in indigenous populations.

Tungiasis Stigma and Control Practices in a Hyperendemic Region in Northeastern Uganda

Neglected tropical diseases are known to be highly stigmatized conditions. This study investigates tungiasis-related stigma and control practices in the impoverished Napak District in rural northeastern Uganda, where tungiasis is hyperendemic and effective treatment is unavailable. We conducted a questionnaire survey with the main household caretakers (n = 1329) in 17 villages and examined them for tungiasis. The prevalence of tungiasis among our respondents was 61.0%. Questionnaire responses showed that tungiasis was perceived as a potentially serious and debilitating condition and that tungiasis-related stigma and embarrassment were common. Among the respondents, 42.0% expressed judging attitudes, associating tungiasis with laziness, carelessness, and dirtiness, and 36.3% showed compassionate attitudes towards people with tungiasis. Questionnaire responses further indicated that people made an effort to keep their feet and house floors clean (important tungiasis prevention measures), but lack of water was a common problem in the area. The most frequent local treatment practices were hazardous manual extraction of sand fleas with sharp instruments and application of various and sometimes toxic substances. Reliable access to safe and effective treatment and water are therefore key to reducing the need for dangerous treatment attempts and breaking the vicious cycle of tungiasis stigma in this setting marked by poverty.

Characterization of tungiasis infection and morbidity using thermography in Kenya revealed higher disease burden during COVID-19 school closures

BACKGROUND

Tungiasis is a neglected tropical skin disease caused by the sand flea Tunga penetrans. Female fleas penetrate the skin, particularly at the feet, and cause severe inflammation. This study aimed to characterize disease burden in two highly affected regions in Kenya, to test the use of thermography to detect tungiasis-associated inflammation and to create a new two-level classification of disease severity suitable for mapping, targeting, and monitoring interventions.

METHODS

From February 2020 to April 2021, 3532 pupils age 8-14 years were quasi-randomly selected in 35 public primary schools and examined for tungiasis and associated symptoms. Of the infected pupils, 266 were quasi-randomly selected and their households visited, where an additional 1138 family members were examined. Inflammation was assessed using infra-red thermography. A Clinical score was created combining the number of locations on the feet with acute and chronic symptoms and infra-red hotspots.

RESULTS

The overall prevalence of tungiasis among all the school pupils who were randomly selected during survey rounds 1 and 3 was 9.3% [95% confidence interval (CI): 8.4-10.3]. Based on mixed effects logistic models, the odds of infection with tungiasis among school pupils was three times higher in Kwale (coastal Kenya) than in Siaya [western Kenya; adjusted odds ratio (aOR) = 0.36, 95% CI: 0.18-0.74]; three times higher in males than in females (aOR = 3.0, 95% CI: 2.32-3.91) and three times lower among pupils sleeping in a house with a concrete floor (aOR = 0.32, 95% CI: 0.24-0.44). The odds of finding an infected person among the household population during surveys before the COVID-19 pandemic was a third (aOR = 0.32, 95% CI: 0.19-0.53) of that when schools were closed due to COVID-19 restrictions and approximately half (aOR = 0.44, 95% CI: 0.29-0.68) in surveys done after school re-opening (round 3). Infection intensity was positively correlated with inflammation as measured by thermography (Spearman's rho = 0.68, P < 0.001) and with the clinical score (rho = 0.86, P < 0.001). Based on the two-level classification, severe cases were associated with a threefold higher level of pain (OR = 2.99, 95% CI: 2.02-4.43) and itching (OR = 3.31, 95% CI: 2.24-4.89) than mild cases.

CONCLUSIONS

Thermography was a valuable addition for assessing morbidity and the proposed two-level classification of disease severity clearly separated patients with mild and severe impacts. The burden of tungiasis was considerably higher in households surveyed during COVID-19 restrictions suggesting underlying risks are found in the home environment more than in school.

Treatment of Animal Tungiasis: What’s New?

In tropical and subtropical countries, particularly in disadvantaged communities, tungiasis is a severe public health problem, which is often neglected by the authorities. The sand fleas Tunga penetrans, predominant in endemic areas, and Tunga trimamillata, whose cases in humans are less frequent, are the cause of this zoonosis. Domestic animals are potential reservoirs and disseminators of tungiasis, so controlling their infection would significantly advance the prevention of human cases. This literature review compiles the most recent studies and innovations in treating animal tungiasis. Studies of approaches to the treatment of animal tungiasis, as well as disease control and prevention, are described. Isoxazolines are highlighted as promising drugs to treat animal tungiasis, with high efficacy and pharmacological protection. The positive impacts of this discovery on public health are also discussed, since dogs are an essential risk factor for human tungiasis.

BOHEMIA: Broad One Health Endectocide-based Malaria Intervention in Africa-a phase III cluster-randomized, open-label, clinical trial to study the safety and efficacy of ivermectin mass drug administration to reduce malaria transmission in two African settings

BACKGROUND

Residual malaria transmission is the result of adaptive mosquito behavior that allows malaria vectors to thrive and sustain transmission in the presence of good access to bed nets or insecticide residual spraying. These behaviors include crepuscular and outdoor feeding as well as intermittent feeding upon livestock. Ivermectin is a broadly used antiparasitic drug that kills mosquitoes feeding on a treated subject for a dose-dependent period. Mass drug administration with ivermectin has been proposed as a complementary strategy to reduce malaria transmission.

METHODS

A cluster randomized, parallel arm, superiority trial conducted in two settings with distinct eco-epidemiological conditions in East and Southern Africa. There will be three groups: human intervention, consisting of a dose of ivermectin (400 mcg/kg) administered monthly for 3 months to all the eligible population in the cluster (>15 kg, non-pregnant and no medical contraindication); human and livestock intervention, consisting human treatment as above plus treatment of livestock in the area with a single dose of injectable ivermectin (200 mcg/kg) monthly for 3 months; and controls, consisting of a dose of albendazole (400 mg) monthly for 3 months. The main outcome measure will be malaria incidence in a cohort of children under five living in the core of each cluster followed prospectively with monthly RDTs DISCUSSION: The second site for the implementation of this protocol has changed from Tanzania to Kenya. This summary presents the Mozambique-specific protocol while the updated master protocol and the adapted Kenya-specific protocol undergo national approval in Kenya. BOHEMIA will be the first large-scale trial evaluating the impact of ivermectin-only mass drug administration to humans or humans and cattle on local malaria transmission TRIAL REGISTRATION: ClinicalTrials.gov NCT04966702 . Registered on July 19, 2021. Pan African Clinical Trials Registry PACTR202106695877303.

Prevalence and Infection Intensity of Human and Animal Tungiasis in Napak District, Karamoja, Northeastern Uganda

Tungiasis is an important but highly neglected cause of morbidity in resource-poor communities in Latin America and sub-Saharan Africa. Data upon which implementation of control measures can be based are scarce. Before piloting an integrated tungiasis control program in three parishes of Napak district, Uganda, a cross-sectional survey involving the systematic examination of humans and domestic mammals was implemented to establish the occurrence patterns of tungiasis. The study population was 5482 residents, of which 4035 (73.6%) participated in the study. The prevalence of tungiasis in humans was 62.8% (95% CI: 61.3-64.3%), with slightly more males than females affected (p = 0.01). Age-specific prevalence and intensity of human tungiasis followed an S-curve pattern, with children of 5-14 years and the elderly (≥60 years) being the most affected. Half of all lesions (50%) had been manipulated by sharp objects. The prevalence of tungiasis in animals was lower (14.2%, 95% CI: 10.9-18.0) than that of humans (p < 0.001). Animal tungiasis occurred in decreasing order of frequency in pigs (80%), dogs (24%), goats (16.3%), cats (8.1%) and sheep (4.9%). In conclusion, human tungiasis was highly prevalent but animal infections were comparatively few in the study area. Nevertheless, effective control measures should be based on One Health principles.

Spatial Distribution of Off-Host Stages of Tunga penetrans in the Soil within the Home Range of Nine Infected Dogs in An Endemic Tourist Area in Brazil

Tungiasis is a neglected disease caused by the sand flea Tunga penetrans, and dogs are considered the main reservoirs in Brazil. This study aimed to identify the role of dogs as tungiasis dispersers and to investigate the presence of T. penetrans in the soil of an endemic tourist area. Nine dogs infected by T. penetrans were included in this study and received GPS collars to analyze their movement through the village. Duplicate sand samples were collected in different areas of the community. Those areas were classified as peridomicile (n = 110), open area (n = 110), beach (n = 50), and river (n = 58). The analysis of the points recorded by the collars showed that the dogs roamed throughout the community, potentially facilitating the spread of the disease. Samples contaminated with developmental forms of the parasite were found in the circulation area of three dogs. Adult fleas were found in 3/328 samples. These data emphasize that infected dogs' roaming can influence the fleas' dispersion in the soil. Statistically, none of the study variables had a significant correlation (p > 0.5) with the presence of T. penetrans in the area analyzed. This study was the first to assess infected dogs' role as tungiasis propagators.

Protocol for a Randomized Control Trial for Tungiasis Treatment in Homa Bay County, Kenya: Dimeticone versus Sodium Carbonate

Tungiasis, a World Health Organization neglected tropical disease, is caused by the female sand flea. Most clinical trials for tungiasis use expensive or impractical drugs, which are difficult for residents to use. However, in western Kenya, communities successfully treat tungiasis with sodium carbonate. We hypothesise that the topical risk-difference of 5% sodium carbonate is no more than 10% non-inferior to dimeticone (NYDA^®) for tungiasis treatment. This is a protocol for a non-inferiority study, which will be randomised and with an observer-blinded control. The study will have two arms: 5% sodium carbonate and NYDA^®, one on each foot, and will take place at state primary schools in Homa Bay County, Kenya. Fleas identified among school children aged 8-14 years with sand-flea lesions will be enrolled in the study. For each participant, the viability of the embedded fleas, clinical signs including inflammation, and symptoms will be monitored for seven days after treatment. The proportion of dead fleas will be compared in the primary analysis. All adverse events will be monitored throughout the study period. We expect to identify the most effective treatment between sodium carbonate and NYDA^® for tungiasis, which can be adopted in the community.

Clinical and epidemiological survey of tungiasis in Madagascar

BACKGROUND

Tungiasis is a dermal parasitic infection, classified as a neglected tropical disease. Madagascar is one of endemic countries which have been committed for decades to control the tungiasis as a public health issue. Despite this medical importance, little is known about the prevalence and epidemiology of the disease in this country.

METHODS

A descriptive cross-sectional survey was performed in two endemic foci of Antananarivo and Toamasina.

RESULTS

In total, 2971 suspected individuals were surveyed. Of them, 643 individuals were excluded due to absence or refusing clinical examinations. Therefore, 2328 individuals with aforementioned criteria were clinically examined, 320 cases (13.7%) were found infected by Tunga penetrans. Of these 320 infected cases, 241 individuals came from rural regions against 79 from urban areas. The sex ratio of infected cases was 1.15 with an age average of 34.7 years old. Most of them were illiterate (185/320, 57.8%) with no habit of feet washing (210/320, 65.6%). The majority (198/320, 61.9%) inhabited in the houses constructed by falafa providing a suitable breeding location for Tunga ectoparasites. Based on clinical examination, most of the patients (298/320, 93.1%) had the lesions on their toes followed by those possessed the lesions on the plantar (140/320, 43.7%). The lesion stages of IV and V were observed in 49.1% (157/320) of visited patients which were more common in rural regions (86%) than in urban areas (14%). For treatment, removing the fleas using needle (122/320, 38.1%), followed by the application of petroleum (100/320, 31.2%) were among the most traditional remedies used by our patients.

CONCLUSION

This investigation highlights a high burden of tungiasis in studied endemic foci in particular in rural regions. These results can be helpful in control management strategies against this parasitosis in Madagascar.

Current status of the knowledge on the epidemiology of tungiasis in the Americas

Objectives.

To present the state-of-the-knowledge on the epidemiology of tungiasis in the Region of the Americas.

Methods.

A search of publications on the epidemiology of tungiasis in the Americas was performed in PubMed and LILACS databases from January 2007 to June 2021. In addition, a manual literature search on articles on the epidemiology of tungiasis was performed.

Results.

A total of 83 articles were analyzed which contained relevant information on tungiasis cases and their geographical distribution, prevalence and risk factors, life cycle, sites where transmission takes place, and zoonotic aspects. The on-host and off-host life cycles have been researched in detail. In certain contexts, the whole life cycle is completed indoors enabling transmission around the whole year. Cases were reported from 10 countries; 71% of them were from Brazil. In the general population, the prevalence varied between 1.0% and 82.6% according to the settings. Age-specific prevalence indicated that children and the elderly bear the highest disease burden. Risk factor studies indicate that tungiasis is associated with severe poverty.

Conclusions.

In the Americas, there are important gaps in information and knowledge of tungiasis. Understanding the burden, epidemiology, distribution, magnitude, related risk factors, and reservoirs, among others, is needed to develop and implement integrated control measures tailored to the context and patterns of transmission in the affected communities.

Parasites causing cutaneous wounds: Theory and practice from a dermatological point of view

A wide range of parasites can infest open wounds, or cause wounds due to the effects of the infestation. Parasitic infestations can involve the skin and subcutaneous tissues, with various clinical manifestations. In case of cutaneous wounds related to infestations, protozoa, helminths and arthropods are the main groups of parasites involved and emerging new aspects have been recently reported. Treating the wound correctly is fundamental in these patients in order to reduce the development of pathological scars and prevent complications. In particular, a gentle debridement for devitalized/infested tissue removal, the appropriate use of topical antiseptics and dressings such as hydrogel, hydrocolloids and antimicrobial dressings can be useful to control superinfections, moisture balance, inflammation and to promote edge proliferation.

Efficacy of oral fluralaner (Bravecto) against Tunga penetrans in dogs: A negative control, randomized field study in an endemic community in Brazil

The sand flea Tunga penetrans is one of the zoonotic agents of tungiasis, a parasitic skin disease of humans and animals. The dog is one of its main reservoirs. This negatively controlled, randomized, double-masked clinical trial evaluated the therapeutic and residual efficacy of fluralaner for treatment of dogs naturally infested with T. penetrans. Sixty-two dogs from an endemically affected community in Brazil were randomly assigned to either receive oral fluralaner (Bravecto chewable tablets) at a dose of 25 to 56 mg fluralaner/kg body weight, or no treatment (31 dogs per group). Dogs were clinically examined using a severity score for acute canine tungiasis (SCADT), parasitological examinations as defined by the Fortaleza classification, and pictures of lesions on days 0 (inclusion and treatment), 7 ± 2, 14 ± 2, 21 ± 2, 28 ± 2, 60 ± 7, 90 ± 7, 120 ± 7 and 150 ± 7. The percentage of parasite-free dogs after treatment was >90% between days 14 and 90 post-treatment with 100% efficacy on study days 21, 28 and 60. Sand flea counts on fluralaner treated dogs were significantly lower (p<0.025) than control dogs on all counts from day 7 to 120. The number of live sand fleas on treated dogs was reduced by > 90% on day 7, > 95% on days 14 and 90, and 100% from day 21 to 60, and with a significant difference between groups from day 7 to 120. From day 7 to day 120, mean SCADT scores were significantly reduced in treated dogs with a mean of 0.10 compared to 1.54 on day 120 in untreated dogs. Therefore, a single oral fluralaner administration is effective for treating and achieving long lasting (> 12 weeks) prevention for tungiasis in dogs.

Tungiasis is a dermatological disease that affects humans and animals infested with sand fleas (Tunga spp.), especially in communities exposed to contaminated sandy and dry soil, where living conditions are precarious and access to basic health is limited. These sand fleas penetrate host skin and cause severe acute and chronic injuries that can dramatically compromise the host’s health. Dogs are a primary reservoir and disseminator of these fleas in South America. In this clinical field trial, the efficacy of a single oral dose of fluralaner (Bravecto chewable tablets) was evaluated for treatment and prevention of tungiasis in dogs in an endemic area of Brazil. The treatment was assessed through absence of live sand fleas and resolution of characteristic tungiasis skin lesions. Fluralaner was 100% effective from the third to the eighth week post-treatment, eliminated live sand fleas and protected against new infestations during the study. Therefore, fluralaner proved to be an excellent therapeutic option for treatment and a highly effective control option for canine tungiasis.

Environmental and Household-Based Spatial Risks for Tungiasis in an Endemic Area of Coastal Kenya

Tungiasis is a cutaneous parasitosis caused by an embedded female sand flea. The distribution of cases can be spatially heterogeneous even in areas with similar risk profiles. This study assesses household and remotely sensed environmental factors that contribute to the geographic distribution of tungiasis cases in a rural area along the Southern Kenyan Coast. Data on household tungiasis case status, demographic and socioeconomic information, and geographic locations were recorded during regular survey activities of the Health and Demographic Surveillance System, mainly during 2011. Data were joined with other spatial data sources using latitude/longitude coordinates. Generalized additive models were used to predict and visualize spatial risks for tungiasis. The household-level prevalence of tungiasis was 3.4% (272/7925). There was a 1.1% (461/41,135) prevalence of infection among all participants. A significant spatial variability was observed in the unadjusted model (p-value < 0.001). The number of children per household, earthen floor, organic roof, elevation, aluminum content in the soil, and distance to the nearest animal reserve attenuated the odds ratios and partially explained the spatial variation of tungiasis. Spatial heterogeneity in tungiasis risk remained even after a factor adjustment. This suggests that there are possible unmeasured factors associated with the complex ecology of sand fleas that may contribute to the disease's uneven distribution.

Evaluating the potentials of randomised integrated control trial on tungiasis in a South-western Nigerian community

Considering the fact that new, safe and incorporable treatment alternatives to therapeutic prophylaxis for tungiasis are lacking and sometimes proving difficult, this present study evaluated the potentials of integrating control approach involving focal premise treatment using 5% emulsifiable concentrate of cypermethrin, and topical application of Piper guineense oil with personal protection. Of the 90 houses selected, their floors were classified into paved rooms & unpaved verandas, paved verandas & unpaved rooms, paved rooms & verandas, and unpaved rooms & verandas, and tested for the presence of sand fleas using the sweeping and beating as well as soil collection and extraction by tullgren funnel method before fumigation. A total of 100 individuals partitioned into four groups of 25 individuals each were assigned 3%, 5%, 10% and 15% of P. guineense oil irrespective of stages of embedded fleas. The mean of sand fleas decreased from 1.14, 0.07, 0.21, and 1.66 to 0.37, 0.02, 0.09 and 1.08 after two weeks of single spray compared to the untreated location (p <  0.001). Furthermore, the mean lesions of stage I reduced to 0 after 2 to 6 days of 3%, 5%, 10% and 15% ointment application, and stage II and III after 10 to 12 days of 10% and 15% application respectively. The difference between tungiasis stages and exposure time for P. guineense ointment was highly significant p = 0.007 and p = 0.0002. Notable reduction in severity score of acute and chronic tungiasis was observed thus indicating effectiveness of the topical ointment. Hexanolic oil extracts of P. guineense in 10% and 15% concentration would kill embedded sand flea and ameliorate the sufferings in endemic settings.

Prevalence and associated factors of Tunga penetrans infestation among 5-14-year-olds in rural Ethiopia

Background

Tunga penetrans, also known as sand flea, causes Tungiasis in humans and animals. Despite its notoriety as an entomological problem, however, the ectoparasite receives little consideration from public health professionals. It is against this background that this article aims to assess the prevalence of and factors associated with Tunga penetrans infestation among 5-14-year-olds in rural Western Ethiopia.

Methods

From November to December 2020, 487 children aged 5 to 14 were selected from four primary schools in a cross-sectional study using systematic random sampling. Clinical exams, Interviews with parents/guardians and observations of the housing and classroom environments were used to collect data. Descriptive statistics and multivariable regression were used to characterize the data and identify factors associated with Tunga penetrans infestation.

Result

Tunga penetrans infestation (Tungiasis) was diagnosed in 138 of the 487 children examined, placing the prevalence at 28.3% (95% CI: 24.2%, 32.2%). Mud plastered walls [AOR: 5.83, % CI (3.44–9.88)], having cats in the house [AOR: 5.91, 95% CI (3.51–10.11)], not having separated sleeping quarters for animals [AOR: 4.60, 95% CI (2.69–7.86)], using self-supplied water [AOR: 6.30, 95% CI (3.33–11.93)], walking>30 minutes to school [AOR: 2.37, 95% CI (1.48–3.80)] were associated with Tungiasis.

Conclusion

In one way or another, several of the identified factors were linked to poverty. Improved house wall materials, fumigation of mud-plastered houses, dusting or spraying insecticides on domestic animals (such as cats), improved access to water, community education about keeping animals separated from living spaces, and hygiene promotion are all needed, with a focus on locally available, low-cost technologies that the poorest families can afford.

Therapeutic Potential of Tea Tree Oil for Tungiasis

Tungiasis (sand flea disease) is a neglected tropical disease caused by penetration of female sand fleas, Tunga penetrans, into a person's skin usually in their feet. The disease inflicts immense pain and suffering on millions of people, particularly children. The condition is most prevalent in Latin America, the Caribbean, and sub-Saharan Africa. Currently, there is no standard drug treatment for tungiasis. The available treatment options are fairly limited and unrealistic to use in endemic areas; as a result, in desperation, the affected people do more harm to themselves by extracting the fleas with non-sterile instruments, further exposing themselves to secondary bacterial infections and/or transmission of diseases such as hepatitis B virus, hepatitis C virus, or HIV. This highlights the urgent need for simpler, safer, and effective treatment options for tungiasis. Tea tree oil (TTO) has long been used as an antiseptic with extensive safety and efficacy data. The evidence on parasiticidal properties of TTO against ectoparasites such as head lice, mites, and fleas is also compelling. The purpose of this review is to discuss the current tungiasis treatment challenges in endemic settings and highlight the potential role of TTO in the treatment of tungiasis.

Dermoscopy of skin infestations and infections (entomodermoscopy) - Part I: dermatozoonoses and bacterial infections

Dermoscopy is an essential in vivo diagnostic technique in the clinical evaluation of skin tumors. Currently, the same can also be said about its implications when approaching different clinical situations in Dermatology. A growing number of reports on dermatological scenarios and diseases have been published, in which dermoscopy has been of great diagnostic help. The term "entomodermoscopy" was coined to describe dermoscopic findings in skin infestations and also in dermatoses of infectious etiology. In part I of this article, the main dermoscopic descriptions of zoodermatoses and bacterial infections will be addressed. In many of them, such as scabies, pediculosis, myiasis, and tungiasis, it is possible to identify the pathogen and, consequently, attain the diagnosis more quickly and use the technique to follow-up therapeutic effectiveness. In other situations that will be described, dermoscopy can allow the observation of clinical findings with greater detail, rule out differential diagnoses, and increase the level of confidence in a clinical suspicion.

Risk factors for scabies, tungiasis, and tinea infections among schoolchildren in southern Ethiopia: A cross-sectional Bayesian multilevel model

Background

Skin problems cause significant sickness in communities with poor living conditions, but they have received less attention in national or global health studies because of their low mortality rates. In many developing regions, the prevalence of parasitic skin diseases among schoolchildren is not reported. Previous studies thus have attempted to identify risk factors for these conditions using the frequentist approach. This study aimed to assess the occurrence and risk factors of skin infections among rural schoolchildren in southern Ethiopia by combining a frequentist and a Bayesian approach.

Methodology/Principal findings

Using three-stage random sampling, we assessed 864 schoolchildren aged 7–14 years from the Wonago district in southern Ethiopia. We detected potential risk factors for scabies, tungiasis, and tinea infections and recorded their hygienic practices and socio-demographic information. The frequentist model revealed a clustering effect of 8.8% at the classroom level and an insignificant effect at the school level. The Bayesian model revealed a clustering effect of 16% at the classroom level and 5.3% at the school level. Almost three-fourths of the sample had at least one type of skin problem, and boys were at higher overall risk than girls (adjusted odds ratio [aOR] 1.55 [95% Bayesian credible interval [BCI] 1.01, 2.28). Risk factors included unclean fingernails (aOR 1.85 [95% BCI 1.08, 2.97]); not washing the body (aOR 1.90 [95% BCI 1.21, 2.85]) and hair (aOR 3.07 [95% BCI 1.98, 4.57]) with soap every week; sharing a bed (aOR 1.97 [95% BCI 1.27, 2.89]), clothes (aOR 5.65 [95% BCI 3.31, 9.21]), or combs (aOR 3.65 [95% BCI 2.28, 5.53]); and living in a poor household (aOR 1.76 [95% BCI 1.03, 2.83]). Washing legs and feet with soap daily was identified as a protective factor for each of the three skin diseases (aOR 0.23 [95% BCI 0.15, 0.33]).

Conclusions/Significance

We observed high variation in skin problems at the classroom level, indicating the presence of shared risk factors in these locations. The findings suggest the need to improve children’s personal hygiene via health education by schoolteachers and health workers.

Skin problems are common disorders in resource poor settings. Scabies and tungiasis are neglected tropical diseases causing significant sickness in communities with poor living conditions. Scabies is dermatosis caused by a burrowing mite, Sarcoptes scabiei var. hominis. Tungiasis is caused by a flea, Tunga penetrans, infesting the skin, usually on the feet or hands. Tinea infection is a fungal dermatophyte infection of the skin and the most common dermatological problem among schoolchildren in Ethiopia, especially tinea capitis. Application of a Bayesian approach to identify possible risk factors for these problems has seldom been used. We found that compared to the frequentist model, the Bayesian model better explained school- and classroom-level variations in skin problems among schoolchildren. Our findings also suggest that transmission of skin infections, especially fungal and scabies infections, frequently occurs in schools and classrooms. We identified several risk factors for these conditions, including low socioeconomic status; unclean fingernails; not washing with soap at least every week; and sharing beds, clothes, and combs. Thus, it is important to improve the personal hygiene of schoolchildren through education. Regular checkups by teachers also can improve skin health and related morbidity in rural schoolchildren in southern Ethiopia.

Tungiasis in domestic, wild, and synanthropic animals in Brazil

Tungiasis is an ectoparasitic skin disease of humans and warm-blooded animals caused by fleas of the genus Tunga (Jarocki, 1938). Dogs, cats, pigs, and synanthropic rodents are the main animal reservoirs. Of the 14 known species, 12 are found in Latin America and, among these, eight are found in Brazil, including the two zoonotic species Tunga penetrans and Tunga trimamillata. Tunga penetrans predominates among humans and Brazilian pets, where the dog is the most affected species, and its presence is a risk factor associated with the disease in humans. Tunga spp. are widely distributed throughout the national territory, with T. penetrans being the most dispersed and the most frequent in animals from endemic areas, especially in underprivileged communities. Infections in animals, associated with inadequate management, favor the spread and perpetuation of the disease. Intense injuries can result in sequelae and serious clinical conditions, compromising the health, welfare, and productivity of animals, as well as leading to death. Health precariousness, lack of control and neglect in the management of populations of domestic and synanthropic animals, poor hygiene habits of individuals, lack of information from both the population and related professionals, lack of effective treatment, and of perception of tungiasis as a disease are among the main challenges for the control of this parasitosis. As recommended for other zoonotic Neglected Tropical Diseases, strategies based on the concept of One Health can guarantee more effective results in the fight against human and animal tungiasis.

The efficacy of topical, oral and surgical interventions for the treatment of tungiasis: A systematic review of the literature

Background

Tungiasis is a neglected disease caused by Tunga penetrans that can be complicated by secondary infections and local tissue destruction. Adequate treatment is important, especially in vulnerable populations; potential treatment options proposed range from surgical extraction to the use of oral and topical medications. We aimed to perform a systematic review to assess the efficacy of topical, oral and surgical interventions for the treatment of tungiasis.

Methodology/Principal findings

The present review is registered in PROSPERO (CRD42021234741). On September 1, 2020, we searched PubMed, EMBASE, Scopus, Web of Science, Science Direct, Scielo and LILACS BVS. We included clinical trials and longitudinal observational studies that evaluated any topical, systemic or mechanical treatment for tungiasis. We used the Revised Cochrane Risk of Bias (RoB) Tool for Randomized Trials for clinical trial analysis. Qualitative and quantitative descriptive syntheses were performed. Our search strategy resulted in 3376 references. Subsequently, 2568 titles/abstracts and 114 full texts were screened. We finally included 19 articles; 9 were classified as clinical trials. Two and 3 articles presented low and some RoB, respectively, according to the tool. Only two articles tested the efficacy of oral medications (niridazole, ivermectin), with discouraging results. Six clinical trials evaluated topical products for the treatment of tungiasis; 2 evaluated dimeticone-based compounds and reported positive results in lesion reduction and cure. None reported significant adverse reactions. Surgical extraction was evaluated only in observational studies.

Conclusions/Significance

We conclude that, although surgical extraction is the most commonly used treatment, there is sufficient evidence supporting the use of occlusive agents, especially manufactured dimeticone-based products.

Tungiasis is a disease caused by Tunga penetrans that affects regions with low socioeconomic status and a lack of proper sanitation. The disease usually has a self-limiting course or can be cured by simple extraction, but complications are not uncommon. In vulnerable populations, such as indigenous communities, children and people with disseminated tungiasis, the development of new treatment strategies is essential for the prevention of undesirable secondary outcomes. We performed a comprehensive systematic review of the literature by searching the most important scientific databases: PubMed, EMBASE, Scopus, Web of Science, Science Direct, Scielo and LILACS BVS. We aimed to assess the efficacy of topical, oral and surgical interventions for the treatment of tungiasis. We included 19 articles, 9 of which were classified as clinical trials. Six clinical trials evaluated topical products for the treatment of tungiasis; 2 evaluated dimeticone-based compounds and reported positive results in lesion reduction and cure. None reported significant adverse reactions. We concluded that, although mechanical extraction is the most commonly used treatment, there is sufficient evidence supporting the use of occlusive agents, especially manufactured dimeticone-based products.

Treatment of tungiasis using a tea tree oil-based gel formulation: protocol for a randomised controlled proof-of-principle trial

INTRODUCTION

Tungiasis (sand flea disease or jigger infestation) is a neglected tropical disease caused by penetration of female sand fleas, Tunga penetrans, in the skin. The disease inflicts immense pain and suffering on millions of people, particularly children, in Latin America, the Caribbean and sub-Saharan Africa. Currently, there is no standard treatment for tungiasis, and a simple, safe and effective tungiasis treatment option is required. Tea tree oil (TTO) has long been used as a parasiticidal agent against ectoparasites such as headlice, mites and fleas with proven safety and efficacy data. However, current data are insufficient to warrant a recommendation for its use in tungiasis. This trial aims to generate these data by comparing the safety and efficacy of a 5% (v/w) TTO proprietary gel formulation with 0.05% (w/v) potassium permanganate (KMnO₄) solution for tungiasis treatment.

METHODS AND ANALYSIS

This trial is a randomised controlled trial (RCT) in primary schools (n=8) in South-Western Kenya. The study will include school children (n=88) aged 6-15 years with a confirmed diagnosis of tungiasis. The participants will be randomised in a 1:1 ratio to receive a 3-day two times a day treatment of either 5% TTO gel or 0.05% KMnO₄ solution. Two viable embedded sandflea lesions per participant will be targeted and the viability of these lesions will be followed throughout the study using a digital handheld microscope. The primary outcome is the proportion of observed viable embedded sand fleas that have lost viability (non-viable lesions) by day 10 (9 days after first treatment). Secondary outcomes include improvement in acute tungiasis morbidities assessed using a validated severity score for tungiasis, safety assessed through adverse events and product acceptability assessed by interviewing the participants to rate the treatment in terms of effectiveness, side effects, convenience, suitability and overall satisfaction.

ETHICS AND DISSEMINATION

The trial protocol has been reviewed and approved by the University of Canberra Human Research Ethics Committee (HREC-2019-2114). The findings of the study will be presented at scientific conferences and published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBERS

Australian New Zealand Clinical Trials Registry (ACTRN12619001610123); PACTR202003651095100 and U1111-1243-2294.

Presence of dogs and proximity to a wildlife reserve increase household level risk of tungiasis in Kwale, Kenya

Introduction

Tungiasis is a ectopic skin disease caused by some species of fleas in the Tunga genus, most notably T. penetrans. The disease afflicts poor and marginalized communities in developing countries. Transmission of tungiasis comprises a complex web of factors including domesticated animals and wildlife. This research explores animal and environmental risk factors for tungiasis in an area adjacent to a wildlife reserve in Kwale, Kenya.

Methods

A two-stage complex sampling strategy was used. Households were selected from three areas in and around Kwale Town, Kenya, an area close to the Kenyan Coast. Households were listed as positive if at least one member had tungiasis. Each household was administered a questionnaire regarding tungiasis behaviors, domesticated animal assets, and wild animal species that frequent the peridomiciliary area. Associations of household tungiasis were tests with household and environmental variables using regression methods.

Results

The study included 319 households. Of these, 41 (12.85%) were found to have at least one person who had signs of tungiasis. There were 295 (92.48%) households that possessed at least one species of domesticated animal. It was reported that wildlife regularly come into the vicinity of the home 90.59% of households. Presence of dogs around the home (OR 3.85; 95% CI 1.84; 8.11) and proximity to the park were associated with increased risk for tungiasis infestation in humans in a multivariate regression model.

Conclusions

Human tungiasis is a complex disease associated with domesticated and wild animals. Canines in particular appear to be important determinants of household level risk.

Clinical interventions for tungiasis (sand flea disease): a systematic review

Tungiasis (sand flea disease) is an epidermal parasitic skin disease occurring in resource-limited communities. There is no standard treatment for tungiasis, and available treatment options are scarce. To our knowledge, this is the first systematic review aimed to assess randomised controlled trials (RCTs) investigating interventions for tungiasis. We systematically searched databases including MEDLINE (EBSCOhost), CENTRAL, CINAHL, PubMed, Web of Science, SciELO, LILACS and Embase (Scopus) for RCTs in any language, from inception of the databases until June 12, 2021. RCTs exploring preventive and therapeutic interventions for tungiasis were eligible. We used the revised Cochrane Collaboration's risk of bias tool to assess the risk of bias and Jadad scale to quantify the methodological quality of the RCTs. Of the 1839 identified records, only eight RCTs involving 808 participants were included, and several methodological deficiencies were identified in most of the trials. Trial interventions included: oral drugs niridazole and ivermectin and topical interventions of ivermectin lotion, metrifonate lotion, thiabendazole lotion, thiabendazole ointment, dimeticones (NYDA), and a neem seed and coconut oils-based mixture for treatment and coconut oil-based lotion (Zanzarin) for prevention. The coconut oil-based lotion for prevention and dimeticones for treatment of tungiasis have displayed the most promise. Most of the RCTs included in this study had low methodological quality. There is a clear unmet need for high-quality RCTs examining safe and effective prevention and treatment alternatives of tungiasis in endemic settings.

Tungiasis in the urban area of Popayán, Colombia: A case report

La tungiasis es una ectoparasitosis endémica en Latinoamérica y está asociada a factores de riesgo como la ruralidad, la pobreza y la convivencia con animales. Popayán, una ciudad al suroccidente de Colombia, fue históricamente afectada por la tungiasis, tanto así que a sus habitantes los apodan "patojos" debido a la forma de caminar de sus habitantes infestados por la pulga. Hoy la enfermedad se creía eliminada. Se presenta el caso de un niño de 12 años procedente del área urbana de Popayán, que consultó por lesiones papulares de bordes circulares, centro negruzco y halo hiperqueratósico en ambos pies, de un mes de evolución. Por los hallazgos clínicos se sospechó tungiasis y se le administró ivermectina. Las lesiones se removieron quirúrgicamente y se enviaron para análisis parasitológico, el cual confirmó la presencia de Tunga penetrans. La evolución del paciente fue satisfactoria. La Secretaría de Salud Municipal de Popayán inspeccionó el domicilio del paciente y encontró perros migrantes del Pacífico colombiano en sus alrededores, algunos con lesiones sospechosas de tungiasis. Se documenta, así, el resurgimiento de esta enfermedad en el área urbana, probablemente debido a la migración de animales desde las zonas rurales. Es importante reconocer la existencia de la pulga en zonas rurales y urbanas, hacer el diagnóstico médico y reportar los casos a los entes de vigilancia. Estas acciones permitirán ofrecer un apropiado manejo y control sanitario de esta ectoparasitosis desatendida en humanos y animales.

Clinical implications and treatment options of tungiasis in domestic animals

Tunga penetrans, Tunga trimamillata and Tunga hexalobulata are the three species of sand fleas which cause tungiasis in domestic animals. Tunga penetrans and T. trimamillata are zoonotic in the tropical and sub-tropical endemic communities of Latin America and Africa. Tungiasis in animals frequently occurs alongside human tungiasis. Currently, most of the attention given to tungiasis is focusing on the human disease, and animal tungiasis is extremely neglected despite its public health and animal health significance. This review highlights recent findings concerning the clinical implications and treatment options but also summarises the occurrence, major features, public health and economic significance of tungiasis in domestic animals. Pigs, dogs, cats and domestic ruminants have been reported to harbour high intensities of sand fleas in endemic communities. High infection intensities cause significant animal morbidity which is often exacerbated by excoriations and secondary bacterial infections which are potentially fatal. In addition to the potential economic losses accruing from tungiasis-related morbidity, infected domestic animals contribute to transmission and persistence of sand fleas and eventually also to severe human disease. Although control of animal tungiasis is possible by adoption of proper husbandry practices, affected communities may not afford the resources required to implement them. Also, there are no widely acceptable and affordable insecticides for treatment of tungiasis in animals. Extension services aiming at increasing awareness on tungiasis and its control should be intensified. Also, available commercial insecticides should be evaluated for therapeutic and prophylactic properties against animal tungiasis.

[Parasitic dermatoses from abroad]

Increased migration, the omnipresent desire to travel, climate change and a globally more mobile population enhance the risk of spreading infectious, tropical pathogens across international borders. In addition to diarrhea and fever, skin diseases present one of the most common reasons for a medical consultation upon return among travelers. These diseases are often caused by parasites. Detailed data on infectious travel diseases is scarce. However, demographic, endemic and travel-related information represent the basic requirements for physicians to choose appropriate diagnostics and adequate treatment for affected patients. This article gives an overview of common parasitic travel dermatoses, their specific diagnostic workup, treatment and preventive measures.

Clinical and macroscopic morphological features of canine tungiasis

Tungiasis is a public health problem in endemic resource-poor communities, where dogs are important reservoirs of Tunga spp., contributing significantly to the process of transmission of this zoonosis. In order to optimize the diagnosis of canine tungiasis, macroscopic morphological characteristics and clinical signs of the lesions were investigated, based on the inspection of 40 dogs infested by T. penetrans from an endemic rural community in northeastern Brazil. Of the 1546 lesions found in these dogs, including all stages of development of the parasite, 89.1% (1378) were located on the paw pads. Dogs aged up to 5 years had the greatest number of lesions. Dark pigmentation and hyperkeratosis of the paw pads made it difficult to identify the lesions. Among all the clinical signs observed were hyperemia (38; 95%), pain (32; 80%), fissure (11; 27.5%), onychogryphosis (29; 72.5%), cluster of lesions (26; 65%), hyperkeratosis (25; 62.5%), lameness (15; 37.5%), and fissure (11; 27.5%). Ectopic lesions were found especially in the nipples (64; 4.1%) and abdomen (51; 3.3%). The maximum diameter of the stage III neosomes was 6 mm. Dogs with a higher number of lesions had a higher degree of hyperkeratosis. Age over 1 year was associated with a higher rate of dispersion of the parasite in the environment (p = 0.04). The identification of the initial stages of tungiasis can guarantee a more effective control of the disease in dogs, which will mainly depend on the treatment of adult animals and the application of continuous preventive actions based on One Health in these communities.

Clinical and pathological aspects of first report of Tunga penetrans infestation on southern brown howler monkey (Alouatta guariba clamitans) in Rio Grande do Sul, Brazil

BACKGROUND

Tungiasis is a neglected neotropical disease caused by penetration of Tunga spp. into the skin of the host.

METHODS

Two primates were rescued from nearby different indigenous villages, and the clinical, pathological, and parasitological features of tungiasis were described. Flea identification occurred through their morphometry and was confirmed with the use of a dichotomous key.

RESULTS

Monkey 1 was parasitized by 23 sand fleas and, after treatment, was assigned to the animal rehabilitation center. Monkey 2 was in poor body condition and died shortly after clinical examination. At necropsy, this primate was parasitized by 26 specimens of sand fleas.

CONCLUSIONS

Both animals altered their tree behavior by staying on the ground for long periods. This parasitic relationship implies the possibility of enlargement of the sand flea dispersion. Thus, this is the first record of Tunga penetrans occurrence in wild Alouatta guariba clamitans.

Epidemiology of tungiasis in sub-saharan Africa: a systematic review and meta-analysis

Tungiasis is a public health disease in many rural and urban slums in sub-Saharan Africa (SSA), primarily affecting children and the elderly. Yet, this disease has received little attention in many sub-Saharan African countries. We conducted a systematic review and meta-analysis to estimate the pooled prevalence of tungiasis and associated risk factors in SSA. We searched AJOL, Google Scholar, Web of Science, and PubMed for population-based studies that reported the prevalence of tungiasis and risk factors in SSA between January 1980 and July 2020. The study employed a random-effects model and heterogeneity to estimate the pooled prevalence and evaluate the Cochran's Q-test respectively across studies that met the inclusion criteria. We screened 104 articles and retrieved 42 full-text articles to evaluate for inclusion in the review. Twenty-seven studies involving 16,303 individuals in seven SSA countries were analyzed. The pooled prevalence of tungiasis in SSA was 33.4% (95% CI: 27.6-39.8), while tungiasis prevalence was 46.5%, 44.9%, 42.0%, 37.2%, 28.1%, 22.7% and 20.1% for Ethiopia, Cameroon, Tanzania, Kenya, Nigeria, Rwanda, and Uganda, respectively. The risk of tungiasis was associated with gender, participants' age groups (4-15 years and ≥60 years), earthen floor, non-regular use of footwear, contact with animals, and residence in rural areas. An integrated approach addressing significant factors in tungiasis prevalence in SSA needs to be designed and implemented by a trans-disciplinary composition of community leaders, health professionals, non-governmental institutions, and policymakers.

Parasite-bacteria interrelationship

Parasites and bacteria have co-evolved with humankind, and they interact all the time in a myriad of ways. For example, some bacterial infections result from parasite-dwelling bacteria as in the case of Salmonella infection during schistosomiasis. Other bacteria synergize with parasites in the evolution of human disease as in the case of the interplay between Wolbachia endosymbiont bacteria and filarial nematodes as well as the interaction between Gram-negative bacteria and Schistosoma haematobium in the pathogenesis of urinary bladder cancer. Moreover, secondary bacterial infections may complicate several parasitic diseases such as visceral leishmaniasis and malaria, due to immunosuppression of the host during parasitic infections. Also, bacteria may colonize the parasitic lesions; for example, hydatid cysts and skin lesions of ectoparasites. Remarkably, some parasitic helminths and arthropods exhibit antibacterial activity usually by the release of specific antimicrobial products. Lastly, some parasite-bacteria interactions are induced as when using probiotic bacteria to modulate the outcome of a variety of parasitic infections. In sum, parasite-bacteria interactions involve intricate processes that never cease to intrigue the researchers. However, understanding and exploiting these interactions could have prophylactic and curative potential for infections by both types of pathogens.

Mapping the Geographic Distribution of Tungiasis in Sub-Saharan Africa

The geographic distribution of tungiasis is poorly understood, despite the frequent occurrence of the disease in marginalized populations of low socioeconomic status. To date, little work is available to define the geography of this neglected tropical disease (NTD). This exploratory study incorporated geostatistical modeling to map the suitability for tungiasis transmission in sub-Saharan Africa (SSA). In SSA, environmental suitability is predicted in 44 countries, including Angola, Nigeria, Ghana, Cameroon, Cote de Ivoire, Mali, Ethiopia, the Democratic Republic of the Congo, Kenya, Gabon, Uganda, Rwanda, Tanzania, Zambia, Zimbabwe, Madagascar, and South Africa. In total, an estimated 668 million people live in suitable areas, 46% (304 million) of which reside in East Africa. These evidence-based maps provide vital evidence of the potential geographic extent of SSA. They will help to guide disease control programs, inform policymakers, and raise awareness at the global level. Likewise, these results will hopefully provide decisionmakers with the pertinent information necessary to lessen morbidity and mortality in communities located in environmentally suitable areas.

Assessing the potentials of two local topical ointments as affordable treatment against tungiasis infestation: A self-experimentation in Igbokoda, Nigeria

Infestations caused by penetration of Tunga penetrans (Siphonaptera: Hectopsyllidae) in cutaneous sub-layers present morbidities and resulting mortalities if surgical treatment remains the obtainable. Considering the neglected nature of this infestation and the absence of marketable product, we report an observation on the use of grounded naphthalene in kerosene ointment, and powder of Piper guineense in coconut oil ointment as affordable treatment of embedded tungiasis flea in Igbokoda. A total of 80 individuals partitioned into two groups of 40 individuals each were assigned the locally made topical ointment irrespective of stages of tungiasis lesions. The mean of stage I, II and III tungiasis lesions treated with grounded naphthalene in kerosene ointment respectively decreased from 1.83, 3.42 and 3.89 to 0 after 5–6 days (p < .05). Also, the mean of stage I, II and III tungiasis lesions treated with grounded P. guineense ointment respectively decreased from 1.52, 3.10 and 5.00 to 0 after 6 to 7 days of treatment exposure (p < .05). Very high significant difference between stages and exposure days of participants assigned the two topical ointment was recorded p < .0001 and p = .0005 respectively. Naphthalene ointment and to a lesser extent P. guineense ointment is best to control and hinder development cycle of embedded fleas irrespective of infested part and stage of infection.

Efficacy and safety of dimeticones in the treatment of epidermal parasitic skin diseases with special emphasis on tungiasis: an evidence-based critical review

Epidermal parasitic skin diseases encompass scabies, pediculosis, cutaneous larva migrans, myiasis, and tungiasis. Tungiasis is probably the most neglected of all Neglected Tropical Diseases (NTD). It occurs in South America, the Caribbean and Sub-Saharan Africa and affects marginalized populations where people live in extreme poverty. In endemic communities the prevalence can be up to 30% in general population and 85% in children. Over time, chronic pathology develops characterized by hyperkeratosis, edema around the nail rim, fissures, ulcers, deformation and loss of nails. This leads to a pattern of disabilities, eventually resulting in impairment of mobility.

Dimeticones are a family of silicon oils with a potential to kill parasites located on top or inside the epidermis by a physical mode of action. They are considered the treatment of choice for pediculosis capitis and pediculosis pubis. With regard to tungiasis, the so called rear abdominal cone of the parasites has been identified as a target for treatment with dimeticones. NYDA®, a mixture of two dimeticones with different viscosity, is the only dimeticone product for which data on the mode of action, efficacy and safety with regard to tungiasis exists. The product has been shown highly effective against embedded sand fleas, even in very intense infection with more than 500 parasites situated on top of each other. A randomized controlled trial showed that seven days after a targeted application of NYDA® 97% (95% CI 94–99%) of the embedded sand fleas had lost all signs of viability.

Comprehensive toxicological investigations on the dimeticones contained in NYDA® showed that there is practically no risk of embryotoxicity, fetotoxicity, teratogenicity, and other toxicity. The safety of dimeticones was also demonstrated in clinical trials with a total of 106 participants with tungiasis, in which not a single adverse event was observed.

Efficacy of a mixture of neem seed oil (Azadirachta indica) and coconut oil (Cocos nucifera) for topical treatment of tungiasis. A randomized controlled, proof-of-principle study

Background

Tungiasis is a neglected tropical skin disease caused by the female sand flea (Tunga penetrans), which burrows into the skin causing intense pain, itching and debilitation. People in endemic countries do not have access to an effective and safe home treatment. The aim of this study was to determine the efficacy of a traditionally used and readily available mixture of neem and coconut oil for treatment of tungiasis in coastal Kenya.

Methodology

Ninety-six children aged 6–14 years with at least one embedded viable flea were randomized to be treated with either a mixture of 20% neem (Azadirachta indica) seed oil in coconut oil (NC), or with a 0.05% potassium permanganate (KMnO₄) foot bath. Up to two viable fleas were selected for each participant and monitored for 6 days after first treatment using a digital microscope for signs of viability and abnormal development. Acute pathology was assessed on all areas of the feet using a previously established score. Children reported pain levels and itching on a visual scale.

Results

The NC was not more effective in killing embedded sand fleas within 7 days than the current standard with KMnO₄, killing on average 40% of the embedded sand fleas six days after the initial treatment. However, the NC was superior with respect to the secondary outcomes of abnormal development and reduced pathology. There was a higher odds that fleas rapidly aged in response to NC compared to KMnO₄ (OR 3.4, 95% CI: 1.22–9.49, p = 0.019). NC also reduced acute pathology (p<0.005), and there was a higher odds of children being pain free (OR 3.5, p = 0.001) when treated with NC.

Conclusions

Whilst NC did not kill more fleas than KMnO₄ within 7 days, secondary outcomes were better and suggest that a higher impact might have been observed at a longer observation period. Further trials are warranted to assess optimal mixtures and dosages.

Trial registration

The study was approved by the Kenya Medical Research Institute (KEMRI) Scientific and Ethical Review Unit (SERU), Nairobi (Non-SSC Protocol No. 514, 1st April 2016) and approved by and registered with the Pharmacy and Poisons Board’s Expert Committee on Clinical Trials PPB/ECCT/16/05/03/2016(94), the authority mandated, by Cap 244 Laws of Kenya, to regulate clinical trials in the country. The trial was also registered with the Pan African Clinical Trial Registry (PACTR201901905832601).

Tungiasis is a disease caused by the female sand flea which burrows into the skin of the feet and causes intense pain and itching. People in endemic tropical areas do not have access to a simple, effective and safe method for treatment at home. The most common treatment used during clinical outreach activities is a foot bath in a disinfectant. Here we report on a clinical trial testing the effectiveness of a mixture of neem and coconut oils to kill the embedded fleas and reduce inflammation, pain and itching. We found the oil mixture reduced the proportion of fleas alive in the foot after 6 days in a similar way as the footbath in disinfectant, which is unavailable to households. However, unlike the footbath, the neem oil treatment caused most of the fleas to rapidly age in the foot and decreased the inflammation, leaving more children pain-free after one week. We conclude the neem and coconut oil mixture could be a promising approach for the treatment of tungiasis but its activity on the fleas might be slower. We need to follow up with longer observation time and test different dosages and application times.

Factors associated with tungiasis among primary school children: a cross-sectional study in a rural district in Rwanda

BACKGROUND

Tungiasis is a relatively frequent ectoparasitosis in low-income settings, yet its morbidity and social impact are still not well understood due to the scarcity of information. In Rwanda, data on the magnitude and conditions leading to the tungiasis is rare. This study sought to determine the prevalence and factors associated with tungiasis among primary school children in Rwandan setting.

METHOD

A descriptive cross-sectional study utilising systematic random sampling method was adopted to select 384 children from three primary schools. From July to October 2018, data were collected on socio-demographic characteristics of children, parents, and households. Logistic regression was applied to analyse socio-demographic factors associated with tungiasis with a level of significance set at P-value< 0.05.

RESULTS

Prevalence of tungiasis among three primary schools was 23%. Factors associated with tungiasis included walking barefoot (AOR: 78.41; 95% CI: 17.91-343.10), irregular wearing of shoes (AOR: 24.73; 95% CI: 6.27-97.41), having dirty feet (AOR: 12.69; 95% CI: 4.93-32.64), wearing dirty clothes (AOR: 12.69; 95% CI: 4.18-38.50), and living in a house with earthen plastered floor (AOR: 28.79; 95% CI: 7.11-116.57). Children infected with tungiasis attended class less frequently (AOR: 19.16, 95%CI: 7.20-50.97) and scored lower (AOR: 110.85, 95%CI: 43.08-285.20) than those non-infected. The low school attendance and poor performance could be partly explained by difficulty of walking, lack of concentration during school activities, and isolation or discrimination from classmates.

CONCLUSION

Tungiasis was a public health challenge among school going children in a rural Rwandan setting. This study revealed that children affected with tungiasis had poor hygiene, inadequate housing environments and consequently poor school attendance and performance. Improving socio-economic conditions of households with special emphasis on hygiene of family members and housing conditions, would contribute to preventing tungiasis.

Prevalence, intensity and risk factors of tungiasis in Kilifi County, Kenya II: Results from a school-based observational study

Introduction

Awareness of the public health importance of tungiasis has been growing in East Africa in recent years, but data on epidemiological characteristics necessary for the planning and implementation of control measures do not exist. The work presented here was part of a larger cross-sectional study on the epidemiology of tungiasis in coastal Kenya and aims at identifying risk factors of tungiasis and severe disease in school children.

Methods

A total of 1,829 students of all age groups from five schools and 56 classes were clinically examined for tungiasis on their feet based on standardized procedures and observations made about the school infrastructure. To investigate the impact of school holidays, observations were repeated after school holidays in a subset of children in one school. In an embedded case-control study, structured interviews were conducted with 707 students in the five schools to investigate associations between tungiasis and household infrastructure, behaviour and socio-economic status.

Results

The overall prevalence of tungiasis was 48%; children below the age of 15 years were the most affected, and boys were twice as likely as girls to be infected. The highest risk of disease was associated with the socio-economic circumstances of the individual student at home. The study indicated that mild to moderate tungiasis could be reduced by a third, and severe tungiasis by over half, if sleeping places of children had hardened floors, whilst approximately a seventh of the cases could be prevented by sealing classroom floors in schools, and another fifth by using soap for daily feet washing.

Conclusion

There is a clear role for public health workers to expand the WASH policy to include washing of feet with soap in school-aged children to fight tungiasis and to raise awareness of the importance of sealed floors.

Tungiasis is a neglected tropical skin disease caused by penetrated sand fleas, the adult female of which burrows into the skin of the feet. The parasite rapidly expands its body size by a factor of 2000. The growth causes immense itching, inflammation, pain and debilitation. The current lack of good treatment methods means people attempt to remove the fleas themselves with non-sterile instruments causing more damage. Control efforts focus on prevention but there is little data to guide this in East Africa. The current study reinforces our previously published results on the household level from the same communities, indicating that prevention needs to focus on hardening the floors of resource-poor families and integrating daily foot washing with soap into water, hygiene and sanitation programs.

Seasonal variation and persistence of tungiasis infestation in dogs in an endemic community, Bahia State (Brazil): longitudinal study

Tungiasis is a zoonosis neglected by authorities, health professionals, and affected populations. Domestic, synanthropic, and sylvatic animals serve as reservoirs for human infestation, and dogs are usually considered a main reservoir in endemic communities. To describe the seasonal variation and the persistence of tungiasis in dogs, we performed quarterly surveys during a period of 2 years in a tourist village in the municipality of Ilhéus, Bahia State, known to be endemic for tungiasis. Prevalence in dogs ranged from 62.1% (43/66) in August 2013 to 82.2% (37/45) in November 2014, with no significant difference (p = 0.06). The prevalence of infestation remained high, regardless of rainfall patterns. Of the 31 dogs inspected at all surveys, period prevalence was 94% (29/31; 95% CI 79.3-98.2%) and persistence of infestation indicator [PII] was high (median PII = 6 surveys, q1 = 5, q3 = 7). Dogs < 1 year of age had a higher mean prevalence of 84.5%, as compared with 69.3% in the older dogs. No significant difference was found between the risk of infestation and age or sex (p = 0.61). Our data indicate that canine tungiasis persisted in the area during all periods of the year. The seasonal variation described in human studies from other endemic areas was not observed, most probably due to different rainfall patterns throughout the year. The study has important implications for the planning of integrated control measures in both humans and animal reservoirs, considering a One Health approach.

Spatial distribution, prevalence and potential risk factors of Tungiasis in Vihiga County, Kenya

Background

Tungiasis is a parasitic disease caused by the sand flea Tunga penetrans also known as jigger flea. Communities living in precarious conditions in tropical and sub tropical countries bear the brunt of the infection. The main objective of this study was to determine the burden of Tungiasis in Vihiga County in Kenya.

Methods

This was a cross-sectional study conducted in 21 villages in 3 Sub-locations in Vihiga County, western Kenya. A total of 437 participants, 5 years old and above were clinically examined for the presence of tungiasis after consenting to take part in the study. Diagnosis was made following standard methods. A semi- structured questionnaire was administered to assess socio-demographic factors, housing, presence and ownership of animals, knowledge and practice related to tungiasis. Data were analyzed using bivariate and multivariate regression analysis. GIS was used to map the geographic distribution of tungiasis in the area.

Results

The overall prevalence was found to be (21.5%; 95% CI: 17.7–25.3%). The cases were analysed and visualized in a map form. Multivariate analysis suggested that the occurrence of tungiasis was associated with variables that indicated low economic status (like a monthly income of Ksh ≤ 1000 (adjusted odds ratio 27.85; 95% CI: 4.13–187.59), earthen floor (0.36; 0.13–1.024) and lack of toilet facilities (4.27; 0.82–22.34), age of participant ≤14 (27.414; 10.02–74.99), no regular use of closed footwear (1.98; 0.987–3.97) and common resting place inside the house (1.93; 0.96–3.89).

Conclusions

Tungiasis is an important health problem in Vihiga County occasioned by the low economic status of the people affected. Factors that point to poverty contribute to the occurrence of tungiasis. These findings suggest a need to design control strategies for tungiasis that are cost effective and easily accessible.

Tungiasis even though curable, continues to cause a lot of morbidity and in some cases death to millions of people living in tropical and subtropical countries. The global burden of tungiaisis is not known unlike for most diseases which attract a lot of attention and funding. There are also gaps on the exact geographical distribution of this disease and the communities affected, hence it is largely ignored and neglected by the scientific community, the health sector, pharmaceutical industries and policy makers. As a consequence, there are no universally accepted methods to treat and control tungiasis. The study attempted to close this gap by combining geographic information system and questionnaire data to visualize the burden and risk factors of tungiasis in Vihiga County, Kenya. The researchers found that tungiasis is an important health burden in Vihiga County, Kenya and that its occurrence was associated with factors that point to poverty. These findings suggest a need to design control strategies for tungiasis that are cost effective and easily accessible by the communities affected.