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Biomedical subjects

Jörg Heukelbach

Publications and source records attributed to Jörg Heukelbach.

At least 19 recordsLinked to original sources
PubMed2006

Morbidity assessment in sand flea disease (tungiasis).

Tungiasis, caused by the sand flea Tunga penetrans, is a health problem in many impoverished communities in Latin America, the Caribbean, and sub-Saharan Africa. Sand flea disease is associated with a broad spectrum of clinical and histological pathology. The factors determining the disease burden in endemic communities are not well understood, and severity of clinical pathology has never been assessed quantitatively. Thus, two severity scores were developed: one for acute disease and one for chronic sequels. These scores were evaluated in a cohort of 70 severely infested patients living in a shantytown in Fortaleza, a capital city in Northeast Brazil. Patients were examined during a period of 25 days and followed-up after a twice daily application of a plant-based repellent to prevent reinfestation. The severity score for acute disease symptoms significantly correlated with the infestation rate and the number of embedded fleas. It turned zero when reinfestation was prevented. The score for chronic disease also significantly correlated with the infestation rate. Tungiasis is associated with considerable acute and chronic morbidity. The degree of acute morbidity is directly related to the number of embedded sand fleas. When transmission is interrupted, the chronic morbidity reflects the infestation rates individuals have experienced in the past.

Adolescent↗
PubMed2006

A plant-based repellent protects against Tunga penetrans infestation and sand flea disease.

Tungiasis is a parasitic skin disease prevalent in impoverished populations in the tropics and associated with considerable morbidity. Treatment options are limited and prophylaxis has never been attempted. We assessed the effectiveness of a plant-based repellent to prevent infestation with Tunga penetrans and sand flea disease in an urban squatter settlement in Fortaleza, Northeast Brazil. Two cohorts were formed. One cohort started with the intervention while another served as control. The plant-based repellent Zanzarin was applied twice daily on the skin of the feet. After 4 weeks and a wash-out-phase of another 2 weeks, cross-over was performed. Study members were examined twice per week for the presence of newly embedded sand fleas. The number of viable and dead sand fleas and the total number of sand flea lesions were determined. Sentinel rats were used to assess local transmission dynamics. Outcome measures were the number of newly embedded sand fleas per individual per day, number of sand flea lesions per individual according to the stage, as well as type and degree of clinical pathology. Zanzarin applied twice daily on the feet reduced the number of newly embedded fleas by 92% (interquartile range 81-100%), the total number of lesions by 87% (81-98%) and reversed tungiasis-associated clinical pathology almost completely. In conclusion, in a setting in which tungiasis is an important health threat, the daily application of a plant-based repellent prevented the infestation with T. penetrans and sand flea disease.

Administration, Topical↗
PubMed2006

Survey of visitors to a National Park in the savannah region of northeast Brazil: practices, incidents and hazardous situations.

BACKGROUND: Wilderness travellers to remote National Parks of Brazil may be particularly at risk of tropical diseases and injury. The aim of this study was to describe injury and illness, potentially hazardous situations, accidents and other incidents experienced by travellers to a remote National Park in Brazil. METHOD: The study was done in the National Park, "Serra da Capivara", in Piauí State northeast Brazil. Key informants were interviewed using semi-structured interviews, and a self-administered questionnaire was used for visitors. Questions included information on health problems and risk behaviour in the park, as well as pre-travel health advice. RESULTS: In total, 14 tour guides, 7 hotel managers and 17 health professionals were interviewed, as key informants. Eighty visitors returned the completed questionnaires (60 Brazilian, 20 foreigners). The key informants reported different risk behaviour of groups and individuals travellers, and incidents most commonly mentioned were minor injuries, insect bites/bee stings and allergic reactions. Seventy percent of the Brazilian and 55% of the foreign visitors had obtained pre-travel health advice, but only 5% of Brazilians and 15% of foreign visitors has obtained this advice from a physician. The most common source of information was other people who already had visited the park and travel books. Of the Brazilians, 13.3% reported some health incident during their stay, most commonly bee bites and headache. Two foreign travellers reported three incidents (insect bites/bee stings, diarrhoea and sunburn). Most commonly reported hazardous situations perceived by the tourists were possible accidents caused by falling from a stairway or falling stones, poisonous animals and insect bites/bee stings. CONCLUSIONS: Surveys conducted at remote tourist destinations are a feasible approach to report vulnerable situations, practices and incidents of visitors to a National Park. We have shown that most travellers are not adequately prepared and many experienced vulnerable situations during their visit to the National Park. It is important that visitors to National Parks in Brazil are encouraged to obtain travel health advice. The most common and potentially serious incident (bee stings) is rarely addressed in pre-travel health advice. Travel health advisers should ensure that they have access to locally relevant information for travellers, so that appropriate preventive measures can be instituted.

Accidents↗
PubMed2006

A study in a community in Brazil in which cutaneous larva migrans is endemic.

BACKGROUND: Cutaneous larva migrans (CLM) is a common but neglected parasitic skin disease in impoverished communities of the developing world. METHODS: To describe the clinical features and the morbidity associated with CLM, active-case finding was performed during rainy and dry seasons in a rural community in the state of Alagoas, Northeast Brazil. RESULTS: A total of 62 individuals received a diagnosis for CLM, and among them there were a total of 75 larval tracks. The number of tracks per person ranged from 1 to 3. Children <9 years old were affected significantly more often than other age groups (P<.001). Children had their lesions mainly on the buttocks, genitals, and hands, whereas in older patients, the majority of lesions were located on the feet. Twenty-four percent of the 75 lesions were superinfected. Bacterial superinfection was more common among children. All but 1 patient complained about itching, and 84% of the 62 patients complained about sleep disturbances. Itching was classified as being severe by 61% of patients. Approximately 40% of the 62 patients had attempted to treat their creeping eruption previously. Larvae moved forward 2.7 mm per day. There was a significant correlation between the length of the track and the duration of infestation ( rho =.53; P<.0001). CONCLUSIONS: CLM is a common parasitic skin disease in this rural community, with different topographic patterns of lesions in children and adults. CLM is associated with considerable morbidity. The length of the track can be used to estimate the duration of infestation.

Adolescent↗
PubMed2006

Scabies.

Scabies is a neglected parasitic disease that is a major public health problem in many resource-poor regions. It causes substantial morbidity from secondary infections and post-infective complications such as acute post-streptococcal glomerulonephritis. Disease control requires treatment of the affected individual and all people they have been in contact with, but is often hampered by inappropriate or delayed diagnosis, poor treatment compliance, and improper use of topical compounds such as permethrin, lindane, or benzyl benzoate. In addition to concerns over toxicity with such compounds, parasite resistance seems to be increasing. Oral ivermectin is an alternative that has been used successfully in community control programmes. Plant derivatives such as turmeric, neem, and tea tree oil are also promising future treatments. The disease is strongly associated with poverty and overcrowding, and the associated stigma can ostracise affected individuals. Treatment of scabies in poor countries needs to integrate drug treatment programmes with efforts to improve the socioeconomic conditions and education programmes to reduce stigma. We expect the future to bring more sensitive and specific clinical and laboratory-based diagnostic methods, as well as new therapeutic strategies.

Adult↗
PubMed2006

High exposure to Tunga penetrans (Linnaeus, 1758) correlates with intensity of infestation.

Tungiasis is a parasitic skin disease widespread in resource-poor urban and rural communities in Brazil. Inhabitants of an urban slum in Northeast Brazil were examined for the presence of tungiasis lesions and followed-up twice a week for a period of three weeks. Each time the number, stages, and topographic localization of lesions were recorded on a documentation sheet. The infestation rate (number of newly embedded sand fleas per individual and day) remained stable during the observation period. The infestation rate was significantly related to the intensity of infestation (total number of lesions present) (rho = 0.70, p < 0.0001) and the proportion of viable lesions (rho = 0.28, p < 0.0001). The results indicate that in an endemic area the infestation intensity and the proportion of viable lesions can be used as a proxy to assess the exposure of individuals at risk for tungiasis. Persistently high infestation rates during the transmission season favour the use of prevention measures against invading sand fleas (such as a repellent) rather than a drug to kill already embedded parasites.

Adolescent↗
PubMed2006

A new shampoo based on neem (Azadirachta indica) is highly effective against head lice in vitro.

Because topical compounds based on insecticidal chemicals are the mainstay of head lice treatment, but resistance is increasing, alternatives, such as herbs and oils are being sold to treat head lice. To test a commercial shampoo based on seed extract of Azadirachta indica (neem tree) for its in vitro effect, head lice (n=17) were collected from school children in Australia and immersed in Wash-Away Louse shampoo (Alpha-Biocare GmbH, Germany). Vitality was evaluated for more than 3 h by examination under a dissecting microscope. Positive and negative controls were a commercially available head lice treatment containing permethrin 1% (n=19) and no treatment (n=14). All lice treated with the neem shampoo did not show any vital signs from the initial examination after immersion at 5-30 min; after 3 h, only a single louse showed minor signs of life, indicated by gut movements, a mortality of 94%. In the permethrin group, mortality was 20% at 5 min, 50% at 15 min, and 74% after 3 h. All 14 head lice of the negative control group survived during the observation period. Our data show that Wash-Away Louse is highly effective in vitro against head lice. The neem shampoo was more effective than the permethrin-based product. We speculate that complex plant-based compounds will replace the well-defined chemical pediculicides if resistance to the commonly used products further increases.

Animals↗
PubMed2005

Identifying risk factors for tungiasis and heavy infestation in a resource-poor community in northeast Brazil.

Tungiasis is a neglected parasitic skin disease caused by penetration of female sand fleas into the epidermis. The ectoparasitosis is widespread in resource-poor communities in South America, the Caribbean and sub-Saharan Africa. To identify risk factors for the presence of sand fleas and severe infestation in an endemic community, we examined the entire population of a traditional fishing village for the presence of embedded sand fleas and determined the number and type of lesions. Demographic, behavioural and environmental characteristics of the population were assessed using a structured questionnaire. Multivariable analysis showed that both occurrence of tungiasis and heavy infestation were significantly related to poor housing conditions (odds ratio [OR]=4.7, 95% CI 1.4-15.8), lack of health education (OR=4.1, 95% CI 2.0-8.6) and presence of animals on the compound (OR=1.9, 95% CI 1.1-3.4). Contrary to common belief, a protective effect of frequent use of closed footwear could not be demonstrated. Based on the population attributable fractions calculated for the major risk factors identified, we conclude that several low-cost interventions would have a considerable impact on the occurrence of tungiasis and heavy infestation.

Adolescent↗
PubMed2005

Therapy of tungiasis: a double-blinded randomized controlled trial with oral ivermectin.

Tungiasis is an ectoparasitosis causing considerable pathology in endemic areas. Standard therapy consists of removing the embedded parasite with a sterile needle. There is no effective chemotherapy at hand. To fill this gap, a double-blinded randomized controlled trial with oral ivermectin was conducted. A total of 54 individuals (27 in the placebo group, 27 in the ivermectin group) was followed up for seven days. They presented a total of 192 lesions. Patients received either ivermectin (300 microg/kg body weight at a single dose, repeated after 24 h) or placebo. Outcome measures included the clinical stage of lesion, presence of erythema, pain, itching, signs of viability of the parasite, and total lysis of flea. The ratio of fleas with total lysis per total number of fleas was slightly higher in the ivermectin group; however, this difference was not statistically significant. There was no significant difference in any of the other outcome measures between the treatment and the placebo group. The results show that oral ivermectin is without any clinically significant efficacy against embedded sand fleas at the dose given.

Adolescent↗
PubMed2005

Ectoparasitic infestations.

Ectoparasitic infestations are highly prevalent in resource-poor populations throughout the world and are associated with considerable morbidity. Reliable data on the epidemiology, immunology, and therapy of ectoparasitic infestations and on the biology of the parasites remain scarce. The control of parasitic skin diseases, such as scabies, pediculosis, tungiasis, myiasis, and cutaneous larva migrans in endemic areas remains a challenge. Using appropriate study designs, it is imperative to increase further the knowledge on the various aspects of the parasites and the infestations they cause.

Journal Article↗
PubMed2005

Seasonal variation of tungiasis in an endemic community.

Tungiasis (caused by the sand flea Tunga penetrans) is hyperendemic in many resource-poor communities in Brazil. To understand transmission dynamics of this parasitic skin disease in a typical endemic area, a longitudinal study was carried out in a slum in Fortaleza in northeastern Brazil. In a door-to-door survey, the population of a randomly selected area (n = 1,460) was examined on four occasions for the presence of embedded sand fleas. Prevalence rates were 33.6% in March (rainy season), 23.8% in June (end of the rainy season), 54.4% in September (peak of the dry season), and 16.8% in January (begin of the rainy season). Tungiasis was more common in males than in females. The intensity of infestation was correlated with the prevalence. The study shows that prevalence of tungiasis and parasite burden vary significantly during the year with a peak in the dry season. These findings have important consequences for the design of control measures.

Adolescent↗
PubMed2004

Investigations on the biology, epidemiology, pathology and control of Tunga penetrans in Brazil. V. Cytokine concentrations in experimentally infected Wistar rats.

Tungiasis is caused by the penetration of the female sand flea Tunga penetrans into the skin of its host. This parasitic skin disease is almost invariably associated with an intense inflammation around embedded fleas, the underlying mechanisms being unknown. A study was undertaken to determine whether Wistar rats can be used as an animal model to assess cytokine kinetics during the natural course of the infection. Laboratory-raised Wistar rats were exposed in cages put on the soil in an area with high human attack rates. Rats were examined daily and blood samples were taken before exposure and at 2, 6, 10, 13, 16 and 20 days after flea penetration. TNF-alpha, IL-1 beta, IFN-gamma, IL-4, IL-10 and CINC (a rat cytokine- induced neutrophil chemoattractant and member of the IL-8 family) were determined by enzyme immunoassay. The results showed an increasing serum concentration of TNF-alpha and IL-1 beta 10-13 days after penetration and a rapid increase in IL-4 2 days after fleas became embedded. During the natural course of the infection, the ratio of the serum concentration of TNF-alpha to that of IL-10 decreased, indicating a relative increase in the secretion of the anti-inflammatory cytokine. The treatment of lesions with silicone oil abrogated the natural disease course and changed the pattern of cytokine secretion. We conclude that the Wistar rat is an appropriate model to study immune responses in tungiasis.

Animals↗
PubMed2004

Selective mass treatment with ivermectin to control intestinal helminthiases and parasitic skin diseases in a severely affected population.

OBJECTIVE: To assess the short-term and long-term impact of selective mass treatment with ivermectin on the prevalence of intestinal helminthiases and parasitic skin diseases in an economically depressed community in north-east Brazil. METHODS: An intervention was carried out in a traditional fishing village in north-east Brazil where the population of 605 is heavily affected by ectoparasites and enteroparasites. The prevalence of intestinal helminths was determined by serial stool examination and the prevalence of parasitic skin diseases by clinical inspection. A total of 525 people out of a target population of 576 were treated at baseline. The majority of these were treated with ivermectin (200 microg/kg with a second dose given after 10 days). If ivermectin was contraindicated, participants were treated with albendazole or mebendazole for intestinal helminths or with topical deltamethrin for ectoparasites. Follow-up examinations were performed at 1 month and 9 months after treatment. FINDINGS: Prevalence rates of intestinal helminthiases before treatment and at 1 month and 9 months after mass treatment were: hookworm disease 28.5%, 16.4% and 7.7%; ascariasis 17.1%, 0.4% and 7.2%; trichuriasis 16.5%, 3.4% and 9.4%; strongyloidiasis 11.0%, 0.6% and 0.7%; and hymenolepiasis 0.6%; 0.4% and 0.5%, respectively. Prevalence rates of parasitic skin diseases before treatment and 1 month and 9 months after mass treatment were: active pediculosis 16.1%, 1.0% and 10.3%; scabies 3.8%, 1.0% and 1.5%; cutaneous larva migrans 0.7%, 0% and 0%; tungiasis 51.3%, 52.1% and 31.2%, respectively. Adverse events occurred in 9.4% of treatments. They were all of mild to moderate severity and were transient. CONCLUSION: Mass treatment with ivermectin was an effective and safe means of reducing the prevalence of most of the parasitic diseases prevalent in a poor community in north-east Brazil. The effects of treatment lasted for a prolonged period of time.

Adult↗
PubMed2004

Ectoparasites--the underestimated realm.

CONTEXT: Ectoparasitoses (infestations with parasites that live on or in the skin) can cause considerable morbidity. Whereas pediculosis and scabies are ubiquitous, cutaneous larva migrans and tungiasis (sand-flea disease) occur mainly in hot climates. The prevalence of ectoparasitoses in the general population is usually low, but can be high in vulnerable groups. Scientific knowledge on how to deal best with parasitic skin diseases in different settings is scanty, and evidence-based measures for control are not available. For head lice and scabies the situation is daunting, because resistance of Pediculus humanus capitis and Sarcoptes scabiei to insecticides is spreading and unpredictable. STARTING POINT: J Hunter and S Barker reported different patterns of resistance in schoolchildren in Brisbane, Australia: full resistance to malathion, permethrin, and pyrethrum in two schools, whereas head lice were susceptible to malathion and, to a lesser extent, to pyrethrums in three other schools (Parasitol Res 2003; 90: 476-78). K Yoon and colleagues found different resistance patterns in the USA and Ecuador (Arch Dermatol 2003; 139: 994-1000). Head lice from Florida were less susceptible to permethrin than those from Texas, and parasites from Ecuador were susceptible to both insecticides tested. WHERE NEXT? The occurrence of resistant pediculosis and scabies is expected to increase numerically and geographically. Clinicoepidemiological studies are urgently needed to identify the factors which govern the emergence and spread of strains of P humanus capitis and S scabiei that are resistant to insecticide or acaricide. Oral treatment with ivermectin could substitute for topically applied compounds, particularly in resource-poor communities where polyparasitism is common. A better understanding of local epidemiology is required to develop control measures. This knowledge has to be applied in combination with environmental sanitation, health education, and culturally acceptable interventions that are affordable by the underprivileged.

Drug Resistance↗
PubMed2004

Investigations on the biology, epidemiology, pathology and control of Tunga penetrans in Brazil: IV. Clinical and histopathology.

Tungiasis is a parasitic skin disease caused by the sand flea Tunga penetrans. This ectoparasitosis is endemic in South America, the Caribbean and sub-Saharan Africa, where it is an important but neglected health problem in resource-poor communities. As part of a study of tungiasis-related morbidity in a typical slum in Fortaleza, Brazil, we identified 86 individuals with tungiasis. Lesions were counted, classified according to the stage of development, and clinical pathology was documented. One hundred and nine lesions were biopsied and examined by histological sectioning. The patients had between 1 and 145 lesions (median 14.5), the majority occurring in clusters. In all, 77% of patients reported severe pain at the site of the lesion, and 52% had one or more nails lost or severely deformed. Intense inflammation and/or fissures hindered 45% of the patients from walking normally. Signs of superinfection were observed in 29%, and signs of generalized inflammation in 2% of patients. Clinical pathology was significantly related to the number of lesions, and the total number of parasites present correlated with the number of fleas occurring in clusters. Clinical pathology was frequently accompanied by a pathological alteration of the epidermis (predominantly hyperplasia, parakeratosis, hyperkeratosis, and spongiosis) and the dermis. Tungiasis causes a broad spectrum of clinical histopathological alterations, and is a serious health threat in a typical, impoverished community in northeast Brazil. The clinical pathology is closely related to the parasite burden of an individual and the clustering of embedded fleas at certain predilection sites.

Adolescent↗
PubMed2004

Efficacy of ivermectin in a patient population concomitantly infected with intestinal helminths and ectoparasites.

Ivermectin (CAS 70288-86-7) is a potent antiparasitic drug. However, studies have not been published evaluating the efficacy of ivermectin in a patient population concomitantly infected with intestinal helminths and ectoparasites. Here the results of an open trial on the efficacy of ivermectin in a heavily poly-parasitized population in northeast Brazil are presented. Two hundred and fifty-one patients were enrolled. Two doses of ivermectin (200 microg/kg) were given at an interval of 10 days. The cure rates for intestinal helminthiases were: 100% for strongyloidiasis and enterobiasis, 99% for ascariasis, 84% for trichuriasis, 68% for hookworm disease, and 50% for hymenolepiasis. Cure rates for ectoparasitoses were: 100% for cutaneous larva migrans, 99% for pediculosis, 88% for scabies and 64% for tungiasis. The results show that two doses of ivermectin are highly efficacious for most intestinal helminths and ectoparasites simultaneously present in an impoverished population. The drug seems to be particularly useful when polyparasitism is expected to occur or when public health measures aim to reduce both intestinal helminthiases and parasitic skin diseases by mass chemotherapy.

Adolescent↗
PubMed2004

Cutaneous larva migrans (creeping eruption) in an urban slum in Brazil.

BACKGROUND: Cutaneous larva migrans (CLM) is caused by the penetration of larvae of animal hookworms into the skin. Knowledge about this ectoparasitosis is mainly based on the examination of travelers or other expatriates. Population-based studies in an endemic area have never been performed. METHODS: A representative population sample of an urban slum in a Brazilian city was examined for the presence of CLM and asked about symptoms associated with the ectoparasitosis. RESULTS: In total, 3.1% (95% confidence interval, 2.2-4.3%) of the 1185 inhabitants examined presented CLM. Forty-three per cent had more than one larval track (range, 1-17). The prevalence rate in males was 4.2% vs. 2.3% in females. CLM occurred at similar prevalence rates in all age groups. All patients complained of moderate or severe itching. In three cases (8.1%), superinfection was present. Most lesions were located on the trunk, legs, and arms. Not a single lesion was located on the feet. CONCLUSIONS: This population-based study showed that CLM is endemic in this deprived community. The number of lesions and their topographic localization are in contrast with those obtained in previous reports based on the examination of individuals or groups affected in small outbreaks. We conclude that the clinico-epidemiologic pattern of CLM in a deprived community is different from that observed in travelers.

Adolescent↗