Tropical dermatology: bacterial tropical diseases

Unmasking the Hidden Burden: A Delayed Diagnosis of Leprosy Patients With Grade 2 Disability and Its Effects on the Healthcare System in Bangladesh

Introduction Leprosy remains a significant cause of preventable disability worldwide. Early diagnosis and treatment of leprosy are critical not only to stop its spread but also to prevent physical and social complications and reduce the disease burden. Objectives The study aims to evaluate the factors that lead to a delayed leprosy diagnosis. Methods This study was conducted in the outpatient departments of Leprosy Control Institute and Hospital, Dhaka, Bangladesh, and at Medical College for Women and Hospital, Dhaka, Bangladesh, from March 2023 to June 2023. A total number of 252 male (148) and female (104) patients were selected with any sign of leprosy, including disability, age ranging from 15 to 74 years. Data was collected in a pre-designed structured questionnaire by the researchers. To assess the risk of independent exposures of Grade 2 leprosy disabilities, we used a logistic regression model. A chi-square test showed the association between significant effects and leprosy disabilities. A p-value of 0.05 was considered as significant. For statistical analysis, STATA version 15 (StataCorp LLC, College Station, Texas, USA) was used. Results The study participants exhibited a higher percentage of disability, with a rate of 25.8% for Grade 2 disabilities. In addition to this, males represented a more considerable proportion, 58.7%, than females among leprosy and disability patients across all levels of disability. In our study, lack of money and painless symptoms showed a significant association (p<0.001) with Grade 2 disability. Conclusion The study reveals that Grade 2 disabilities are more common in males and are particularly prevalent in lower socioeconomic groups.

Cutaneous tuberculosis in the pediatric population: A review

Importance

Tuberculosis (TB) is a significant health concern, affecting over 1.5 million people annually worldwide, with the incidence increasing in the United States from 2020 to 2021. The pediatric population is particularly vulnerable to TB. Extrapulmonary manifestations of TB include cutaneous tuberculosis (CTB).

Observations

There are 8 forms of CTB. Lupus vulgaris (LV) is the second most common form of pediatric CTB which presents nontender plaques or nodules with ulceration that progress to well-defined, scaly plaques. Tuberculous chancre results from exogenous inoculation and lesions contain large amounts of acid-fast bacilli (AFB). Clinically, tuberculous chancre presents as erythematous papules which form firm nontender ulcers. Tuberculosis verrucose cutis (TVC) presents as small papules surrounded by inflammation that develops into a wart-like lesion. Periorificial lesions are rare and present as painful ulcers in the oral or perineal regions. Scrofuloderma is the most common form of pediatric CTB and presents as nodules that ulcerate, forming purulent sinus tracts. Tuberculosis miliaris cutis disseminate presents as widespread papules and crusted vesicles. Metastatic abscesses present as multiple nodules that may ulcerate or form draining sinus tracts. Lastly, tuberculid forms include lichen scrofulosorum (LS), which presents as lichenoid papules which may form plaques and scale, and papulonecrotic tuberculid, which presents as necrotic papules. All forms of cutaneous tuberculosis can be treated with the standard 6-month, four-drug anti-tuberculosis treatment (ATT). Some cases of CTB may require debriding and surgical management in addition to ATT.

Conclusions and Relevance

Determining the type of CTB can be challenging clinically. Histopathology is needed to make the diagnosis. Chest x-ray and a review of systems should be obtained for CTB patients to determine if there are other extrapulmonary manifestations of TB. All types are treated with 6 months of ATT.

Pathologic and Immunohistochemical Evidence of Possible Francisellaceae among Aborted Ovine Fetuses, Uruguay

The only genus of the Francisellaceae family known to contain species pathogenic to mammals is Francisella, for which reported cases in the Southern Hemisphere have been limited to Australia. We describe severe necrotizing and inflammatory lesions and intralesional immunohistochemical identification of Francisella sp. lipopolysaccharide among aborted ovine fetuses in Uruguay.

Ficus septica exudate, a traditional medicine used in Papua New Guinea for treating infected cutaneous ulcers: in vitro evaluation and clinical efficacy assessment by cluster randomised trial

BACKGROUND AND OBJECTIVES

Infected cutaneous ulcers are major health problems for children living in rural areas of Papua New Guinea. The inaccessibility of affected populations and lack of access to basic healthcare, make a local plant-based therapy an attractive treatment option. We assessed Ficus septica exudate in biological assays relevant to wound healing. We then carried out a clinical trial to determine the exudate's efficacy in healing small cutaneous ulcers compared with Savlon antiseptic cream, and soap and water washing.

METHODS

Pre-clinical in vitro assessment of the exudate was carried out using assays to monitor the pro-inflammatory responses of M1 macrophages and neutrophils, antibacterial assays using known ulcer pathogens, an Ames test for mutagenicity and LC-MS chemical analysis of the exudate. An open label cluster-randomised clinical trial was performed, enrolling participants from three different clusters with skin lesions less than 1 cm in diameter. Each cluster comprising 50 participants was randomly assigned to one of three treatment arms namely topical exudate, topical Savlon antiseptic cream, and standard care (soap and water treatment), all administered daily for 2 days. The primary outcome was clinical healing/improvement measured at days 7 and 14, assessed by three dermatologists using blinded photographs. The primary analysis was assessed as non-inferiority of F. septica treatment based on the risk difference for healing/improvement.

RESULTS

In vitro, the exudate which is rich in the alkaloid ficuseptine, was found to be non-mutagenic whilst also inhibiting pro-inflammatory responses and exhibiting antibacterial activity. When administered to participants enrolled in the clinical trial, no significant differences were observed between the healing efficacy of F. septica exudate and the two comparator treatments (Savlon antiseptic cream and soap/water treatment). At day 14, but not at day 7, the efficacy of F. septica exudate for healing/improving the ulcers was non-inferior to Savlon antiseptic cream or water/soap treatment.

CONCLUSIONS

F. septica exudate is non-mutagenic and has both bactericidal and anti-inflammatory properties. When applied topically to small cutaneous ulcers, the exudate has a healing effect that is non-inferior to Savlon antiseptic cream and standard treatment with soap and water at day 14. Our findings, which should be confirmed in larger clinical trials, have important public health implications.

Ulcerative skin lesions among children in Cameroon: It is not always Yaws

Outbreaks of yaws-like ulcerative skin lesions in children are frequently reported in tropical and sub-tropical countries. The origin of these lesions might be primarily traumatic or infectious; in the latter case, Treponema pallidum subspecies pertenue, the yaws agent, and Haemophilus ducreyi, the agent of chancroid, are two of the pathogens commonly associated with the aetiology of skin ulcers. In this work, we investigated the presence of T. p. pertenue and H. ducreyi DNA in skin ulcers in children living in yaws-endemic regions in Cameroon. Skin lesion swabs were collected from children presenting with yaws-suspected skin lesions during three outbreaks, two of which occurred in 2017 and one in 2019. DNA extracted from the swabs was used to amplify three target genes: the human β2-microglobulin gene to confirm proper sample collection and DNA extraction, the polA gene, highly conserved among all subspecies of T. pallidum, and the hddA gene of H. ducreyi. A fourth target, the tprL gene was used to differentiate T. p. pertenue from the other agents of human treponematoses in polA-positive samples. A total of 112 samples were analysed in this study. One sample, negative for β2-microglobulin, was excluded from further analysis. T. p. pertenue was only detected in the samples collected during the first 2017 outbreak (12/74, 16.2%). In contrast, H. ducreyi DNA could be amplified from samples from all three outbreaks (outbreak 1: 27/74, 36.5%; outbreak 2: 17/24, 70.8%; outbreak 3: 11/13, 84.6%). Our results show that H. ducreyi was more frequently associated to skin lesions in the examined children than T. p. pertenue, but also that yaws is still present in Cameroon. These findings strongly advocate for a continuous effort to determine the aetiology of ulcerative skin lesions during these recurring outbreaks, and to inform the planned mass treatment campaigns to eliminate yaws in Cameroon.

Evaluation of Cypholophus macrocephalus sap as a treatment for infected cutaneous ulcers in Papua New Guinea

Cypholophus macrocephalus sap is used to treat bacterially infected cutaneous leg ulcers in Papua New Guinea. High resolution LC-MS analysis of the sap revealed it to be rich in sulphated flavonoids. We assessed the effects of the sap on the differentiation and pro-inflammatory anti-microbial responses of M1 macrophages using IL-6 and TNF-α ELISAs and found significant increases in M1 macrophage IL-6 expression with concentrations as low as 243 ng/ml sap. Neutrophil IL-6 and TNF-α expression was also significantly increased but to a lesser degree. Matrix metalloproteinases (MMPs) 1, 2, 8 and 9 which are known to contribute to the toxic nature of wound exudates were inhibited by the sap at 24 μg/ml. The sap was tested with several bacterial species known to colonize cutaneous ulcers in Papua New Guinea but proved not to be active. Cypholophus sap stimulates pro-inflammatory, anti-microbial M1 macrophage and neutrophil responses at very low concentrations, whilst also inhibiting MMPs. The combination of an enhanced innate immune response and inhibition of MMPs in ulcer exudate, may contribute to the eradication of bacteria and healing of these infected ulcers. The sap concentrations used in these assays are readily achievable in an in vivo context.

A singular case of advanced caries sicca in a pre-Columbian skull from East Tennessee

OBJECTIVE

Documentation of an advanced case of tertiary stage treponemal disease.

MATERIALS

The well-preserved cranium and mandible of an adult male (Burial G) from the Early Woodland period (900 BCE-200 CE) Wilhoite site (40GN10) from east Tennessee.

METHODS

Macroscopic examination of the cranio-facial periostosis on Burial G for pathognomonic indicators of treponemal disease.

RESULTS

There are extensive contiguous nodular lesions on the frontal, parietals, temporals, and occipital bones. The frontal squama additionally exhibits radial scaring and circumvallate cavitating lesions. Radial scars are also present on both zygomatic bones and the endocranial surface of the calotte. There is rounding of the nasal margins in addition to periostosis on the palate.

CONCLUSIONS

Burial G unequivocally exhibits the pathognomonic reactive changes of caries sicca, radial scarring, and cavitating lesions.

SIGNIFICANCE

The Early Woodland date in combination with the advanced degree of pathognomonic reactive change is exceptional, and to date, without parallel in the pre-Columbian archaeological record of North America. Any case approaching the severity displayed here is invariably late prehistoric.

LIMITATIONS

The absence of postcrania does not permit assessment of frailty or synergism of secondary conditions.

SUGGESTIONS FOR FURTHER RESEARCH

More comprehensive documentation of pre-Columbian treponemal cases is merited.

Identification of Mycobacterium leprae and Mycobacterium lepromatosis in Formalin-Fixed and Paraffin-Embedded Skin Samples from Mexico

Background

The causative agents of leprosy are the well-known Mycobacterium leprae and the newly discovered Mycobacterium lepromatosis. This agent was found in 2008, and it was found to be the cause of diffuse lepromatous leprosy in two Mexican patients.

Objective

The objective of this work was to determine if M. leprae and M. lepromatosis were present in formalin-fixed and paraffin-embedded skin samples from cases from different regions in Mexico.

Methods

A total of 41 skin samples were obtained from 11 states of Mexico. All patients' samples were diagnosed by clinical and histopathological analyses. Total DNA was isolated using a Qiagen-DNeasy blood and tissue kit and molecular identification was achieved by two semi-nested polymerase chain reactions.

Results

The 41 patient included 33 samples from men and 8 samples from women; 29 samples were polymerase chain reaction (PCR)-positive to Mycobacterium and 12 samples were PCR-negative. From those 29 samples, 13 were PCR-positive to M. leprae, 8 to M. lepromatosis and 8 were positive to both species. The histopathological diagnosis included; Nodular lepromatous leprosy (NLL); Diffuse lepromatous leprosy (DLL); and Borderline leprosy (BL). The 29 PCR-positive samples were classified as follow: 14 NLL, 4 DLL, and 11 BL. In the 12 samples negative to Mycobacterium, 7 showed the NLL, 2 DLL and 3 BL.

Conclusion

These findings add evidence to the M. leprae and M. lepromatous distribution, clinical forms and participation of dual infections in Mexico.

Acquired disorders with hypopigmentation: A clinical approach to diagnosis and treatment

Acquired hypopigmented skin changes are commonly encountered by dermatologists. Although hypopigmentation is often asymptomatic and benign, occasional serious and disabling conditions present with cutaneous hypopigmentation. A thorough history and physical examination, centered on disease distribution and morphologic findings, can aid in delineating the causes of acquired hypopigmented disorders. The second article in this 2-part continuing medical education series focuses on conditions with a hypopigmented phenotype. Early diagnosis and appropriate management of these disorders can improve a patient's quality of life, halt disease progression, and prevent irreversible disability.

Acquired disorders with depigmentation: A systematic approach to vitiliginoid conditions

Acquired disorders with depigmentation are commonly encountered by dermatologists and present with a wide differential diagnosis. Vitiligo, the most common disorder of acquired depigmentation, is characterized by well-defined depigmented macules and patches. Other conditions, such as chemical leukoderma, can present with similar findings, and are often easily mistaken for vitiligo. Key clinical features can help differentiate between acquired disorders of depigmentation. The first article in this continuing medical education series focuses on conditions with a vitiligo-like phenotype. Early recognition and adequate treatment of these conditions is critical in providing appropriate prognostication and treatment.

Tropical ulcer plant treatments used by Papua New Guinea's Apsokok nomads

ETHNOPHARMACOLOGICAL RELEVANCE

The tropical ulcer is a debilitating bacterial infection that is common in Papua New Guinea. Deploying healthcare infrastructure to remote and inaccessible rainforest locations is not practical, therefore local plants may be the best treatment option. Here we present an ethnobotanical survey of the tropical ulcer plant medicines used by the semi-nomadic Apsokok who roam the remote central mountains of Papua New Guinea's West New Britain Province. In vitro biological activity in assays relevant to tropical ulcer wound healing is also presented.

MATERIALS AND METHODS

Focus groups and semi-structured interviews were used to acquire information on the uses of plants, vouchers of which were identified by comparison with authentic herbarium specimens. Antibacterial disc diffusion assays with Staphylococcus aureus and Fusobacterium ulcerans, MMP-9 enzyme inhibition and dermal fibroblast stimulation assays were carried out on plant saps and aqueous extracts of plant material. LC-MS was used to identify known plant metabolites.

RESULTS

The ethnobotanical survey identified sixteen species that were used to treat tropical ulcers, all of which were applied topically. A subset of twelve species were investigated further in vitro. Four species produced zones of inhibition with S. aureus, all 12 species provided low level inhibition of MMP-9 and 8 species stimulated dermal fibroblast proliferation, although cytotoxicity occurred at higher concentrations. The extract of Homalium foetidum Benth. inhibited S. aureus and MMP-9 while at lower sub-cytotoxic concentrations stimulated fibroblast proliferation. Trans-3-O-p-coumaroylquinic acid cis-3-O-p-coumaroylquinic acid were detected in the aqueous extract of H. foetidum.

CONCLUSIONS

Topical application of plant saps to wounds results in very high localised concentrations of plant metabolites which is likely to result in inhibition of MMP proteases. H. foetidum is a candidate plant for tropical ulcer treatment in remote areas.

Tropical Skin Diseases in Children: A Review-Part II

Tropical skin diseases are infectious conditions influenced by factors such as nutrition, housing, and the environment. Migration patterns have caused these conditions to be seen all around the world, not only in developing countries. Many of these diseases have a different presentation in childhood, which changes the diagnostic approach and management options. In this article, we review some of the most common tropical mycobacterial, protozoan, parasitic, and viral dermatologic conditions in children, including their epidemiologic, clinical, diagnostic, and therapeutic aspects.

Differential Diagnosis of Skin Ulcers in a Mycobacterium ulcerans Endemic Area: Data from a Prospective Study in Cameroon

Background

Clinical diagnosis of Buruli ulcer (BU) due to Mycobacterium ulcerans can be challenging. We aimed to specify the differential diagnosis of skin lesions in a BU endemic area.

Method

We conducted a prospective diagnostic study in Akonolinga, Cameroon. Patients presenting with a skin ulcer suspect of BU were included. M. ulcerans was detected using swabs for Ziehl-Neelsen staining, PCR and culture. Skin punch biopsies were taken and reviewed by two histopathologists. Photographs of the lesions were taken and independently reviewed by two dermatologists. Final diagnosis was based on consensus, combining the results of laboratory tests and expert opinion.

Results/ Discussion

Between October 2011 and December 2013, 327 patients with ulcerative lesions were included. Median age was 37 years (0 to 87), 65% were males, and 19% HIV-positive. BU was considered the final diagnosis for 27% of the lesions, 85% of which had at least one positive laboratory test. Differential diagnoses were vascular lesions (22%), bacterial infections (21%), post-traumatic (8%), fistulated osteomyelitis (6%), neoplasia (5%), inflammatory lesions (3%), hemopathies and other systemic diseases (2%) and others (2%). The proportion of BU was similar between HIV-positive and HIV-negative patients (27.0% vs. 26.5%; p = 0.940). Half of children below 15 years of age were diagnosed with BU, compared to 26.8% and 13.9% among individuals 15 to 44 years of age and above, respectively (chi2 p<0.001). Children had more superficial bacterial infections (24.3%) and osteomyelitis (11.4%).

Conclusion

We described differential diagnosis of skin lesions in a BU endemic area, stratifying results by age and HIV-status.

In some areas of Africa, Australia or Japan, a specific skin infection presents as a wound which progressively increases in size in children and people of any age. The agent which causes this infection is named Mycobacterium ulcerans, close to the tuberculosis agent. This wound, also named Buruli ulcer (BU), may be confused with other common cutaneous diseases. During two years in Akonolinga, Cameroon, we evaluated the wounds of all patients who presented with suspected BU. This wound presentation was most frequently recorded in young children and males. Buruli ulcer was indeed the most frequent diagnosis in this area. However, with the help of laboratory and radiological techniques, we found that many of those patients not diagnosed with BU were suffering from: vascular insufficiency (older persons), benign superficial infections and bone infections (children). This observation is important and should help improve the diagnosis and treatment of patients with skin ulcers in Africa.

Tuberculosis and Leprosy: Classical Granulomatous Diseases in the Twenty-First Century

Leprosy and tuberculosis are chronic mycobacterial infections that elicit granulomatous inflammation. Both infections are curable, but granulomatous injury to cutaneous structures, including cutaneous nerves in leprosy, may cause permanent damage. Both diseases are major global concerns: tuberculosis for its high prevalence and mortality, and leprosy for its persistent global presence and high rate of neuropathic disability. Cutaneous manifestations of both leprosy and tuberculosis are frequently subtle and challenging in dermatologic practice and often require a careful travel and social history and a high index of suspicion.

Yaws

INTRODUCTION

Yaws, caused by Treponema pallidum ssp. pertenue, is endemic in parts of West Africa, Southeast Asia and the Pacific. The WHO has launched a campaign based on mass treatment with azithromycin, to eradicate yaws by 2020.

SOURCES OF DATA

We reviewed published data, surveillance data and data presented at yaws eradication meetings.

AREAS OF AGREEMENT

Azithromycin is now the preferred agent for treating yaws. Point-of-care tests have demonstrated their value in yaws.

AREAS OF CONTROVERSY

There is limited data from 76 countries, which previously reported yaws. Different doses of azithromycin are used in community mass treatment for yaws and trachoma.

GROWING POINTS

Yaws eradication appears an achievable goal. The programme will require considerable support from partners across health and development sectors.

AREAS TIMELY FOR DEVELOPING RESEARCH

Studies to complete baseline mapping, integrate diagnostic tests into surveillance and assess the impact of community mass treatment with azithromycin are ongoing.

Haemophilus ducreyi associated with skin ulcers among children, Solomon Islands

During a survey of yaws prevalence in the Solomon Islands, we collected samples from skin ulcers of 41 children. Using PCR, we identified Haemophilus ducreyi infection in 13 (32%) children. PCR-positive and PCR-negative ulcers were phenotypically indistinguishable. Emergence of H. ducreyi as a cause of nongenital ulcers may affect the World Health Organization's yaws eradication program.

Endemic treponemal diseases

The endemic treponemal diseases, consisting of yaws, bejel (endemic syphilis) and pinta, are non-venereal infections closely related to syphilis, and are recognized by WHO as neglected tropical diseases (NTDs). Despite previous worldwide eradication efforts the prevalence of yaws has rebounded in recent years and the disease is now a major public health problem in 14 countries. Adequate data on the epidemiology of bejel and pinta is lacking. Each disease is restricted to a specific ecological niche but all predominantly affect poor, rural communities. As with venereal syphilis, the clinical manifestations of the endemic treponemal diseases are variable and can be broken down in to early stage and late stage disease. Current diagnostic techniques are unable to distinguish the different causative species but newer molecular techniques are now making this possible. Penicillin has long been considered the mainstay of treatment for the endemic treponemal diseases but the recent discovery that azithromycin is effective in the treatment of yaws has renewed interest in these most neglected of the NTDs, and raised hopes that global eradication may finally be possible.

Clinical and laboratory aspects of the diagnosis and management of cutaneous and subcutaneous infections caused by rapidly growing mycobacteria

Rapidly growing mycobacteria (RGM) are known to cause pulmonary, extra-pulmonary, systemic/disseminated, and cutaneous and subcutaneous infections. The erroneous detection of RGM that is based solely on microscopy, solid and liquid cultures, Bactec systems, and species-specific polymerase chain reaction (PCR) may produce misleading results. Thus, inappropriate therapeutic measures may be used in dermatologic settings, leading to increased numbers of skin deformity cases or recurrent infections. Molecular tools such as the sequence analyses of 16S rRNA, rpoB and hsp65 or PCR restriction enzyme analyses, and the alternate gene sequencing of the superoxide dismutase (SOD) gene, dnaJ, the 16S-23S rRNA internal transcribed spacers (ITS), secA, recA1, dnaK, and the 32-kDa protein gene have shown promising results in the detection of RGM species. PCR restriction enzyme analyses (PRA) work better than conventional methods at identifying species that are closely related. Recently introduced molecular tools such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), pyrosequencing, DNA chip technology, and Beacon probes-combined PCR probes have shown comparable results in the detection of various species of RGM. Closely related RGM species (e.g., Mycobacterium fortuitum, M. chelonae, and M. abscessus) must be clearly differentiated using accurate molecular techniques because their therapeutic responses are species-specific. Hence, this paper reviews the following aspects of RGM: (i) its sources, predisposing factors, clinical manifestations, and concomitant fungal infections; (ii) the risks of misdiagnoses in the management of RGM infections in dermatological settings; (iii) the diagnoses and outcomes of treatment responses in common and uncommon infections in immunocompromised and immunocompetent patients; (iv) conventional versus current molecular methods for the detection of RGM; (v) the basic principles of a promising MALDI-TOF MS, sampling protocol for cutaneous or subcutaneous lesions and its potential for the precise differentiation of M. fortuitum, M. chelonae, and M. abscessus; and (vi) improvements in RGM infection management as described in the recent 2011 Clinical and Laboratory Standards Institute (CLSI) guidelines, including interpretation criteria of molecular methods and antimicrobial drug panels and their break points [minimum inhibitory concentrations (MICs)], which have been highlighted for the initiation of antimicrobial therapy.

Increased serum circulatory levels of interleukin 17F in type 1 reactions of leprosy

PURPOSE

Leprosy is a chronic infectious disease caused by Mycobacterium leprae affecting mainly skin and peripheral nerves. Acute inflammatory episodes in the borderline immunological spectrum of the disease cause severe nerve and tissue damage leading to deformities. Finding of any serological marker for leprosy reactions will help in prediction of reactions and in early treatment intervention. The objective of this study was to measure the serum circulatory levels of Interleukin 17F (IL 17F) and to correlate the levels with type 1 and type 2 reactional states and with clinico-histopathological spectrum of leprosy. We studied IL 17F to delineate its role and its clinical implications in leprosy reactions.

METHODS

Patients were classified based on the Ridley DS and Jopling WH Classification and blood samples (5 ml each) were collected from 80 active untreated leprosy cases in Type 1 reaction (T1R), 21 cases in Type 2 (Erythema Nodosum Leprosum ENL) reaction (T2R), 80 cases without reaction (NR), and 94 non-leprosy cases (NL). Serum was separated and measured for IL 17F levels using ELISA (Commercial Kits, R&D Systems Inc., USA).

RESULTS

IL 17F levels were significantly higher in the T1R group when compared to the NR group (p < 0.001). The borderline lepromatous group showed the highest levels of IL 17F among the other groups in the disease spectrum. Bacteriological index (BI) showed negative correlation with the IL 17F levels.

CONCLUSION

The results specify that serum circulatory levels of IL 17F are elevated during T1Rs in the borderline spectrum of the disease and thus may play a role in the regulation of inflammatory responses associated with reactions in leprosy.

Granuloma inguinale (Donovanosis)

The authors present images of two of the most common clinical forms of granuloma inguinale (donovanosis) in males and females. Donovanosis is considered a sexually transmitted disease that is endemic in tropical and subtropical regions of the world. Two microscopic images are also shown, one of a direct smear (the presence of Donovan bodies within large mononuclear cells identified using Giemsa stain) and the other of typical histological findings (rod-shaped Donovan bodies within a mononuclear histiocyte).

Cutaneous metastases of rectal mucinous adenocarcinoma mimicking granuloma inguinale

A 46-year-old man complained of ulcerovegetative lesions in the anogenital region, which he had noted one month prior to presentation. The patient had a history of travel to African countries. Therefore, the ulcerovegetative lesions of the patient were suspected to be granuloma inguinale (GI). Calymmatobacterium granulomatis was not observed in the direct examination of scrapings collected from the base of the ulcerovegetative lesion. Instead, a histological examination revealed cutaneous metastasis of mucinous adenocarcinoma of the rectum. Therefore, a diagnosis of GI was eliminated. As the patient did not report his history of rectal cancer and had travelled to African countries, we had primarily focused on the diagnosis of GI.

Leprosy reactions: the effect of gender and household contacts

Various host-related factors have been reported as relevant risk factors for leprosy reactions. To support a new hypothesis that an antigenic load in local tissues that is sufficient to trigger the immune response may come from an external supply of Mycobacterium leprae organisms, the prevalence of reactional leprosy was assessed against the number of household contacts. The number of contacts was ascertained at diagnosis in leprosy patients coming from an endemic area of Brazil. The prevalence of reactions (patients with reactions/total patients) was fitted by binomial regression and the risk difference (RD) was estimated with a semi-robust estimation of variance as a measure of effect. Five regression models were fitted. Model 1 included only the main exposure variable "number of household contacts"; model 2 included all four explanatory variables ("contacts", "fertile age", "number of skin lesions" and "bacillary index") that were found to be associated with the outcome upon univariate analysis; models 3-5 contained various combinations of three predictors. Male and female patients were analyzed separately. In females, household contacts were a significant predictor for leprosy reactions in model 1 [crude RD = 0.06; 95% confidence interval (CI) = 0.01; 0.12] and model 5 (RD = 0.05; CI = 0.02; 0.09), which included contacts, bacillary index and skin lesions as predictors. Other models were unsatisfactory because the joint presence of fertile age and bacillary index was a likely source of multicollinearity. No significant results were obtained for males. The likely interpretation of our findings might suggest that in female patients, leprosy reactions may be triggered by an external spreading of M. leprae by healthy carrier family members. The small number of observations is an obvious limitation of our study which requires larger confirmatory studies.

Peptide amphiphiles and porous biodegradable scaffolds for tissue regeneration in the brain and spinal cord

Many promising strategies have been developed for controlling the release of drugs from scaffolds, yet there are still challenges that need to be addressed in order for these scaffolds to serve as successful treatments. The RADA4 self-assembling peptide spontaneously forms nanofibers, creating a scaffold-like tissue-bridging structure that provides a three-dimensional environment for the migration of living cells. We have found that RADA4: (1) facilitates the regeneration of axons in the brain of young and adult hamsters, leading to functional return of behavior and (2) demonstrates robust migration of host cells and growth of blood vessels and axons, leading to the repair of injured spinal cords in rats.

Buruli ulcer

Buruli ulcer, an infectious disease caused by Mycobacterium ulcerans, is the third most prevalent mycobacteriosis, after tuberculosis and leprosy. This atypical mycobacteriosis has been reported in over 30 countries, mainly those with tropical and subtropical climates, but its epidemiology remains unclear. The first autochthonous cases of infection in Brazil have recently been described, making this diagnosis important for Brazilian dermatologists. Clinical manifestations vary from nodules, areas of edema, and plaques, but the most typical presentation is a large ulcer, usually in the limbs. Despite considerable knowledge about its clinical manifestations in some endemic countries, in other areas the diagnosis may be overlooked. Therefore, physicians should be educated about Buruli ulcer, since early diagnosis and treatment, including measures to prevent disability, are essential for a good outcome.

Fighting mycobacterial infections by antibiotics, phytochemicals and vaccines

Buruli ulcer is a neglected disease caused by Mycobacterium ulcerans and represents the world's third most common mycobacterial infection. It produces the polyketide toxins, mycolactones A, B, C and D, which induce apoptosis and necrosis. Clinical symptoms are subcutaneous nodules, papules, plaques and ulcerating oedemae, which can enlarge and destroy nerves and blood vessels and even invade bones by lymphatic or haematogenous spread (osteomyelitis). Patients usually do not suffer from pain or systematic inflammation. Surgery is the treatment of choice, although recurrence is common and wide surgical excisions including healthy tissues result in significant morbidity. Antibiotic therapy with rifamycins, aminoglycosides, macrolides and quinolones also improves cure rates. Still less exploited treatment options are phytochemicals from medicinal plants used in affected countries. Vaccination against Buruli ulcer is still in its infancy.

Clinical and epidemiological characteristics of imported infectious diseases in Spanish travelers

INTRODUCTION

Spain could be a potential area in Europe for the development and spread of emerging diseases from the tropics due to its geoclimatic characteristics, but there is little information on infectious diseases imported by travelers. The aim of this article was to analyze clinical-epidemiological characteristics of infectious diseases imported by Spanish travelers from the tropics.

METHODS

A retrospective descriptive study of 2,982 travelers seeking medical advice who return ill from the tropics was conducted. Demographic data, details of travel (destination, type, and duration), preventive measures, clinical syndromes, and diagnoses were analyzed.

RESULTS

Nearly half (46.5%) the travelers had traveled to sub-Saharan Africa; 46.5% reported a stay exceeding 1 month (and almost a quarter more than 6 months). Following pre-travel advice, 69.1% received at least one vaccine and 35.5% took malarial chemoprophylaxis with variations according to geographical area of travel. In all, 58.8% of this took chemoprophylaxis correctly. Most common syndromes were fever 1,028 (34.5%), diarrhea 872 (29.3%), and cutaneous syndrome 684 (22.9%). Most frequent diagnoses were traveler's diarrhea (17.2%), malaria (17%), and intestinal parasites (10.4%). The three main syndromes in travelers to the Caribbean-Central America, Indian subcontinent-Southeast Asia, and other areas were diarrhea, fever, and cutaneous syndrome (p < 0.05); in sub-Saharan Africa were fever, cutaneous syndrome, and diarrhea (p < 0.05); and in South America were cutaneous syndrome, diarrhea, and fever (p < 0.05). Travelers to sub-Saharan Africa showed a higher frequency of malaria, rickettsiosis, filariasis, and schistosomiasis (p < 0.05); those to South America showed cutaneous larva migrants, other ectoparasitosis, and cutaneous/mucocutaneous leishmaniasis; and those to the Indian subcontinent-Southeast Asia showed intestinal parasitosis, arboviriasis, and enteric fever (p < 0.05).

CONCLUSIONS

Increased international travel is a key factor for the development and spread of emerging pathogens. Information on these diseases is essential to establish early warning mechanisms and action plans. Spain represents a unique setting for this.

Skin infections in developing countries

PURPOSE OF REVIEW

In developing countries, where the majority of people have a low income and live in resource-poor settings, skin infections are prevalent. Data from recent studies provide insight into the most common skin infections and their management.

RECENT FINDINGS

Several studies confirm that skin infections account for the majority of pediatric mortality and morbidity in developing countries. They are prevalent in resource-poor settings and rural areas in certain parts of the world. Also, hot, humid climates and overcrowding predispose to skin infections. Most of the skin infections are curable with effective medication.

SUMMARY

Skin infections are of particular importance in developing countries. This review focuses on the most common skin infections and summarizes the most recent knowledge on the epidemiology, morbidity, and treatment in resource-poor settings.

Secondary yaws: an endemic treponemal infection

Although yaws is rare in developed countries, as worldwide travel has become commonplace, it is essential to recognize this condition when evaluating patients who traveled from endemic regions. Herein, we discuss a case of secondary yaws presenting as extensive expanding annular lesions to raise awareness of this condition.

[Update on the epidemiology, diagnosis and treatment of sexually-transmitted infections]

In the last decade, cases of sexually-transmitted infections (STIs) have progressively increased in Europe. The reasons for this increase are unclear, but may involve changes in social behavior, migration and international travel, coupled with the emergence of risk groups that have not been taken into sufficient consideration to date. The routine use of molecular diagnostic techniques for many of these infections has solved many problems of sensitivity and the suitability of samples for microbiological diagnosis: non-invasive samples can be used, which has undoubtedly contributed to the increase in the number of cases. Moreover, molecular methods have also been introduced for antibiotic and antiviral susceptibility testing, as well as for molecular characterization of clinical isolates. All of these factors, together with the approval of the vaccine against the human papillomavirus, have changed the landscape of STIs across Europe.

Leprosy: ongoing medical and social struggle in Vietnam

BACKGROUND

Until recently, leprosy had been prominent in 33 countries worldwide, and Vietnam was ranked among the top 14 endemic countries.

OBJECTIVE

The leprosy situation in Vietnam was reviewed as a sample of the worldwide ongoing medical and social struggle to assess the need for continued support for leprosy control activities and for social programs of integration of leprosy victims into the community.

METHODS

A search was conducted of official Vietnamese publications, World Health Organization documents, major electronic databases, and popular leprosy Web sites; as well, notes from visits to local leprosy clinics and interviews with health workers were checked.

RESULTS

Important achievements were realized through national determination and international collaboration. In contrast with the impressive performance statistics at the national level, and despite strong government efforts for leprosy control, the results obtained at the province-city and district-commune levels still exhibit deficiencies in case detection, treatment, and socioeconomic integration of leprosy victims.

CONCLUSION

The struggle to eliminate such a complex and destructive infectious disease as leprosy does not end with the cure. Deep-seated medical and social problems remain. These problems are best solved through community-based approaches.

How to prevent immunological reactions in leprosy patients and interrupt transmission of Mycobacterium leprae to healthy subjects: two hypotheses

The basis of World Health Organization strategy for leprosy elimination is that the only source and reservoir for infection are patients with the disease. It was assumed that multi drug therapy (MDT) would reduce transmission of Mycobacterium leprae, but there is no convincing evidence for this. Furthermore, even if MDT has been proved to be extremely effective against the infectious disease, a noticeable proportion of leprosy patients can suffer from immunologic hypersensitivity reactions which are now the most significant issue in the managements of the disease. In endemic areas it was found that: M. leprae survives outside human body; healthy individuals harbor M. leprae bacilli in nasal cavity and shed micro-organisms in environment; there is widespread subclinical transmission of M. leprae with transient infection of the nose resulting in the development of a mucosal immune response. This disparate clinical, epidemiologic, and microbiologic evidence leads to the first hypothesis: that antigenic load in local tissues, sufficient to trigger the immune response, comes from external supply of M. leprae organisms. The hypothiocyanite anion (OSCN-) is generated in vivo by the reaction of thiocyanate with hydrogen peroxide catalyzed by lactoperoxidase. OSCN- is an antimicrobial oxidizing agent that prevents growth of bacteria, fungi, and viruses. OSNC- exists in lower airway secretions and lung has never been reported to be affected by leprosy. There is a sufficient concentration of OSCN- in the saliva, and accordingly mouth is rarely affected by leprosy. By contrast, the concentration of this compound is low or nil in nasal and lacrimal secretions and leprosy very often affects nose and eyes. The second hypothesis is that OSCN- may also protect from leprosy. Recently a method of OSCN- production, not involving enzymatic steps or use of toxic heavy-metal salts, has been patented. Studies on the susceptibility of M. leprae to hypothiocyanite could be carried out and, in case of positive results, the substance might be used in order to sterilize the nasal cavity of healthy carriers and prevent transmission of M. leprae to healthy subjects and to leprosy patients in whom it may trigger an immune response.

Biologia molecular aplicada às dermatoses tropicais

São apresentados conceitos básicos sobre célula, código genético e síntese protéica, e sobre algumas técnicas de biologia molecular, tais como PCR, PCR-RFLP, seqüenciamento de DNA, RT-PCR e immunoblotting. São fornecidos protocolos de extração de nucleotídeos e de proteínas, como salting out no sangue periférico e métodos do fenol-clorofórmio e do trizol em tecidos. Seguem-se exemplos comentados da aplicação de técnicas de biologia molecular para o diagnóstico etiológico e pesquisa em dermatoses tropicais, com ênfase na leishmaniose tegumentar americana e hanseníase.

Imported tropical infectious ulcers in travelers

Skin ulcers are a commonly encountered problem at departments of tropical dermatology in the Western world. Furthermore, the general dermatologist is likely to be consulted more often for imported chronic skin ulcers because of the ever-increasing travel to and from tropical countries. The most common cause of chronic ulceration throughout the world is probably pyoderma. However, in some parts of the world, cutaneous leishmaniasis is one of the most prevalent causes. Mycobacterium ulcerans is an important cause of chronic ulcers in West Africa. Bacterial infections include pyoderma, mycobacterial infections, diphtheria, and anthrax. Pyoderma is caused by Staphylococcus aureus and/or beta-hemolytic streptococci group A. This condition is a common cause of ulcerative skin lesions in tropical countries and is often encountered as a secondary infection in travelers. The diagnosis is often made on clinical grounds. Antibacterial treatment for pyoderma should preferably be based on culture outcome. Floxacillin is generally active against S. aureus and beta-hemolytic streptococci. Infection with Mycobacterium ulcerans, M. marinum, and M. tuberculosis may cause ulcers. Buruli ulcers, which are caused by M. ulcerans, are endemic in foci in West Africa and have been reported as an imported disease in the Western world. Treatment is generally surgical, although a combination of rifampin (rifampicin) and streptomycin may be effective in the early stage. M. marinum causes occasional ulcerating lesions in humans. Treatment regimens consist of combinations containing clarithromycin, rifampin, or ethambutol. Cutaneous tuberculosis is rare in travelers but may be encountered in immigrants from developing countries. Treatment is with multiple drug regimens consisting of isoniazid, ethambutol, pyrazinamide, and rifampin. Cutaneous diphtheria is still endemic in many tropical countries. Cutaneous diphtheria ulcers are nonspecific and erythromycin and penicillin are both effective antibacterials. Antitoxin should be administered intramuscularly in suspected cases. Anthrax is caused by spore-forming Bacillus anthracis. This infection is still endemic in many tropical countries. Eschar formation, which sloughs and leaves behind a shallow ulcer at the site of inoculation, characterizes cutaneous anthrax. Penicillin and doxycycline are effective antibacterials. Cutaneous leishmaniasis is caused by different species belonging to the genus Leishmania. The disorder is one of the ten most frequent causes of skin diseases in travelers returning from (sub)tropical countries. The clinical picture is diverse, ranging from a painless papule or nodule to an ulcer with or without a scab. Treatment depends on the clinical manifestations and the species involved.Sporotrichosis, chromo(blasto)mycosis, and mycetoma are the most common mycoses that may be accompanied by ulceration. Infections are restricted to certain regions and often result from direct penetration of the fungus into the skin. Anti-mycotic treatment depends on the microorganism involved. The most common causes of infectious skin ulceration encountered in patients from tropical countries who present at a department of tropical dermatology are reviewed in this article.

Yaws disease in a wild gorilla population and its impact on the reproductive status of males

We evaluated the prevalence of skin lesions in a gorilla population in the Republic of Congo. The observed lesions were typical of yaws, a treponematosis described in gorillas and humans living in tropical regions. Among the 377 gorillas identified, 17% presented skin lesions, mainly on their faces. The worst cases presented physical handicaps because of the deep lesions. As in humans, lesions break out when individuals are young. Lesions were more prevalent among males than females above 8 years old. This sex-bias prevalence could result from the behavioral characteristics of males through a greater exposure to wounds. Lesions were also more prevalent in unmated adult males (either solitaries or those living in nonbreeding groups) than in males leading breeding groups. In the case of the latter, nonaffected and affected leading males had a similar number of infants and juveniles. Still, none of the leading males ever presented serious handicaps because of the skin lesions. This suggests that adult females could favor males without lesions. Finally, lesions were more prevalent among immature animals in nonbreeding groups than in breeding groups, suggesting that either young animals with lesions disperse earlier from their natal groups, or that the disease spreads faster in nonbreeding groups. Our results provide some insights into the spread of a disease in a wild population. Further studies are required to determine if the vigor of males affects the development of the disease and if affected individuals experience social discrimination inducing a negative impact on population dynamics.