Imported tropical infectious ulcers in travelers

Leg ulceration due to cutaneous melioidosis in a returning traveller

A 26-year-old man, returned to the UK having travelled extensively in Asia. He was referred with a 3-month history of distal leg ulceration following an insect bite while in Thailand. Despite multiple courses of oral antibiotics, he developed two adjacent ulcers. A wound swab isolated an organism identified as Burkholderia thailandensis The histology of the skin biopsy was non-specific. A diagnosis of cutaneous melioidosis was made, based on clinical and microbiological grounds. The ulcers re-epithelialised on completion of intravenous ceftazidime followed by 3 months of high dose co-trimoxazole and wound care. Many clinical microbiology laboratories have limited diagnostics for security-related organisms, with the result that B. pseudomallei, the causative bacterium of melioidosis, may be misidentified. This case highlights the importance of maintaining high levels of clinical suspicion and close microbiological liaison in individuals returning from South-East Asia and northern Australia with such symptoms.

Geographic distribution and genetic characterization of poxviruses from human infections in Georgia, 2009-2014

Anthrax is endemic in Georgia, as are multiple zoonotic poxviruses. Poxvirus-associated infections share some clinical manifestations and exposure risks with anthrax, and so it is important to distinguish between the two. With this in mind, an archived collection of anthrax-negative DNA samples was retrospectively screened for poxviruses, and of the 148 human samples tested, 64 were positive. Sequence analysis confirmed the presence of orf virus, bovine papular stomatitis virus, and pseudocowpox virus. This study provides evidence of previously unrecognized poxvirus infections in Georgia and highlights the benefit of the timely identification of such infections by improving laboratory capacity.

Pyoderma gangrenosum: a review with special emphasis on Latin America literature

Pyoderma gangrenosum is a neutrophilic dermatosis characterized by chronic ulcers due to an abnormal immune response. Despite the existence of diagnostic criteria, there is no gold standard for diagnosis or treatment. In Latin America, recognizing and treating pyoderma gangrenosum is even more challenging since skin and soft tissue bacterial and non-bacterial infections are common mimickers. Therefore, this review aims to characterize reported cases of pyoderma gangrenosum in this region in order to assist in the assessment and management of this condition. Brazil, Mexico, Argentina, and Chile are the countries in Latin America that have reported the largest cohort of patients with this disease. The most frequent clinical presentation is the ulcerative form and the most frequently associated conditions are inflammatory bowel diseases, inflammatory arthropaties, and hematologic malignancies. The most common treatment modalities include systemic corticosteroids and cyclosporine. Other reported treatments are methotrexate, dapsone, and cyclophosphamide. Finally, the use of biological therapy is still limited in this region.

Other Potentially Life-Threatening Conditions with Mucocutaneous Findings (Leptospirosis, Typhoid Fever, Dengue, Diphtheria, Murine Typhus)

There are several conditions with mucocutaneous findings that are potentially life-threatening, particularly in certain vulnerable populations. In this chapter, leptospirosis, typhoid fever, dengue, diphtheria, and murine typhus are reviewed. The disease time course of classic and atypical presentations is detailed to assist making the diagnosis in subtle cases. Associated symptoms are discussed as well as a comparison with disease mimics and differential diagnoses. Key diagnostic features are emphasized, and evidence-based management of each condition is detailed in this chapter.

[Cutaneous diphtheria after a minor injury in Sri Lanka]

Cutaneous dipththeria is an infectious bacterial disease endemic in tropical regions, but rarely diagnosed in Germany. Following travel in Sri Lanka, a 60-year-old German presented to our dermatological clinic with a skin ulcer and extensive erythematous erosive edema of his left foot. Corynebacterium diphtheriae was isolated from a swab of the lesion. There were no clinical signs of toxic diphtheria. The patient was treated with penicillin G and erythromycin, followed by a slow healing of the lesion. The isolated strain could be identified as toxigenic C. diphtheriae mitis. Due to increased travel activity, dermatologists should have uncommon infections like cutaneous diphtheria in mind.

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.

Corynebacterium ulcerans cutaneous diphtheria

We describe the case of a patient with cutaneous diphtheria caused by toxigenic Corynebacterium ulcerans who developed a right hand flexor sheath infection and symptoms of sepsis such as fever, tachycardia, and elevated C-reactive protein, after contact with domestic cats and dogs, and a fox. We summarise the epidemiology, clinical presentation, microbiology, diagnosis, therapy, and public health aspects of this disease, with emphasis on improving recognition. In many European countries, C ulcerans has become the organism commonly associated with cutaneous diphtheria, usually seen as an imported tropical disease or resulting from contact with domestic and agricultural animals. Diagnosis relies on bacterial culture and confirmation of toxin production, with management requiring appropriate antimicrobial therapy and prompt administration of antitoxin, if necessary. Early diagnosis is essential for implementation of control measures and clear guidelines are needed to assist clinicians in managing clinical diphtheria. This case was a catalyst to the redrafting of the 2014 national UK interim guidelines for the public health management of diphtheria, released as final guidelines in March, 2015.

Corynebacterium diphtheriae and the returned tropical traveler

BACKGROUND

In Western countries, nontoxigenic Corynebacterium diphtheriae is known to cause skin and soft tissue infections (SSIs), upper respiratory tract infections, and occasionally invasive disease. Its role as a skin pathogen in returned travelers from tropical destinations where the organism is endemic is often forgotten. A retrospective analysis of a large Australian private pathology laboratory's experience with C. diphtheriae was performed to identify how frequently overseas travel was associated with C. diptheriae infection/colonization.

METHODS

All C. diphtheriae isolates cultured from 2002 to 2012 were reviewed. Recorded clinical information regarding recent travel, country, and cause of infection was assessed. Antibiotic susceptibility was verified on all isolates.

RESULTS

In all there were 72 patients who had C. diphtheriae isolated on clinical specimens, and information about prior travel was available for 63. Seventy percent of these were healthy individuals with an SSI and history of recent travel to a tropical nation. Ninety-seven percent had associated copathogens. Two isolates were penicillin resistant. There was uniform susceptibility to cephalothin, clindamycin, erythromycin, and vancomycin, with 14% resistance to trimethoprim/sulfamethoxazole and 4% resistance to tetracycline. Only one isolate was a toxigenic strain.

CONCLUSION

The majority of C. diphtheriae isolated were from SSIs in otherwise healthy travelers returning from tropical destinations, rather than classical risk groups. Clinicians and laboratories need to be aware of this potential source of C. diphtheriae infection due to rare toxigenic strains.

Chronic leg ulcers as a rare cause for the first diagnosis of epidermolysis bullosa dystrophica

Chronic leg ulcers occur most frequently in the elderly population as a result of an underlying vascular disease especially chronic venous insufficiency. But it also occurs less commonly in younger people due to other aetiologies, for example, infections, vasculitis, neoplasia or genetic diseases. The following case report presents chronic leg ulcers as a rare cause for the first diagnosis of dystrophic epidermolysis bullosa. We report about a 21-year-old man with painful chronic leg ulcers resistant to different wound treatments for 4 months. After exclusion of the more common vascular aetiologies and reviewing the patient's family history, we considered an epidermolysis bullosa dystrophica which could be confirmed by genetic analyses. We treated the patient with debridement, modified negative pressure therapy with non-adhesive foil and skin grafting. The chronic leg ulcers healed completely. This case report demonstrates that the family history and genetic diseases should be considered as rare causes for therapy-refractory chronic leg ulcers, especially in young patients.

Comparative ethnobotany and in-the-field antibacterial testing of medicinal plants used by the Bulu and inland Kaulong of Papua New Guinea

ETHNOPHARMACOLOGICAL RELEVANCE

The island of New Britain in Papua New Guinea is an area of great floristic and cultural diversity that has received little attention from ethnobotanists. Here we present the results of a comparative medicinal ethnobotanical survey of the Bulu and inland Kaulong; two distinct people groups inhabiting lowland rainforest on different sides of the island. A high proportion of species are used in the treatment of bacterial infections and plants with antibacterial activity were identified in the field using a specially developed antibacterial assay kit. Follow up testing with human pathogens was used to evaluate active plant material in more detail.

MATERIALS AND METHODS

Rapid appraisal techniques were used to survey both people groups with all data corroborated by three or more separate sources. Plants from both groups were tested in-the-field with a portable antibacterial test kit based on the agar diffusion assay, using a pressure cooker to sterilise glassware and media. Follow up laboratory based tests were carried out using standardised agar dilution protocols for drug resistant and drug sensitive strains of Staphylococcus aureus and Streptococcus pneumoniae.

RESULTS

We find surprisingly little overlap in the plant species used by the two people groups with only 1 out of 70 species used for the same purpose. There is also a difference in emphasis in the conditions treated with 53% of Kaulong medicinal plants dedicated to treating tropical ulcers compared with only 8% of in the Bulu group. In-the-field testing identified Garcinia dulcis bark (a Kaulong tropical ulcer treatment) to have antibacterial activity and follow up tests against a drug resistant strain of Staphylococcus aureus (a pathogen implicated in tropical ulcer pathogenesis) revealed the crude bark extract to be potently active with an MIC of just 1 mg/ml.

CONCLUSIONS

The results demonstrate extreme differences in medicinal plant use between two people groups living a mere 100 km apart and suggests the two medicinal plant systems have developed in isolation from one another. In-the-field antibacterial testing of plant extracts was found to be a valuable technique that enabled early identification of active plant material.

Clinical pleiomorphism in human leishmaniases, with special mention of asymptomatic infection

This review gives an update of current knowledge on the clinical pleiomorphism of Leishmania, with a special emphasis on the case of asymptomatic carriage. The first part describes the numerous unusual expressions of the disease that occur besides the classic (visceral, cutaneous, and mucocutaneous) forms of leishmaniases. The second part deals with progress in the understanding of disease outcome in humans, and the possible future approaches to improve our knowledge in the field. The third part highlights the role of the too often neglected asymptomatic carrier compartment. This group could be key to understanding infraspecific differences in virulence and pathogenicity of the parasite, as well as identifying the genetic determinants involved in the expression of the disease.

Skin disorders among travellers returning from tropical and non-tropical countries consulting a travel medicine clinic

OBJECTIVE

To evaluate the causes and risks for imported skin disorders among travellers.

METHODS

Data of 34,162 travellers returning from tropical and non-tropical countries and presenting at the outpatient travel medicine clinic of the University of Munich, Germany, between 1999 and 2009 were analyzed for this study. Of these, 12.2% were diagnosed with skin disorders.

RESULTS

Main destinations visited were Asia (40%), Africa (27%) and Latin America (21%). Tourism in the form of adventure travel/backpacking (47%) and package holidays (23%) was the most common purpose of travel. The leading causes of skin disorders were arthropodal (23%), bacterial (22%), helminthic (11%), protozoan (6%), viral (6%), allergic (5%) and fungal (4%). The 10 most frequently diagnosed specific skin diseases associated with specific destinations were insect bites (17%, Southern Europe), cutaneous larva migrans (8%, Asia and Latin America), cutaneous leishmaniasis (2.4%, Mediterranean Region/Middle East), dengue fever (1.5%, Asia), rickettsioses (1.3%, Southern Africa), myiasis (0.8%, Central America), filarioses (0.7%, Africa), tick bites (0.6%, Central/Eastern Europe), schistosomiasis (0.6%, Africa) and tungiasis (0.6%, Africa). Travellers in sub-Saharan Africa had the highest relative risk of acquiring skin disorders.

CONCLUSION

As more than 20% of all skin disorders among returned travellers were caused by arthropods and about 50% by infectious pathogens, pre-travel consultations should include specific prophylaxis and consider the most important risk factor for the travel destination.

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.

Nontuberculous mycobacterial skin infections: recognition and management

Mycobacterial organisms have re-emerged as an important cause of infectious disease worldwide. Both tuberculosis and nontuberculous mycobacterial infections remain endemic in many parts of the world and are becoming more common in patients with iatrogenic immunosuppression and HIV infection. The nontuberculous mycobacteria, often referred to as mycobacteria other than tuberculosis (MOT), are of special significance to the dermatologist because they often present in the skin, typically after exposure to an aqueous environment. Presentations range from indolent nodules with sporotrichoid spread to acute suppurative folliculitis and abscess formation. Infection with MOT should be considered whenever routine bacterial cultures are negative. Cultures should be obtained, but empiric therapy must often be started while cultures are pending. Some data suggest that clarithromycin may be the best initial empiric therapy.