Experimental leprosy in three species of monkeys.

Eleven mangabey monkeys inoculated with Mycobacterium leprae developed lepromatous-type leprosy. Nine of the mangabeys were inoculated with M. leprae isolated from a mangabey with naturally acquired lepromatous leprosy. Immune function was depressed in some of these animals after dissemination of the disease. Two mangabeys developed lepromatous leprosy after inoculation with human M. leprae passaged in an armadillo. Three rhesus and three African green monkeys inoculated with mangabey-derived M. leprae also developed lepromatous leprosy. Mangabeys may be the first reported nonhuman primate model for the study of leprosy. Rhesus and African green monkeys may also prove to be reproducibly susceptible to the disease.

[Study of names and folklore associated with Mycobacterium ulcerans infection in various endemic countries in Africa]. / Etude des appellations et des représentations attachées à l'infection à Mycobacterium ulcerans dans différents pays endémiques d'Afrique.

The purpose of this article is to present names used for Mycobacterium ulcerans infection (Buruli ulcer) and explain their meanings in various African languages. Representations associated with the disease were also studied. The study approach involved qualitative analysis of information from interviews and literature. Interviews were conducted with the directors of various programs and management centers. Findings from 9 African countries where Buruli ulcer is known to be endemic, i.e., Benin, Cameroon, Congo-Brazzaville, Côte d'Ivoire, Ghana, Uganda, Democratic Republic of Congo, Southern Sudan and Togo, showed that the names used for the disease could be classified into three categories based on the geographical origin of infection, the features of the observed lesions, and aspects of ost often associated with belief in witch-craft, i.e., bad luck, fetishes, and curses. Representation of the disease in different African languages were similar and appear to demonstrate a good understanding of the disease in the countries where Buruli ulcer is prevalent. The impact of the representations of the disease on therapeutic choices and itineraries is also discussed.

Naturally acquired leprosy in the nine-banded armadillo: a decade of experience 1975-1985.

A decade has passed since our first report of naturally acquired leprosy in the nine-banded armadillo. Our studies and those of others during this period confirm the identification of the etiologic agent as Mycobacterium leprae. Confirmation is based on the results of histopathologic examination and microbiologic evaluations that included attempts to culture the organism, flourescent antibody studies, mycolic acid analysis, and DNA determinations demonstrating complete relatedness between the natural agent and M. leprae. Surveys involving large numbers of animals demonstrate a significant prevalence of the disease in armadillos captured in Louisiana and Texas. The discovery of naturally acquired leprosy in a chimpanzee in 1977 and a sooty mangabey monkey in 1979 reinforce the concept of leprosy as a zoonosis. Extensive contact with armadillos has been implicated by other observers in seven patients with leprosy in Texas. We believe the prevalence of leprosy in wild armadillos requires that they be considered a source of infection in patients from geographic areas where leprosy and armadillos co-exist.

Current concepts in the pathogenesis of leprosy. Clinical, pathological, immunological and chemotherapeutic aspects.

In recent years there have been notable advances in the laboratory investigation and field management of leprosy. Progress, however, continues to be hindered by the lack of efficient methods for early diagnosis and implementation of control and treatment measures. Diagnosis is still made on the same principles as a century ago (clinical and histopathological findings), and only 1 in 3 known patients worldwide receives optimal chemotherapy. In 1988, nearly 1 in 10 newly diagnosed patients already had debilitating deformities. Contributing factors are operational, administrative and financial difficulties in implementing multidrug therapeutic regimens, inadequately trained personnel, and lack of priority and political commitment to leprosy control. The formulation and implementation of multidrug therapy is the most important development in leprosy in the past 10 years. Dapsone monotherapy was the mainstay for treatment and control for approximately 40 years, but secondary dapsone-resistant strains, first noted in 1964, now infect as many as 50% of all new patients. Multidrug regimens recommended by the WHO consist of various combinations of therapy using dapsone, rifampicin, clofazimine and a thionamide. Duration of therapy is limited to 6 months for paucibacillary and 2 years or more for multibacillary patients; relapse rates thus far are low. The average cost of treatment worldwide, including the cost of drugs, is estimated at $US150 per patient. The recent annual drop of nearly 8% in newly registered patients may be due to the implementation of these therapeutic regimens. Newer drugs that may be introduced into these regimens include fluoroquinolones, minocycline and clarithromycin. While knowledge of the microbiology of the leprosy bacillus and host response has advanced remarkably, there is little improvement in the understanding or amelioration of social aspects of leprosy. Better treatment and control reduces the stigma, but improvements in the attitudes of patients and society towards leprosy are as important as advances in medical science in achieving ultimate eradication of the disease.

Mycotic granuloma caused by Phialophora repens.

This is the first reported infection by the saprophytic fungus, Phialophora repens. The infection was a solitary granulomatous nodule in the scalp of a Zaïrian man with advanced lepromatous leprosy. The patient was being treated by long-term prednisolone therapy. In tissue sections there were nonpigmented microcolonies composed of irregularly branched septate hyphae. A darkly pigmented fungus was isolated on Sabouraud's medium. The mycologic features of the etiologic agent were typical of P. repens. The infection was treated successfully by excision of the nodule.

Failure of levamisole to alter the lepromin reaction.

In a study of 37 leprosy patients, the oral administration of levamisole failed to provoke an increase in both the Fernandez and Mitsuda reactions to lepromins of human and armadillo origin. We interpret this as evidence against an effective specific immunostimulatory capability of levamisole in leprosy patients under the conditions of the study. Current knowledge of the mechanism of levamisole action supports the concept that the fundamental immunologic defect in lepromatosus leprosy may reside in the lymphocyte and not the macrophage, or the respective related functions of these two cell forms.

Dipetalonema streptocerca (Macfie and Corson, 1922): description of the adult female.

Morphologic features of the adult female Dipetalonema streptocerca and microfilariae are described and illustrated from serial paraffin sections of biopsied skin from eight Africans. Characteristic features include a maximum diameter of 85 microns, a thin, smooth cuticle, and uteri that fill the body cavity. D. streptocerca is briefly compared to Onchocerca volvulus.

Heat treatment of Mycobacterium ulcerans infections without surgical excision.

Eight patients from Zaire with Mycobacterium ulcerans infection were treated by the local application of heat to maintain a temperature of approximately 40 degrees C in the ulcerated area. All lesions healed without surgical intervention and without local recurrences during follow-up periods of up to 22 months. This study shows that local heat promotes healing of M. ulcerans lesions. We postulate that the mechanism is primarily by direct inhibition of multiplication of M. ulcerans. Other possible contributory effects are discussed.

Streptocerciasis: observation of adult male Dipetalonema streptocerca in man.

In 75 biopsy specimens of skin from 34 patients with streptocerciasis who had been treated with diethylcarbamazine, we found 39 female and six male adult Dipetalonema streptocerca in the dermal collagen. This is the first report of adult male D. streptocerca in man, and identifying features are described.

Onchocerciasis: invasion of deep organs by Onchocerca volvulus.

Autopsies of two patients with onchocerciasis in the Republic of Zaïre are reported. In one patient elephantiasis who died following diethylcarbamazine therapy there were large numbers of microfilariae of Onchocerca volvulus in the kidney, liver, pancreas, and lung. In the second patient, who also had leprosy and hyperinfection strongyloidiasis, we found an encapsulated adult O. volvulus in the wall of the thoracic aorta.

Recovery of intact male and female Dipetalonema streptocerca from man.

When attempts at teasing adult Dipetalonema streptocerca free from biopsy specimens of human skin proved futile a digestion procedure was initiated. Punch biopsy specimens fixed in Michel's solution (ammonium sulfate) were incubated at 25 degrees C for 3 days in a 1.0% solution of collagenase in tris-HCl buffer. Intact worms were carefully teased out of the digested collagen and camera lucida drawings and measurements were then possible. This marks the first description of intact D. streptocerca adults recovered from man.

Naturally acquired and experimental leprosy in nonhuman primates.

Naturally-acquired leprosy has been observed in chimpanzees and sooty mangabey monkeys. Experimental multibacillary leprosy was established in 24 of 36 mangabey monkeys, 7 of 34 rhesus monkeys, and 15 of 19 African green monkeys following intravenous and intradermal inoculation of Mycobacterium leprae. The experimental disease strongly resembles leprosy in humans clinically, histopathologically, and immunologically. Thus, in addition to nine-banded armadillos in Louisiana and Texas, chimpanzees and sooty mangabeys in Africa, in the wild or in captivity, may serve as a zoonotic source of M. leprae. Investigators using chimpanzees and monkeys should be alerted to the possibility of naturally-acquired leprosy.

Human Mycobacterium ulcerans infections developing at sites of trauma to skin.

In Zaire, we studied 180 patients with Mycobacterium ulcerans infections and found 14 with a history of antecedent trauma at the site of the lesion (e.g., gunshot and land mine injuries, penetrating wood splinters, and scorpion stings). Two patients developed lesions following hypodermic injections. We believe that trauma is an important mode of transmitting M. ulcerans infections, or of introducing the etiologic agent into the dermis of subcutaneous tissue from superficially contaminated skin.

Streptocerciasis: degeneration of adult Dipetalonema streptocerca in man following diethylcarbamazine therapy.

Thirty-three patients in Zaire with streptocerciasis were treated daily with diethylcarbamazine (DEC) for 21 days. Histopathologic studies of biopsy specimens with papules of skin established that during DEC treatment adult male and female Dipetalonema streptocerca die and degenerate. DEC may thus produce radical cures of streptocerciasis.

The use of IS2404 restriction fragment length polymorphisms suggests the diversity of Mycobacterium ulcerans from different geographical areas.

Buruli ulcer, caused by Mycobacterium ulcerans, has been reported in five continents: Africa, Asia, Australia, and North and South America. In the present study, restriction fragment length polymorphism with the recently described M. ulcerans specific insertion sequence IS2404 as a probe, was applied to Mycobacterium shinshuense, Mycobacterium marinum, and 14 clinical M. ulcerans isolates originating from six geographic areas: Africa (n = 6), Australia (n = 2), Mexico (n = 1), south Asia (n = 2), Asia (n = 1), and South America (n = 2). Using this probe, six subtypes of M. ulcerans, related to the six geographic origins of the isolates were distinguished, confirming that M. ulcerans can be divided into subgroups corresponding to different geographic variants of the same species.

Transmission of Mycobacterium ulcerans to the nine-banded armadillo.

Animal models for Mycobacterium ulcerans infections (Buruli ulcer) include guinea pigs, rats, and mice, but each has limitations in replicating the spectrum of human disease. Here, 19 adult nine-banded armadillos were inoculated intradermally with M. ulcerans. Injection sites were examined and skin samples obtained for histologic and microbiology studies. Necropsies were conducted to assess systemic involvement. In group 1 (n = 4), 2 animals developed progressive skin ulcers with undermined borders at the injection sites within 6-10 weeks. Biopsies showed features similar to human disease including extensive necrosis in the deep dermis and subcutaneous fat, mixed cellular infiltrates, and acid-fast bacilli (AFB). In group 2 (n = 15), 5 animals developed progressive skin ulcers, 3 had evanescent papulo-nodules, 3 died shortly after inoculation of unknown causes, and 4 showed no signs of infection. Lesion samples from 3 animals with progressive ulcers were culture positive for AFB. Our findings indicate that nine-banded armadillos are susceptible to M. ulcerans and may develop cutaneous lesions that closely mimic Buruli ulcer.

Experimental leprosy in African green monkeys (Cercopithecus aethiops): a model for polyneuritic leprosy.

Three African green monkeys (Cercopithecus aethiops) were inoculated intravenously and intracutaneously with Mycobacterium leprae derived from a naturally infected mangabey monkey. All developed cutaneous lesions at inoculation sites. One developed disseminated cutaneous lesions, while the cutaneous lesions in the other two regressed and eventually disappeared. The animals were examined at necropsy five years after inoculation. All three had active leprosy infection in peripheral nerves with extensive inflammation and fibrosis. The disease histologically resembled borderline-lepromatous leprosy. These findings add a new dimension to animal models of leprosy.

Leprosy.

Growing out of the successful transmission of leprosy to armadillos, making available large quantities of M. leprae, there have been remarkable recent advances in the knowledge of the leprosy bacillus. These bacilli and their isolated chemical constituents provide organisms for in vitro testing of new drugs, reagents for the study of the immunologic dysfunction in leprosy patients, development of early diagnostic methods, and the preparation of candidate vaccines. Leprosy is usually transmitted by the nasorespiratory route, but occasionally, there is transplacental infection. There are reports suggesting that patients have acquired leprosy by contact with wild M. leprae-infected armadillos in Louisiana and Texas. Perturbations in lymphocyte-macrophage interaction appear to be most closely related to the defective CMI in leprosy. The helper T/suppressor T cell populations vary markedly in lesions of the various forms of leprosy, with enhanced suppression of T-cell activity in lepromatous disease. Infiltration of IL-2 and gamma-interferon seems to stimulate CMI in situ in lesions of lepromatous leprosy. Vaccination of lepromatous patients with a killed M. leprae-plus-BCG preparation stimulates CMI and clears tissues of leprosy bacilli, providing an immunotherapeutic approach to the management of leprosy. Immunoprophylactic vaccine trials are in progress, and initial results should be available in 1991. Because of drug resistance, dapsone monotherapy of leprosy is no longer recommended. Multidrug regimens, composed of dapsone, rifampin, and clofazimine or a thioamide, are now required and appear to reduce the incidence of leprosy when applied assiduously. Newer experimental drugs that may eventually be included in these regimens include the fluoroquinolones, minocycline, and clarithromycin. There is no clear evidence that the early serologic diagnosis of leprosy is generally applicable. Favorable response to therapy in multibacillary patients, however, may be assessed by noting drops in levels of M. leprae-specific antigens in blood and urine and, to a lesser extent, levels of specific antibodies in serum. There are conflicting reports on the influence of AIDS on leprosy. There are no convincing data showing that AIDS and leprosy affect each other. Although chemotherapy offers the best current hope for the control of leprosy, effective immunoprophylaxis and improved socioeconomic conditions in endemic areas are thought to be essential in programs for the eradication of leprosy.

Unusual cutaneous infectious and parasitic diseases.

The cutaneous manifestations of thirteen unusual infections and parasitic diseases are described. Their geographic distribution, morphologic features of the causative organism, histopathologic changes, criteria for diagnosis, and treatment are included.

Anti-leprosy protective vaccination of rhesus monkeys with BCG or BCG plus heat-killed Mycobacterium leprae: lepromin skin test results.

Groups of rhesus monkeys (RM) were vaccinated and boosted with living Mycobacterium bovis Bacillus Calmette-Guerin (BCG) or BCG + low dose (LD) heat-killed Mycobacterium leprae (HKML) or high dose (HD) HKML or were unvaccinated. Animals vaccinated with BCG + LD and HD HKML were lepromin skin tested 2 weeks after boosting. All groups were lepromin tested 37 and 46 months after challenge with live M. leprae. Fernandez (72 h) and Mitsuda (28 day) responses were recorded. Ten of 10 rhesus monkeys in each of the two BCG + HKML-vaccinated groups significantly converted to strong positive Fernandez status within 2 weeks of boosting, compared to one of six positives in the unvaccinated unchallenged normal control group. Both BCG + HKML groups were significantly protected from clinical leprosy. Six of 10 in each of the two BCG + HKML groups significantly converted to Mitsuda positivity within 2 weeks of boosting compared to zero of six in the normal control group. The sizes of the Mitsuda responses were larger in the LD group than the HD HKML vaccinated/boosted group, suggesting suppression by vaccination with higher doses of HKML in combination with BCG. Fernandez responses were negative in normal RM as well as in the unvaccinated, ML-challenged group and the BCG-vaccinated, ML-challenged group at 37 or 46 months after ML inoculation, although the BCG-vaccinated group was significantly protected from leprosy and the unvaccinated group was not. In contrast, at 37 months the Fernandez reaction was positive in the BCG plus LD and the BCG plus HD HKML-vaccinated groups, both of which were significantly protected from clinical leprosy. By 46 months, the Fernandez responses were below significance in all groups. Thus, Fernandez reactivity is not a reliable correlate to protection from experimental leprosy in RM. Mitsuda responses became strongly positive in all four ML-challenged groups by 37 months and remained strongly positive at 46 months after ML inoculation, suggesting that strong Mitsuda reactivity reflects responses to living ML. BCG or BCG + LD or HD HKML vaccination/boosting of RM produced significant clinical protection from leprosy and there was a good correlation between protection from LL forms of leprosy and positive Mitsuda skin test responses after challenge with live ML. Positive Mitsuda responses were generated in essentially all individuals after challenge with live ML, and this response was primed by prior vaccination/boosting with BCG + HKML as shown by conversion to positivity 2 weeks after boosting. The data show that resistance to clinical leprosy is reflected by Mitsuda responses in ML-exposed RM, similar to results from human studies, and confirm the suitability of RM as a model for leprosy vaccine studies.