Search

The cause of endomyocardial fibrosis in Uganda remains unknown in spite of studies dating back to 1948. Herbal decoctions have been used by traditional healers for countless generations to treat many complaints, especially fever. We present evidence - ethnic, geographical, tribal, pathological and distribution by age - that the toxic herbal decoctions taken as medicines in Uganda can cause endomyocardial fibrosis.

This paper presents statistical evidence showing how variations in the attributes of road users can lead to variations in the probabilities of sustaining different levels of injury in motor vehicle accidents. Data from New South Wales, Australia, is used to estimate two models of multiple choice which are reasonably commonplace in the econometrics literature: the ordered logit model and the ordered probit model. Our estimated parameters are significantly different from zero at small levels of significance and have signs which are consistent with our prior beliefs. As a benchmark for comparison, we consider the risks faced by a 33-year-old male driver of a 10-year-old motor vehicle who is involved in a head-on collision while travelling at 42 kilometres per hour. We estimate that this benchmark victim will remain uninjured with a probability of almost zero, will require treatment from a medical officer with a probability of approximately 0.7, will be admitted to hospital with a probability of approximately 0.3, and will be killed with a probability of almost zero. We find that increases in the age of the victim and vehicle speed lead to slight increases in the probabilities of serious injury and death. Other factors which have a similar or greater effect on the probabilities of different types of injury include seating position, blood alcohol level, vehicle type, vehicle make and type of collision.

Two black African women and one black American man had carcinomas of cervix, perineum, and sigmoid colon, respectively. In each of these patients, trophozoites of Entamoeba histolytica had invaded the surface of the tumor, and in some areas had invaded more deeply into the stroma between the tumor cells. Although it is well known that cutaneous amebiasis of anus, penis, vulva, and cervix can mimic squamous cell carcinoma, it may be, perhaps, less well known that carcinomas at these sites may be colonized by trophozoites of E. histolytica. In patients with amebiasis but without an associated carcinoma, a correct diagnosis of amebiasis spares the patient unnecessary and sometimes mutilating surgery. But a diagnosis of amebiasis, when there is an unrecognized underlying carcinoma, delays effective treatment of the carcinoma. A smear that establishes a diagnosis of cutaneous amebiasis, therefore, should be followed by biopsy to exclude or confirm an underlying carcinoma.

Enterobius worms or their eggs, or both, are present in preserved tissue sections or tissue specimens of 259 patients whose medical records are on file at the Armed Forces Institute of Pathology, Washington D.C., U.S.A. The most common site of infection (86.5%) was found to be the lumen of the appendix, where the worms provoke no reaction. Of the 259 patients 11 (4.2%) had worms and/or eggs in granulomas of the abdominal and pelvic peritoneum, and an equal number had granulomas on the peritoneum of the salphinx or on the surface of the ovary. There were also ectopic worms and/or eggs in granulomas on the peritoneum of the small and large intestines (2.7%). These Enterobius granulomas form around degenerating adult worms, around discrete eggs, around clusters of eggs, and, we believe, also around the tracks of migrating worms. Three patients (1.2%) had worms in perianal abscesses. A necrotic granuloma, removed from the lung of one patient, surrounded a degenerating adult worm. This suggests that the worm, carried to the lung as an embolus, impacted in a pulmonary arteriole. A stool specimen of one patient contains eggs of Enterobius, and that of another patient contains an adult Enterobius. This is the largest recorded histopathological study of enterobiasis in man.

A 72-year-old Filipino man who had emigrated to Canada had an abdominal infection with a proliferating acephalic larval cestode. Small, irregularly shaped parasites were within the substance of a lymph node, where they provoked a fibrogranulomatous and eosinophilic reaction. The parasite is described and is identified as an undifferentiated sparganum or tetrahyridium based upon comparison with two similar parasites from patients in Taiwan and Paraguay.

The World Health Organization's Collaborating Centre for the Histopathology of Filarial Diseases of Man contains specimens of lymph node from 13 patients infected by the filarial nematode Loa loa. Ten of these nodes have distinctive microscopic features characterized by distended sinuses that contain histiocytes and eosinophils and by atrophy of lymphoid follicles. Less striking features include fibrosis of capsule and trabeculae, dilated lymphatic vessels of capsule and medulla, and inflammatory cell infiltrates. We believe that these changes, although in themselves nonspecific, are characteristic of lymphadenitis caused by Loa loa. These 10 lymph nodes were removed from the inguinal region--one from each of 10 native Zairians . At the time of herniorrhaphy the nodes in eight patients were found to be enlarged and were removed for diagnosis. Seven of the 10 patients were infected with Dipetalonema perstans as well as Loa loa, and one of these seven had three filarial infections--L. loa, D. perstans and D. streptocerca . Lymph nodes from other patients infected by other filariae that were available for study at the AFIP did not have these histopathologic features.

Specimens of skin from four Cameroon patients with severe onchocercal dermatitis, before and after treatment with diethylcarbamazine (DEC), were studied by light and electron microscopy. Microfilariae of Onchocerca volvulus have ultrastructural features resembling those of microfilariae of other genera. Between the surface layer of the cuticle and the trilaminate membrane, there is an electrolucent zone which is much wider in degenerating microfilariae than in intact microfilariae. Widening of the zone may result from DEC-induced release of component(s) of the cuticle, possibly collagen or mucopolysaccharide. Between the cuticle and dermal collagen there are granular deposits which might be immune complexes involving the collagenous component of cuticle. Others have shown that DEC does not kill microfilariae in vitro. Treatment with DEC presumably "unmasks" microfilariae in the skin so that they are recognized as foreign bodies and are destroyed by the host's defenses. Histiocytes and eosinophils are seen in close proximity to degenerating microfilariae. Enzymes from histiocytes and eosinophils might readily penetrate the cuticle altered by DEC treatment, and digest various components within the microfilariae. Alternatively, the widening of the electrolucent zone might result directly from the action of leucocytic or histiocytic enzymes, after the microfilaria has been killed by other mechanisms.

Liesegang rings (LRs) are periodic precipitation zones from supersaturated solutions in colloidal systems. They are formed by a process that involves an interplay of diffusion, nucleation, flocculation or precipitation, and supersaturation. Examples include LRs of calcium carbonate in oölitic limestone (in nature), LRs of silver chromate in gelatin (in vitro), and LRs of glycoprotein in pulmonary corpora amylacea (in vivo). Here we describe LRs in lesions from 29 patients--mostly lesions of the kidney, synovium, conjunctiva, and eyelid. The LRs formed in cysts, or in fibrotic, inflamed, or necrotic tissue. The LRs in this study varied greatly in shape and size, measuring 7-800 microns. Special stains and energy-dispersive radiographic analysis or scanning electron microscopy revealed that some LRs contained calcium, iron (hemosiderin), silicon, and sulfur. Some pathologists have mistaken LRs for eggs, larvae, or adults of the giant kidney worm, Dioctophyma renale. D. renale is a large blood-red nematode that infects a variety of fish-eating mammals, especially mink. Fourteen documented infections of humans have been recorded, usually with adult worms expelled from the urethra. The adult worms are probably the largest helminth to parasitize humans. Eggs of D. renale are constant in size (60-80 microns X 39-47 microns), contain an embryo, and have characteristic sculpturing of the shell. Liesegang rings should not be mistaken for eggs, larvae, or adults of D. renale, or for any other helminth.

One accidental and 17 natural human infections caused by Penicillium marneffei have been reported in the literature. The accidental infection, in Paris, followed inoculation of a culture from a Vietnamese bamboo rat into the finger of a mycologist. All patients with natural infections had lived or traveled in the Far East. Nine of these patients were Chinese, all from Guangxi Zhuang Autonomous Region. The four additional infections from Guangxi reported herein bring the total to 21 natural infections. P. marneffei is a primary pathogen of humans, causing two clinical types of disease: focal infection and fatal, progressive, disseminated infection. There are three histopathologic reactions: (1) granulomatous; (2) suppurative; and (3) anergic and necrotizing. The first two reactions are seen in patients with "normal" immunity and the third in patients with compromised immunity. P. marneffei is unique among species of Penicillium because of its thermal dimorphism, its recognized ecologic niche (restricted to the Far East), and its propensity to infect the lungs and the reticuloendothelial system and to proliferate within histiocytes.

Biopsy specimens from 17 Zairians with chromomycosis are described. Patients ranged in age from 20 to 50 years, with a mean of 37.2 (+/- 10.2). Chromomycosis was suspected clinically in only 3 of the 17 patients. In 14 patients the lesions were on the lower limbs and in 3 on the arms. The lesions were chronic, in one patient persisting for 9 years. The diagnosis was established in each patient by finding typical thick-walled brown fungi within the lesions. Some fungi were in abscesses, others were in histiocytes or giant cells. The fungi and the inflammatory reaction were concentrated in the upper dermis. Acanthosis, hyperkeratosis, and parakeratosis were constant features and pseudoepitheliomatous hyperplasia (PEH) was a feature in 10 patients. Transepithelial elimination (TEE) of fungi was a conspicuous feature in eight specimens. Microscopic features suggested TEE in an additional three. PEH and TEE were associated in all specimens. In patients with TEE, the diagnosis may be confirmed quickly by smearing surface scrapings and finding the characteristic brown fungi.

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.

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.

Clinicopathological studies on lymph nodes of 32 Africans with onchocerciasis--some complicated by hanging groin and elephantiasis of the genitalia--revealed atrophic lymphoid tissue, lymphoedema, chronic inflammation and fibrosis. We identified microfilariae of Onchocerca volvulus in nodes of 24 of 32 Africans (75%). There microfilariae were most numerous in the capsule and in the fibrous tissue of the medulla, but smaller numbers were also found within lymphoid tissue, in dilated lymphatics and in blood vessels. We believe that in Africians, antigens released from microfilariae of O. volvulus lead to the deposition of immune complex in tissues, which in turn causes inflammation and fibrosis and eventually obstructive lymphadenitis. This causes hanging groin and, possibly, also elephantiasis. A distinctive pattern of perivascular fibrosis contains "fibrinoid material" that we interpret as immune complexes involving microfilarial antigens. In contrast, nodes from two Yemenites with severe onchocercal dermatitis of the lower limbs (sowda) had hyperplastic follicles, minimal fibrosis and no microfilariae.

The Mazzotti reaction is a frequent complication in patients with onchocerciasis being treated with diethylcarbamazine (DEC); and more severe manifestations of this reaction may be unacceptable in many patients. It has recently been demonstrated that prednisone modifies the severity of this reaction and reduces the microfilaricidal activity of DEC. A clinical trial was performed at the National Leprosy Training Center in Wau, Sudan, to evaluate the clinical and histologic effect of the use of corticosteroids in patients receiving DEC. Administration of a low dose of dexamethasone (3 mg/day), begun after onset of the Mazzotti reaction, modifies the progression of the Mazzotti reaction without interfering with the microfilaricidal efficacy of DEC. Pretreatment with low-dose dexamethasone--prior to beginning DEC therapy--prevents the development of the Mazzotti reaction and greatly reduces the microfilaricidal activity. Administration of diphenhydramine, after onset of the Mazzotti reaction, has no effect on the course and intensity of the Mazzotti reaction nor on microfilaricidal activity. We recommend that low-dose corticosteroids be administered in conjunction with DEC--after onset of the Mazzotti reaction--and that they be tapered rapidly.

We investigated the association between eosinophil degranulation, as evidenced by the deposition of granule major basic protein (MBP), and the killing of microfilariae of Onchocerca volvulus in vivo following treatment with diethylcarbamazine (DEC). Utilizing an immunofluorescence procedure for the cellular and extracellular localization of eosinophil MBP in formalin-fixed, paraffin-embedded tissues, we studied skin biopsies from onchocerciasis patients before and during treatment with topically or orally administered DEC. Before DEC, there was little or no inflammatory response in either dermis or epidermis and microfilariae were essentially intact. Immunofluorescent staining for MBP revealed some filamentous fluorescence associated with dermal collagen fibers, very few eosinophils, and no fluorescence in association with intact microfilariae. In contrast, during treatment with DEC, immunofluorescent staining for MBP revealed extensive eosinophil infiltrates in both dermis and epidermis with numerous intraepidermal eosinophil abscesses containing degenerating microfilariae. An intense extracellular immunofluorescence for MBP surrounded degenerating microfilariae in the dermis and epidermis in both the presence and absence of eosinophil infiltrates as early as 4.5 hours after starting therapy. Many intact nondegenerating microfilariae were also present, but they did not show immunofluorescent staining for MBP nor a surrounding inflammatory infiltrate. The results show that immediately following administration of DEC, eosinophils localize and degranulate around microfilariae in the skin and release granule MBP onto or in close proximity to the parasite's surface. Because of the striking association between eosinophil localization, degranulation, and deposition of MBP onto microfilarial surfaces, and the degeneration of microfilariae in the skin, these observations support the hypothesis that the eosinophil, through helminthotoxic granule proteins such as MBP, damages the microfilariae of O. volvulus.

Two patients with Buruli ulcer (infection by Mycobacterium ulcerans) in the Foya region of Liberia have recently been reported. We describe three more patients which together with the two original patients establish the Mayor River basin as an endemic area of Buruli ulcer. We also describe a patient from the St. Paul River basin. This disease, unrecognized in Liberia before 1978, now seems to be widespread in Liberia and has been reported in neighboring Sierra Leone and observed in Ivory Coast as well. The possibility of Buruli ulcer appearing in other regions of West Africa should be anticipated. Diagnosis involves finding acid-fast bacilli in smears of the exudate from typical lesions or by finding in biopsy specimens the characteristic zone of coagulation necrosis containing acid-fast bacilli. The bacillus, Mycobacterium ulcerans, stains readily with the Ziehl-Neelsen (ZN) and Fite-Faraco (FF) procedures. Treatment is excision when the lesion is small and by debridement and grafting, combined with heat and chemotherapeutic agents when the lesion is large.

Sowda is an unusual form of onchocerciasis in Yemenites that differs from African onchocerciasis. Clinical and pathological studies were performed on 18 patients in Yemen Arab Republic (North Yemen). Biopsies of skin and lymph nodes were taken, and then processed at the Armed Forces Institute of Pathology, Washington, D.C. The most striking clinical features were swollen, darkened, pruritic, papular skin changes that were usually limited to one leg, more rarely to one arm, and large soft regional lymph nodes. Dermal changes were deeper and more diffuse than in African onchocerciasis, with many large fibroblasts and plasma cells. Microfilariae of Onchocerca volvulus were much rarer in skin from Yemenites with sowda. When patients were treated with diethylcarbamazine, the dermatitis became suddenly worse as the microfilariae degenerated and provoked acute inflammation. The dermatitis decreased after several days of treatment. Enlarged lymph nodes from sowda have shown follicular hyperplasia, in contrast to follicular atrophy and perivascular fibrosis that are characteristic of lymph nodes from cases of African onchocerciasis. Cell-mediated and humoral immunity may be more active in sowda than in African onchocerciasis.

Yaws (buba, Frambösie, pian), a non-venereal treponematosis of skin and bones is a tropical disease that affects primarily children. Eradication programs launched between 1950 und 1970 reduced the incidence substantially; resurgences, however, have been reported from several countries. We have studied a geographically isolated focus of yaws in the Ubangi area of northwestern Zaire. In survey I, in 1981, of the 4.407 participants from 11 villages, 348 (7.9%) had active lesions of yaws. All patients and their contacts were treated immediately with benzathine penicillin G. In survey II, in 1982, in 6 of the previously studied villages, of 5,390 participants, 136 (2.5%) had active lesions of yaws. In 1981, the predominance of primary lesions (86%) and high numbers of patients in all age groups, with the highest prevalence (23.4%) in children 10-14 years of age, suggest that yaws recently recurred at this focus. In 1982, only 25.7% of the lesions were primary and the highest prevalence (6.5%) had shifted to the younger age group of 5-10 years-old. In survey I more males (63%) were infected in the age group 0-24 years, and more females (89%) in those over 40 years. In survey II, more males (61.3%) were infected in the age group 0-14 years, and only females (100%) in the age groups 25 years and older. Seventy-one percent (1981) and 86% (1982) of the initial lesions were on the lower limbs. Participation of the population in survey I was 41.7% and was greatest (62%) in the locality where there was a newly established dispensary. In survey II, participation rose to 73.8%. Areas adjacent to the focus of yaws with longstanding dispensaries were free of yaws.(ABSTRACT TRUNCATED AT 250 WORDS)

Three infants, born prematurely, died after clinical illnesses of 67, 65, and 60 days from infection by Malassezia furfur. Each infant had been nourished with lipid emulsions delivered through deep-line catheters. The infections, all discovered at autopsy, were characterized by massive involvement of lungs. Two of the three had endocardial vegetations containing M. furfur; all three had lesions in liver, kidney, and spleen, and two had lesions in adrenal, pancreas, and colon. In addition, one of the infants had acute meningoencephalitis caused by M. furfur. In some of the distant organs, yeast cells of M. furfur were growing in the lumina of small vessels, filling the lumina, but causing no vasculitis or infarction. In addition to these benign collections of yeasts within vessels, there were acute inflammatory lesions as well. These were consolidation, vasculitis, granulomatous inflammation, septic thrombosis, and septic infarction of lung and foci of necrosis and inflammation in kidney and liver. Two previously reported autopsies described neonates with lesions in lung and heart. The authors' three cases for which autopsies were performed had lesions in lung and heart too but, in addition, had dissemination with acute lesions in kidney and liver. Finally, one patient had a severe meningoencephalitis caused by M. furfur.

There is great need for a simple, inexpensive, and sensitive diagnostic test for onchocerciasis, especially in endemic areas where trained personnel and laboratory facilities are limited. Diethylcarbamazine (DEC) was applied as a "patch test" to the skin of 45 patients with onchocerciasis in the Southern Sudan. 75 tests were done on these 45 patients, and 69 (92%) were positive. A positive reaction was a papular eruption beneath the patch. Histopathological studies of the skin beneath the patch revealed the microscopic features of a severe Mazzotti reaction, including degenerating microfilariae in the upper dermis and within epidermal eosinophilic abscesses.

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.

The authors report clinical and histopathologic changes in six patients with symptomatic loiasis. One patient had cutaneous swellings, three patients presented with hydrocele, one patient developed bowel obstruction, and one had generalized fatal loiasis. The first five patients had localized lesions provoked by adult worms; all were surgically removed. The sixth patient died of disseminated loiasis that included a severe loal encephalitis. The authors discuss the mechanism of "Calabar" swellings, the reaction to adult Loa loa worms and loal encephalitis.

The silvered leaf monkey (Presbytis cristatus) from South Kalimantan ( Borneo ), Indonesia is a natural host for a variety of filarial nematodes including Brugia malayi and Wuchereria kalimantani . Experimental studies show that it is host for W. bancrofti, a filarial nematode causing elephantiasis in man. Presbytis cristatus is a gregarious primate of primary and secondary forests, roaming in troops of 20-30 members. Primarily a fruit and leaf eater under natural conditions, this monkey can adapt to a laboratory diet of commercial monkey chow supplemented with fruits and vegetables. Troops, led by an alpha male, immediately respond to protect their young during stressful or dangerous situations. Infants are born singly and are bright orange. Transition to the adult grey and black coloration begins three to five months after birth. Silvered leaf monkeys can be readily trapped. Initially they are aggressive and will attack but become tractable several days after capture. Reaching upward is an important feeding behavior of the silvered leaf monkey and they will not feed from the floor of the cage. In the laboratory they are nonaggressive and lend themselves to various procedures such as blood drawing and examination. Silvered leaf monkeys travel well in commercial animal transport cages. In the United Stages they are not an endangered species and can be readily imported. In Indonesia they are not protected by law and can be exported.

The usual pattern of onchocercal dermatitis in Africans and Guatemalans is a generalized and symmetrical dermatitis located on legs, arms and trunk. These patients appear to be anergic, with depressed immune responses and numerous microfilariae in the skin. In contrast, "sowda" is an unusual type of onchocercal dermatitis found in Yemenites and in a minority of African patients. Here the dermatitis is localized and asymmetrical - typically confined to one limb or one region of the body. Patients with sowda appear to be hypergic, with active humoral and cellular immune responses; microfilariae are rare or absent. This study describes two Guatemalan patients with sowda-type dermatitis. The diagnosis in these two patients is based on the asymmetrical papular pruritic dermatitis, rare or absent microfilariae, a positive Mazzotti reaction, and histopathologic changes characteristic of the sowda-type onchocercal dermatitis.

A nodule removed from the cecum of a 25-year-old Zairian man contained a degenerated adult nematode. The surrounding tissue contained larvae and eggs in various stages of cleavage. Eggs and larvae were indistinguishable from those of Angiostrongylus costaricensis. These morphological features are described. The diameter and cuticle, and the anatomic location of the adult worm is consistent with A. costaricensis. The tissue reaction was chronic with granulomatous inflammation and numerous eosinophils. This is the first report of abdominal angiostrongylosis of a human in Africa.

Eight patients with fatal penicilliosis caused by Penicillium marneffei are reported. All were natives of southern rural Guangxi, and none had a predisposing illness or evidence of altered immunity. The distinctive features of P. marneffei include proliferation of yeast-like cells within histiocytes, followed by the development of focal necrosis and, eventually, large abscesses. Outside the histiocytes, the fungi elongate, become slightly curved, and form septa. In vitro, P. marneffei produces a red pigment which diffuses into the culture medium. The differentiation between P. marneffei and Histoplasma capsulatum is described, and possible reservoirs for P. marneffei are discussed.

The autopsy of a man who died of Hodgkin disease revealed that a peculiar metazoan parasite had proliferated and disseminated throughout his body. The parasite could not be identified; however, electron microscopical studies revealed that it had the structure of a flatworm. This, together with its shape and structure, convinced us that the parasite was an aberrant sparganum manifesting uncontrolled proliferation and dissemination.