Giant scrotal elephantiasis in a migrant from Niger.

We hereby describe the case of a giant scrotal elephantiasis due to infection by Wuchereria bancrofti, imported in Belgium. We briefly discuss diagnostic methods, their subtlety, and therapeutic possibilities.

Parasitological, serological and clinical evidence for high prevalence of podoconiosis (non-filarial elephantiasis) in Midakegn district, central Ethiopia.

OBJECTIVE: To determine whether the elephantiasis in Midakegn district, central Ethiopia, is filarial or non-filarial (podoconiosis) using serological, parasitological and clinical examinations, and to estimate its prevalence. METHODS: At house-to-house visits in 330 randomly selected households, all household members who had elephantiasis were interviewed and clinically examined at the nearby health centre to confirm the presence of elephantiasis, check the presence of scrotal swelling and rule out the other causes of lymphoedema. A midnight blood sample was obtained from each participant with elephantiasis for microscopic examination of Wuchereria bancrofti microfilaria. A daytime blood sample was obtained from half of the participants for serological confirmation using the immuno-chromatographic test card. RESULTS: Consistent with the features of podoconiosis, none of the elephantiasis cases had consistently worn shoes since childhood; 94.3% had bilateral swelling limited below the level of the knees; no individual had thigh or scrotal elephantiasis; parasitological test for microfilariae and serological tests for W. bancrofti antigen were negative in all samples. The prevalence of the disease was 7.4% and it peaked in the third decade of life, the most economically active age. CONCLUSION: Midakegn District has a high prevalence of podoconiosis and no filarial elephantiasis. Prevention, treatment and control of podoconiosis must be among the top priorities of public health programmes.

Elephantiasis nostras verrucosa in a patient with systemic sclerosis.

Elephantiasis nostras verrucosa (ENV) is an unusual skin condition characterized by dermal fibrosis and hyperkeratotic verrucous lesions resulting from chronic nonfilarial lymphoedema. The condition is similar to 'elephantiasis tropica', in which elephantiasis develops secondary to filariasis. Lymphatic obstruction can be primary or due to various causes such as surgery, tumour, radiation, congestive heart failure or obesity. Recurrent attacks of cellulitis lead to further impairment of lymphatic drainage, causing permanent swelling, dermal fibrosis and epidermal thickening. We report a case of a 56-year-old man with systemic sclerosis (SS), who presented with painful lesions on both legs, consistent with ENV. He developed extensive, fungating, papillomatous lesions on the skin of the legs, toes and dorsa of the feet over a period of 3 years. Histology revealed dense dermal fibrosis, oedema of the papillary dermis and extensive pseudo-epitheliomatous changes. To our knowledge, this is the first report of ENV in which SS was considered to be the primary cause for the impairment of lymphatic flow.

Elephantiasis of non-filarial origin (podoconiosis) in the highlands of north-western Cameroon.

Lymphoedema, a condition of localized fluid retention, results from a compromised lymphatic system. Although one common cause in the tropics is infection with filarial worms, non-filarial lymphoedema, also known as podoconiosis, has been reported among barefoot farmers in volcanic highland zones of Africa, Central and South America and north-western India. There are conflicting reports on the causes of lymphoedema in the highland regions of Cameroon, where the condition is of great public-health importance. To characterise the focus of lymphoedema in the highlands of the North West province of Cameroon and investigate its real causes, a cross-sectional study was carried out on the adults (aged > or =15 years) living in the communities that fall within the Ndop and Tubah health districts. The subjects, who had to have lived in the study area for at least 10 years, were interviewed, examined clinically, and, when possible, checked for microfilaraemia. The cases of lymphoedema confirmed by ultrasonography and a random sample of the other subjects were also tested for filarial antigenaemia. The interviews, which explored knowledge, attitudes and perceptions (KAP) relating to lymphoedema, revealed that the condition was well known, with each study community having a local name for it. Of the 834 individuals examined clinically, 66 (8.1%) had lymphoedema of the lower limb, with all the clinical stages of this condition represented. None of the 792 individuals examined parasitologically, however, had microfilariae of W. bancrofti (or any other filarial parasite) in their peripheral blood, and only one (0.25%) of the 399 individuals tested for the circulating antigens of W. bancrofti gave a positive result. In addition, none of the 504 mosquitoes caught landing on human bait in the study area and dissected was found to harbour any stage of W. bancrofti. These findings indicate that the elephantiasis seen in the North West province of Cameroon is of non-filarial origin.

Non-filarial elephantiasis in the Mt. Elgon area (Kapchorwa District) of Uganda.

Following reports of a high frequency of elephantiasis in Kwen County (Kapchorwa District) on the slopes of Mt. Elgon in Uganda, a baseline survey for lymphatic filariasis was carried out in three villages in the affected area. Individuals aged 1 year and above were examined for chronic manifestations of lymphatic filariasis, and for specific circulating filarial antigens and microfilariae of Wuchereria bancrofti. Elephantiasis was observed in all age groups from 10 years and above. The overall prevalence was 4.5%, and the prevalence among individuals aged >/=20 years was 8.2%. Males and females were equally affected. However, there were only few cases of hydrocele (overall prevalence in males of 1.0%) and blood examinations were negative for W. bancrofti circulating antigens and microfilariae. Sampling of potential filariasis mosquito vectors revealed low densities of Anopheles gambiae s.l. and An. funestus, and none of these were infected with filarial larvae. In view of the low hydrocele to elephantiasis ratio, the absence of filarial infection in humans and mosquitoes, the high altitude (1500-2200 m above sea level) and the volcanic soil type, it is concluded that elephantiasis seen in this area is not of filarial origin but most likely is due to podoconiosis (endemic non-filarial elephantiasis).

Elephantiasis in Pawe settlement area: podoconiosis or bancroftian filariasis?

During a pilot trial of animal trypanosomiasis control in 3 villages in Pawe settlement area of Region 6 found in northwest Ethiopia, a high frequency of people with swollen legs/feet was observed. House-to-house search in one of the villages (Village 24) indicated 68 persons, 28 males and 40 females (age ranging from 15 to 69 years) had elephantiasis of one kind or another. Based on the local population census the prevalence of elephantiasis was estimated to be 6%. Clinical examination of the 68 persons showed that about 63% had lymphoedema and/or groin lymph node swelling while parasitological examination of night blood collected between 21 and 23 hours turned to be negative. The type, magnitude and distribution of elephantiasis in Ethiopia are discussed and further study is suggested to elucidate the aetiology of the one in Pawe settlement area.

Bancroftian filariasis: profile of serum antifilarial antibody and circulating parasite antigen.

Forty-five serum specimens collected from persons living in a filaria-endemic community in Maili Nane, Coastal Kenya were analyzed by ELISA for levels of isotype specific antifilarial antibody and by Og4C3 ELISA for circulating parasite antigen. Mean levels of IgG1, IgG2, and IgG3 were lower in microfilaraemic persons than in amicrofilaraemic individuals. In contrast, mean levels of antifilarial IgG4 were significantly higher in microfilaraemic persons (p = 0.0374). Serum samples from all microfilaremic persons were positive for circulating antigen as were 15% of samples from amicrofilaremic and asymptomatic persons. The Og4C3 antigen assay may have value as a technique for identifying and targeting communities for control efforts.

Pathologic changes of human onchocerciasis: implications for future research.

Onchocerciasis--infection by Onchocerca volvulus--has four cardinal manifestations: dermatitis, subcutaneous nodules, sclerosing lymphadenitis, and eye disease. The first three are discussed here. The dermatitis begins when microfilariae degenerate in the dermis. This process is accompanied by inflammation, with degranulation of eosinophils and deposition of the major basic protein of the eosinophil granules on the cuticle of the microfilariae. So far as is known, the chronic effects of onchocerciasis are all a consequence of the degeneration of microfilariae. Subcutaneous nodules contain coiled adult worms and have an outer layer of fibrous scar and a central inflammatory cell exudate, which may cavitate. Perfusion of India ink reveals arborization of capillaries around adult worms, which derive nutrition from these networks. Onchocercal lymphadenitis is characterized initially by histiocytic hyperplasia and follicular atrophy and later by fibrosis and obstruction of lymph flow, a condition causing adenolymphocele ("hanging groin") and elephantiasis of the genitalia. Some patients appear to have immune tolerance to degenerating microfilariae, perhaps as a result of exposure in utero to microfilarial antigens in the maternal circulation. In contrast, other patients (Yemenites, for example) have a localized but intense response to a few microfilariae; these patients are hypersensitive--perhaps because they were not exposed to microfilarial antigens in utero. Autopsy data on infection of deep organs are limited.

Antigen-specific suppressor T lymphocytes in human lymphatic filariasis.

Immune responses to parasite antigens are much lower in patients with microfilaremia than in persons with other manifestations of brugian filariasis. To determine whether hyporeactivity is associated with changes in populations of lymphocytes that regulate immune responses, we quantitated helper and suppressor T cells in the blood of patients infected with Brugia malayi. Increased numbers of suppressor T cells were present in 15 of 17 patients with microfilaremia and in six of 11 patients with elephantiasis. This increase correlated with hyporeactivity to filarial antigens but not to nonparasite antigens. Removal of suppressor T cells activated in vivo or in vitro improved reactivity to filarial antigens. These results suggest that immunosuppression induced by filarial parasites is a possible mechanism of survival of these organisms in an immunocompetent host.

Tanzania filariasis project: studies on microfilaraemia and selected clinical manifestations of Bancroftian filariasis.

In a total of 1977 males aged 5 years and over examined in 21 cluster samples on the coast of Tanzania, the overall rate for microfilariae of Wuchereria bancrofti was 32%. Hydrocoele and elephantiasis rates were 39% and 3%, respectively. The rates and severity of these 2 clinical manifestations increased in the older age groups. Both the microfilarial density and prevalence increased rapidly in the early age groups, followed by a levelling off and then a slight fall in old age. There was no association between microfilarial densities or rates and the overall prevalence of hydrocoele, but a negative association was demonstrated between microfilaraemia and hydrocoeles and elephantiasis. A comparison between the length of residence in an endemic area and the microfilarial and clinical sign rates showed evidence for the long incubation period for W. bancrofti and for the slow development of hydrocoeles and elephantiasis.

Studies on Bancroftian filariasis in Liberia, West Africa. I. Distribution and prevalence in the north-western savanna area.

A nightblood survey was carried out in 17 villages in the savanna area in Upper Lofa in Liberia. A total of 1968 people was examined for the prevalence of microfilariae of Wuchereia bancrofti and for clinical symptoms of filariasis. 279 (14,2%) persons proved to be microfilaria carriers. Men were almost twice (19,0%) as much infected than women (10,4%). Only two cases of leg elephantiasis and one breast elephantiasis were found. Enlargements of scrotum were seen in 60 men (6,9%). The scrotal enlargement rate increased steadily with age.

[Filarian elephantiasis in French Polynesia (Wuchereria bancrofti var. pacifica). II. Biological aspects]. / Eléphantiasis filariens en Polynésie francaise (Wuchereria bancrofti, var. pacifica). 2. Aspects biologiques.

Realized in French Polynesia among 274 patients with elephantiasis, this survey studied the microfilaremia, the eosinophily, the immunoglobulin titers and the antifilarian antibodies (done by passive hemagglutination) for Wuchereria bancrofti var. pacifica. Patients with elephantiasis seldom have circulating microfilariae in their blood. Hypereosinophily is frequent but rarely high. It is similar to the one patients with microfilaremia. There is a trend towards neutropenia during lymphangitic crisis that occur on an elephantiasis limb. The IgE titer is clearly increased, the IgG one is lesser elevated. The mean values are identical to those encoutered among microfilariae asymptomatic cariers. On the other hand the serodiagnosis is more frequently positive among elephantiasic patients.

Clinical features of timorian filariasis among immigrants to an endemic area in West Flores, Indonesia.

Fifty-nine persons, who immigrated into a Brugia timori endemic area from non-filarial areas on the island of Flores, Indonesia were examined for filariasis after residing in the village for 2 to 10 years. Six persons had B. timori microfilaremia and 31 had filarial disease. The disease seems to affect immigrants from non-filarial areas severely within a relatively short period. Among those residing in the village, for 2 years, the microfilaria rate was 5% and the elephantiasis rate 21%. Selective treatment using 50 mg diethylcarbamazine per Kg body weight was given to all microfilaria (Mf) positive persons. Approximately one year later the Mf-rate by finger stick and Nuclepore filtration was 9% and 18% respectively. There was indirect indications that the Mf-rate might increase with the passage of time. However, the total filarial disease rate remained constant during the one year period. The relationship between these findings and American servicemen exposed to filariasis during World World II is briefly discussed.

The association of clinical filariasis and Wuchereria bancrofti infections in Jakarta.

In a study carried out in Jakarta, Indonesia between 1969--1977, patients with clinical manifestations of filariasis were examined for microfilaremia. Finger blood (3 X 20 microliter) were examined by conventional methods, venous blood by membrane filtration, urine and hydrocele fluid by concentration methods. A total of 1,422 patients were examined and 182 (12.8%) were positive by blood smear; however, examination by membrane filtration and concentration of urine and hydrocele fluid did not appreciably increase the association between clinical manifestations and Wuchereria bancrofti infection. Approximately 16% of the patients without patent infection were indirectly associated with filariasis, since they co-habitated with persons with microfilaremia. Results of these studies showed that more than 60% of the patients were without patent infection. Factors that may be responsible for these findings are briefly discussed.

Studies with Brugia pahangi. 11. Measurement of lymph flow in infected cats.

Rates of lymph flow in cats were measured by calculating the disappearance of radioactive colloidal gold (198Au) from the feet of (1) uninfected cats, (2) cats infected for various periods after primary infection with Brugia pahangi, and (3) cats repeatedly challenged with B. pahangi infective larvae over long periods. The results of the study showed that (1) there is great variation in gold disappearance rates in different cats in all 3 groups above, (2) the cat lymphatic system is functionally highly efficient, and (3) in a cat with lymphoedema and early elephantiasis, there was a significant impairment of gold removal from the affected foot. The study proved useful in finding lymph drainage rates in the various animals but did not, as hoped, show any pattern of lymph flow decrease which might have enabled the use of the technique as a diagnostic tool for lymphatic pathology prior to the occurrence of external clinical manifestations of filariasis.