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Biomedical subjects

H Fuglsang

Publications and source records attributed to H Fuglsang.

At least 37 records · Page 2Linked to original sources
PubMed1977

The concentration of microfilariae in the skin near the eye as a simple measure of the severity of onchocerciasis in a community and as an indicator of danger to the eye.

The parsitological and ophthalmological findings in an onchocerciasis survey in 8 villages (832 persons) and 5 primary schools (285 children) in Cameroon are reportedl The use of the coneoscleral punch/microtiter plate quantitative skin snip technique greatly facilitated this study, and its advantages over the weighed skin snip method are discussed. This simple technique could be used by paramedical personnel to detect the number of people in a community who have more than 15 microfilariae in a snip near the eye. This is shown to be a measure of the intensity of infection, and a good indicator of the number of people at risk of developing ocular pathology.

Adolescent↗
PubMed1976

Studies on onchocerciasis in the United Cameroon Republic. III. A four year follow-up of 6 rain-forest and 6 Sudan-savanna villages.

After an interval of four years the same observers used the same standardized techniques to re-examine 1,016 people in 12 heavily infected rain-forest and savanna villages in Cameroon. The changes in the number of nodules and in the concentration of microfilariae in the skin and eye are described. These latter changes are correlated with the development and/or deterioration of eye lesions and visual impairment. In both the rainforest and the savanna there was a strong association between the development of eye lesions and a high concentration of microfilariae, not only in the eye but also in the skin, and more so at the shoulder than at the buttock. The importance of these findings for the prevention of blindness is discussed.

Adolescent↗
PubMed1976

Morphology of posterior segment lesions of the eye in patients with onchocerciasis.

Posterior segment ocular lesions were examined in 244 selected patients with onchocerciasis from the Sudan-savanna and rain-forest areas of the United Cameroon Republic. Fluorescein fundus angiography was performed on 210 cases. As a result of this study the following conclusions were drawn: 1. The heterogeneity of single lesions, and the occurrence of different types of lesion in a single eye or two eyes, prevented subdivision of the disease into distinct forms and suggested that inflammation alone was responsible for fundus lesions in onchocerciasis. 2. Optic nerve disease, alone or in the presence of choroido-retinal changes, was responsible for a large proportion of the blindness due to posterior segment lesions in onchocerciasis (87.6 per cent in this series).

Adolescent↗
PubMed1976

Droplet degeneration of the cornea in North Cameroon. Prevalence and clinical appearances.

The prevalence of droplet degeneration of the cornea in a defined population of 517 persons in north Cameroon was similar in males and females, but severe changes were commoner in elderly men. Most cases showed only mild changes of granularity and droplet formation in Bowman's zone, but they were sometimes widespread. More severe changes were seen in only nine patients. The clinical appearances are compared with those described from other parts of the world. In support of the aetiological role of direct sunlight, droplet degeneration was much more prevalent in the savanna than in the rain-forest in Cameroon. The condition ranges in severity from very mild to very severe, but difficulties in differential diagnosis, particularly in advanced cases, make it doubtful whether the same basic condition is being described in all cases. These doubts will be resolved only by properly conducted epidemiological studies in different parts of the world.

Adolescent↗
PubMed1976

Onchocercal dermatitis: ultrastructural studies of microfilariae and host tissues, before and after treatment with diethylcarbamazine (Hetrazan).

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.

Adult↗
PubMed1976

Effects of diethylcarbamazine on ocular onchocerciasis.

A single 10-14 day course of diethylcarbamazine (DEC) was given under betamethazone cover to 18 patients (Group A) with ocular onchocerciasis, and the effects were studied in detail over 1-2 years. A comparison was made with the findings in 21 patients (Group B) who received a similar course to be followed by a weekly suppressive 100-200 mg dose of DEC. A further 18 patients (Group C) served as controls. The initial DEC course provoked severe general reactions, but ocular complications could be controlled by betamethazone. The weekly suppressive dose was not acceptable to the majority of patients, and only one young patient with severe iritis who improved during the initial course took the weekly tablet voluntarily over 2 years. The initial DEC course reduced the numbers of microfilariae in the eye and was of temporary benefit to lesions of the anterior segment, but it did not affect lesions of the posterior segment. A possible adverse effect on the optic disc is discussed. Any beneficial long term effect was almost confined to Group B, and to lesions of the anterior segment. The best to hope for in lesions of the posterior segment was arrest of further development. The findings at the end of the trial were as follows: No. of lesions (see article).

Adolescent↗
PubMed1976

Effects of suramin on ocular onchocerciasis.

39 patients (Group A) with ocular onchocerciasis in the Sudan-savanna of north Cameroon were given 4-6 g of suramin and followed in detail over 1-2 years. 39 other patients (Group B) received suramin followed 2 weeks later by a 6-7 day course of diethylcarbamazine (DEC). A further 18 patients (Group C) received placebo injections and were followed in the same way by the same observers. Suramin caused serious general reactions among the 100 patients who started the course - 1 case of stomatitis, 1 exfoliative dermatitis, and several cases of severe prostration, among which 2 ended fatally. These reactions underline the urgency for further studies on the toxicity of suramin, which is without doubt an efficient macro- and micro-filaricidal drug. Changes which occurred in the ocular lesions are described in detail. There was an initial aggravation of punctate and sclerosing keratitis, and sometimes a serious aggravation or development of anterior uveitis, corresponding to the peak microfilaricidal effect of the drug. The possibility of a simultaneous adverse effect on the optic disc is discussed. Despite these reactions, which might have been avoided by prior elimination of microfilariae by DEC, the eyes were in general quieter at 3 months and thereafter than before treatment. However, no posterior segment lesion improved after suramin, and the majority remained unchanged. The findings at the end of the trial were as follows: No. of lesions (see article).

Adolescent↗
PubMed1976

The head nodule and ocular onchocerciasis in Africa.

In a population survey in 1970/72 the prevalence of head nodules was found to be 1.7% in 1098 cases of onchocerciasis in the rain-forest and 0.6% in 1128 cases in the Sudan-savanna of Cameroon. In a follow-up survey in the same villages 3-4 years later more attention was given to the detection of head nocules, and the corresponding prevalences were 5.5 and 5.0%. In the follow-up survey a strong associated was demonstrated between the presence of head nodules and lesions of both the anterior and posterior segments of the eye. The relative risks of having eye lesions in patients with head nodules compared with those without were 2.9 and 7.5 in the rain-forest and savanna respectively. In a group of 483 clinic cases with ocular onchocerciasis from the savanna palpable head nodules were detected in 23.6%, and in a further 140 selected cases from the same area with posterior segment eye lesions, head nodules were detected in 31.4%. Confirmation of the onchocercal origin of the nodules was obtained in doubtful cases by biopsy. Many head nodules probably remain undetected in onchocerciasis surveys. They are often very small, flat, and hard, and tightly adherent to the under-lying periosteum, and the patient will often point out the presence of a nodule even when none has been detected after careful examination. The presence of a head nodule has long been one of the recognized "risk factors" associated with a high prevalence of blindness in Central America, but there have been no detailed studied in African onchocerciasis. A trial is in progress to assess the effect of nodulectomy on the development of ocular lesions.

Adolescent↗
PubMed1976

Seasonal variation in the concentration of Onchocerca volvulus microfilariae in the skin?

Repeated multiple skin snips in 18 persons with onchocerciasis from the Sudan-savanna of West Africa suggested the possibility of a seasonal variation in microfilarial concentrations. This variation may be an evolutionary adaptation of the parasite to the climate conditions that affect the seasonal distribution of the vector, but a migration of the microfilariae in the skin layers caused by the Simulium bites cannot be excluded.

Adolescent↗
PubMed1975

The prognostic value of head nodules and microfilariae in the skin in relation to ocular onchocerciasis.

The examination of 250 cases of onchocerciasis from the Sudan-savanna of northern Cameroon showed a strong association between microfilarial invasion of the eye and microfilarial skin concentrations at the outer canthus. It was also shown that the presence of a head nodule was associated with a high microfilarial skin concentration around the eye. It is suggested that these findings are of practical importance in the field for the early detection of cases at risk of developing serious ocular lesions.

Adolescent↗
PubMed1975

The Onchocerca volvulus transmission potentials and associated patterns of onchocerciasis at four Cameroon Sudan-savanna villages.

The intensity of O. volvulus infection, and the prevalence of certain eye lesions and of blindness, are compared in 4 hyperendemic Cameroon Sudan-savanna villages. The pattern of the disease is related to the annual transmission potentials to which the communities were exposed, and the results are compared with those obtained previously in forest villages. The prevalence and intensity of O. volvulus infections in S. damnosun were more closely related to the prevalence of positive skin snip than to the mean concentrations of microfilariae in the skin. Owing to the differential dispersal of nulliparous and parous flies in savanna, the annual transmission potentials were related more closely to the numbers of parous flies than to the total fly population. Factors governing the exposure of persons to infective flies are discussed. Seasonal transmission, which was usually light, did not lead to severe onchocerciasis; the more perennial the transmission the heavier was its degree, and the more prevalent were eye lesions and blindness. Annual transmission potentials of about 500, 1750, 1800+ and 2900 were associated with an increase in the mean intensity of infection and in the prevalence of eye lesions, while the onchocerciasis blindness rate in persons over 20 years old rose from nil to 3.3, 9.2 and 10 per cent respectively. Annual transmission potentials of 4400 and 19000 were recorded on the banks of S. damnosum breeding rivers in the area, but no villages were sited at such places and it is probable that no community could survive under such conditions. The bearing of these findings on the anticipated effects of S. damnosum control operations in savanna is discussed.

Animals↗