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Biomedical subjects

R H Webber

Publications and source records attributed to R H Webber.

At least 19 recordsLinked to original sources
PubMed1998

The potential role of peripheral health workers and community key informants in the rapid assessment of community burden of disease: the example of lymphatic filariasis.

Data for planning disease control programs in most developing countries is often not available because they are usually expensive to gather. This study explored the potential use of peripheral health staff and community key informants in gathering community-level data about lymphatic filariasis. Agreement between findings of health workers and those of physicians was very high (kappa 0.66-0.87) for the clinical conditions examined. The prevalence of hydrocele was found to be a good predictor of communities at risk of filariasis. Community key informants provided very useful qualitative and quantitative data on the prevalence of clinical filariasis. The need to use nontraditional health professionals in gathering data for planing control programs is discussed.

Community Health Workers↗
PubMed1996

Permethrin-impregnated bednets are more effective than DDT house-spraying to control malaria in Solomon Islands.

A field trial compared DDT house-spraying with permethrin-impregnated bednets for malaria control in Solomon Islands from 1987 to 1991. Mortality-rates of malaria vector Anopheles farauti in exit window traps were 11.6% from an untreated hut, 10.1% from a hut sprayed with DDT 2 g/m2, and 98% of those from a hut in which the occupants used bednets treated with permethrin 0.5 g/m2. Since bioassays of the DDT-sprayed walls (15 min exposure in W.H.O. standard test cones) gave 77% mortality of An.farauti, it was concluded that the insignificant impact of DDT could be explained by the exophilic behaviour of endophagic vectors, whereas the greater impact of permethrin was attributed to the more effective exposure of An.farauti females to the impregnated bednets-attracted by the occupants. The parous rate was higher indoors, except in the area with permethrin-impregnated bednets. It was therefore concluded that permethrin-impregnated bednets reduced the mean longevity of An.farauti and hence its vectorial capacity. The circumsporozoite (CS) antigen positivity rate of An.farauti in the DDT area was 0.18% outdoors, significantly less than 1.42% indoors. In the comparison area CS rates were 0.65% outdoors and 0.75% indoors. CS antigen was not detected in An.farauti from the bednet area, indicating the apparent prevention of malaria transmission. As DDT spraying was so much less effective, it was discontinued in 1993 and permethrin-impregnated bednets are now the principal malaria control method in Solomon Islands.

Animals↗
PubMed1994

A community-based study of acute respiratory infections among preschool children in Syria.

A longitudinal community-based study of the epidemiology of acute respiratory infections (ARI) in children less than 5 years old was carried out in a low income peri-urban area of Syria. A total of 1030 children were followed up by weekly morbidity surveillance for a period of 24 weeks, starting September 1989. The results revealed that, on average, a child suffered 3.4 episodes of ARI per 100 child-days at risk. The average prevalence of ARI was 23 per cent of time of observation. The peak age-specific incidence occurred in children 6-12 months old for cough/cold, and in children 0-5 months for pneumonia. Male children experienced higher incidence and prevalence of ARI. The most frequently reported symptoms were nasal discharge and cough.

Acute Disease↗
PubMed1994

Malaria in Hubei Province, China: approaching eradication.

In the last six years, there has been a steady reduction of Plasmodium vivax malaria in Hubei Province with an API (annual parasite incidence) of 0.134 per thousand by 1992. This is especially so in the south, east, west and north-west parts of the province. Much of this reduction has been produced by a policy of repeated radical treatment in the non-malaria season. In the centre of Hubei, where Anopheles anthropophagus is the chief vector, malaria is still a problem. The key factors in destabilizing malaria are a sudden increase in the number of An. anthropophagus, introduction of non-immunes into the endemic area, and the village doctors' diminished interest in malaria surveillance activities. Impregnated bed nets are possibly the best strategy for reducing malaria, but where the prevalence is reduced to a sufficiently low level efficient case finding and detection are able to contain malaria and produce a continued reduction.

Animals↗
PubMed1993

The economic impact of Plasmodium falciparum malaria on education investment: a Pacific Island case study.

A small but intensive study was carried out adopting a simple method which attempts to quantify the economic consequences Plasmodium falciparum malaria on education investment through school pupil absenteeism in a community in Solomon Islands. In a randomized sample of 4,920 cases of P. falciparum malaria in a community, 2,886 occurred in children of primary school age group of 7 to 13 years. On average a case gave rise to a mean school absenteeism of 5.3 days. In the final analysis a total of 11,028 pupil days schooling were lost due to the sampled cases of malaria caused by the species. This is equivalent to 55.14 school pupil years as a child is expected to attend school for 200 days in a year. A primary school teacher with an average annual salary of US$3,990.00 is expected to teach 6,500 school pupil days a year. When this is adopted as an economic indicator for investment in education the loss is calculated to be US$6,769.57 or equivalent to US$1.38 per case. When this is applied nationally, assuming that rates are similar for 79,203 cases of P. falciparum reported in 1990, the total consequence for investment in education is US$108,966.00, which is equivalent to 27.31 teachers being paid for not teaching, an unacceptable impact for a small nation like the Solomon Islands.

Absenteeism↗
PubMed1993

Measuring effectiveness of malaria control: a simplified method for primary health care. Preliminary report.

Based on the infant parasite rate where an increasing number of infants become positive for each month of age (until a plateau is reached) a measure is developed using surveillance blood slides of all cases of malaria at the start of the transmission season. The fortnightly PCD returns from the beginning of the malaria transmission season are plotted on log-log paper and the angle the slope of the line makes with the axis is compared with similar results obtained from the intervention. The difference between the angles measures the effectiveness. The measure can be used in places that have a marked seasonal pattern (for all ages). Where immunity is shown to be a factor, only positive children should be utilized. In areas where malaria is not seasonal, the infant parasite rate, using the rate of acquiring infection rather than the overall value, will provide an alternative indicator. This evaluation tool is being tried in seasonal and non-seasonal parts of the world.

Animals↗
PubMed1992

Structured short-answer questions: an alternative examination method.

A structured short answer (SSA) examination has been developed for the MSc, Community Health in Developing Countries, to test competence in international public health. Questions can test knowledge or aim to assess problem-solving ability, but have the advantage that the candidates construct their own answer (rather than choosing from pre-formed answers in an MCQ), yet encourage sufficient precision for answers to be easily marked. The SSA more closely reflects participatory teaching and self-directed learning. Illustrated material is widely used.

Community Medicine↗
PubMed1988

Immunohistochemistry of biogenic polypeptides in nerve cells and fibres of the guinea pig inferior mesenteric ganglion after perturbations.

Immunohistochemistry of peptide- and dopamine-beta-hydroxylase-(DBH)-containing varicose nerve fibres and ganglion cells, respectively, in the guinea pig inferior mesenteric ganglion was investigated following a) transsection of mesenteric (colonic) branches, b) transsection of central (lumbar splanchnic, intermesenteric and hypogastric) branches, and c) transplantation into the spleen. The findings indicate that pathways of different opioid peptides are not identical. Met-enkephalin- and met-enkephalin-arg-phe- (cleavage products from pre-proenkephalin) containing fibres course in central branches to make contact in the inferior mesenteric ganglion. Dynorphin- and alpha-neo-endorphin- (deriving from pre-prodynorphin) containing fibres as well as leu-enkephalin- (included in the dynorphin sequence) fibres appear to rise not only from central and from enteric somata, but also from intraganglionic noradrenergic neurons. Similar pathways seem to be used by VIP- and by neurotensin-immunoreactive fibres, although intraganglionic neurotensin-immunoreactive cell bodies are rare. Practically all substance P- and most CGRP-immunoreactive fibres enter the ganglion via central branches and, to a large extent, traverse it, but some CGRP-immunoreactive influx appears to come from the intestine. The origin of intraganglionic substance P- and CGRP-immunoreactive fibres after ganglion transplantation remained unidentified. Somatostatin- and neuropeptide Y-immunoreactive fibres predominantly have an intraganglionic origin as have DBH-immunoreactive noradrenergic fibres. The demonstrated alterations in neuropeptide immunoreactivity of intraganglionic and periganglionic nerve fibres following the applied transsection procedures contribute to the present knowledge on origin and destination of peptidergic transmitter segments in the guinea pig inferior mesenteric ganglion. Moreover, the present study provides evidence that intrinsic participation in intraganglionic fibre supply is more extensive than hitherto believed.

Animals↗
PubMed1985

A poliomyelitis survey the simple way: the Tanzanian experience.

A simple cost effective survey to assess the need for a rehabilitation service for individuals disabled by poliomyelitis was carried out making the maximum use of the existing government administration. The field team consisted solely of a medical officer and a health officer. The prevalence rate for paralytic poliomyelitis in the Mbeya region of Tanzania was 2.95/1000 persons. The rate for children under 10 years was 1.15/1000, suggesting that the expanded immunisation programme started in 1977 was being successful. With approximately 4000 cases of paralytic poliomyelitis in the Mbeya region a rehabilitation service would seem to be justified. If poliomyelitis surveys are required for rehabilitation purposes they must include all age groups. In this survey, had only school children been considered, as recommended by the World Health Organisation, two thirds of the cases would have been excluded, thereby hardly justifying a rehabilitation service.

Adolescent↗
PubMed1985

Anthrax in Lake Rukwa Valley, Tanzania: a persistent problem.

An epidemic of 239 human cases of anthrax is reported in the Rukwa Valley area of Tanzania. Although the infecting source was meat from animals dying of the disease, no intestinal cases occurred. Those infected were predominantly males between 15 and 35. The epidemic was seasonal, reaching a peak towards the end of the dry period when cattle were close grazing, and declining rapidly once the rains started and the grass began to grow. The increasing magnitude of annual epidemics suggests that the problem will get worse unless major efforts are made to vaccinate cattle before the epidemic period.

Adolescent↗
PubMed1984

Chemoprophylaxis of malaria in non-immune residents in Dar es Salaam, Tanzania.

The malaria infection rates in non-immune residents of Dar es Salaam on various chemoprophylactic regimens were compared with that (37.1%) in those not taking prophylactic antimalarials. Among 647 people resident in Dar es Salaam for 1-6 years the two groups with the lowest infection rates by person-episodes (2.0% and 1.5%) were those taking proguanil 200 mg daily alone or with chloroquine base 300 mg weekly. Infection rates (16.9% and 14.0%) were also significantly lower than in the no-prophylaxis group in those taking chloroquine base 300 mg weekly combined with 'Fansidar', 'Maloprim' (each one tablet weekly), or proguanil 100 mg daily. No significant reduction in the malaria attack rate was found in those taking chloroquine base 300 mg or 600 mg weekly (31.2%), pyrimethamine 25 mg weekly (27.3%), proguanil 100 mg daily (46.4%), maloprim one tablet weekly (40.4%), or a combination of chloroquine base 300 mg weekly and pyrimethamine 25 mg weekly (27.1%). Similar results were obtained when the infection rates per year of exposure were compared. Proguanil was associated with fewest user complaints and fansidar with most.

Adolescent↗
PubMed1981

The maximum density of anopheline mosquitoes that can be permitted in the absence of continuing transmission of filariasis.

Using two years of mosquito collections from two fixed stations on Guadalcanal it was possible to compare the average man-biting rate with the prevalence of microfilaraemia. One area was found to be free of infection while the other still had one positive case. The DDT residual spraying had caused a change in biting habits of A. farauti No. 1 allowing a greater density of mosquitoes to bite man at times when they had lower microfilaria densities. This difference was compared with the pre-spray density so that the maximum permissible number of mosquitoes biting man without transmission of filariasis taking place, could be calculated. A theoretical value for m of 19.84 had been worked out previously; this study gave a corrected observed value of m of approximately 20, very close to the calculated theoretical value. The situation studied here probably showed incomplete interruption of transmission, so it was considered preferrable to recommend a figure of 0.66 average vector man-biting rate per hour indoors for the critical value.

Animals↗
PubMed1978

Some aspects of the historical development of the autonomic nervous system.

On the occasion of the twentieth anniversary of the death of Albert Kuntz (1879--1957), it is fitting that his great accomplishments be remembered. Present knowledge of the autonomic nervous system has been acquired and recorded over a long period of time. The contributions have been made by many investigators, from the crude observations of the early workers to the refinements and techniques of modern day scientists. Professor Kuntz was one of the great contributors to our present knowledge of the automatic nervous system; this paper is a small tribute in memory of his many accomplishments.

Animals↗