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Biomedical subjects

F O Richards

Publications and source records attributed to F O Richards.

At least 19 recordsLinked to original sources
PubMed2006

Urban lymphatic filariasis in central Nigeria.

Wuchereria bancrofti and the other mosquito-borne parasites that cause human lymphatic filariasis (LF) infect over 120 million people world-wide. Global efforts are underway to stop transmission of the parasites, using annual, single-dose mass drug administrations (MDA) to all at-risk populations. Although most MDA to date have been in rural settings, they are also recommended in urban areas of transmission. It remains unclear whether there is significant urban transmission in West Africa, however, and the need for urban MDA in this region therefore remains a matter of debate.Clinic-based surveillance, for the clinical manifestations of LF, has now been used to identify areas of urban transmission of W. bancrofti in Jos, the major urban population centre of Plateau state, Nigeria. The eight clinics investigated were all located in slum areas, close to vector breeding sites, and were therefore considered to serve at-risk populations. Over a 1-month period, selected providers in these clinics sought hydrocele, lymphoedema, elephantiasis, or acute adenolymphangitis among the patients seeking treatment. The consenting patients who were suspected clinical cases of LF, and a cohort of patients suspected to be cases of onchocerciasis, were tested for W. bancrofti antigenaemia. All the patients were asked a series of questions in an attempt to determine if those found antigenaemic could only have been infected in an urban area. During the study, 30 suspected clinical cases of LF were detected and 18 of these (including two patients who were found to be antigenaemic) lived in urban areas. Of the 98 patients with exclusively urban exposure who were tested for filarial antigenaemia, six (6.1%) were found antigenaemic. Clinic-based surveillance appears to be a useful tool for determining if there is W. bancrofti transmission in an urban setting.

Adolescent↗
PubMed2005

Mass ivermectin treatment for onchocerciasis: lack of evidence for collateral impact on transmission of Wuchereria bancrofti in areas of co-endemicity.

There has long been interest in determining if mass ivermectin administration for onchocerciasis has 'unknowingly' interrupted lymphatic filariasis (LF) transmission where the endemicity of the two diseases' overlaps. We studied 11 communities in central Nigeria entomologically for LF by performing mosquito dissections on Anopheline LF vectors. Six of the communities studied were located within an onchocerciasis treatment zone, and five were located outside of that zone. Communities inside the treatment zone had been offered ivermectin treatment for two-five years, with a mean coverage of 81% of the eligible population (range 58-95%). We found 4.9% of mosquitoes were infected with any larval stage of W. bancrofti in the head or thorax in 362 dissections in the untreated villages compared to 4.7% infected in 549 dissections in the ivermectin treated villages (Mantel-Haenszel ChiSquare 0.02, P = 0.9). We concluded that ivermectin annual therapy for onchocerciasis has not interrupted transmission of Wuchereria bancrofti (the causative agent of LF in Nigeria).

Journal Article↗
PubMed2005

Community-directed interventions strategy enhances efficient and effective integration of health care delivery and development activities in rural disadvantaged communities of Uganda.

The community-directed interventions (CDI) strategy achieved a desired coverage of the ultimate treatment goal (UTG) of at least 90% with ivermectin distribution for onchocerciasis control, and filled the gap between the health care services and the communities. However, it was not clear how its primary actors--the community-directed health workers (CDHW) and community-directed health supervisors (CDHS)--would perform if they were given more responsibilities for other health and development activities within their communities. A total of 429 of 636 (67.5%) of the CDHWs who were involved in other health and development activities performed better than those who were involved only in ivermectin distribution, with a drop-out rate of 2.3%. A total of 467 of 864 (54.1%) of CDHSs who were involved in other health and development activities also maintained the desired level of performance. They facilitated updating of household registers (P<0.05), trained and supervised CDHWs, and educated community members about onchocerciasis control (P<0.001). Their drop-out rate was 2.6%. The study showed that the majority of those who dropped out had not been selected by their community members. Therefore, CDI strategy promoted integration of health and development activities with a high potential for sustainability.

Community Health Services↗
PubMed2005

Significant decrease in the prevalence of Wuchereria bancrofti infection in anopheline mosquitoes following the addition of albendazole to annual, ivermectin-based, mass treatments in Nigeria.

A prospective entomological survey was conducted in four sentinel villages in central Nigeria from 1999-2002, to assess the impact of annual, single-dose, mass drug administrations (MDA), with a combination of ivermectin and albendazole, on the transmission of Wuchereria bancrofti. As they were also endemic for human onchocerciasis, the four villages had received annual MDA based on ivermectin alone for 7 years prior to the addition of albendazole. Resting Anophelines gambiae s. l., An. funestus and Culex species were collected from 92 sequentially sampled households and dissected. Mosquitoes harbouring any larval stage of W. bancrofti were classified as 'infected', and those containing the third-stage larvae of the parasite were classified as 'infective'. Over the 41-month observation period, 4407 mosquitoes were captured and dissected, of which 64% were An. gambiae s. l., 34% An. funestus, and 1% Culex species. The baseline data, from dissections performed before the addition of albendazole to the MDA, showed high prevalences of mosquito infection (8.9%) and infectivity (2.9%), despite apparently good treatment coverages during the years of annual ivermectin monotherapy. Only the anopheline mosquitoes were found to harbour W. bancrofti larvae. After the third round of MDA with the ivermectin-albendazole combination, statistically significant decreases in the prevalences of mosquito infection (down to 0.6%) and infectivity (down to 0.4%) were observed (P<0.0001 for each). The combination of albendazole and ivermectin appears to be superior to ivermectin alone for reducing the frequency of W. bancrofti infection in mosquitoes.

Albendazole↗
PubMed2004

Missed treatment opportunities, for pregnant and breast-feeding women, in onchocerciasis mass-treatment programmes in south-eastern Nigeria.

During annual rounds of mass treatment against onchocerciasis, women who are pregnant or nursing neonates should not to be offered ivermectin. The aim of the present study was to determine how many women were not treated, as a result of this policy, in four villages in south-eastern Nigeria. Of the 1714 women of reproductive age present during the 2000 round of mass treatment, 599 (35%) were excluded because they were pregnant or nursing babies aged < 1 month. Most (56%) of the 599 excluded women were, however, treated individually later in the year. Of the 264 excluded women who did not receive a dose of ivermectin at all in 2000, 123 (47%) said they would have actively sought ivermectin treatment had they been made aware of the short duration of exclusion for nursing. If they had all known of the short duration of the exclusion and when and how to locate and receive treatment in their villages after the round of mass treatment, 91% of the women excluded from the round of mass treatment would probably have been treated later in the year. Better treatment systems, follow-up and health education, targeted at pregnant and lactating women, would improve treatment coverage of this group after parturition and early nursing.

Adult↗
PubMed2002

Implementing community-directed treatment with ivermectin for the control of onchocerciasis in Uganda (1997-2000): an evaluation.

Over the period 1997-2000, an evaluation was made, in 10 districts of Uganda, of the onchocerciasis-control programme based on community-directed treatment with ivermectin (CDTI). This programme is supported by the Ministry of Health, the African Progamme for Onchocerciasis Control (APOC) and The Carter Center Global 2000 River Blindness Programme. The data analysed came from: (1) monthly and annual reports; (2) annual interviews, in randomly-selected communities in selected districts, with heads of household, community leaders and ivermectin distributors; (3) participatory evaluation meetings (PEM); (4) participant observation studies; and (5) key informants. The percentage of treated communities in the 10 study districts achieving satisfactory treatment coverage [i.e. > or = 90% of the annual treatment objective (ATO)] rose from 46.0 in 1997 to 86.8 in 2000. This improvement was largely attributable to the adoption of collective CDTI decision-making by community members, avoidance of paving monetary incentives to the ivermectin distributors, and the satisfaction with the programme of those who had been treated. Coverage improved as the numbers of community members who were involved in choosing the method of distribution and in selecting their own community-directed health workers (CDHW) increased. Health education was also critical in improving individual members' involvement in decision-making, and in mobilizing other community members to take part in CDTI. Involvement of kinship groups, as well as educated community members as supervisors of CDHW, also helped to increase coverage. In a regression model, satisfaction with the programme was revealed as a significant predictor of the achievement of the target coverage (P<0.001). Cost per person, as an indicator for sustainability, varied with the size of the population under treatment, from at least U.S. $0.40 when the district ATO was <15,000 people, to U.S. $0.26 with an ATO of 15,000-40,000 and less than U.S. $0.10 when the district ATO exceeded 40,000 people. These results cast doubt on the validity of the current APOC indicator for sustainability, of a cost of no more than U.S. $0.20/person for all CDTI projects, whatever the size of the population to be treated. Although some women were involved in decision-making, their current involvement as supervisors or CDHW was minimal. Most of the present data were obtained through monitoring and operational-research activities that have been carried out, in an integrated fashion, within the Ugandan CDTI programme since its launch. It is recommended that assessment, monitoring and evaluation be widely used within all CDTI efforts. Operational research should remain focused and appropriate and directly involve the personnel who are executing the programme.

Community Health Services↗
PubMed2001

Community-directed health (CDH) workers enhance the performance and sustainability of CDH programmes: experience from ivermectin distribution in Uganda.

The performance and 'drop-out' rates of ivermectin (Mectizan) distributors in the Ugandan programme for community-directed treatment with ivermectin (CDTI) were investigated and related to the manner in which the distributors were recruited. Distributors, from randomly selected communities endemic for onchocerciasis in seven of the 10 affected districts, were interviewed. Questionnaires were initially completed for 296 communities (in which ivermectin had been distributed in 1998 but not in 1999) and then extended to another 310 communities (in which ivermectin had been distributed in both study years). Discussions were also held with some other community members, in participatory evaluation meetings (PEM) in 14 communities from four districts. Despite the CDTI being labelled as 'community-directed', the first round of interviews and questionnaires revealed that there were in fact three categories of distributors: 322 (69.4%) of those questioned had been selected by community members and were therefore truly community-directed health workers (CDHW) but 101 (22%) were community-based health workers appointed by the leaders of the local council (CBHW-LC) and 41 (9%) were self-appointed volunteers (CBHW-SA). During 1999, only the CDHW received good community support; they still helped to mobilise and educate their community members and advocate CDTI, and 98% of them agreed that they would distribute ivermectin during the following year. In contrast, many of the CBHW-LC were neither supported nor appreciated by the community members. Presumably in consequence, many of the CBHW-LC did not help to mobilise or educate their community members in 1999, nor did they advocate CDTI. Almost all (95%) of the CBHW-LC said that they would not be available to distribute in the following year, and were therefore regarded as total 'drop-outs' from the CDTI. The CBHW-SA were better supported by community members than were the CBHW-LC, they did more to advocate the CDTI, and 93% reported that they would distribute ivermectin during the following year. The 'drop-out' rates for 1999 were < 2% for the CDHW, 7% for the CBHW-SA, and 95% for the CBHW-LC. The results also indicated that the CBHW-SA were not as reliable as the CDHW. Similar results were obtained from the second round of questionnaires, in which 224 (73%) of the interviewees were CDHW, 57 (18%) were CBHW-LC and 28 (9%) were CBHW-SA. The results of the PEM showed that the CDHW, who mainly came from the same kinship groups as the people who selected them, were likely to achieve higher ivermectin coverage within a week than the other categories of distributors. It is clear that, for the optimum performance and sustainability of the CDTI, the distributors used should be CDHW selected by their own community members.

Adolescent↗
PubMed2001

The Carter Center's assistance to river blindness control programs: establishing treatment objectives and goals for monitoring ivermectin delivery systems on two continents.

Periodic mass treatment with ivermectin in endemic communities prevents eye and dermal disease due to onchocerciasis. As part of an international global partnership to control onchocerciasis, The Carter Center's Global 2000 River Blindness Program (GRBP) assists the ministries of health in ten countries to distribute ivermectin (Mectizan, donated by Merck & Co.). The GRBP priorities are to maximize ivermectin treatment coverage and related health education and training efforts, and to monitor progress through regular reporting of ivermectin treatments measured against annual treatment objectives and ultimate treatment goals (e.g., full coverage, which is defined as reaching all persons residing in at risk villages who are eligible for treatment). Since the GRBP began in 1996, more than 21.2 million ivermectin treatment encounters have been reported by assisted programs. In 1999, more than 6.6 million eligible persons at risk for onchocerciasis received treatment, which represented 96% of the 1999 annual treatment objective of 6.9 million, and 78% of the ultimate treatment goal in assisted areas.

Africa↗
PubMed2000

Controlling onchocerciasis by community-directed, ivermectin-treatment programmes in Uganda: why do some communities succeed and others fail?

In Uganda, human onchocerciasis is controlled by annual, mass, community-directed, ivermectin-treatment programmes (CDITP) in all endemic communities where the prevalence of the disease is > or = 30%. This is a practical, long-term and cost-effective strategy. In some communities, this system succeeds in providing treatment at the desired level of coverage (i.e. 90% of the annual treatment objective, which is itself equivalent to all those individuals eligible to take ivermectin). Other communities, however, fail to reach this target. The aim of the present study was to determine the factors that were significantly associated with success or failure in achieving this target. The data analysed were answers to a questionnaire completed by 10 household heads randomly selected from each of 64 randomly selected endemic communities (of which 36 succeeded and 28 failed to reach their coverage target) in the four districts of Kabale, Moyo, Nebbi and Rukungiri. Among the programme-related factors investigated, success was associated, at a statistical level of significance (P < or = 0.05), with involvement of community members in: (1) decisions about the execution of the programme; (2) attendance at health-education sessions; (3) selection of the community-based distributors (CDB); and (4) rewarding CBD in kind. In general, the involvement of community members in the planning and execution of a CDITP (and the resultant sense of pride in community ownership) was more likely to produce successful results than when external health workers or even community leaders or local councils took responsibility.

Adolescent↗
PubMed2000

In rural Ugandan communities the traditional kinship/clan system is vital to the success and sustainment of the African Programme for Onchocerciasis Control.

In rural Ugandan communities where onchocerciasis is meso- or hyper-endemic, control of the disease is now being carried out using a strategy of community-directed programmes for the annual distribution of ivermectin to all persons eligible to take the drug. For these programmes to achieve their annual target coverage of at least 90% of the population eligible to take ivermectin, and to continue to sustain themselves for 10-15 years or more, even after external donor funding ceases, it has been found essential to replace the initial community-based strategy, imposed from outside, by a community-directed strategy developed by the community members themselves. Furthermore, it is essential for success that full use be made of the traditional social system, which is very strong in all rural communities in Uganda. This system is based on patrilineal kinships and clans, governed by traditional law, and in it women pay an important role. If this system is ignored or by-passed by government health personnel or by the sponsors and promoters of the programme, the communities are likely to fail to reach their targets. When rural communities increase in size and complexity, following development and the arrival of migrant families, they become semi-urbanized. The kinship/clan system is then weakened, community-directed drug distribution is much more difficult to organize, and coverage targets are not often achieved. This effect is of minor importance in a rural disease, such as onchocerciasis, but is likely to be of greater significance in the control of diseases, such as tuberculosis and lymphatic filariasis, which thrive in urban environments.

Community Health Workers↗
PubMed1998

Onchocerciasis.

Explore the source record for details and available documents.

Communicable Disease Control↗
PubMed1995

Preventing toxoplasmic encephalitis in persons infected with human immunodeficiency virus.

Toxoplasmic encephalitis (TE) is the second most common AIDS-related opportunistic infection of the CNS. It occurs in 10%-50% of patients with AIDS who are seropositive for antibodies to Toxoplasma gondii and have CD4+ T lymphocyte counts of < 100/mm3. Primary toxoplasmic infection usually is acquired by ingestion of T. gondii oocysts from soil contaminated by cat feces or by ingestion of tissue cysts present in undercooked red meats. In patients with AIDS, TE probably results from the reactivation of Toxoplasma tissue cysts that remained latent after the primary infection. Detection of IgG antibodies to Toxoplasma indicates prior infection and the possible presence of tissue cysts and, thus, risk for developing TE. A regimen of trimethoprim-sulfamethoxazole or dapsone plus pyrimethamine with leucovorin is recommended for persons infected with the human immunodeficiency virus (HIV) and who are seropositive for IgG to Toxoplasma after their CD4+ T lymphocyte counts fall to < 100/mm3. HIV-infected persons who are seronegative for IgG to Toxoplasma should be counseled to protect themselves from primary toxoplasmic infection by eating only well-cooked meats and washing their hands after outdoor activities involving soil contact; if they have a cat, they should feed it only commercial or well-cooked foods, keep it indoors, and make sure that the litter box is changed daily. HIV-infected persons who are Toxoplasma seropositive may also be advised about these preventive behavioral practices.

AIDS-Related Opportunistic Infections↗
PubMed1995

Knowledge, attitudes and practices during a community-level ivermectin distribution campaign in Guatemala.

Community acceptance and participation are essential for the success of mass ivermectin chemotherapy programmes for onchocerciasis (river blindness). To explore the local understanding of the purpose of ivermectin and willingness to continue taking the drug, we performed questionnaire surveys in four communities with hyperendemic onchocerciasis after each of three ivermectin treatment rounds. More than 100 respondents participated in each KAP survey, representing the heads of 30% of the households in each community. The respondents rarely stated that the goal of the ivermectin treatment programme was to prevent visual loss. Instead, they said they were taking the drug for their general well-being, to cure the onchocercal nodule (filaria), or to cure the microfilaria, a term newly introduced by agents of the treatment programme. The principal reason identified for refusal to take ivermectin was anxiety about drug-related adverse reactions, and there were marked differences between communities in acceptance of treatment. In one community over 50% of residents initially refused to take ivermectin, although participation rates improved somewhat after programmatic adjustments. We recommend that ivermectin distribution programmes establish surveillance activities to detect where acceptance is poor, so that timely and community-specific adjustments may be devised to improve participation.

Community Health Planning↗
PubMed1995

Knowledge, beliefs, and practices in relation to malaria transmission and vector control in Guatemala.

As part of an effort to involve community members in malaria control activities, we studied knowledge, beliefs, and practices of residents of both the Pacific coastal plain and northeastern Guatemala related to malaria transmission and Anopheles albimanus control. Most residents recognized the role of mosquitoes in malaria transmission, but few knew how mosquitoes acquired their infections or understood the risk of having an untreated person in their midst. If this were more widely known, residents might put greater pressure on infected patients to seek timely and appropriate antimalarial treatment. Seventy-three percent of families owned one or more bed nets; however, even though most informants believed that bed nets help protect against malaria, the major reason for using them was to prevent nuisance mosquito bites. It is concluded that efforts should be made to promote bed net use by seeking ways to make them more affordable and by emphasizing their effectiveness as a barrier to nuisance mosquitoes. Although residents have a very positive opinion of the National Malaria Service spray teams, it is proposed that cooperation might be improved if malaria workers would emphasize the fact that house spraying reduces the numbers of nuisance mosquitoes and other pest insects, rather than focusing solely on malaria prevention, which most informants believed was less important. This study emphasizes the importance of understanding community beliefs and practices when planning or evaluating vector control activities.

Adult↗