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Biomedical subjects

A Bosman

Publications and source records attributed to A Bosman.

At least 19 recordsLinked to original sources
PubMed2000

Evaluation of two PCR-based procedures for typing Clostridium perfringens.

Two polymerase chain reaction (PCR)-based procedures for typing Clostridium, perfringens, which affects most domestic animals, were compared and evaluated for efficiency as substitute to the guinea-pig intradermal test routinely used in our laboratory, namely a multiplex PCR and a protocol based on the individual amplification of gene sequences specific for each toxin. Reference isolates of C. perfringens types A, B, C and D as well as cultures from clinical specimens were tested. The sensitivity and specificity of the PCR was confirmed on reference isolates. There was similarity in results on 43 of the 46 samples typed by all 3 methods. Clear results were obtained by PCR on 5 clinical samples that showed either equivocal or weak skin reactions in guinea-pigs. The multiplex PCR protocol, in combination with the evaluation of bacterial growth, is a better alternative to in vivo toxin typing, since C. perfringens can only be incriminated as cause of a disease when it is present in large numbers in the intestine.

Animals↗
PubMed1999

[Syphilis in addicted pregnant women: better care through more awareness and contract between organizations involved].

Three women, aged 21, 20 and 30 years, were cocaine users and pregnant. There had been no prenatal monitoring until they reported with uterine contractions. Blood of the first two women was then tested; serology revealed active syphilis infections: their children had died in utero. The blood of the third woman had been tested as part of a street project; it revealed an active syphilitic infection but she could not be found for treatment. After delivery, the child showed withdrawal symptoms. The first and third women and the child of the third woman were treated with benzylpenicillin. The system for screening and treating drug-addicted pregnant women should be intensified.

Adult↗
PubMed1999

[Increase of early syphilis in Rotterdam (1995-1997): more (addicted) prostitutes and their clients].

OBJECTIVE: To detect risk groups in an increase of early (infectious) syphilis. DESIGN: Retrospective study of patient records. METHOD: Data from visitors with an early syphilis were collected from their respective medical records in the outpatient clinic for sexually transmitted diseases (STD) of the Academic Hospital Rotterdam-Dijkzigt, the Netherlands, over the years 1993-1997. In particular, data on risk behaviour and risk groups were collected. To obtain an indication of the (possible) causes of the increase in the number of visitors with early syphilis, (shifts in) characteristics of this population over the years were compared. RESULTS: 195 patients with early syphilis had visited the outpatient clinic, 130 males and 65 females, mean ages ranging from 30.9 (1993) to 38.1 years (1997). Most infected persons (68%) came to the outpatient clinic because of symptoms. The number of women who came to the outpatient clinic through partner notification increased considerably, from an average of 5% in 1993-1995 to 36% in 1996. Over the years a relative increase of (drug addicted) prostitutes and their clients was observed (1993-1995: 39%; 1996: 56%). CONCLUSION: The cause of the increase, or failure to decrease, of the number of syphilis-infected visitors in the STD outpatient clinic of the Academic Hospital Rotterdam-Dijkzigt should probably be sought among (drug addicted) prostitutes and their visitors.

Adult↗
PubMed1999

[Increase of early syphilis in a red light district in Rotterdam (1995-1997) and preventive treatment].

The number of cases of syphilis in Rotterdam has increased dramatically since 1995. The prevalence of early syphilis in 1997 was highest among street prostitutes (16%). Some prostitutes could not be reached for further evaluation and treatment, probably due to their addiction to hard drugs. Prophylactic treatment for syphilis was given to most street prostitutes in a cruising zone during a screening programme for sexually transmitted diseases (STD) in January 1997. Since then, STD checkups were performed regularly in the cruising zone. The prevalence of early syphilis in the cruising zone dropped to 1.3% in 1998. The total number of reported cases of syphilis in Rotterdam also decreased sharply in 1998.

Adult↗
PubMed1999

[Two patients with acute hepatitis B from the same piercing salon].

Hepatitis B was diagnosed in two homosexual men aged 41 and 31 years. Both had undergone piercing on the same day in the same saloon. The word piercing means application of decorations in the skin which is pierced for the purpose. The breeching of the skin combined with the conditions under which this is performed leads to a risk of transmission of especially viral infections. An assumed connection between the patients was supported by the results of molecular-biological examination of the hepatitis B virus isolates. The piercings were applied with the same pair of pincers, which was not sterilized in between. In view of these findings hygienic measures were taken in the piercing saloon in question to prevent future transmission of infections. Piercing entails health risks that are not always recognized either by those who do it or by those who have it done.

Acute Disease↗
PubMed1999

[Screening policy for travellers from Rotterdam for hepatitis A antibodies prior to eventual immunization: favourable cost-benefit ratio].

OBJECTIVE: To evaluate costs and benefits of the screening and immunisation policy for hepatitis A virus (HAV) infection among travellers from Rotterdam. DESIGN: Descriptive and cost-benefit analysis. METHOD: From the data of the Municipal Health Service Rotterdam (GGD), the Netherlands, the details were collected on individuals travelling frequently to HAV endemic countries, who were born before 1950, or had lived for more than 10 years in an HAV endemic country or had ever suffered jaundice. Persons to whom these criteria applied were screened for HAV antibodies at the GGD before immunisation for HAV in the period January 1st 1996-June 30th 1998. Screening and vaccination policies were compared with a cost analysis. RESULTS: Antibodies against HAV were found in 79% of 1466 screened people. The lowest prevalence of antibodies was found among Dutch nationals (67%). A significantly higher prevalence was found amongst individuals from Turkey/Morocco (96%) and from the Cape-Verde Islands (97%). In the cost analysis the break even point, the prevalence level of HAV antibodies in the population at which screening cost as much as blind prophylaxis, lay for passive immunisation between 69% and 93%. For active immunisation this point lay around 17%. CONCLUSION: The selection criteria for prevaccination screening are effective in identifying individuals with a high probability of being immune against HAV infections. The current screening policy for antibodies against HAV is cost effective.

Cost-Benefit Analysis↗
PubMed1999

Outbreak of hepatitis A in Rotterdam associated with visits to 'darkrooms' in gay bars.

An unexpectedly large number of hepatitis A virus (HAV) infections were notified among homosexual men in Rotterdam in the first five months of 1998. A case control study was conducted to investigate the hypothesis that this outbreak was associated with sexual practices and to collect information with which to focus preventive activities. Notified cases and controls selected from male members of a gay sports club completed anonymous questionnaires about known risk factors for HAV infection and sexual behaviour. Single variable analysis showed that HAV infection was associated with sexual contact with anonymous sex partners (odds ratio (OR) 4.6; 95% confidence interval (CI) 1.0-23.2) and with visits to 'darkrooms' in gay bars (OR 6.2; 95% CI 1.5-26.8). A negative association with travel abroad to western countries was observed (OR 0.4; 95% CI 0.1-1.3). The associations with visits to darkrooms (OR = 9.2; 95% CI 1.6-52.4) and travel abroad to western countries (OR 0.1; 95% CI 0.02-0.9) remained significant in a multivariable logistic regression analysis. This risk group was targeted for health education and vaccination and darkroom owners were advised to provide hygiene facilities.

Adult↗
PubMed1999

Opportunities, problems and perspectives for malaria control in sub-Saharan Africa.

Environments conducive to high malaria transmission and widespread poverty are at the roots of the 'malaria giant', which affects 46 countries in Africa. The recent interest in and momentum of work on malaria, in endemic countries and the international community, is unprecedented and opens new perspectives for controlling the disease. Significant steps included: (i) the allocation of US$20 million by WHO for accelerated implementation of malaria control in 34 African countries in 1997-98; (ii) the Declaration on Malaria by the Heads of States of the Organization of African Unity and the establishment of the African Initiative for Malaria Control in 1997; (iii) the concomitant mobilisation of the research community in the Multilateral Initiative on Malaria; (iv) the G8 Summit in 1998 in Birmingham asking for higher commitment to malaria control, particularly in Africa; and (v) the Roll Back Malaria initiative set as a WHO priority project in 1998. However, experiences have proved the alarming 'resilience' of the malaria system in Africa, showing devastating consequences when malaria returns to the original levels after intensive control is interrupted. Effective malaria control in Africa requires long-term action, firmly rooted in the social development of the country.

Africa South of the Sahara↗
PubMed1999

Community-based malaria control in Tigray, northern Ethiopia.

Community-based control activities have been a major component of the Tigray regional malaria control programme since 1992. A team of 735 volunteer community health workers treat on average 60,000 clinical malaria cases monthly during the high malaria transmission season. Ensuring access for the rural population to early diagnosis and treatment has contributed to a significant decrease in death rate in under-five children at the village level from 1994 to 1996. Mapping and geographic information system (GIS) technologies have been introduced to support planning for control by assessment of community-based coverage. With further development, GIS will be used in stratification, and to assess the impact of water resources development on malaria transmission and intensity.

Adult↗
PubMed1999

Implementation of malaria control.

Global trends of infant and child mortality have decreased over the last 30 years, while the proportion of malaria deaths has progressively increased due to the deteriorating situation in sub-Saharan Africa. The Global Malaria Control Strategy promoted by WHO has encountered several obstacles to its implementation. Early diagnosis and prompt treatment can reduce malaria mortality, but there is still low investment on safe and effective modalities of care delivery at the periphery, where most of the malaria burden exists. Selective vector control (indoor residual spraying and insecticide-treated nets) plays a significant role outside Africa, but its wider use is limited by cost/affordability problems and operational issues (supply, delivery and logistics). Alternative methods such as environmental management and biological control are cost-effective only under very specific epidemiological situations. In most countries forecasting, early detection and containment of malaria epidemics is deficient, and there is separation between the research and control communities, particularly in Africa. Involvement of the internal agencies, strategic investments in capacity building and institutional networking are needed to strengthen capacity for malaria and research in the countries. The major responsibility is to guide the expenditure made by the communities (which far out-weigh the limited share of national health budgets) towards the most cost-effective approaches to reduce malaria mortality and morbidity.

Child, Preschool↗
PubMed1999

Thrombospondin related adhesive protein (TRAP), a potential malaria vaccine candidate.

We have investigated whether naturally induced immunity to Plasmodium falciparum thrombospondin related adhesive protein contributes to protection against malaria in humans. We have carried out a case control study in children living in an endemic region of West Africa to reveal associations between PfTRAP seroprevalence and the risk of cerebral malaria. Sera collected from the case and control groups were analysed by ELISA to compare their serum reactivity against PfTRAP, the circumsporozoite protein and the merozoite surface protein 1. Children with uncomplicated malaria had a significantly higher PfTRAP seroprevalence when compared to children with cerebral malaria. The risk of developing cerebral malaria appeared to depend on the reciprocal relationship between sporozoite inoculation rates and humoral immunity against PfTRAP. Our results suggest that naturally induced humoral immunity against PfTRAP contributes to the development of protection against severe malaria. Experimentally induced immunity against TRAP in different rodent models has consistently proven to elicit a high degree of protection against malaria. This together with the functional properties of TRAP and data describing CD4 and CD8 epitopes for PfTRAP indicate that this molecule could increase the protective efficiency of available sporozoite malaria vaccines.

Africa, Western↗
PubMed1998

Natural polymorphism in the thrombospondin-related adhesive protein of Plasmodium falciparum.

We have developed a typing system using natural sequence variation in the thrombospondin-related adhesive protein (TRAP) gene of Plasmodium falciparum. This method permits a haplotype to be assigned to any particular TRAP gene. We have applied this method to a hospital-based, case control-study in Mali. Previous sequence variation and conservation in TRAP has been confirmed. Particular TRAP haplotypes can be used as geographic hallmarks. Because of the high level of conflict between characters, we have examined the phylogenetic relationships between parasites using a network approach. Having received patient samples from urban and periurban areas of Bamako, the majority of haplotypes were closely related and distinct from TRAP sequences present in other continents. This suggests that the structure of TRAP can only tolerate a limited number of sequence variations to preserve its function but that this is sufficient to allow the parasite to evade the host's immune system until a long-lived immune response can be maintained. It may also reflect host genetics in that certain variants may escape the host immune response more efficiently than others. For vaccine design, sequences from the major regional variants may need to be considered in the production of effective subunit vaccines.

Animals↗
PubMed1998

Malaria, schistosomiasis, and intestinal helminths in relation to microdams in Tigray, northern Ethiopia.

A survey was undertaken in Tigray, Northern Ethiopia, to assess the prevalence of malaria, schistosomiasis, and intestinal helminths in relation to microdams. The survey took place from March to June 1995, during the dry season, at 41 microdams. At each site the village nearest the dam (within thirty minutes walk) was selected, ten households were randomly chosen, and all family members were examined for malaria and intestinal parasites. The overall study sample was 2271 people, of all age groups. Plasmodium falciparum infection was documented in four villages (at 10% of microdams); prevalence was 1.2% (range 0-20% by village). Larvae of Anopheles gambiae s.l. were found at one microdam. Infection with intestinal schistosomiasis was documented in 20 villages (at 49% of microdams), and one third of those infected had moderate to heavy infections. Biomphalaria species, the intermediate host snails of Schistosoma mansoni, were found at 16 microdams (39%), and snails infected by mammalian cercariae were found in one locality. Infections with soil-transmitted nematodes were prevalent: hookworm was detected in more than two thirds of the villages, and Ascaris lumbricoides and Trichuris trichiura were present in almost half of the villages. Out of 2078 stool examinations, the prevalence of S. mansoni infection was 7.2% (range 0-48% by village), of A. lumbricoides 2.3% (range 0-31%), of T. trichiura 2.4% (range 0-21%), and of hookworm 8.9% (range 0-78%). The prevalence of malaria, S. mansoni and hookworm was higher at altitudes below 2000 metres above sea level. S. mansoni was more prevalent in microdams built more than 5 years before the survey, while T. trichiura was more prevalent at recently constructed microdams. The widespread distribution of schistosomiasis and intestinal helminths, and the presence of malaria infection during the dry season confirm that microdams create favourable conditions for the transmission of these parasitic diseases. Health safeguards must be incorporated into the planning, construction, and operation of microdams and irrigation systems in order to prevent or reduce these diseases. In areas with high prevalence, control activities should be intensified.

Adolescent↗
PubMed1996

Community participation in malaria control in Tigray region Ethiopia.

During the Ethiopian civil war from 1974 to 1991, the Tigrean People's Liberation Front established a primary health care system in Tigray in which community residents helped to plan and implement health services through health committees and community health workers (CHWs). To strengthen and update this system, a Community-Based Malaria Control Programme was initiated in 1992. The primary objectives of the Programme are to reduce malaria morbidity and mortality and to prevent malaria in pregnant women through early diagnosis and treatment of cases, chemoprophylaxis during pregnancy, and vector control by environmental management. A secondary objective is to introduce a cost-sharing scheme for eventual development of a village revolving fund. A total of 681 volunteers chosen by their communities have received malaria training and serve a rural population of 1,682319 (CHW/population ratio 1:2,500). The principal success of the programme at this stage is that a significant proportion of the rural population at risk for malaria is now being treated at the village level. During the last major transmission season from September through November 1993, each CHWs treated a mean of 45178 clinical malaria cases per month. Under-utilization of treatment services by women and children under 5 years and low chemoprophylaxis coverage of pregnant women have been documented. After focus group discussions with community members and CHWs to identify the reasons for these problems, changes in programme policies were made to improve coverage of these groups. Since 1992, considerable progress toward meeting programme objectives has been made, and continued evaluation will allow for interventions that should further strengthen the malaria control efforts in the region.

Child, Preschool↗
PubMed1995

Plasmodium falciparum malaria in sympatric ethnic groups of Burkina Faso, west Africa.

Plasmodium falciparum parasite rate, parasite density and anti-CS antibodies were assessed in 196 subjects (age > 10 yrs) belonging to three sympatric West African ethnic groups, namely Mossi, Rimaibé and Fulani, all exposed to very high seasonal malaria transmission in the same rural village near Ouagadougou, Burkina Faso. No interethnic differences were noted in the use of antimalaria measures nor in the exposure to malaria vectors. However, interethnic differences were found in each of the three malariological indices. The Fulani appeared markedly less parasitized and more responsive to the CS-antigen than the Mossi and the Rimaibé who had very similar indices, except in the case of parasite density. These findings suggest a higher resistance to malaria of the Fulani ethnic group, possibly involving human genetic factors and/or the influence of extrinsic variables (e.g., socio-cultural) among which diet differences should be considered.

Adolescent↗
PubMed1994

[A measles epidemic in an adequately vaccinated middle school population].

OBJECTIVE: To assess the extent of a measles epidemic in a secondary school. DESIGN: Retrospective and questionnaire investigation. SETTING: Secondary school, Bilthoven. METHOD: Questionnaire followed by laboratory testing for measles and other infectious diseases with exanthema. RESULTS: The response rate was 99% (935/949 pupils, aged 12-21 years, vaccination rate 92%). Seventy-seven students underwent laboratory investigations. Measles virus was isolated in 2 suspected patients. Thirty-three of 37 patients with clinical or laboratory criteria of measles had been vaccinated. Complications of measles were not detected. Infection was also detected in patients with relatively few or atypical symptoms. The protective efficacy of measles vaccine could be determined because the attack rate of the school population was less than 5%. CONCLUSION: Primary failure of the measles vaccine might be the cause of the minor epidemic but the results do not cast doubt on the efficacy of the current measles vaccination programme.

Adolescent↗
PubMed1994

Efficacy of a single dose of mebendazole on prevalence and intensity of soil-transmitted nematodes in Zanzibar.

The efficacy of a single-dose of mebendazole to treat intestinal helminths was studied in Pemba Island, Zanzibar, with the view of incorporating it in future control programmes. A single Kato-Katz stool examination was performed on 2,269 individuals from all age groups. 1,883 individuals were treated with 500 mg of mebendazole (250 mg for children below two years) and re-examined one month and four months after therapy. A total of 466 presented themselves for all three surveys and the data has been reported in this study. The overall cure rate for ascariasis was 93.2% and reduction of egg load after treatment was 89.8% in persistent positive cases. Although the cure rates were lower in trichuriasis (25.6%) and hookworm (17.8%) infections, egg reduction was more evident with 47% for Trichuris trichiura and 51.9% for hookworms. A single dose of mebendazole results not only in a high cure rate for ascariasis but also in a decrease in intensity of ascariasis, trichuriasis and hookworm infections, thereby contributing to its incorporation into low-budget control programmes in developing countries.

Adolescent↗