Tuberculosis control in Pakistan: critical analysis of its implementation.
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Antitubercular Agents↗
Biomedical subjects
A De Muynck
Publications and source records attributed to A De Muynck.
Multi-centre evaluation of repeatability and reproducibility of the direct agglutination test for visceral leishmaniasis.
OBJECTIVE: To evaluate the repeatability and reproducibility of the serological direct agglutination test (DAT) for visceral leishmaniasis (VL) with aqueous antigen in a multi-centre study in VL-endemic areas in Sudan, Kenya and Nepal. METHODS: Repeatability within each centre and reproducibility between the centres' results and an external reference laboratory (Belgium) was assessed on 1596 triplicate plain blood samples collected on filter paper. RESULTS: High kappa values (range 0.86-0.97) indicated excellent DAT repeatability within the centres. The means of the titre differences between the reference laboratory and the centres in Sudan, Kenya and Nepal (2.3, 2.4 and 1.1, respectively, all significantly different from 0) showed weak reproducibility across centres. 95% of the titre differences between the reference laboratory and the respective centres were accounted for by large intervals: 0.6-9 fold titre variation for Sudan, 0.7-8 fold for Kenya and 0.26-4 fold for Nepal. CONCLUSION: High repeatability of DAT confirms its potential, but reproducibility problems remain an obstacle to its routine use in the field. Reproducibility was hindered by alteration of the antigen through temperature and shaking, especially in Kenya and Sudan, and by nonstandardization of the test reading. DAT handling procedures and antigen quality must be carefully standardized and monitored when introducing this test into routine practice.
Agglutination Tests↗
A randomised trial of the impact of counselling on treatment adherence of tuberculosis patients in Sialkot, Pakistan.
SETTING: Tuberculosis Department, Bethania Hospital, Sialkot, Pakistan. OBJECTIVE: To determine whether intensive counselling can improve treatment adherence. DESIGN: In a randomised controlled intervention trial of 1,019 adult tuberculosis patients, 49% were assigned to the intervention group and 51% to the control group. Baseline data were obtained through semi-structured interviews. Patients were followed until the end of treatment (cure, default, referral or death). The intervention included counselling at the start of treatment and at each subsequent visit for ambulatory patients, or weekly for hospitalised patients. Counselling combined health education with strategies to strengthen patients' self-efficacy. Control group patients received the usual care. The outcome measure was treatment default. RESULTS: The default rate was 54% in the control group and 47% in the intervention group: the default risk ratio was 0.87, implying a reduction in defaulting of 13%. The impact was stronger in women, ambulatory patients, re-treatment patients, women who worked in the home, and patients who were not the main provider, those with a poor knowledge of the disease or those with a short treatment delay. CONCLUSIONS: Intensive counselling has a significant, although limited, impact on treatment adherence.
Adolescent↗
[Study of the factors determining an unexpected occurrecne of Chagas cardiomyopathy in Sucre, Bolivia].
The purpose of this case-control study carried out between February 1, 1994 and December 22, 1994 at the "Instituto de Gastroenterologia Boliviano-Japonés" in Sucre, Bolivia was to determine risk factors for chronic Chagas cardiomyopathy in adult patients with positive serological tests for Trypanosoma cruzi. A total of 196 subjects were included. Inclusion criteria were positive serological tests for Trypanosoma cruzi, residence in the city of Sucre, Bolivia for at least 3 months, and age over 14 years. There were 62 cases presenting electrocardiographic findings consistent with Chagas cardiomyopathy and 134 controls presenting normal electrocardiographic findings. Both cases and controls underwent a standardized protocol including physical examination and laboratory tests. Interviews were set up to evaluate personal and familial history of Chagas disease, socioeconomic status, and presence of Triatoma infestans in the home. Bivariate analysis of data indicated that Chagas cardiomyopathy was associated with the following risk factors: heart rate (p < 0.05), fecaloma (p < 0.05), occupation requiring strenuous physical exertion (p < 0.001), proximity with domestic animals (p < 0.005), especially pigs (p < 0.005), dwelling features including outbuildings, more than 2 bedrooms, and inside ceilings (p < 0.001). Multivariate analysis revealed the following risk factors: occupation requiring strenuous physical exertion (p < 0.005), a yard around the house (p < 0.05), and inside ceilings (p < 0.05). The results of this study show that prevention of chronic Chagas cardiomyopathy in Sucre, Bolivia will depend on improvement of living conditions.
Adolescent↗
[Schistosoma intercalatum bilharziasis: clinical and epidemiological considerations].
Schistosoma intercalatum bilharziasis continues to raise numerous questions regarding pathogenicity and gravity. The parasite was identified recently and the last fully described outbreak occurred 10 years ago in the city of Bata, Equatorial Guinea. Geographically Schistosoma intercalatum biharziasis is limited to one part of the African continent but has shown a tendency to spread. Hybridization of Schistosoma intercalatum and Schistosoma haematobium has been observed. The main clinical manifestation of Schistosoma intercalatum is rectal bleeding. The endoscopic appearance of lesions is variable and non-specific ranging from granulomas or polyps to ulcerations. Complications include severe rectitis or genital involvement such as salpingitis with secondary sterility. Spontaneous abortion has also been reported. Association with salmonella and klebsiella infection has been confirmed and can lead to life-threatening situations. Few studies have been performed to assess the value of diagnostic tests. The sensitivity of stool smears and urinary sedimentation testing is 81.7% and 56.3% respectively using the two examinations as references for one another. The sensitivity of immunological tests is generally good but varies depending on the reference technique used. Specificity can be affected by cross-reaction with other schistosomas or trematodes and even with nematodes and hematozoons. Treatment with a single dose of Biltricide has proven to be effective. Prevention requires education of the population at risk and use of molluscacides. The control strategy must be adapted in function of the epidemiology of the disease, diagnostic data, cost and effectiveness of screening and treatment.
Abortion, Spontaneous↗
[Evaluation of the Ivory Coast sentinel surveillance system for antimalarial drug sensitivity].
This study was performed to assess the sentinel surveillance system on malaria resistance in Cote d'Ivoire using a new method. Evaluation was based on documentation describing routine products and on activity reports obtained from the surveillance system. A qualitative approach was used to assess system design and quantitative approach to assess its operation. Degree of satisfaction with evaluation criteria was scored on a scale of 1 to 5. Score reproducibility in this study was good. Overall the system was considered as satisfactory. The strong points of the system are relevance, functions, sustainability, and data quality. The weak points are poor planning, overcentralization, and underuse of information. Correction of these weakness will require concentration by all parties at the national level involved in the surveillance system. The evaluation method used was simple, cheap and reproducible and thus could serve as an alternative approach for evaluation of sentinel surveillance systems in areas with scarce resources.
Antimalarials↗
Perception and social consequences of tuberculosis: a focus group study of tuberculosis patients in Sialkot, Pakistan.
Treatment defaulting is one of the major causes of the failure of TB control programs. In Bethania Hospital, Sialkot, defaulting rates are high: 72% for the standard 12 months course and 56% for the 8 months course. Attrition is especially important in the first weeks of treatment: < 70% of the patients start the 10th week of treatment. A focus group discussion study has been carried out to gain a better understanding of the impact of social stigmatization, treatment cost and pregnancy on defaulting. The study population consisted of 3 male and 3 female groups each with 8 hospitalized TB patients. The study shows that TB is perceived as a very dangerous, infectious and incurable disease. This perception has many social consequences: stigmatization and social isolation of TB patients and their families: diminished marriage prospects for young TB patients, and even for their family members: TB in one of the partners may lead to divorce. Due to fear patients often deny the diagnosis and reject the treatment. While both male and female TB patients face many social and economical problems, female patients are more affected. Divorce and broken engagements seem to occur more often in female patients. Females are usually economically dependent on their husbands and family in law, and need their cooperation to avail of treatment. The belief that pregnancy enhances the risk for relapse decreases their marriage prospects. Pregnancy is also a reason for stopping TB treatment as both are considered as incompatible. The findings of this study reveal the urgent need for a health education campaign to convince the general population that tuberculosis is curable. All health care providers should act as destigmatizers.
Adolescent↗
[Contribution of a mathematical model in the control of a parasitosis: the case of human African trypanosomiasis due to Trypanosoma brucei gambiense].
Trypanosoma brucei gambiense sleeping sickness transmitted by tsetse flies (Glossina spp.) is lethal if not treated adequately. The endemicity was generally well under control in the sixties. However, since the seventies the disease is returning in most of its old foci, with alarming endemic levels in several areas. Mathematical modelling provides a rational basis for finding the optimal strategies to control these recrudescences. We present a deterministic model of the basic transmission of trypanosomiasis between human and vector hosts in natural situations. The parameters were quantified on the basis of available evidence from the literature. The model predicts a stable equilibrium state with very high prevalences: approximately 95% of humans and 27% of flies being infected. The model further shows that the build-up of an epidemic is initially very slow, and it takes several months before the equilibrium state is reached. Consequently communities have enough time to avoid catastrophic situations by migrating to safer areas. If is therefore unlikely that such high equilibrium situations will occur in practice. The expression of the basic reproductive rate R0, the number of new infections during the lifetime of an infected subject with high values of R0 implies that efforts to diminish transmission to levels where the disease cannot maintain itself in the population, have to be substantial. The necessary reduction of fly numbers in order to enable eradication, has been calculated. In almost all situations a reduction of at least 90% is necessary, which is in accordance with the field experiences of vector control programmes. The present model can be considered as a starting point in the further development of a complete simulation model, which could be applied in supporting decision making in trypanosomiasis control.
Animals↗
[Relationship between Plasmodium parasitemia and febrile episodes in various population groups in Kinshasa, Zaire].
The objective of this study was to determine the relative importance of determinants of fever-episodes in an environment with perennial malaria transmission. In 6 neighbourhoods of Kinshasa with different degrees of urbanization, 120 clusters of children younger than 10 years were selected over a one year period and followed up for 2 weeks each. In the 4,816 children retained for analysis 906 fever episodes were registered, which corresponds to an average incidence rate of 4.9 episodes per child per year. Seven hundred (77.3%) of the fever cases had a positive thick film (IF) but of the 3,289 children with a positive TF only 21.3% presented fever during the observation period. Nevertheless, high parasite densities formed, without neglecting the role of other infectious etiologies, the mayor pathogenic mechanism associated with fever. The risk for a fever episode was, in multivariate analysis, 40 times higher in children with at least one positive TF than in children with a negative TF on both day 1 and day 14, and amongst the ones with a positive TF the risk was 3 times higher in children with a parasitemia above 3,000 trophozoites/microliter blood. The habitat constituted another important independent determinant: the relative risk for fever was 1.48 for non-urbanized neighbourhoods, which probably reflects the low malaria transmission in the urbanized ones, but 2.1 for semi-urbanized against peripheral neighbourhoods, where the parasite index is high. Low socio-economic status, the short dry season and young age formed, in this order, further factors to the take into account.
Animals↗
Risk factors assessment for T. b. rhodesiense sleeping sickness acquisition in S.E. Uganda. A case-control study.
The major risk factors associated with acquisition of T. b. rhodesiense sleeping sickness in the Busoga focus, S.E. Uganda were investigated using a case-control study. 122 cases and 244 matched controls were used in the study. For each case two age-, sex- and resistance controls (1 matched nearest neighbour control and 1 village control) were selected. Patients and controls answered the same questionnaire which had been developed and field tested before the field study started. A logistic regression model for a 1:2 matched case control design was fit to the data. The following factors were found significant: cases spent more time outside their village of residence than controls and visited more SS high risk areas than controls, more cases than controls collected firewood in the forests. Generally, cases had less domestic animals grazing near the places of man-fly contact, especially near water and firewood collecting and bathing points, and near farms and gardens, than controls. Cases had more antecedents of sleeping sickness in the family. Generally cases had a less well developed information network than controls, and belonged economically to a less powerful group. Based on these results we may conclude that the risk to develop T.b. rhodesiense sleeping sickness depends upon a multitude of economical, cultural and human behaviour factors. These factors should be taken into account in the planning and monitoring of sleeping sickness control programmes.
Adolescent↗
Uptake of preventive health care among Mediterranean migrants in Belgium.
STUDY OBJECTIVE: The aim was to investigate the influence of ethnicity on the demand for preventive care by Mediterranean migrants in Belgium. DESIGN: This was a survey of patient contacts with general practitioners. SETTING AND PATIENTS: 33 general practitioners working in Belgian localities with the highest migrant density collaborated in the study. During two months they recorded information on consultations with an estimated 72,600 clients. Participation was obtained from all subjects attending for preventive care or for a new episode of illness (n = 6256). MAIN RESULTS: An average of 30% of the patients sought preventive care, but multivariate analysis showed ethnicity to be a strong independent predictor of this type of demand. The higher primary preventive uptake by female Moroccans and Turks and the higher secondary preventive uptake by males from the same ethnic groups, as compared with the Belgian reference population, contrasted with a lower demand for tertiary prevention in migrants of either gender. The relative demand for preventive care by the more acculturated migrants was, however, quite similar to the demand of the Belgian population. CONCLUSIONS: The differential uptake of primary preventive care could be partly explained by the higher fertility rates of immigrant women, and the differential secondary uptake by a lower incidence of tuberculosis in the indigenous population. The meagre demand for tertiary prevention by Moroccan and Turkish migrants could be due to weaker compliance with treatments for chronic disorders, which is related to the perceptions of illness in these ethnic groups. The establishment of cross cultural mechanisms of dialogue should enhance compliance and improve the access of immigrants to the benefits of tertiary preventive care.
Adolescent↗
Assessment of patients' health status in family medicine.
General Practitioners feel increasing pressure from Public Health authorities to evaluate their work but generally accept outcome indices such as morbidity and mortality are too far away from GP practices to allow direct evaluation conclusions. A simple instrument is needed to assess the evolution in the health status of the populations the GP serves. To design such an instrument we developed a short, inexpensive questionnaire, to be filled in by the GP, that covers as many fields of health care as possible and reflects as closely as possible the specific approach in family practice. To construct this instrument five Guttman scales were first developed that refer to the five frameworks of though that a general practitioner uses, and submitted them to a process of validation. A composite index (SAMI) was mathematically derived from these five scales; it proved to be a valid instrument for measuring health status. To field test the SAMI index, a prospective cohort study was carried out in two subpopulations, Belgians and migrants, consulting seven GP practices. The evolution of four reasons for encounter (low back pain, pregnancy, diabetes and epigastralgia) were monitored by means of the five scales and the SAMI index. The evaluative conclusion that, despite special efforts of the GPs, their approach to migrants has to be reconsidered, is drawn. Above all the field test has shown that the five measurement scales and the global SAMI index are valid instruments, of easy use in general practice, that allow to assess the global health status of patient populations and give opportunities for evaluation of PHC services.
Back Pain↗
Tropical doctors and statistics.
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Humans↗
Migration, acculturation and utilization of primary health care.
This study explored the roles of acculturation, urban-rural provenance and length of residence as determinants of the utilization pattern of first line health services by Moroccan, Turkish and Italian migrants in Belgium. Concurrently, utilization characteristics were recorded in Belgian reference patients. With increasing acculturation the demand for preventive care decreased, vague complaints became more prevalent, the delay before consulting for a curative problem shortened and the prognosis improved. There was no correlation between the occurrence of psychological problems and acculturation but, except for 15-44 year old female migrants, the rate of social problems was negatively associated with this study factor. Migrants with an urban background consulted earlier and presented more frequently vague complaints than migrants from rural provenance. We observed no significant influence of length of residence on utilization characteristics and only a marginal influence on morbidity pattern. Although acculturation seems to be a strong determinant of the migrant's utilization pattern of primary health care services, it does not consistently lead to a decrease of utilization differentials with the Belgian reference population. This may imply that there is a need for public health interventions targeted at ethnic minorities.
Acculturation↗
Can the causal model approach contribute to the study of the epidemiology and the control of sleeping sickness?
A causal model links together, in an hierarchical manner, a set of hypotheses about the causes of, and mechanisms leading to, a phenomenon under study. Initially used in nutrition studies for identifying the variables to be observed, such models have proven useful in the choice and evaluation of interventions, as well as in the selection of relevant special studies to be carried out inside a broader research programme. The authors describe a technique of model building used by nutritionists, and argue that this approach could be of benefit in the study and control of african trypanosomiasis. Their hypothesis is that although causal models do not substitute for mathematical models, the latter ones, and epidemiological models in general, would be (1) more correct logically; (2) fitting reality more closely; and (3) more useful for the analyst, the decision maker and the field worker, if they were built from an preceding causal model.
Humans↗
The incubation time of relapses after treatment of multibacillary leprosy with rifampicin containing regimens.
In order to determine the duration of follow-up needed to evaluate the efficacy of short-course bactericidal regimens for multibacillary leprosy, information is needed on the incubation time of relapses after stopping treatment. Several groups of patients, who had been on rifampicin-containing regimens, were followed up for periods ranging from 4 to 10 years. Two groups of relapses were observed: early relapses occurring within 3.5 years after stopping treatment, with a median incubation time of 1 year and 10 months (upper limit of 95% confidence interval: 2 years); and late relapses occurring more than 3.5 years after stopping treatment, with a median incubation of 5 years. Early relapses are probably due to insufficient treatment, and late relapses to persisting bacilli or to reinfection. It is concluded that the efficacy of short-course RMP-containing therapeutic regimens can be evaluated by observing the occurrence of early relapses, 50% of which occur before 2 years after the end of therapy.
Drug Therapy, Combination↗
Selective isolation of mycobacteria from soil: a statistical analysis approach.
We compared four decontamination methods for the isolation of mycobacteria from soil specimens. Different media were used: Löwenstein-Jensen, Ogawa and various modified Ogawa media. Statistical analysis demonstrated that the best results (low contamination and high positivity rates) were obtained when the specimens were incubated in trypticase soy broth, treated with solutions containing malachite green and cycloheximide, then decontaminated with sodium hydroxide and inoculated onto Ogawa media. The lowest contamination rates were obtained with Ogawa medium containing 500 micrograms cycloheximide ml-1. The use of these techniques is proposed for the isolation of mycobacteria from heavily contaminated clinical specimens as well as from soil.
Culture Media↗
Effects of freezing and thawing on the viability and the ultrastructure of in vivo grown mycobacteria.
The influence of different frequencies of freezing-thawing cycles on the viability of in vivo grown mycobacteria was investigated. Pieces of armadillo tissues naturally or experimentally infected with Mycobacterium leprae were analyzed. The viability of M. leprae was determined by mouse foot pad titration. The viability of cultivable mycobacteria, sometimes present in armadillo tissues, was determined by culture. Electron-microscopic studies were performed on fresh or frozen-thawed armadillo tissues with natural leprosy and on livers of C57BL/6 mice experimentally infected with M. avium or M. lepraemurium. We found that the percentage of viable M. leprae bacilli is identical for naturally infected and experimentally infected tissues, frozen and thawed once. When the tissues were subjected to a second freezing-thawing cycle, a considerable loss of viability was observed (65%-97%). A third freezing-thawing cycle was lethal for most of the M. leprae cells, and after four freezing-thawing cycles no viable bacilli were found. The cultivable mycobacteria present in some armadillo tissues were found to be more resistant than M. leprae to freezing-thawing since these mycobacteria could still be cultivated after four freezing-thawing cycles. The results of the electron-microscopy study support the conclusion that M. leprae is more sensitive to freezing-thawing than the cultivable mycobacteria and show that the cytoplasmic membrane appears to be the target for the lethal action of freezing-thawing on mycobacterial cells. These results emphasize the importance of avoiding repeated thawing and refreezing of M. leprae-infected tissues when viable M. leprae cells need to be studied.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗