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Biomedical subjects

M Christian

Publications and source records attributed to M Christian.

At least 55 records · Page 3Linked to original sources

Controlled clinical trial of two multidrug regimens with and without rifampin in highly bacilliferous BL/LL south Indian patients: a five-year report.

A controlled clinical trial of two multidrug regimens in multibacillary lepromatous and near-lepromatous patients with a bacterial index (BI) of 2.5 or more was conducted. Patients were randomly allocated to either a two-drug regimen of dapsone plus clofazimine for 60 months or a four-drug regimen of rifampin, isoniazid, dapsone, and clofazimine for the first 3 months and clofazimine plus dapsone for the next 57 months. There was no difference between the rifampin and nonrifampin regimens with respect to the clinical improvement or bacteriological status of the patients at 60 months. Reactive states and neuritis were observed to be equal in the two patient groups.

Adolescent↗

Impact of MDT on incidence rates of leprosy among household contacts. Part 1. Baseline data.

This preliminary study from Gudiyatham Taluk, the leprosy control area of the Schieffelin Leprosy Research & Training Centre, investigated the incidence rates of leprosy among household contacts during the period 1970-1985. The incidence rates of leprosy among the household contacts prior to and during the initiation of multi-drug therapy are presented here. The overall incidence rate among the household contacts was 4 per 1000 person-years at risk. Contacts of multibacillary and paucibacillary cases had a relative risk of 3-6 times and 2-4 times the risk of leprosy in the general population, respectively. The incidence rates among children were higher than adults; the peak age-specific incidence rate was between 5-9 years, and nearly one third of the primary cases were children. These findings are presented and the methodological issues discussed.

Age Factors↗

Infectivity of secondary dapsone-resistant cases.

The incidence rate of leprosy among 517 household contacts of 113 cases of secondary dapsone resistance with 5074 person years at risk were studied. The incidence rate of leprosy was 4.3 per 1000 person years at risk, which is very similar to the incidence rate (4.8) among household contacts of lepromatous cases. Two, possibly three, cases of primary dapsone resistance were detected among the 27 contacts who developed multibacillary leprosy. There was no evidence of dapsone resistance among 48 paucibacillary leprosy cases assessed when treated with dapsone monotherapy. The possibility that secondary dapsone-resistant cases will infect and will result in an increase in the number of primary dapsone-resistant cases needs to be investigated further.

Adult↗

Relapse rates in lepromatous leprosy according to treatment regularity.

In Gudiyatham Taluk, South India, 1008 lepromatous (LL) and borderline lepromatous (BL) patients were studied. They had previously been smear positive, had attained smear negativity, and continued on DDS monotherapy. "Relapse" was defined as the reappearance of Mycobacterium leprae in skin smears. The area is endemic for leprosy. The lower relapse rates in the first three years of smear negativity alone were associated with more-regular treatment during both past smear positivity and smear negativity. From the fourth year of smear negativity onward, only the more-regular treatment during smear negativity was associated with lower relapse rates; whereas patients with more-regular treatment during past smear positivity had no lower risk of relapse than those with less-regular treatment. The finding that regularity of treatment during smear positivity seems to have no effect on relapse rates beyond the third year of smear negativity is discussed. In a leprosy-endemic area, it is argued that beyond the first three years of smear negativity in an LL or BL patient, sources of M. leprae outside the patient may be more responsible for relapse than the patient's own bacilli.

Dapsone↗

Geographical variations in the occurrence of leprosy: possible roles played by nutrition and some other environmental factors.

The considerable variation in leprosy prevalence among 35 villages and field areas in South India was compared with variations in their socioeconomic and nutritional conditions. Using villages/field areas and aggregates thereof as observational units, leprosy prevalence rates were found to be significantly lower in field areas than in villages. Moreover, there was a significant correlation between the occurrence of malnutrition in children 1 to 4 years of age and the prevalence of leprosy. The possible association between the occurrence of malnutrition in childhood and leprosy is discussed in light of the present knowledge of leprosy, immunocompetence, and malnutrition. Strategies for further illumination of the hypothesized importance of malnutrition among children are discussed.

Body Height↗

Relapse rates among nonlepromatous patients released from control.

A total of 1701 nonlepromatous patients treated with dapsone monotherapy for at least 4 1/2 years and released from control were followed up and examined for evidence of relapse. They contributed a total of 5254 person years of risk, and there were 51 relapses (3%), giving an overall relapse rate of 9.7/1000 person years of risk. This paper examines the effect of various factors on the risk of relapses, such as age, sex, and classification of the disease; duration and regularity of treatment; percentage of attendance; deformity grade; number of patches and lepromin status. Some of the factors studied, such as age, sex, classification, percentage of attendance, and the number of patches in association with the lepromin status, were found to significantly influence the risk of relapse in these patients. Therapy in nonlepromatous leprosy is discussed in light of these findings.

Adolescent↗

DDS-resistant infection among leprosy patients in the population of Gudiyatham Taluk, South India. Part 3. Prevalence, incidence, risk factors, and interpretation of mouse foot pad test results.

At the Schieffelin Leprosy Research and Training Centre, Karigiri, India, a study of the population of Gudiyatham Taluk revealed that the prevalence of dapsone (DDS)-resistant infection among lepromatous (LL) and borderline lepromatous (BL) leprosy patients treated for a minimum of three years was 3.3% (33 per 1000), with an average annual incidence of 0.28% per year. DDS-resistant infection was diagnosed when review of skin smear readings showed a continuing increase in the number of Mycobacterium leprae in successive smears despite adequate DDS treatment. The attainment of smear negativity in an LL or BL patient was found to be a favorable prognostic sign, indicating a reduced risk of DDS-resistant infection. No association was found between the incidence of DDS-resistant infection on the one hand and either the regularity or the initial dosage of DDS treatment on the other. Ninety-five (88.0%) out of 108 successful mouse foot pad tests on patients with a Bacterial Index (BI) greater than or equal to 2+ detected DDS-resistant M. leprae. The mouse test detected bacilli resistant to 0.01% w/w DDS in mouse diet not only among patients deteriorating despite adequate DDS monotherapy, but also among patients improving on DDS monotherapy. Since the mouse test as presently used does not measure the proportion of M. leprae in a sample that are resistant to DDS, the detection of DDS-resistant bacilli in the mouse test may not always indicate that the patient will fail to respond to DDS monotherapy.

Dapsone↗

The significance of dapsone (DDS)-resistant Mycobacterium leprae in untreated patients.

In a stable rural population of South India, 18 consecutive untreated persons newly discovered to have leprosy with a Bacterial Index (BI) greater than or equal to 2+ were tested for Mycobacterium leprae resistant to dapsone (DDS) by the mouse foot pad test. Of 12 successful tests, five detected resistant M. leprae. Known contact with a treated patient in the ten years preceding the diagnosis of leprosy was not found to increase the risk of DDS-resistant M. leprae occurring in an untreated, newly diagnosed patient. This data is consistent with the bulk of evidence in the field of bacteriology, which makes it seem unlikely that treated patients are the only source, or even the major source, of resistant M. leprae in untreated patients. Bacterial mutants resistant to a drug have been shown to precede initial use of the drug. Tests for drug-resistant bacteria in untreated patients before a drug is widely used in a community are likely to be important for subsequent evaluation of resistance to the drug in that community.

Dapsone↗

Response to dapsone (DDS) monotherapy in leprosy patients of Gudiyatham Taluk, South India: comparison between the 1960s and the 1970s.

At the Schieffelin Leprosy Research and Training Centre, Karagiri, India, 148 lepromatous (LL) and borderline lepromatous (BL) leprosy patients registered for treatment in the years 1971 to 1973 were found to respond as well to dapsone (DDS) monotherapy as 391 LL and BL patients registered in 1964 to 1966, as indicated by clearance of Mycobacterium leprae from skin smears during the initial seven years of therapy in each patient. Apparently, the efficacy of DDS monotherapy has not been progressively diminishing since the introduction of DDS monotherapy into the area.

Dapsone↗

Follow-up of lepromatous (LL and BL) patients on dapsone (DDS) monotherapy after attainment of smear negativity in Gudiyatham Taluk, South India.

At the Schieffelin Leprosy Research and Training Centre, Karigiri, India, an analysis of "relapse" rates was undertaken on all the 1293 residents of Guidyatham Taluk who were known to have lepromatous (LL) or borderline lepromatous (BL) leprosy and had attained "smear negative" status. "Relapse" was defined as the reappearance of acid-fast bacilli (AFB) in skin smears, whether by reinfection from other patients or from the patient's own persisting organisms. The "relapse" rate decreased steadily with the time elapsed after the attainment of smear negativity: 2.8% (2.8 per 100 patients per year) in the initial two years; 1.1% from the third year onwards; and 0.9% from the ninth year onwards. Of the 1293 patients, 694 (53.7%) had taken greater than or equal to 80% regular dapsone (DDS) treatment during smear negativity. In this group, the "relapse" rate from the third year onwards was only 0.7% per year. The vast majority (90.9%) of LL and BL patients on DDS monotherapy in the area had at some point attained smear negative status. It appears important to study whether a limited period of DDS monotherapy after the attainment of negative skin smears would be an effective alternative to life-long DDS treatment in LL and BL patients.

Dapsone↗