Alpha-thalassaemia and globin gene rearrangements in French Polynesia.

The prevalence of alpha-thalassaemia and various globin gene rearrangements was determined in 1992 individuals living on 11 islands in French Polynesia. The gene frequencies for alpha(+)-thalassaemia (almost exclusively the -alpha 3.7III deletion form) range from 5.3% to 19.2%. Haematological indices on 177 heterozygotes and 27 homozygotes for the -alpha 3.7III variant showed considerable overlap with indices of normal individuals; although there was a broad correlation of average indices with alpha-globin genotype, individual values were a poor indication of genotype. A non-deletion form of alpha(+)-thalassaemia (alpha alpha Th), triplicated alpha genes (alpha alpha alpha) and single zeta gene (-zeta) chromosomes were present at low frequencies (< 1%), whereas triplicated gamma gene (gamma gamma gamma) and triplicated zeta (zeta zeta zeta) arrangements were more common (1.1-16.3%). alpha 0-thalassaemia, probably introduced from Southeast Asia in the early part of this century, was observed in a number of individuals of Chinese and Chinese/Polynesian ancestry. Because of the high frequency of alpha(+)-Thalassaemia on some islands, it therefore seems likely that haemoglobin H disease (resulting from the interaction between alpha 0 and alpha(+)-thalassaemia) must occur in parts of French Polynesia.

Ivermectin 400 micrograms/kg: long-term suppression of microfilariae in Bancroftian filariasis.

Forty-three Wuchereria bancrofti carriers were given 4 successive semi-annual single doses of ivermectin 100 micrograms/kg (IVER 100). The geometric mean microfilaremia (mf) recurrence percentages, compared to the pre-initial treatment mf level, were 35%, 21%, 17% and 17% at 6, 12, 18 and 24 months respectively. However, the recurrence of mf 6 months after the fourth treatment remained high in 15 individuals, considered as 'bad responders'. At month 24, the subjects were randomly allocated into 2 groups: the first group was treated with a fifth dose of IVER 100 and the second with a first, single dose of 400 micrograms/kg of ivermectin (IVER 400). At month 30, the mf recurrence percentage was significantly higher in patients treated with IVER 100 than in those receiving IVER 400 (61% vs. 8%, P < 0.05). In the IVER 100 group, 6 of the 8 'bad responders' remained 'bad responders', whereas only 2 of 7 did so in the IVER 400 group. Only 3 additional patients in the IVER 100 group became consistently amicrofilaraemic, whereas 9 did so in the IVER 400 group. Two 'good responders' in the IVER 100 group became 'bad responders'. A single dose of 400 micrograms/kg of ivermectin has been demonstrated to be efficient for the treatment of carriers refractory to repeated doses of 100 micrograms/kg and to result in better long-term mf suppression. These results suggest a possible effect of 400 micrograms/kg of ivermectin on macrofilaria.

Low predictive value of PGL-I serology for the early diagnosis of leprosy in family contacts: results of a 10-year prospective field study in French Polynesia.

In 1983, a cohort study to follow up the family contacts of leprosy cases was implemented in French Polynesia to assess the usefulness and applicability of phenolic glycolipid-I (PGL-I) serology in a leprosy control program. A total of 1201 contacts (666 females, 535 males) have been included in the study. The IgM anti-PGL-I seroprevalence determined on the initial sera was 17%. It was significantly higher among females than males (20% vs 15%, p = 0.02). From 1983 to 1992, 4 out of 204 (2%) anti-PGL-I seropositive contacts developed the disease (1 indeterminate, 1 BT, 1 BL, 1 LL) compared with 10 out of 997 (1%) seronegative contacts (4 indeterminate, 3 BT, 1 BB, 2 TT). Of these 10 patients, only 3 (2 indeterminate, 1 BT) converted to seropositivity when leprosy was diagnosed. The risk of developing leprosy was not significantly higher among seropositive than among seronegative groups (2% vs 1%, p = 0.2). A PGL-I circulating antigen test performed on 216 selected sera at entry into the trial showed a higher antigen prevalence when the antibody level was higher. PGL-I antigen was detectable in 5 of 12 patients tested prior to diagnosis (1 LL, 1 BL, 3 indeterminate). The median time to externalize the disease was not significantly different among antibody-positive and -negative contacts (17 vs 25 months, p = 0.3). The relative risk of developing leprosy for contact individuals was 30.8 times that of noncontacts, and 15% of the total new cases detected between 1983 and 1992 emerged from the study population.(ABSTRACT TRUNCATED AT 250 WORDS)

Tuberculosis in leprosy patients detected between 1902 and 1991 in French Polynesia.

From 1902 onward, notification and follow up of leprosy patients has been systematic in French Polynesia. Since 1960, a tuberculosis control program and a register has also been implemented. From 1902 to 1959, 673 cases of leprosy were detected [346 multibacillary (MB), 138 paucibacillary (PB), and 179 unclassified due to the loss of medical files by the time of classification which was done during the 1980s]. Of these 673 cases, 89 (13.2%) died from tuberculosis, giving a mean annual death rate of tuberculosis in leprosy patients of 232 per 100,000. Mortality from tuberculosis in leprosy patients detected between 1901 and 1930 was 20.7%, and decreased to 8.04% in patients detected from 1931 to 1959. In total, it was estimated that 26.4% of the leprosy cases had developed tuberculosis. From 1960 to 1991, 350 new cases of leprosy were detected (141 MB, 209 PB). Of them, 12 (3.4%) developed tuberculosis (7 before detection of leprosy, 5 after detection of leprosy). The dramatic decrease of the proportion of leprosy patients who developed tuberculosis between the periods 1902-1959 (26.4%) and 1960-1991 (3.4%) might be related to the important decline of the tuberculosis situation since 1960. From 1902 to 1959, mortality from tuberculosis occurred significantly more frequently in MB patients (13%) than in PB patients [4%, relative risk (RR) = 3.21, p = 0.003]. From 1960 to 1991, the incidence of tuberculosis seemed more frequent in MB patients (RR = 2.96, p = 0.07) whatever the sequence of detection of the two diseases. Our study suggests that lepromatous patients could share factors of susceptibility to mycobacterial diseases with patients developing tuberculosis.

Chemoprophylaxis of leprosy with a single dose of 25 mg per kg rifampin in the southern Marquesas; results after four years.

In January-February 1988, a program of chemoprophylaxis for leprosy, using a single 25 mg/kg dose of rifampin, was conducted among 2786 (98.7%) inhabitants of the Southern Marquesas and 3144 South Marquesan "emigrants" and their families. Among the treated population, during the 4 years which followed the implementation of the program, two leprosy patients were detected, one of whom can be considered as a failure of chemoprophylaxis because she was not known by the leprosy control unit. During the same period (1988-1991), a decrease in detection rates for leprosy in the entire French Polynesian population has been observed, an event which makes the interpretation of these findings very difficult. Nevertheless, according to presently available data, the effectiveness of chemoprophylaxis with a single dose of 25 mg/kg rifampin is estimated to be about 40% to 50%. When considering not only the results of the present study but also the financial and logistic constraints raised by such a program, one is led to the conclusion that chemoprophylaxis, even with a single dose of rifampin, is not likely to become an effective component of leprosy control programs.

Leprosy in French Polynesia. Epidemiological trends between 1946 and 1987.

The analysis of computerized data (OMSLEP system) on patients from French Polynesia followed since 1940 has shown a decrease in the mean annual detection rates for leprosy, all forms combined, from 24.73 per 100,000 inhabitants in 1946 to 8.1 per 100,000 in 1987 (y = -0.49 x + 45.83; p < 0.05). In fact, the decrease was significant (y = -1.18 x + 83.54; p < 0.05) during the first half of the study period (1946-66), but not during the second half (1967-87). Similarly, a significant decrease in all of the specific mean annual detection rates (according to the form of leprosy and to the sex and age of patients), in the proportion of multibacillary patients among the total of newly detected cases, and in the proportion of all patients with disabilities at the onset of leprosy was observed only during the first half of the study period (1946-66). Nevertheless, when comparing age-specific cumulative detection rates, calculated by 10-year age groups over the period 1946-66, to those of the period 1967-87, an ageing of the leprosy population was noted. Finally, the decrease of mean annual detection rates was greater in the smaller populations of remote islands than in the population of Tahiti, the main island, where 70% of the total population were living during the study period. This decline was shown to correspond to an effective improvement of the leprosy situation which could be attributed, among other factors (such as economic development and systematic BCG vaccination), to the implementation of a control programme for leprosy in 1950. The introduction in 1982 of multidrug therapy for all patients suffering active leprosy has raised the hope of a subsequent decline of leprosy in French Polynesia in the near future.

Mass chemoprophylaxis of lymphatic filariasis with a single dose of ivermectin in a Polynesian community with a high Wuchereria bancrofti infection rate.

In April 1991 supervised mass prophylaxis of lymphatic filariasis with a single dose of ivermectin, 100 micrograms/kg, was carried out in a Polynesian village with a high infection rate of Wuchereria bancrofti in humans and active transmission by the vector mosquito, Aedes polynesiensis. Of 876 inhabitants aged 3 years or more (pregnant women excluded), 864 (98.6%) were treated. Simultaneously, venous blood samples were collected from 577 (97.5%) of the 595 inhabitants aged 15 years or more, of whom 122 (21.4%) were found to be microfilaria (mf) carriers (86 males and 36 females). The geometric mean microfilariae (GMM) count was 358.7 mf/ml for the whole group, 387 mf/ml for males (range 1-8160 mf/ml) and 280 mf/ml for females (range 1-7769 mf/ml). Following treatment, 33 (3.8%) of the 864 persons treated experienced some adverse reactions (21 with grade 1 and 12 with grade 2). Of the 33 with reactions, 29 were among the 122 (23.8%) mf carriers and 4 among the 831 (0.5%) non-microfilaraemic persons. Six months later, 123 (21.1%) of 584 inhabitants sampled were microfilaraemic: the GMM count for the whole group was 106 mf/ml (1-8177), with 29 mf/ml (1-3740) in 35 female and 177 mf/ml (1-8177) in 88 male carriers. Of these 123, 15 (whose GMM count was 4.5 mf/ml; range 1-204) were amicrofilaraemic 6 months before, and 19 had a microfilaraemia level higher than that 6 months earlier, before treatment. 117 of the 122 carriers identified in April were resampled: comparison of their GMM counts before and 6 months after mass treatment indicated that treatment with a single dose of 100 micrograms/kg ivermectin resulted in a reduction of microfilaraemia by 69%.

Wuchereria bancrofti infection in human and mosquito populations of a Polynesian village ten years after interruption of mass chemoprophylaxis with diethylcarbamazine.

In 1991, a study on Wuchereria bancrofti microfilariae (mf) and infection rates was carried out in the human and mosquito populations of a Polynesian village where, 10 years before, the mf prevalence rate was 6.4% and twice-yearly mass treatment with 3 mg/kg of diethylcarbamazine (DEC) was interrupted. Venous blood samples were collected from 575 (97%) individuals aged 15 years or more, of whom 122 (21.4%) were mf positive. The mf carrier prevalence rate was 27.4% in males, significantly higher than that of 14% in females; it increased from 7-12% in the youngest age group (15-19 years) to 40-50% in the oldest (> or = 60 years) for both males and females. 387 mosquito collections were performed and 1748 female Aedes polynesiensis were dissected, of which 1176 were parous. Among the latter, 114 (9.7%) were infected with Wuchereria bancrofti larvae at L1, L2 or L3 stages. The mean number of larvae per mosquito was 2.46 (range 1-15). Of the 114 infected mosquitoes, 30 harboured L3 larvae, giving a 2.55% infective rate; the mean number of L3 larvae per mosquito was 1.15 (range 1-2). Such findings indicate that the interruption of systematic twice-yearly mass treatment with DEC (3 mg/kg) has resulted, after 10 years, in a substantial increase of microfilarial prevalence in humans, and in high infection rates in mosquitoes.

Compared efficacy of repeated annual and semi-annual doses of ivermectin and diethylcarbamazine for prevention of Wuchereria bancrofti filariasis in French Polynesia. Final evaluation.

In October 1989, 58 apparently healthy Polynesian Wuchereria bancrofti carriers, in whom microfilarial (mf) density was greater than or equal to 100 mf/ml, were randomly allocated to treatment groups receiving single doses of either ivermectin at 100 mcg/kg or diethylcarbamazine (DEC) at 3 and 6 mg/kg. Six months later, half of the carriers initially treated with ivermectin 100 mcg/kg or DEC 3 mg/kg were given a second similar dose while the rest were given a placebo. Six months later again, all of the carriers received a last treatment dose similar to the initial one. The results observed during the 12-month period which followed this last treatment have confirmed that (i) in terms of immediate clearance or complete negativation of microfilaremia, the efficacy of ivermectin is higher than that of DEC (at dosage of 3 or 6 mg/kg), (ii) DEC is more effective than ivermectin in sustaining the reduction of microfilaremia over a longer period of time and (iii) the efficacy of repeated single doses of either DEC 3 mg/kg or ivermectin 100 mcg/kg is much higher when given semi-annually than annually.(ABSTRACT TRUNCATED AT 250 WORDS)

Dengue 1 epidemic in French Polynesia, 1988-1989: surveillance and clinical, epidemiological, virological and serological findings in 1752 documented clinical cases.

An epidemic of dengue 1 occurred in French Polynesia in December 1988 and June 1989. This paper records (i) the trend of the outbreak and its surveillance and (ii) the clinical, epidemiological and virological data obtained from 1752 documented cases. The epidemic reached its peak in February in Tahiti Island, 7 weeks after its recognition. Among 6034 suspect cases reported by sentinel physicians, 60.3% were < 20 years old. The illness was classical dengue. No fatality or case of dengue haemorrhagic fever/dengue with shock syndrome was reported. Of 4792 patients subjected to laboratory testing, 41% were confirmed as positive. The serological attack rate was c. 40%. The estimated number of dengue infections in the Windward Islands was about 20,000. Transmission was associated with Aedes aegypti. Study of documented cases showed a higher confirmation rate in both the civilian population < 15 years old (46.5%) and the susceptible French military population (47.6%) than in older civilians (31.1%, P < 0.05). Furthermore, primary dengue infections were predominant in both of the first 2 groups. The diagnosis was mostly confirmed (i) by virus isolation on day < 5 of illness and (ii) by detection of immunoglobulin (Ig) M on day > or = 5 of illness. The study showed that adequate surveillance of an epidemic requires both clinically and laboratory-based systems.

Are Streptomyces bacteria involved in the ciguatoxicity of the surgeon fish Ctenochaetus striatus?

Several Streptomyces strains have been isolated from the digestive tract of the herbivorous fish C. striatus, a preeminent ciguateric fish of Polynesian waters. In order to study the possible role played by these bacteria in the toxicity of this fish, the quantitative and qualitative distributions of these isolates within toxic and non toxic fish are compared. The preliminary results are discussed.

Single versus repeated doses of ivermectin and diethylcarbamazine for the treatment of Wuchereria bancrofti var. pacifica microfilaremia. Results at 12 months of a double-blind study.

In October 1989, 58 apparently healthy Polynesian Wuchereria bancrofti carriers in whom microfilarial (mf) density was greater than or equal to 100 mf/ml were randomly allocated to treatment groups receiving single doses of either ivermectin at 100 mcg/kg or diethylcarbamazine (DEC) at 3 and 6 mg/kg. Six months later, half of the carriers initially treated with ivermectin 100 mcg/kg or DEC 3 mg/kg were given a second similar dose while the rest were given a placebo. By day 360 (6 months after retreatment), comparison of adjusted geometric mean mf counts per group indicated that (i) among the 3 treatments given once a year the DEC 6 mg/kg dose resulted in the highest efficacy, (ii) nevertheless, regarding either ivermectin 100 mcg/kg or DEC 3 mg/kg, 2 successive doses resulted in higher efficacy than one annual dose and (iii) though no significant difference could be evidenced between efficacy of ivermectin 100 mcg/kg and DEC 3 mg/kg given twice a year, DEC seemed to sustain the mf reduction for a longer period of time. During the 3 days following retreatment, adverse reactions (mild to moderate) were observed in 46% of carriers treated with microfilaricidal drugs and in 20% of those treated with placebo. These results suggest that single dose therapy with either DEC or ivermectin is safe and effective for prevention of lymphatic filariasis due to Wuchereria bancrofti in French Polynesia. The real impact on transmission by the vector, Aedes polynesiensis, of the complete negativation of microfilaremia observed during the previous part of the trial in carriers treated with ivermectin should be evaluated in a community-based trial including entomological study.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic values of ELISA-IgG4 as compared to ELISA-IgG and indirect immunofluorescence, for the routine diagnosis of bancroftian filariasis in the South Pacific. Application on capillary blood collected on filter paper.

For the serodiagnosis of lymphatic filariasis, serological assays restricted to the detection of specific IgG4 antibodies enhanced the specificity. In French Polynesia, Wuchereria bancrofti is the sole human filaria and other pathogenic parasites are infrequent. In order to define a simple and cheap serological test, we have compared the diagnostic value of indirect immunofluorescence test (IFI-WBp), ELISA-IgG and ELISA-IgG4 assays. The specificity, sensitivity, R.O.C. curves of each test have been analyzed. No significant difference was found between those 3 tests, except that the reproducibility and the predictive value were lower using IFI-WBp than using the two ELISAs. Significant correlation was found between IgG and IgG4 anti-Brugia malayi antibody titers (r = 0.512, p less than 10(-5)). For large scale seropidemiological studies, ELISA-IgG can be performed with finger prick blood absorbed on filter paper, but not ELISA-IgG4. In conclusion, ELISA-IgG a less expensive and less time consuming method than ELISA-IgG4, can be used for the routine serodiagnosis as well as for seroepidemiological studies on bancroftian filariasis in the South Pacific islands.

The treatment of microfilaremia due to Wuchereria bancrofti var. pacifica: ivermectin versus diethylcarbamazine. / Traitement de la microfilarémie à Wuchereria bancrofti var. pacifica: ivermectine versus diethylcarbamazine.

In October 1989, a controlled, double-blind parallel group trial was implemented to compare both efficacy and tolerability of single doses of ivermectin and diethylcarbamazine (DEC). Fifty eight apparently healthy Wuchereria bancrofti carriers were hospitalized and randomly allocated to treatment with ivermectin 100 mcg/kg, DEC 3 or 6 mg/kg. Six months later, half of those initially treated with ivermectin 100 mcg/kg and DEC 3 mg/kg were given a second similar dose while the rest were given a placebo. After initial treatment, clearance of microfilaremia was complete in 22 of the 23 carriers treated with ivermectin and in one only of the 35 treated with DEC. Adjusted geometric mean microfilaremia was significantly lower (p less than 0.01) in carriers treated with ivermectin than in those treated with DEC at one, but neither at 3 (p = 0.26) nor at 6 months (p = 0.63). The comparison of adjusted geometric mean microfilaremia per group indicated that (i) regarding either ivermectin 100 mcg/kg or DEC 3 mg/kg, 2 successive doses resulted in higher efficacy than one annual dose and (ii) efficacy of 2 successive doses of ivermectin 100 mcg/kg or DEC 3 mg/kg were not significantly different. During the 3 days following initial treatment, adverse reactions were observed in 80% of the treated carriers of whom 14% suffered a grade 3 reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Longitudinal study on relapses of leprosy in Polynesian multibacillary patients on dapsone monotherapy between 1946 and 1970.

Between 1946 and 1970, 295 new leprosy patients were detected in French Polynesia, of whom 145 were multibacillary. Of these 145, put on dapsone monotherapy, 131 reached bacteriological negativity in a period of time ranging from 2 to 12 years (average 4.72 years) and were followed-up for a period of time ranging from 19 to 43 years (median follow-up period after bacteriological negativity; 18 years). Among the 131 patients, 36 relapses were detected, the first one 4 years after bacteriological negativity and the last one 26 years after. The crude relapse rate was 27.5%, the risk of relapse was 1.39 per 100 patient years and the cumulative relapse probability, calculated using the lifetable method, reached 0.38 +/- 11 by year 31 of the study. From these findings one may assume that, at least in French Polynesia, one-third to one-half of multibacillary patients put on dapsone monotherapy would relapse if still present 36 years after bacteriological negativity. Such results re-emphasize the need for leprosy patients to be treated with multidrug therapy as recommended by WHO.

Effect of two successive annual treatments with single doses of ivermectin on microfilaraemia due to Wuchereria bancrofti var. pacifica.

Between 1986 and 1988 a single-blind, dose-ranging study was carried out in French Polynesia to determine the efficacy and tolerability of single 50, 100, 150 and 200 micrograms/kg doses of ivermectin in Wuchereria bancrofti carriers. Forty male microfilariae (mf) carriers between 18 and 50 years of age, in whom mf density was greater than or equal to 20 mf/ml, were treated twice at a one-year interval. Twelve months after the second treatment, in carriers who were given a dose greater than or equal to 100 micrograms/kg, mean mf density was 4-7% of the initial pretreatment mf density. Therefore, several successive annual treatments with single doses greater than or equal to 100 micrograms/kg of ivermectin should result in reducing mf densities to a very low level. Nevertheless, at 9 months after the second treatment, residual parasitaemia ranged from 1 to 2182 mf/ml (median 85) in 30 patients. Finally, in patients with pretreatment mf counts less than or equal to 150 mf/ml, mean mf density was 2.8 and 8.9 mf/ml, respectively, during the 2 six-month periods following treatment, while in patients with pretreatment mf densities greater than 150 mf/ml (median 1500) it was 92.3 and 334.1 mf/ml during the same periods. These results suggest that, when implementing filariasis control programmes, the best strategy might be administration of several treatments with a single dose of ivermectin every 6 months to the entire population, at least in French Polynesia. Afterwards, when mf densities had been reduced to a relatively low level (100-150 mf/ml), annual treatments could be considered.

Assessment of anti-phenolic glycolipid-I IgM levels using an ELISA for detection of M. leprae infection in populations of the South Pacific Islands.

Anti-phenolic glycolipid-I (PGL-I) IgM levels were determined in 96% of the general population of the Southern Marquesas and Maupiti, remote islands of French Polynesia, where the average annual detection rates of leprosy during the past 30 years have been 57.1 and 4.4 per 100,000, respectively. The seropositivity in these two areas was 4.3% and 4.2%, respectively. No significant difference (p greater than 0.05) was found between either these two figures or between the percentages of persons with high (greater than or equal to 0.500 OD) anti-PGL-I IgM levels (9.2% and 5.3%). In the two islands, the age distributions of anti-PGL-I IgM were very similar; the percentage of positive responders was higher in females than in males and higher in adolescents than in adults. These results suggest that the usefulness of the determination of anti-PGL-I IgM levels by ELISA, using the synthetic trisaccharide as antigen, for detecting Mycobacterium leprae infection in leprosy control programs is extremely doubtful.

Ivermectin for treatment of bancroftian filariasis in French Polynesia: efficacy in man, effect on transmission by vector Aedes polynesiensis.

Forty male Polynesian W. bancrofti carriers with mf counts greater than or equal to 20/ml were treated with a single ivermectin 50, 100, 150 or 200 mcg/kg dose. Following therapy, mf levels fell to less than 1% of pretreatment levels in the carriers treated with the 3 highest doses. After one month, negativation rate was 40% in patients treated with a 50 mcg/kg dose, significantly lower than in patients treated with higher doses. Recurrence of microfilaremia was observed by 3 months, mf recurrence percentages were significantly lower in patients treated with the 3 highest doses than in patients treated with a 50 mcg/kg dose. At 6 months, mf recurrence percentages reached 49.8, 12.6, 14 and 5.4% of pretreatment levels in carriers treated with 50, 100, 150 and 200 mcg/kg, respectively. No significant difference was observed between mf levels by group at 6 and 12 months. With respect to efficacy, a dose greater than or equal to 100 mcg/kg appeared superior to 50 mcg/kg dose; no significant difference between the 3 highest doses was observed. Some patients developed headache, myalgia and fever within 24 hours following therapy, none of adverse reactions were considered serious. In vector Ae. polynesiensis fed on carriers 6 months after treatment, average numbers of mf ingested and average numbers of L3 cephalic larvae were lower than those observed in mosquitoes fed on non-treated carriers with comparable mf counts.(ABSTRACT TRUNCATED AT 250 WORDS)

[The detection of IgM antibodies to phenolglycolipid I for serodiagnosis of Hansen's disease and monitoring the contact population in Polynesia. Five year evaluation]. / La détection des IgM anti-PGLI pour le sérodiagnostic des malades hanséniens et la surveillance des sujets contacts en Polynésie. Bilan sur 5 ans.

This study was conducted to assess the usefulness of IgM anti-PGLI antibody test, for the diagnosis of leprosy and of the subclinical infection among contact population. Even if the specificity (97.7%), sensitivity (98% for the multibacillary, but 36% for the paucibacillary) and efficiency (97.7%) of the test for the diagnosis of patients are good, its positive predictive value which is the proportion of true patients among the seropositive subjects detected in the population was very low (1.17% in Polynesia), because of the very low prevalence of leprosy. For the diagnosis of the subclinical infection, our experience based on the follow up of a population of 1,123 contacts, showed that such a control program would have low feasibility and low cost-effectiveness. After 5 years, the proportion of individuals developing the disease was not different among the seropositive than among the seronegative subjects. Finally, only 17.5% of the new cases of leprosy detected, were issued from the contact population followed. In conclusion and in a practical point of view, although this test may contribute to the diagnosis of patients, it is not likely useful neither for the diagnosis nor for the prognosis of leprosy in a population.