Multicenter study of street foods in 13 towns on four continents by the food and environmental hygiene study group of the international network of pasteur and associated institutes

An international multicenter study of ready-to-eat foods, sandwiches, and ice creams or sorbets sold in the streets and their vendors was carried out to assess the microbiological quality of these foods and to identify characteristics of the vendors possibly associated with pathogens. Thirteen towns in Africa, America, Asia, and Oceania were involved in the study. A single protocol was used in all 13 centers: representative sampling was by random selection of vendors and a sample of foods bought from each of these vendors at a time and date selected at random. Microbiological analyses were carried out using standardized Association Française de Normalisation methods, and the use of a standardized questionnaire to collect data concerning the characteristics of the vendors. Fifteen surveys were carried out, with 3,003 food samples from 1,268 vendors. The proportion of unsatisfactory food samples was between 12.7 and 82.9% for ice creams and sorbets and between 11.3 and 92% for sandwiches. For ice creams and sorbets, the sale of a large number of units (>80 per day) increased the risk of unsatisfactory food by a factor of 2.8 (95% confidence interval [CI]: 1.5 to 5.1), lack of training in food hygiene by 6.6 (95% CI: 1.1 to 50). and by a factor of 2.8 (95% CI: 1.4 to 5.4) for mobile vendors. These risk factors were not identified for sandwiches, this difference may be due to the presence of a cooking step in their preparation. These results show that the poor microbiological quality of these street foods constitutes a potential hazard to public health, that the extent of this hazard varies between the cities studied, and that vendors' health education in food safety is a crucial factor in the prevention of foodborne infections.

Chemoprophylaxis of leprosy in the southern Marquesas with a single 25 mg/kg dose of rifampicin. Results after 10 years

In 1988, a programme of leprosy chemoprophylaxis, employing a supervised, single 25 mg/kg dose of rifampicin, was implemented in the Southern Marquesas Islands. Of the 2786 inhabitants, 2751 (98.7%) were treated. In addition, 3144 South Marquesans living elsewhere in French Polynesia were administered the same chemoprophylaxis. During the following 10 years, seven leprosy patients were detected among those who had been administered chemoprophylaxis. Of these, two were very likely missed cases of leprosy, and cannot be considered a failure of chemoprophylaxis. The epidemiometric projection model, based on cases of leprosy observed in the Southern Marquesas during the 20 years preceding implementation of the programme, predicted that 17 leprosy cases could be expected in the South Marquesan population if no chemoprophylaxis were given. In fact, only five cases were detected in the treated population, a number significantly smaller than 17, suggesting that the chemoprophylaxis was 70% effective, assuming that no change of detection rate would have occurred without chemoprophylaxis. However, during the 10 years following implementation of the chemoprophylaxis programme, the detection rate in the Polynesian population that was not administered chemoprophylaxis declined by about 50%. Therefore, the effectiveness of the chemoprophylaxis was only 35-40%.

[How does one treat the osteitis and osteoarthritis of the extremities in older leprosy patients using granulated table sugar?]

A common problem of osteitis and septic arthritis is the recurrent bone infection after surgical debridement, a problem frequently encountered in patients with sequela leprosy. In these cases the authors propose the use of an ancient method of post surgical wound care based on the treatment with ordinary granulated sugar. The hyperosmolar climate created this way in the wounds inhibits the bacterial growth, enhances bacterial death and therefore permits the growth of granulation tissue in order to recover the debrided nude bones. At ILAD (Leprosy Institute of Dakar), 36 osteitis and septic arthritis were treated and healed during the last 2 years from March 1995 to March 1997 using this technic. All the wounds healed in the mean-time of 44 days. Only two of them needed a second debridement and healed afterwards. Up to now the method using ordinary sugar was applied in the treatment of infected wounds, eschars and postsurgical infections. Our experience shows that it also can be indicated to treat bone infections. This method is easy to apply also under often difficult field conditions and is very cheap.

[Can plantar ulcers associated with leprosy be treated in the field. Results of experience in Senegal]

The introduction of a program for the treatment of plantar ulcers (PU) in field conditions in Senegal was studied. The program was complementary to the Health Education and Protective Footwear to Prevent Disability (POD) initiatives within the Senegalese anti-leprosy program. The wound care given in health centers was coded and simplified. Access to hospitals was made easier for those patients requiring surgery. More than 30% of patients with PU were treated each year, with a mean of 62% cured. An increasing number of leprosy patients have been admitted to regional hospitals for surgery. Never before have patients with signs of leprosy had access to general hospitals. This study emphasizes the need for regular supervision of the individuals treating wounds.

Field trial on efficacy of supervised monthly dose of 600 mg rifampin, 400 mg ofloxacin and 100 mg minocycline for the treatment of leprosy; first results

In 1995, a field trial was implemented in Senegal in order to evaluate the efficacy of a regimen based on the monthly supervised intake of rifampin 600 mg, ofloxacin 400 mg and minocycline 100 mg to treat leprosy. During the first year of the trial, 220 patients with active leprosy (newly detected or relapsing after dapsone monotherapy) were recruited: 102 paucibacillary (PB) (60 males and 42 females) and 118 multibacillary (MB) (71 males and 47 females). All of them accepted the new treatment (none requested to be preferably put under standard WHO/MDT), no clinical sign which could be considered as a toxic effect of the drug was noted, and none of the patients refused to continue treatment because of any clinical trouble. The compliance was excellent: the 113 patients (PB and MB) detected during the first 6 months of the trial have taken six monthly doses in 6 months, as planned. The rate of clearance and the progressive decrease of cutaneous lesions was satisfactory. Although it is too soon to give comprehensive results, it should be noted that no treatment failure was observed in the 56 PB patients who have completed treatment and have been followed up for 6 months. The long-term efficacy of the new regimen is to be evaluated on the rate of relapse during the years following the cessation of treatment. If that relapse rate is acceptable (similar to that observed in patients after treatment with current standard WHO/ MDT), the new regimen could be a solution to treat, for instance, patients very irregular and/or living in remote or inaccessible areas since no selection of rifampin-resistant Mycobacterium leprae should be possible (a monthly dose of ofloxacin and minocycline being as effective as a dose of dapsone and clofazimine taken daily for 1 month). Nevertheless, until longer term results of this and other trials become available, there is no justification for any change in the treatment strategy, and all leprosy patients should be put under standard WHO/MDT.

[Simplification and codification of treatment for leprous plantar ulcers]

Practically leprous plantar ulcers (PU) are difficult to treat and heal under field condition. Considering the important number of patients showing a PU, the directors of national leprosy control programmes are determined, within the programmes on prevention of disabilities (POD), to treat the PU in the field. Therefore it appears to be essential to codify and simplify their treatment thus enabling it to be effective. The healing of PU being the only criteria of effectiveness of the technique. Four clinical stages were defined, each corresponding to a precise way of treatment using only essential and basic products at low cost. During the trainings about the treatment techniques and attitudes much emphasize is given on the discharge of the PU, on the trimming of the wound and on the products to use according to PU's evolutionary stage.

[Should biopsy be done on the sensory branch of the radial nerve in leprosy patients? Apropos of 112 cases]

Biopsies of the superficial sensory branch of the radial nerve are contested. Some authors mention it to be simple and without harm, but others are formally against this procedure. At ILAD, 274 biopsies were made between 1986 to 1992. We present a review of 112 leprosy patients for whom biopsy was done. On 112 reexamined patients, we observed 2 benign neuroma, hence 2%. The comparison of nerve function before biopsy and after, of 63 of the 112 patients, reexamination shows no significant modification of the functional score. Given even the occurrence of benign neuroma in only 2% of the cases, the authors do not recommend the biopsy of the superficial sensory branch of the radial nerve. For research purposes on neuritis in leprosy, as well as to assure diagnosis in primary neuritic leprosy, we propose the biopsy of the sensory branch of the musculo cutaneous nerve at elbow level.

Control of bancroftian filariasis in an endemic area of Polynesia by ivermectin 400 micrograms/kg

Community treatment with ivermectin was implemented in Opoa, French Polynesia from April 1991 to October 1993. All consenting inhabitants aged 3 years or more were treated with twice-yearly single doses of ivermectin, pregnant women excepted. A dosage of 100 microgram/kg was used for the 3 first treatments and then abandoned because it did not reduce the prevalence of microfilariae (mf) carriers. With a dosage of 400 micrograms/kg dosage, this prevalence decreased dramatically from 21% to 7%, and the mf level in carriers dropped to only 0.5% of its initial value after 3 treatments. The 400 micrograms/kg dosage was well tolerated and compliance was excellent. The twice-yearly single dose strategy with ivermectin at 400 micrograms/kg is safe and highly effective for filariasis control in an endemic area.

Pseudoepitheliomatous hyperplasia in trophic ulcers in leprosy patients. A 28-case study

Between 1984 and 1993, pseudoepitheliomatous hyperplasia developing in chronic ulcers were observed in 28 former Senegalese leprosy patients, which amounts to an annual frequency of 1.9 per 1000 ulcers. Correct diagnosis could only be made by histopathological examination of specimens taken from the depth of the lesion. Amputation was carried out on 17 patients and local excision on the other 10. Recurrence of growth was observed in 8 of the 10 patients treated by excision; in all of these 8 cases below knee amputation had to be subsequently performed. From our experience, it may be assumed that local excision should be carried out only in the case of small tumours. Since the aim of surgical procedure is to allow the patient to have physical autonomy, below knee amputation, followed by adaptation of prosthesis, should be the procedure chosen in the other cases.

[External canthopexy using the Edgerton-Montandon procedure in lagophthalmos of leprosy patients. Technique and indications. Apropos of 30 cases]

This paper deals with the results observed in 21 ancient leprosy patients suffering from lagophthalmos (13 of whom suffered from bilateral lagophthalmos) and treated by the Edgerton-Montandon surgical procedure which associates lateral canthopexy and tarsorraphy. Eighteen of the 21 treated patients were reviewed at one month after the procedure and, overall, results could be evaluated for 30 eyes. Improvement was noted in all of the 30 eyes and, globally, the residual palpebral fissure (during voluntary closing of the eyes by the patient) decreased from 6.7 mm before the procedure to 1.8 after the procedure. The following recommendations may be proposed. For young patients with intact corneal sensation, the Gillies procedure remains the procedure of choice to correct lagophthalmos. For older patients with corneal anesthesia, at high risk of blindness, the Edgerton-Montandon procedure should be recommended.

[Tumoral proliferations in chronic plantar ulcers: how to treat?]

Between 1983 and 1994, 66 Senegalese leprosy patients were seen for cauliflower growths developed in chronic plantar ulcer (CPU), (2 patients had each 2 tumors). 68 biopsies for pathological examination were taken: the diagnosis of squamous cell carcinoma was effectively made in 39 cases (38 patients) and that of pseudo-epitheliomatous hyperplasia in the remaining 29 cases (28 patients). The mean annual frequency of cauliflower growths was 0.45 per 100 CPU. Among these tumors, the percentage of carcinoma was 57%. Of the 38 patients with a carcinoma, 5 refused amputation and all of them died. The 33 others were amputated and of these 8 died as a direct result of their carcinoma (24%). In the case of the 28 patients with hyperplasia, amputation was carried out on 18 patients and local excision on 10. In the months following the operation 8 recurrences were observed in 10 of the patients on whom excision had been carried out. These recurrences were treated by amputation. This gives a total of 93% of amputations in the cases of hyperplasia. These facts lead as to conclude that at least in countries where pathological examination is not available below knee amputation is the most reasonable action to take in the proliferative tumors developed on a CPU.

Wuchereria bancrofti (Filariidea: Dipetalonematidae) and its vector Aedes polynesiensis (Diptera: Culicidae) in a French Polynesian village

In March 1991, a study on Wuchereria bancrofti (Cobbold, 1887) infection rates in its vector, Aedes polynesiensis Marks, was carried out in a village of French Polynesia. Our data were collected 10 yr after the suspension of human mass chemoprophylaxis and served as a baseline for pending ivermectin treatment scheduled in 1991-1993. In total, 1,789 biting females were collected, of which 1,740 were dissected and 1,183 (68%) were parous. Among these, 106 (8.96%) were infected with W. bancrofti and 34 (2.87%) harbored infective L3 larvae. The mean number of larvae per infected mosquito was 2.69, and the mean number of L3 larvae per L3 positive mosquito was 1.44. The Ae. polynesiensis biting index was 4.7 bites per 15 min, but varied significantly among habitats. The highest parous biting rates occurred in fields and peridomestic gardens and the lowest was close to houses. The proportion of parous infected and infective mosquitoes was higher in peridomestic habitats (0.25 infective bites per 15 min) than in domestic habitats (0.09) or in fields (0.11).

Single doses of ivermectin 400 micrograms/kg-1: the most effective dosage in bancroftian filariasis

Forty-three Wuchereria bancrofti carriers were given four successive semi-annual single doses of ivermectin 100 micrograms.kg-1 (IVER 100). The geometric mean microfilaremia (mf) recurrence percentage as compared to the pre-initial treatment mf level was 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 several individuals: 15 have been considered as 'bad responders' and 28 as 'good responders' individuals. At month 24 (M 24), they were randomly allocated into 2 groups. A first group was treated with a fifty and a sixth dose of IVER 100, at M24 and M30, respectively; the second one was treated, at the same time, with single doses of IVER 400 micrograms.kg-1 (IVER 400). At M 36, the mf recurrence percentage (mf M36/mf M0) was significantly higher in patients treated with IVER 100 than IVER 400 (11% vs 1%, p < 10(-4). From the group IVER 100, 6 out of the 8 'bad responders' remained 'bad responders' whereas there were none of the 7 in the group IVER 400. Moreover, there were only 2 more patients in the group IVER 100 showing sustained complete zero mf, whereas they were 13 in the group IVER 400. Single doses of IVER 400 were effective on 'bad responders'; IVER 400 must be recommended for semi-annual mass treatment in bancroftian filariasis.

Wuchereria bancrofti filariasis in French Polynesia: age-specific patterns of microfilaremia, circulating antigen, and specific IgG and IgG4 responses according to transmission level

The age-specific patterns of microfilaremia, Og4C3 antigenemia, anti-Brugia malayi IgG and IgG4 were assessed in 3 villages of low, medium and high transmission level for Wuchereria bancrofti filariasis. The prevalence rates for each of the 4 markers were clearly age dependent and their patterns strongly associated with the transmission level. The antigenemia prevalence rate was consistently higher than the microfilaremia prevalence rate, in all age groups. The prevalences of anti-B. malayi IgG and IgG4 responses were very similar and much higher than those of microfilaremia or antigenemia. Antibody responses reached the plateau at an earlier age and at a higher prevalence with increased intensity of transmission. For all the markers, the prevalence rates were significantly higher in males than in females.

Fibronectin-binding antigen 85 and the 10-kilodalton GroES-related heat shock protein are the predominant TH-1 response inducers in leprosy contacts

Peripheral blood mononuclear cells from 27 healthy leprosy contacts were analyzed for lymphoproliferation and TH-1 cytokine secretion (interleukin-2 and gamma interferon) in response to heat shock proteins with molecular masses of 65, 18, and 10 kDa from Mycobacterium leprae and the 30-32-kDa antigen 85 (Ag 85) from Mycobacterium bovis BCG. Cells from 18 and 19 of 19 lepromin-positive contacts proliferated or produced TH-1 cytokines in response to the M. leprae 10-kDa protein and to Ag 85, respectively. Limiting-dilution analysis for two lepromin-positive contacts indicated that about one-third of M. leprae-reactive T cells displayed specificity to the M. leprae 10-kDa protein and Ag 85. The M. leprae 65- and 18-kDa proteins were less potent TH-1 response inducers: gamma interferon and interleukin-2 could be measured in 14 and 19 lepromin-positive contacts, respectively. In contrast, very low or undetectable proliferative and cytokine responses were found for 8 lepromin-negative contacts. Our data demonstrate that the fibronectin-binding Ag 85 and the 10-kDa GroES homolog are powerful mycobacterial TH-1 response inducers in the vast majority of lepromin-positive contacts and suggest that they might be valuable candidates for a future subunit vaccine.

Double-blind controlled trial of a single dose of the combination ivermectin 400 micrograms/kg plus diethylcarbamazine 6 mg/kg for the treatment of bancroftian filariasis: results at six months

In 1993, a three-arm double-blind controlled trial was implemented in French Polynesia to compare the tolerance and efficacy of a single dose of the combination ivermectin (IVR) 400 micrograms/kg plus diethylcarbamazine (DEC) 6 mg/kg vs. IVR 400 micrograms/kg alone vs. DEC 6 mg/kg alone, for treatment of Wuchereria bancrofti carriers. Of the 57 treated male patients in whom microfilaria (mf) densities ranged from 22 to 4709 mg/mL, 3 groups of 19 were randomly selected and allocated to one of the 3 treatments. Side effects were experienced by 34 patients (60%), but none suffered a severe reaction. Grade of reaction did not differ between treatment group, but was significantly correlated with the pretreatment mf density. Six months after treatment, 26%, 32% and 53% of patients were amicrofilaraemic in the DEC, IVR and IVR+DEC groups, respectively. Mf levels were 6.3%, and 3.1% and 1.0% of the pretreatment level, respectively, significantly lower in the IVR+DEC group than in both the IVR and DEC comparison groups. The combination IVR+DEC showed promise in term of sustained mf decrease, and could be an effective alternative for lymphatic filariasis control programmes.

Low positive predictive value of anti-Brugia malayi IgG and IgG4 serology for the diagnosis of Wuchereria bancrofti

Enzyme-linked immunosorbent assays (ELISAs) for anti-Brugia malayi immunoglobulin (Ig) G and IgG4 were evaluated on sera from 1561 subjects in French Polynesia for the serodiagnosis of Wuchereria bancrofti filariasis, compared with the test for Onchocerca gibsoni circulating antigen (Og4C3) as a 'gold standard'. The sensitivity of the ELISA-IgG and ELISA-IgG4 assays was 90.8% and 94.5%, and the specificity was 45.9% and 50.7%. The positive predictive values were 41% and 45% respectively for an antigen prevalence rate of 30%. Thus antibody prevalences exceeded by two-fold the antigen prevalence, which itself exceeded by two-fold the prevalence of microfilaraemia.

T-cell-epitope mapping of the major secreted mycobacterial antigen Ag85A in tuberculosis and leprosy

Lymphoproliferation and gamma interferon (IFN-gamma) secretion in response to 28 overlapping 20-mer synthetic peptides covering the complete sequence of the mature (295-amino-acid) 85A component of the major secreted, fibronectin-binding antigen 85 complex from Mycobacterium tuberculosis and Mycobacterium bovis BCG (MTAg85A) was examined by using peripheral blood mononuclear cell (PBMC) cultures from healthy tuberculin- and lepromin-positive volunteers and from patients with tuberculosis and leprosy. Peptide recognition was largely promiscuous, with a variety of human leukocyte antigen haplotypes reacting to the same peptides. PBMC from all tuberculin-positive subjects reacted to Ag85, and the majority proliferated in response to peptide 6 (amino acids 51 to 70), peptides 13, 14, and 15 (amino acids 121 to 160), or peptides 20 and 21 (amino acids 191 to 220). PBMC from tuberculosis patients demonstrated a variable reactivity to Ag85 and its peptides, and the strongest proliferation was observed against peptide 7 (amino acids 61 to 80). MTAg85A peptides were also recognized by PBMC from healthy lepromin-positive volunteers and paucibacillary leprosy patients (again in a promiscuous manner), but despite a 90% homology between the 85A proteins of M. leprae and M. tuberculosis, the peptides recognized were different. PBMC from lepromin-positive healthy contacts reacted against peptide 2 (amino acids 11 to 30), peptide 5 (amino acids 41 to 60), and peptides 25 and 26 (amino acids 241 to 270). PBMC from paucibacillary patients reacted preferentially against peptide 1 (amino acids 1 to 20) and peptide 5. Multibacillary patients were not reactive to Ag85 or the MT85A peptides. IFN-gamma production was generally detected simultaneously with positive lymphoproliferative responses, although peptide 1 mostly stimulated proliferation and peptides 27 and 28 mostly elicited an IFN-gamma response. In conclusion, regions 41 to 80 and 241 to 295 demonstrated powerful and promiscuous T-cell-stimulatory properties, resulting in proliferative responses and IFN-gamma secretion, respectively, in the majority of reactive subjects tested in this study. These results could be of value in the development of a subunit vaccine for tuberculosis and leprosy.

Efficacy of ivermectin for the treatment of head lice (Pediculosis capitis)

Twenty six male and female patients aged 5 to 17 years who had head lice infestation confirmed by eggs presence and received treatments with a single 200 mu/kg oral dose of ivermectin in open fashion. At day 14 after treatment, 20 responded to the treatment (77%), and 6 patients (23%) presented with a complete disappearance of eggs and all clinical symptoms. At day 28, 7 patients were healed (27%), but 4 patients of the 6 healed at day 14 presented with signs of reinfestation. This study suggests that ivermectin is a promising treatment of head lice, and a second dose at day 10 should be appropriate for a further comparative trial.

Og4C3 circulating antigen, anti-Brugia malayi IgG and IgG4 titers in Wuchereria bancrofti infected patients, according to their parasitological status

This study involved 221 microfilaremic (Mf+), 302 amicrofilaremic (Mf-) antigen positive (AG+) and 1454 Mf-antigen negative (AG-) individuals living in endemic villages. Whatever the group considered, antigen and antibody titers were widely distributed. Og4C3 antigen, detected both in Mf- and Mf+ patients, was significantly higher in Mf+ patients. The Mf parasitological status did not significantly influence the antifilarial antibodies levels in the infected AG+ individuals, although IgG4 was more discriminant. In the supposedly uninfected individuals (Mf-AG-), anti-filarial IgG and IgG4 could be detected in a large proportion of the group. Og4C3 circulating antigen test was confirmed to be a good marker of active Wuchereria bancrofti infection.

Og4C3 circulating antigen: a marker of infection and adult worm burden in Wuchereria bancrofti filariasis

Og4C3 circulating filarial antigen was detected in the sera of 94.5% (259/274) of microfilaremic patients, 32% (239/751) of persons with presumption of filariasis, and 23% (11/48) of chronic filariasis patients. The antigen level was correlated with the microfilariae (Mf) density and patient age (P < .01). It remained stable in patients treated with microfilaricidal drugs. Og4C3 antigen, undetectable in Mf culture media, was demonstrated to be a rare somatic Mf antigen. It appears to be an excreted or secreted antigen from adult filaria. It could be used as a marker of infection and an indicator of adult worm burden.

Advantages of ivermectin at a single dose of 400 micrograms/kg compared with 100 micrograms/kg for community treatment of lymphatic filariasis in Polynesia

In April and October in 1991-1993, 5 supervised single doses of ivermectin were given to inhabitants aged > or = 3 years in a Polynesian district: the first 3 treatments were with 100 micrograms/kg and the 2 latter with 400 micrograms/kg. At each treatment, about 97% of the eligible population (899) were treated and blood samples were collected just before treatment from 96% of the 613 inhabitants aged > or = 15 years. Following the 5 successive treatments, adverse reactions were observed in, respectively, 23.8, 13, 6.2, 13.6 and 7.9% of the microfilariae (mf) carriers, and in less than 1% of amicrofilaraemic subjects. Neither the frequency nor the intensity of adverse reactions was significantly different between single doses of 100 micrograms/kg and 400 micrograms/kg. Although the geometric mean microfilaraemia (GMM) was reduced, the mf carrier prevalence remained unchanged before and after 3 mass treatments with 100 micrograms/kg (21.4 and 20.7% respectively), and the mf recurrence rate 6 months after each dose of 100 micrograms/kg was roughly stable (respectively, 34.3%, 21.6% and 31.2% of the initial GMM). In contrast, after one dose round of 400 micrograms/kg, the mf carrier prevalence decreased significantly to 14.9% (P < 10(-6)), and the mf recurrence rate dropped to 9.9% (P < 10(-3)) of the initial GMM. These results confirm the safety and the effectiveness of 400 micrograms/kg of ivermectin for lymphatic filariasis control.

Rate of relapse in multibacillary patients after cessation of long-course dapsone monotherapy supplemented by a final supervised single dose of 1500 mg of rifampin

When multidrug therapy was implemented in Senegal, 406 multibacillary (MB) patients who had been treated for more than 10 years by dapsone alone, and who had become clinically inactive and skin-smear negative, were released from treatment. Of these 406 patients, 298 were given a supervised single dose of 1500 mg of rifampin. Subsequently, 302 of them (229 who had been given rifampin and 73 who had not) were followed up by means of annual clinical and bacteriological examinations. Of the former 229 followed up for a mean period of 4.9 years, 34 patients relapsed (22 males and 12 females), giving a crude relapse rate of 15% and an overall risk of relapse of 3.1 per 100 patient-years. Of the latter 73 followed up for a mean period of 2.4 years, 5 relapsed (4 males and 1 female), giving a crude relapse rate of 6.8% and an overall risk of relapse of 2.9 per 100 patient-years. Such results, which are in agreement with those of a similar study conducted recently in Mali, indicate that the intake of a single dose of 1500 mg of rifampin by MB patients when they are released from long-course dapsone monotherapy does not result in a decrease of the relapse rate. Therefore, MB patients who have been treated with dapsone alone, even for long periods, should be put under multidrug therapy prior to their release from control.

T cell reactivity against antigen 85 but not against the 18- and 65-kD heat shock proteins in the early stages of acquired immunity against Mycobacterium leprae

T cell proliferation and interferon-gamma (IFN-gamma) production of peripheral blood mononuclear cells (PBMC) from 20 household contacts were tested against the 18- and 65-kD heat shock proteins from Mycobacterium leprae (ML18 and ML65 respectively) and antigen 85 from Myco. bovis bacille Calmette-Guérin (BCG) (Ag 85) during a 12-months follow-up study. Among the eight contacts that became positive, eight showed positive reactivity against Ag 85, 5/8 against ML65 and 4/8 against ML18 at the end of the study. Of the 16 contacts who were lepromin-positive either at first or second testing, all responded to Ag 85, 11 to ML 65, but only eight reacted to ML18 antigen. Contacts who were lepromin-positive at first testing developed responses to ML18 only at second testing. In contrast, among the four contacts that remained lepromin-negative during the follow up, three proliferated to Ag 85 either at first or second testing, but only one produced IFN-gamma against Ag 85 at the end of the study. These results demonstrated that T cell reactivity and particularly IFN-gamma secretion against Ag 85, but not against ML18 and ML65, might be a predominant mechanism in the early stages of acquired protective immunity against Myco. leprae.

Ivermectin plus diethylcarbamazine: an additive effect on early microfilarial clearance

The effects of ivermectin, diethylcarbamazine (DEC), and the combination of both drugs on levels of microfilaremia (mf) were studied in 30 male Polynesian Wuchereria bancrofti carriers. Microfilarial densities were measured 30 min (H1/2), 1 hr (H1), and 2, 4, 8, 24, and 96 hr (H2, H4, H8, H24, and H96) after supervised single doses of ivermectin plus DEC (400 micrograms/kg plus 1 mg/kg, respectively, 400 micrograms/kg plus 3 mg/kg, respectively, and 400 micrograms/kg plus 6 mg/kg, respectively), DEC (6 mg/kg) alone, and ivermectin (400 micrograms/kg and 100 micrograms/kg, respectively) alone given to six groups of five patients each. The results showed that 1) DEC alone or combined with ivermectin induced a rapid clearance of mf after drug intake; at H1/2, the number of circulating microfilariae was reduced to 16%, 8%, 28%, and 31%, respectively, of pretreatment values in the groups receiving ivermectin plus DEC (400 micrograms/kg plus 1 mg/kg, 400 micrograms/kg plus 3 mg/kg, and 400 micrograms/kg plus 6 mg/kg) and DEC (6 mg/kg) alone; 2) ivermectin alone induced a rapid increase of mf densities during the first 2 hr, followed by a sharp decrease from H4 to H96; and 3) between H8 and H96, mf clearance was almost complete with the combination of ivermectin and DEC. A comparison among groups did not show any synergistic interaction between ivermectin and DEC on the clearance of microfilaria, with the effect of each drug being additive to each another.

[Characterization of chronic plantar ulcers in former leprosy patients]

Between 1988 and 1992, 21 biopsies for pathological examination were taken from 20 Senegalese leprosy patients suffering from chronic plantar ulcers (CPU) suspected of malignant transformation. The diagnosis of squamous cell carcinoma was effectively made in 13 cases and that of pseudoepitheliomatous hyperplasia in the remaining 8 cases. The mean period of time between the onset of CPU and that of malignant transformation was 10 years (range: 1 to 15 years); the mean annual frequency of the malignant transformation was 2 per 1,000 CPU. In countries where pathological examination is not available, below knee amputation could be considered whenever main clinical signs of malignant transformation are present. In countries where pathological examination is available, the therapeutic decision may differ according to the diagnosis: below knee amputation supplemented with block dissection of inguinal lymph nodes whenever possible in cases of carcinoma; below knee amputation depending on the function status of the foot and on the volume of tumor in case of pseudo-epitheliomatous hyperplasia.

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)

Comparison of ivermectin and benzyl benzoate for treatment of scabies

A randomized investigator-blinded trial of oral ivermectin 100 micrograms/kg single dose vs. benzyl benzoate 10% application in the treatment of scabies, was conducted in 1992 in French Polynesia. In total, 44 patients aged 5-56 years were included in the study: 23 in the group ivermectin (IVER) and 21 in the group benzyl benzoate (BB). At day 30 after treatment, the cumulative recovery rates were 70% (16/23) in the group IVER, and 48% (10/21) in the group BB, 95% confidence intervals 51-87% and 29-70% respectively. The rates of recovery were greater in the group IVER at day 7, 14 and 30, but the difference was not statistically significant. Our results show that oral ivermectin is a valuable alternative to benzyl benzoate local treatment.

Long-term efficacy of single-dose treatment with 400 micrograms.kg-1 of ivermectin in bancroftian filariasis: results at one year

In April 1992, a safety trial was performed with a single dose of ivermectin 400 micrograms.kg-1 (IVER 400). In 37 bancroftian filariasis carriers, 6 and 12 months after IVER 400 treatment, the microfilaremia recurrences were 3.2% and 13.5%, respectively. As compared to results from other studies with diethylcarbamazine and IVER at different dosages and periodicities, the dosage of IVER 400 seems the most effective; but a yearly intake might not be sufficient.

Microfilariae recurrence in Polynesian Wuchereria bancrofti carriers treated with repeated single doses of 100 micrograms/kg of ivermectin

Forty-six Polynesian carriers of Wuchereria bancrofti were treated with 3 successive single doses of ivermectin, 100 micrograms/kg, given every 6 months. Immediate microfilaricidal activity of ivermectin was excellent in all carriers, since residual mean microfilaraemia levels, 2 d after each of the 3 treatments, were less than 1% of pretreatment levels. Before initial treatment, geometric mean microfilaraemia was 500 microfilaria (mf)/ml for the whole group (range 21-6398 mf/ml); 6 months after each successive treatment it was 197, 108 and 87 mg/ml, respectively, 39.4, 21.6 and 17.4% of the pre-initial treatment level. By considering the mean percentage recurrent level at 6 months after the 3rd treatment (36.8%) as a threshold, it was possible to classify the carriers into 2 groups: 17 in whom the percentage recurrent level was > 36.8% and who were considered as 'fast repopulating' individuals, and the remaining 29 who were considered as 'slow repopulating' individuals. In the latter group, 6 months after each of the 3 treatments, the recurrent microfilaremia levels were 22.7%, 8.0% and 4.9% of the pre-initial treatment level, respectively, while they were 95.1%, > 100% and > 100% in the former. The constant recurrence of mf suggests that ivermectin, at a dosage of 100 micrograms/kg, had no effect on adult worms in 'fast repopulating' individuals, whereas the progressive lessening in recurrence of mf suggests some activity (sterilizing or killing) of ivermectin on W. bancrofti macrofilariae in 'slow repopulating' individuals.(ABSTRACT TRUNCATED AT 250 WORDS)

Periodicity of Wuchereria bancrofti var. pacifica filariasis in French Polynesia

In 1992, a study on microfilaremia periodicity was carried out on 12 Wuchereria bancrofti carriers in the Marquesas islands. Blood samples were collected simultaneously every 4 hours during a 48 hour period by finger-prick and venipuncture for determination of microfilaremia by both blood film and membrane filtration technique methods, and for determination of antigenemia. The membrane filtration results showed no significant nycthemeral variations between the microfilaria densities at hours 16:00, 20:00, 24:00, 04:00, 08:00 and 12:00. Conversely, the blood film method showed a significant difference between the microfilaria densities: the microfilaremia was higher during the day (12:00-20:00 hours) than during the night (24:00-08:00 hours). As for antigenemia, using Og 4 C3 monoclonal antibody, there was no significant fluctuation during 48 hours. These results confirm that W. bancrofti var. pacifica is subperiodic and diurnal in French Polynesia. In particular, they substantiate the validity of examining venous blood by the membrane filtration technique as the judgment criterion of choice in therapeutic trials and of examining capillary blood during peak hours by the blood film method for evaluating the endemic level in a population.

Safety trial of single-dose treatments with a combination of ivermectin and diethylcarbamazine in bancroftian filariasis

A supervised safety trial of the treatment with a combination of ivermectin 400 micrograms.kg-1 (IVER 400) plus increasing doses of diethylcarbamazine (DEC), given simultaneously in single dose, was performed on five groups of Polynesian Wuchereria bancrofti carriers, 49 males aged 25 to 73 years, in whom microfilaremia ranged from 1 to 6,137 mf/ml. The trial was hospital-based, open, dose-escalating (1 group per week). Safety of an unchanging dose of IVER 400 and ascending doses of DEC were studied in the 5 following groups: group 1- IVER 400 plus DEC 1 mg.kg-1, 12 patients; group 2- IVER 400 plus DEC 3 mg.kg-1, 17 patients; group 3- IVER 400 plus DEC 6 mg.kg-1, 10 patients. Two control groups were included in the study, group 4- DEC 6 mg.kg-1 alone, 5 patients; group 5-: IVER 400 alone, 5 patients. Carriers were examined and questioned regarding their experience of adverse reactions, which were graded 0 to 3 according to severity, at 6, 12 and 24 hours and at 4 days after treatment. Biological examination was performed 4 days before and 4 days after treatment and included determination of microfilaremia, complete blood count, liver function tests and assessment of creatinine and urea levels. Adverse reactions were observed in 51% of 49 carriers (15 of grade 1, 8 of grade 2, 2 of grade 3). None was considered serious and they all disappeared in 2 days. The main symptoms were fever > or = 37.5 degrees C, myalgia, arthralgia, headache, asthenia, anorexia, vertigo and chills. Adverse reactions of patients were not significantly different between the five groups.(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.

Seroepidemiological survey of HTLV-I infection in French Polynesia, Cook Islands and Fiji

Different population groups of French Polynesia, Cook Islands and Fiji were screened for Human T-Lymphotropic Virus type I (HTLV-I) antibodies. Among 1487 individuals sampled in French Polynesia, twelve were considered Western Blot (WB) indeterminate and one was considered WB-positive for HTLV-I infection. This positive subject originated from France and was a blood donor. Out of 196 Polynesians of the Cook Islands, one was WB-indeterminate. Among populations sampled in Fiji, one of 222 Melanesians was found WB-indeterminate and one of 211 Indians was WB-indeterminate.

Effects of chemotherapy on antibody levels directed against PGL-I and 85A and 85B protein antigens in lepromatous patients

IgG antibodies against antigens 85A and 85B from Mycobacterium bovis BCG, IgM antibodies against phenolic glycolipid-I (PGL-I) and circulating PGL-I antigen were measured in the serum of 11 patients with lepromatous leprosy receiving multidrug therapy (MDT). Before treatment, 6 patients were reactive to antigen 85A, 10 patients to antigen 85B, and 11 patients to PGL-I; circulating PGL-I was detected in the sera of all of them. After 2 years of MDT PGL-I antigen could no longer be detected in all of the patients, except for two who were not compliant with treatment. IgG antibodies directed against the 85A and 85B antigens and IgM antibodies against the PGL-I antigen also decreased significantly during treatment but more slowly. The determination of circulating PGL-I antigen remains the most appropriate tool for monitoring lepromatous leprosy under MDT.

Results of a safety trial on single-dose treatments with 400 mcg/kg of ivermectin in bancroftian filariasis

Two groups of Polynesian Wuchereria bancrofti carriers, 17 females aged 21 to 84 years and 20 males aged 26 to 57 years, in whom microfilaraemia ranged from 1 to 10,121 mf/ml and from 1 to 6,484 mf/ml, respectively, were given a supervised singledose treatment with 400 mcg/kg of ivermectin. Carriers were examined and questioned regarding their experience of adverse reactions, which were graded 0 to 3 according to severity, at 6, 12 and 24 hours and at 4 days after treatment. Biological examinations which included determination of microfilaraemia, complete blood count, liver function tests and assessment of creatinine and urea levels were performed at 4 days before and 4 days after treatment. Adverse reactions were observed in 65% of female and in 70% of male carriers; they were of grade > or = 2 in 35% of carriers in both groups. None as considered serious; they all disappeared in 24-48 hours. The main symptoms were headache, fever > or = 37.5 degrees C and myalgia in females. One male vomited 3 hours after treatment; as a result the drug was not ingested and no decrease of microfilaraemia was noted. Twelve days afterwards, he was given a second 400 mcg/kg dose, he experienced again a grade 1 reaction and his microfilaraemia fell to zero. The 37 carriers in the present study were matched with 37 other Polynesian carriers treated with a 100 mcg/kg single dose of ivermectin in previous trials for pretreatment mf density and sex: no significant difference could be found in adverse reactions between the 2 treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)

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%.

Leprosy in French Polynesia. The possible impact of multidrug therapy on epidemiological trends

In 1982, following the recommendations of a WHO study group, multidrug therapy (MDT) was introduced into French Polynesia to treat all patients suffering from active leprosy, and--only on request--those still on dapsone monotherapy. After 5 years, a clear-cut decrease of prevalence and mean annual detection rates for leprosy (except for detection rates among children aged less than 15 years, many of such cases being detected early by increased household contact training) has been observed. There was also a decrease in the proportion of newly detected cases with disabilities. During the 21-year period preceding the introduction of MDT into the control programme, mean annual detection rates for leprosy had remained stable, and this led to the consideration that such a decrease was due neither to the natural decline of the disease nor to the economic improvement of the country. Our results, together with the fact that, to date, the relapse rate was nil in the Polynesian patients put on MDT, strongly suggest that the implementation of MDT has resulted in a decrease of detection rates for leprosy which may be a consequence of a decrease in the transmission of the disease.

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.

A comparative study of detection methods for evaluation of microfilaremia in lymphatic filariasis control programmes

The evaluation of microfilaremia (mf) was performed in 96% of the population aged 15 years or more in a village of Moorea, one of the Society Islands in French Polynesia. Finger-prick and venous blood samples were collected simultaneously from 782 individuals in order to compare the results obtained by the standard blood film method and the membrane filtration technique. Of the 782 blood-sampled inhabitants 69 (8.8%) were found mf positive. 39 (5%) were mf positive by both methods and 30 were mf positive by the membrane filtration technique only. In these latter 30 carriers the geometric mean mf count was 19.7 mf/ml, significantly lower than that of 651.1 mf/ml in the 39 carriers positive by both techniques. Using the membrane filtration technique, the mf carrier prevalence rate increased from 1.9% in the youngest age group (15-19 years) to 16.9% in the oldest (< or = 60 years) while using the blood film method, it increased from 1.3% to 12.7%. Roughly, when using the membrane filtration technique, the mf carrier prevalence rate was 1.77 higher than that found using the blood film method, considering either the whole population or successive age-groups. Moreover, when using the blood film method in the 40 years and more age group, the mf carrier prevalence rate was 10%, a proportion similar to the 8.8% prevalence rate determined by the membrane filtration technique in the whole population. Further studies are planned to assess whether the last finding may be confirmed in other Polynesian populations.(ABSTRACT TRUNCATED AT 250 WORDS)

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)

IgA immunoassay for the diagnosis of bancroftian filariasis

In some parasitic infection such as toxoplasmosis, specific IgA is a highly reliable marker of active infection. In bancroftian filariasis, only 10 of 20 (50%) and 3 of 20 (15%) of the microfilaremic patients were positive for IgA anti-Brugia malayi using respectively indirect ELISA and immunocapture ELISA tests. As regard to these low sensitivities, the detection of specific IgA is unlikely to be a useful test for the diagnosis of active Wuchereria bancrofti infection.

[Ivermectin or diethylcarbamazine in spaced dosages in Bancroft's filariasis: which protocol?]

58 apparently healthy Polynesian Wuchereria bancrofti carriers were randomly allocated to 5 treatment groups: 1) two annual doses of ivermectin 100 mcg/kg, 2) three semi-annual doses of ivermectin 100 mcg/kg, 3) two annual doses of diethylcarbamazine (DEC) 3 mg/kg, 4) semi-annual doses of DEC 3 mg/kg, 5) two annual doses of DEC 6 mg/kg. Results observed during the 12-month period which followed last treatment have confirmed that efficacy of ivermectin is higher than that of DEC in terms of immediate clearance or complete negativation of microfilaremia, but not in terms of sustained reduction and that 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. They also have indicated that (i) 6 months after last treatment: 3 semi-annual doses of 100 mcg/kg of ivermectin have resulted in high reduction of microfilaremia (85%) and, 2 annual doses of 6 mg/kg and 3 semi-annual doses of 3 mg/kg of DEC have resulted in even greater reduction (96 and 98% respectively) and (ii): 12 months after last treatment, the greatest reductions of microfilaremia (95 and 92%) have been observed in carriers treated, respectively, with 3 semi-annual doses of 3 mg/kg or with 2 annual doses of 6 mg/kg of DEC.(ABSTRACT TRUNCATED AT 250 WORDS)

[Evaluation of the efficacy of mannitol in the treatment of ciguatera in French Polynesia]

Up till now, in the French Polynesia and in New Caledonia, people showing ciguatera intoxication receive a standard treatment: calcium + vitamins B6 and C by intravenous way and in addition, some drugs arriving to cure some symptomatic manifestations. In 1988, an investigation carried out in Majuro, Marshall Islands concluded that intravenous mannitol is efficient in the treatment of serious intoxications with suspecting cerebral oedema. Since, such a treatment has been utilized with success in several endemic areas. Our therapeutic evaluation was arrived to determine whether mannitol's efficiency is higher than the standard treatment in the ciguatera intoxications of mean seriousness. This investigation was carried out on two randomized groups: The first one receiving mannitol (250 cc intravenous at 20% injected in 1 h) the second one receiving the standard treatment (intravenous perfusion glucose serum 250 cc with 1 g of vitamins C, 250 mg of vitamin B6 and 1 g of calcium gluconate injected in 1 h). Seriousness of clinical status was evaluated according to a scale of score from 0 to 50, based on the importance of the clinical manifestations paresthesia, aches, asthenia, cardiovascular and digestive signs. Only patients getting a score at least 20 were included in this investigation. Clinical status of each patient was evaluated before any treatment (initial score) at the end of perfusion and at the 24th hour. Efficiency of each treatment respectively was evaluated according to the differences between these three different scores. CHI 2 and U Mann's and Whitney's tests were utilized for the statistical analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Cumulative mortality rates in Aedes polynesiensis after feeding on polynesian Wuchereria bancrofti carriers treated with single doses of ivermectin, diethylcarbamazine and placebo

During a therapeutic trial, batches of 672 to 1979 laboratory-bred Aedes polynesiensis, the mosquito vector of lymphatic filariasis in French Polynesia, were fed on Wuchereria bancrofti carriers one, three and six months after they had been treated with either single doses of ivermectin at 100 mcg/kg, diethylcarbamazine (DEC) at 3 and 6 mg/kg or placebo. High mortality rates were observed during the 15-day period following the blood-meal in mosquitoes fed on carriers treated with microfilaricidal drugs and were significantly higher in mosquitoes fed on carriers treated with ivermectin than in those fed on carriers treated with DEC. Though its intensity decreased with the passage of time, the phenomenon was observed in mosquitoes fed on carriers up to six months after treatment, especially in those fed on carriers treated with ivermectin. By decreasing the number of mosquitoes able to transmit the infection, this lethal effect on Ae. polynesiensis might represent an additional advantage of ivermectin in lymphatic filariasis control programs.