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.

Adolescent↗

PubMedDate not supplied

One year evaluation of immunogenicity conferred by a Chinese hamster ovary cell recombinant hepatitis B vaccine in a French Polynesian newborn immunization programme.

In 1988, a hepatitis immunization programme, using a Chinese hamster ovary (CHO) cell recombinant vaccine, was implemented for newborn children in the Austral archipelago (French Polynesia). Three different schedules were used: (i) 4 vaccine doses at months (M) 0, M1, M2 and M12; (ii) 3 vaccine doses at M0, M1, M6; and (iii) 3 vaccine doses at M0, M1, M2. Results at the one year follow-up may be summarized as follows. Of 197 infants who received one or more doses of CHO-recombinant vaccine, (i) none was an HBsAg carrier; (ii) 89.5% had anti-HBs-antibody titres greater than 10 miu/ml; and (iii) 95.9% had seroconverted for at least one of the 2 antibodies studied (anti-HBs or anti-pre-S2). After 2 doses (M0, M1), anti-HBs seroconversion rate and geometric mean titre were, respectively, 82.6% and 98.47 miu/ml. After 3 doses, seroconversion rates and geometric mean titres were, respectively, 91.1% and 200.59 miu/ml using schedule M0, M1, M2, and 100% and 1253.4 miu/ml using the M0, M1, M6 schedule. None of the 7 vaccinated neonates born to HBsAg/HBeAg positive mothers was found to be an HBsAg carrier. These preliminary results indicate that, in field conditions, vaccination with a CHO-recombinant vaccine resulted in high immunogenicity.

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PubMedDate not supplied

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%.

Adolescent↗

PubMedDate not supplied

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.

Adolescent↗

PubMedDate not supplied

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)

Adolescent↗

PubMedDate not supplied

Similar feeding preferences of Anopheles gambiae and A. arabiensis in Senegal.

This study in Senegal compared the feeding preferences of Anopheles gambiae and A. arabiensis while controlling for equal accessibility to hosts located outdoors under bed net traps. All fed A. gambiae complex females were identified with the aid of the polymerase chain reaction and their blood meal sources were identified by enzyme-linked immunosorbent assay. A total of 605 anophelines, including 281 A. gambiae and 301 A. arabiensis, were captured, 32.2% in the human-baited traps and 67.8% in bovine-baited traps. 30.3% of A. gambiae fed in the former and 69.7% fed in the latter; the corresponding figures for A. arabiensis were 29.6% and 70.4%. Thus, when the hosts were located outdoors and made equally available, the feeding preferences of A. gambiae and A. arabiensis were similar (P = 0.81). These results suggest that biases existed in previous studies, most of which suggested that A. arabiensis was more zoophilic than A. gambiae. Alternatively, the feeding behaviour of these 2 species may differ in various parts of Africa.

Animals↗

PubMedDate not supplied

A cohort study of Plasmodium falciparum diversity during the dry season in Ndiop, a Senegalese village with seasonal, mesoendemic malaria.

Prolonged carriage of Plasmodium falciparum in humans during the dry season is critical for parasite survival, as the infected subjects constitute a major reservoir in the absence of transmission. Yet, very little is known about the host/parasite interactions contributing to parasite persistence. In order to study the characteristics of P. falciparum infections during the dry season, we have genotyped parasites collected from untreated, asymptomatic individuals during 3 cross-sectional surveys conducted during the dry season in Ndiop, a Senegalese village with seasonal, mesoendemic malaria. Monthly entomological surveillance did not detect any transmission during that period. Parasite prevalence decreased markedly in the children aged < 7 years after 7 months of undetected transmission, but was stable in older children and adults throughout the dry season. In all chronically infected individuals, infection complexity remained stable, but there were substantial fluctuations of individual genotype(s), reflecting complex dynamics of multiple-clone infections during chronic asymptomatic parasite carriage. This fluctuation resulted in changes in the msp1 and msp2 allelic distribution within the cohort after 7 months of undetected transmission, contrasting with the stability observed during the preceding rainy season in that village.

Adolescent↗

PubMedDate not supplied

Short report: IgG1/IgG3 antibody responses to various analogs of recombinant ypfmsp119--a study in immune adults living in areas of Plasmodium falciparum transmission.

To further characterize protective-type (IgG1/IgG3) antibody responses to Plasmodium falciparum blood stage in putatively immune individuals' plasma, we have tested for various analogs of the 19 kDa C-terminus of the MSP1 antigen obtained as secreted recombinant proteins from Saccharomyces cerevisiae. One of four proteins was then identified on the basis of consistent IgG3, along with less variable IgG1 recognition. This protein has thus been selected for further functional assays of IgG1/IgG3 antibodies.

Animals↗

PubMedDate not supplied

Increased multiplicity of Plasmodium falciparum infections and skewed distribution of individual msp1 and msp2 alleles during pregnancy in Ndiop, a Senegalese village with seasonal, mesoendemic malaria.

Pregnancy is associated with a greater susceptibility to Plasmodium falciparum infections, which may result in serious complications affecting both the mother and the fetus. To compare allelic diversity and multiplicity of infection in the same women during and outside pregnancy, we conducted a retrospective analysis of the monthly fingerprick blood samples collected during a longitudinal survey conducted in Ndiop, a Senegalese village with mesoendemic malaria. Merozoite surface protein-1 (msp1) block 2 and merozoite surface protein-2 (msp2) genotypes were determined for 308 blood samples collected from 20 women. Pregnancy was associated with a significantly higher prevalence of P. falciparum infection, higher parasite densities, and a higher multiplicity of infection. The highest multiplicity of infection was observed in the youngest pregnant women. Because of co-linearity, it was not possible to dissociate the impact of age from that of parity on multiplicity of infection. Some individual msp1 and msp2 alleles showed a highly skewed pregnancy-associated distribution. These results indicate that pregnancy is associated with increased permissiveness to a large number of clones, as well as with infection by specific genotypes.

Adolescent↗

PubMedDate not supplied

[The non-insulin-dependent diabetic (type II) in Tahiti].

The authors report on the monitoring in the Diabetology Service of the Territorial Hospital Center of Papeete (French Polynesia) of 51 Polynesians, diabetics non insulin-dependent over periods of 12 to 30 months (average 26.5 months) from July 1988 to December 1991. 31 males and 20 females (sex-ratio 1.5). Mean age: 55.9 (extremes: 22 and 76 old years). Non insulin-dependent diabetes risk factors: heredity (43%), obesity (67%), new-born babies with a weight more than 4 kg (10%). Revealing factors of diabetes: systematic check-up (37%), clinical complications (36%), cardinal signs (20%). Recorded complications are: 1. microangiopathy: nephropathy (25%) including 7 renal insufficiency and 2 patients under dialysis; retinopathy (29%); 2. macroangiopathy: cardiovascular accident 1 case; angor 4 cases; obliterative arteritis of inferior limbs 5 cases; 3. neuropathy 9 cases (17%); 4. high arterial tension 55%; 5. metabolic complications (20%): 4 acidocetosis; 2 hyperosmolar coma; 4 severe hypoglycemia; 6. 16 diabetic feet (32%) among them 8 amputations; 7. 45 infectious complications in 27 patients are reviewed. Review of the complications according to diseases ancientness; before 10 years of evolution, each patient suffered of at least one complication, after 10 years, each patient got an average of 2 complications. Review of diabetic balance: 80% of the patients present a mean glycemia greater than 1.50; 54% present a postprandial glycemia greater than 2 gr. and 34% a A1 C Hb greater than 9%. The possible treatments are reviewed. During this monitoring, mortality was one case; 35 patients were admitted totaling 881 days of hospitalization.

Adult↗

PubMedDate not supplied

[Cerebral vascular accidents in French Polynesia].

The authors report on the results of a survey on cardiovascular accidents hospitalized between 01 April 1990 and 31 January 1991 carried out in the Services of Medicine and Cardiology in the Territorial Hospital Center of Papeete. This survey was: 56 cardiovascular accidents: 1/4 (hemorrhagic and 3/4 (42) ischemic. Mean age 59 (extremes 23-86). 36 males (64%); 20 females (36%). 50 Polynesians; 6 Chinese people. Among the risk factors recorded, 38 (68%) were hypertensed patients; 17 (30%) were due to tabagism and 15 (25%) to diabetes; 3 (5%) are known to be carriers of a hypercholesterolemia. 59% of the patients had no case history; 25% the cardiovascular accidents have been observed in patients with cardiopathy; 12.5% are recurrent cardiovascular accidents. Clinically, 5 transient ischemic accidents (12%) out of 42 cardiovascular ischemic accidents. High arterial tension was recognized in 12/14 (86%) of hemorrhagic cardiovascular accidents and in 26/42 (62%) of ischemic cardiovascular accidents. In 42 ischemic cardiovascular accidents, 31 patients suffered from cardiopathy (74%) of which 15 (36%) presented an embolic cardiopathy. Interest of echography and electrocardiogram are discussed. Ultrasonic exam of carotid vessels was found abnormal in almost half of the cases when utilized (12/26). Finally, etiological diagnosis was certain in 17 cases, of presumption in 16 cases, and in 9 cases, it was not possible to precise any cardiovascular etiology. Tomodensitometric tests are discussed. 86% of the ischemic cardiovascular accident were treated with anticoagulants/thrombocyte antiagglutination. 24% of the patients died, 50% recovered incompletely and 26% completely.

Adult↗