[Incidence of HIV infection in consultants reviewed after a first negative test in an anonymous and free screening center at the Institut Pasteur of Cambodia, 1996-1999]. / Incidence de l'infection VIH parmi les consultants revus après un premier test négatif au centre de dépistage anonyme et gratuit de l'Institut Pasteur du Cambodge, 1996-1999.

A retrospective study was performed to determine the incidence of HIV seroconversion among repeat consultants attending the voluntary testing and counselling centre of the Institut Pasteur of Cambodia as well as factors associated with HIV seroconversion. From 1996 to 1999, 5541 repeat consultants were selected for the study. Exclusion criteria included being aged under 15 years, having initially tested positive or inconclusive and a time span of fewer than 30 days since the last test. In all, 276 persons had seroconverted to HIV, giving an incidence rate of 5.56 per 100 person-years. The seroconversion rate declined from 8.46% in 1996, to 3.06% in 1999 (chi 2 test for trend, p = 10(-5)). Among the risk factors analysed, 3 were significantly associated with lack of seroconversion: being a student (RR = 0.53, p = 0.032) or a civil servant (RR = 0.63, p = 0.012) and systematic condom use with causal partners (RR = 0.37, p = 10(-5)). The decline of HIV seroconversion among repeat consultants attending the VCT centre over the study period may reflect changes in risk behaviour and the beneficial impact of counselling.

[Dengue epidemic in New Caledonia (1989). Environmental factors and prevention]. / Epidémie de dengue en Nouvelle-Calédonie (1989). Facteurs environnementaux et prévention.

An extensive dengue epidemic was reported in New Caledonia en 1989. Environmental factors (temperature and rainfalls) directly controlled the mosquitos population at the end of 1988. The introduction of a new dengue virus, transmitted by Aedes aegypti, was responsible for an epidemic that occurred in January-April 1989 and lasted until July 1989. The estimated number of cases was 25,000 and the attack rate was close to 120 per thousand inhabitants for a six month-period. The epidemic involved mainly the adult population in 84% of cases and 6-8% of patients was admitted in hospital with thrombopenia, leucopenia, minor haemorrhages in 2/3 of cases and 12 patients died with severe hemorrhagic disease or shock syndrome; initial serological results from suspected cases were positive against dengue by haemaglutination inhibition. Two dengue viruses were involved (dengue 1 and dengue 3) but dengue 3 was by far the most common. Ultra-low volume aerosols of diluted insecticide (decamethrine K'Othrine, Roussel) from road vehicles and aircraft was used from February to May to kill the adult mosquitoes (adulticiding). The efficacy dependent on the interaction of the insecticide and the flying mosquitoes is relative and debated but played probably a major role on the transmission, though the reduction of breeding sites was primarily uncovered. Since the epidemic, only sporadic cases were observed in 1991 and 1992.

[Genital infections with Chlamydia trachomatis in pregnant women in New Caledonia]. / Les infections génitales a Chlamydia trachomatis chez la femme enceinte en Nouvelle-Calédonie.

Chlamydia trachomatis was researched from 400 pregnant women. 76 of them were found infected and 129 carried serological signs of infection. We purpose a detection at the end of pregnancy interesting women with sexually transmitted diseases background and those with serological positive results (greater than 1/64). Then, treatment of the mother will be an useful method of prevention against neonatal infection.

[Respective importance of vertical and horizontal transmission of hepatitis B in the Australian archipelago (French Polynesia). Preliminary results of the vaccination of newborns]. / Importance respective des transmissions verticale et horizontale de l'hépatite B dans L'archipel des australes (Polynésie Française). Résultats préliminaires de la vaccination chez les nouveau-nés.

A seroepidemiological survey of hepatitis B was conducted in 1988 in the Austral archipelago (French Polynesia) in a randomly selected sample of 957 persons, has showed an infection rate (at least one positive marker) with HBV of 64.1% for the entire archipelago. Among women of child-bearing age, HBs Ag carriage rate was 11.45% of whom 19.1% were so HBe Ag carriers. Among infants HBs Ag carriage rate was 2.1% and among juveniles it was 10.6%. In this area horizontal transmission of HBV is essential. An immunization program was implemented in August 1988 using a recombinant vaccine (GenHevac BTM). At one year of the program, 97% of the children had received at least one dose of vaccine, 90% had HBs-antibodies titer higher than 10 mUI/ml, 96% had seroconverted for at least one of the two antibodies (anti-HBs and/or anti-preS2) and any of them was neither HBs Ag carrier nor anti-HBc IgM antibodies carrier. Finally, among 7 neonates whose mother were positive for both HBs Ag and HBe Ag, 6 were immunes and the last one, aged of 1 month (one dose received only), was not HBs Ag carrier. These preliminary results show that vaccination with GenHevac BTM to be immunogenic and effective in field conditions.

[Reappearance of dengue in New Caledonia from 1985 to 1988]. / Réapparition de la dengue en Nouvelle-Calédonie de 1985 à 1988.

From 1971 to 1980, dengue outbreaks occurred in New-Caledonia due to dengue viruses type 2, 1 and 4 successively. After an eclipse of four years, dengue reappeared in 1985 through 1988. Out of 109 cases confirmed by virus isolation, dengue serotypes 1, 2, 3 and 4 caused 15, 23, 17 and 54 cases respectively; in 28 other cases, the Flavivirus type could not be identified and in 26 cases an Alphavirus (Ross River) was pointed out. The DEN 3 virus, unknown in New-Caledonia before 1985, was discretely transmitted until 1988. The 1989 outbreak showed the necessity of rigorous vector control measures.

[Infection with the human immunodeficiency virus (HIV) in French Polynesia]. / Infection par le virus de l'immunodéficience humaine (VIH) en Polynésie Française.

HIV case finding tests are performed since three years in French Polynesia. Ratio of seropositivity is 2.4/10,000 inhabitants. The 45 seropositive patients found in three years belong to groups at risk (homosexual males; multi-transfusion recipients; addicts). As far as donors are concerned, no seropositivity was actually observed through the 16,881 tests carried out in 30 months. Outbreak of HIV seems to be recent in Tahiti.

Chlamydia trachomatis genital infections in Tahiti.

The rate of Chlamydia trachomatis infection was determined in three populations in Tahiti by means of a direct immunofluorescence test performed in specimens, tissue culture and detection of chlamydial antibody in serum specimens using a single-serotype indirect immunofluorescence test. Chlamydia trachomatis was recovered in 53% of 53 bar girls, 24% of 75 women attending a public maternity clinic for routine care, and 37% of 71 men attending a sexually transmitted disease clinic with acute or subacute urethritis. The presence of chlamydial antibody in a high proportion of the groups studied confirmed the high frequency of chlamydial infections (62.3%, 66.6% and 83.1% respectively). Neisseria gonorrhoeae infection was often associated with chlamydial infection in both bar girls and men with urethritis (11.4% and 18.3% respectively). With regard to clinical manifestations, 58.3% (7/12) of bar girls and 23.2% (10/43) women at the maternity clinic without clinical complaints were found to be Chlamydia trachomatis-positive. The presence of Chlamydia trachomatis in these asymptomatic persons highlights their important role in spread of this organism in Tahiti. The findings indicate that routine testing for Chlamydia trachomatis is warranted in patients attending the sexually transmitted disease and public maternity clinics in Tahiti.

[Evaluation of regimens for mass-treatment of onchocerciasis by diethylcarbamazine (author's transl)]. / Evaluation de protocoles de traitement collectig de l'onchocercose par la diethylcarbamazine.

We tested three regimens to find the most effective, best tolerated and most practical therapeutic scheme for the mass treatment of onchocerciasis by diethylcarbamazine. The schemes with a short induction cure followed by a single dose of medication every two months were better than a long and only curative course of medication without maintenance doses. The schemes with induction cure and maintenance doses given every two months were more effective and practical than weekly maintenance doses with or without induction cures tried by other authors. The preferred treatment protocol is the following: an induction cure of ten days with a starter dose of 25 mg the first day, 50 mg the second, 100 mg the third, 200 mg for each of the remaining seven days. This induction procedure is extremely effective and is well maintained by a single dose of 200 mg every two months. After one year, the dermal microfilarial density was found to increase slightly. The study must be continued to determine whether a second course of induction therapy is necessary.