Sentinel physician's network in Reunion Island: a tool for infectious diseases surveillance.

UNLABELLED: The surveillance of infectious diseases in Reunion Island is based on a sentinel network of family physicians (FPs) coordinated by the Indian Ocean regional institute for public health surveillance (French acronym OI Cire). The objectives are to identify and monitor outbreaks of influenza, gastroenteritis, and chicken pox, and to characterize circulating influenza viruses. The network can monitor other potentially epidemic diseases. METHOD: The Réunion sentinel network ensures a continuous and permanent surveillance. Physicians send their weekly activity data to the Cire that collects, processes, and interprets it; they also collect samples for biological surveillance of influenza. Statistical thresholds, based on historical data and the estimated numbers of incident cases, are calculated to follow the trend, detect outbreaks, and quantify their impact. RESULTS: The network currently includes 56 FPs and pediatricians, accounting for 6.5% of FPs on the island. The network has clarified the seasonality of influenza during the austral winter and identified the seasonality of acute diarrhea with an epidemic peak when school starts in August. The sentinel FPs's reports allowed monitoring the epidemic trend and estimating the number of cases during the 2005 and 2006 chikungunya outbreaks and 2009 influenza A (H1N1) outbreaks. CONCLUSION: The network has proven its contribution, responsiveness, and reliability for epidemiological surveillance during outbreak. It is an essential tool for infectious diseases surveillance in Reunion Island.

[Discovery and follow-up of a lead-poisoning outbreak in a shantytown of Le Port, Reunion Island]. / Investigation et gestion d'un foyer de saturnisme infantile dans un quartier de la commune du Port, Île de la Réunion.

BACKGROUND: A national survey conducted in 2008-2009 by the French Institute for Public Health Surveillance for detection of lead impact in childhood identified a high blood lead level in a young boy living in the town of "Le Port", Reunion Island. Previously, cases of lead-poisoning on the island had been exceptional; only a dozen cases were reported in the 1980s in adults, related to the use of lead-containing instruments for food preparations. METHODS: The family of the index case was invited to participate in screening tests and an environmental investigation was conducted using a standardized questionnaire. Screening was then broadened to the neighborhood of the index case and samples of soil outside the home and in the immediate vicinity were taken. The environmental survey was then extended with soil samples taken from the entire geographical area. Information was then provided to local inhabitants (87 families and 287 people) in order to encourage lead blood testing for all children under six years and all pregnant women living in the area. RESULTS: The index case lived in the neighborhood of "The Oasis", a shantytown of Le Port. The results of soil analysis revealed heterogeneous pollution of superficial soils by lead throughout the area of the shantytown, the highest level recorded (5200mg/kg) reached more than 300 times the background level of the natural soils of the island. The screening identified 76 cases of childhood lead-poisoning (blood lead level greater or equal to 100µg/L) among 148 samples (51%). All cases of blood poisoning involved children under the age of 15 years. The median age of children with a positive test was 5.6 years; the median blood lead level was 196µg/L [102-392µg/L]. CONCLUSION: The main hypothesis to explain the contamination of the soil in the area of the shantytown is the presence of waste deposits (car batteries) and diffuse activities of metal recovery. The authorities managed to remove all the families from the environmental exposure to lead by rapidly ensuring rehousing outside the contaminated area.

A major outbreak of gastroenteritis in Réunion Island in 2012: first identification of G12 rotavirus on the Island.

Between August and November 2012 a severe outbreak of gastroenteritis occurred on Réunion Island, affecting more than 50,000 cases, particularly young children. Virological analyses showed that the virus responsible for this epidemic was rotavirus. Genotyping of stool samples indicated circulation of rotavirus type G3P[8] but also G12P[8], highlighting the risk of global emergence of this genotype in the coming years.

[New vector control measures implemented between 2005 and 2011 on Reunion Island: lessons learned from chikungunya epidemic]. / L'evolution de la lutte anti-vectorielle entre 2005 et 2011 a la Réunion: les enseignements de l'epidémie de chikungunya.

A major chikungunya outbreak concerned 38% of people living in Reunion Island in 2005-2006. Chikungunya is an arthropod-born-virus disease conveyed by mosquitoes called Aedes albopictus. The health agency in Indian Ocean is responsible for vector control. Previously, in the early 40s, vector control concerned only malaria prophylaxis in La Réunion. Then, during the chikungunya outbreak, a new vector control team was installed and learned from this epidemic. The lessons drawn from chikungunya outbreak in La Réunion are about global executive management and organization linked the local partners and population. The lessons also concern technical topics such as the need of scientific research about vectors and vector-control methods. Finally, the regional cooperation in Indian Ocean (Réunion, Maurice, Seychelles, Comoros, Madagascar) has to be developed to share epidemiologic and entomologic data in order to prevent new chikungunya or dengue outbreak.

Re-emergence of dengue in Reunion, France, January to April 2012.

Since January 2012, 20 autochthonous cases of dengue virus (DENV) infection have been identified in Réunion. The first cases were detected on the western coast, but the two co-circulating viruses (DENV-1 and DENV-3) seemed to have spread later to different cities of the island. There is a non-negligible risk of increase in viral transmission over the following weeks, so health professionals and public health authorities in Réunion are preparing to face a potential epidemic.

Epidemic dengue 2 in the city of Djibouti 1991-1992.

From October 1991 to February 1992, an outbreak of acute fever (in which thick blood films were negative for malaria) spread rapidly in the city of Djibouti, Djibouti Republic, affecting all age groups and both nationals and foreigners. The estimated number of cases was 12,000. The clinical features were consistent with a non-haemorrhagic dengue-like illness. Serum samples from 91 patients were analysed serologically for flavivirus infection (dengue 1-4, West Nile, yellow fever, Zika, Banzi, and Uganda-S), and virus isolation was attempted. Twelve strains of dengue 2 virus were isolated. Dengue infection was confirmed by a 4-fold or greater rise in immunoglobulin (Ig) G antibody in paired serum specimens, the presence of IgM antibody, or isolation of the virus. Overall, 46 of the suspected cases (51%) were confirmed virologically or had serological evidence of a recent flavivirus infection. Statistical analysis showed that the presence of a rash was the best predictor of flavivirus seropositivity. In November 1992, Aedes aegypti was widespread and abundant in several districts of Djibouti city. A serological study of serum samples collected from Djiboutian military personnel 5 months before the epidemic showed that only 15/177 (8.5%) had flavivirus antibodies. These findings, together with a negative serosurvey for dengue serotypes 1-4 and yellow fever virus performed in 1987, support the conclusion that dengue 2 virus has only recently been introduced to Djibouti.

[Dissimilar glucose-6-phosphate dehydrogenase (G-6-PD) deficiency in the Afars and the Somalis of Djibouti]. / Deficience dissimilaire de la glucose-6-phosphate deshydrogenase (G-6-PD) chez les afars et les Somalis de Djibouti.

In order to determine the prevalence of deficient activity of the enzyme glucose-6-phosphate dehydrogenase (G-6-PD) among the inhabitants of the east African Republic of Djibouti, we analyzed by the methaemoglobin reduction test the blood of 170 Djiboutian males, 81 Afars and 89 Somalis. Eight subjects were found to be G-6-PD deficient, 1 Afar and 7 Somalis (1.2% versus 8%; P = 0.02). We conclude that in Djibouti, health care providers should consider the presence of potential G-6-PD deficiency in their patients, especially in males of the Somali ethnic group. Indeed, many medications are contraindicated in the G-6-PD deficient subjects, and primaquine and pyrimethamine-sulfadoxine (FANSIDAR) have to be considered dangerous anti-malarial drugs for Somali males as long as their level of G-6-PD activity has not been determined. Since in Djibouti many acute falciparum cases are presenting with severe icteric anaemia, we hypothesize that some of these haemolytic anaemias might not be caused by the parasitic infection alone, but that some malaria patients might become aggravated through the administration of haemolytic drugs in case they are G-6-PD deficient. Finally, we propose that our study should be expanded to include the systematic determination of the variants of the enzyme in all subjects found G-6-PD deficient, since the clinical manifestations of G-6-PD deficiency are directly related to the type of variant present.

Observations on sexually transmitted diseases in promiscuous males in Djibouti.

Observations are reported on 7 sexually transmitted diseases in a heterosexual population of 105 promiscuous males in Djibouti, East Africa. Neisseria gonorrhoeae was cultured from urethral swabs from 34 subjects. Six isolates were beta lactamase positive (18%). High levels of resistance to antimicrobials were noted with penicillin, spectinomycin and cotrimoxazole, while tetracyclines and erythromycin were unvariably effective. Six patients had Chlamydia urethritis, one of whom had concomitant gonococcal urethritis. Half of the sera reacted positive for antibodies to Chlamydia. A total of 31 subjects had a positive treponemal FTA-Abs test; of these, only 14 had a reactive RPR test. Nineteen individuals were positive for HBsAg. One subject had a western blot confirmed HIV-1 infection, while none had antibodies to HIV-2 or HTLV-I.