Investigation of Dengue Infection in Asymptomatic Individuals during a Recent Outbreak in La Réunion.

The number of dengue cases has increased dramatically over the past 20 years and is an important concern, particularly as the trends toward urbanization continue. While the majority of dengue cases are thought to be asymptomatic, it is unknown to what extent these contribute to transmission. A better understanding of their importance would help to guide control efforts. In 2019, a dengue outbreak in La Reunion resulted in more than 18,000 confirmed cases. Between October 2019 and August 2020, 19 clusters were investigated in the south, west, and east of the island, enabling the recruitment of 605 participants from 368 households within a 200 m radius of the home of the index cases (ICs). No active asymptomatic infections confirmed by RT-PCR were detected. Only 15% were possible asymptomatic dengue infections detected by the presence of anti-dengue IgM antibodies. Only 5.3% of the participants had a recent dengue infection confirmed by RT-PCR. Although the resurgence of dengue in La Réunion is very recent (2016), the rate of anti-dengue IgG positivity, a marker of past infections, was already high at 43% in this study. Dengue transmission was focal in time and space, as most cases were detected within a 100-m radius of the ICs, and within a time interval of less than 7 days between infections detected in a same cluster. No particular demographic or socio-cultural characteristics were associated with dengue infections. On the other hand, environmental risk factors such as type of housing or presence of rubbish in the streets were associated with dengue infections.

Knowledge, Attitudes, Beliefs, and Practices Regarding Dengue in La Réunion Island, France.

Since 2017, La Réunion island has been facing a major epidemic of dengue. Despite actions carried out by the anti-vector control department, public authorities have failed to contain this epidemic. As individual involvement is key to success in vector control, we carried out a mixed-methods study on population knowledge, attitudes, beliefs, and practices (KABP) regarding dengue infection risk in La Réunion. The study combined quantitative data collected through a questionnaire administered to a representative sample of 622 people to assess the use of protective measures and the perception of severity and risk of dengue, and a sample of 336 people to assess the level of knowledge and concern about dengue, as well as qualitative data collected through semi-structured interviews among 11 individuals who had previously completed the questionnaire. The study results show that 63% of the surveyed population had a good level of knowledge associated with age, education, and socio-professional category variables-78% considered dengue to be a serious threat, and concern was estimated at 6/10, while 71% were likely to use protective measures. The interviews revealed contradictory behaviors in the implementation of recommended actions, in conflict with personal beliefs regarding respect of human body and nature. The study also revealed a loss of confidence in public authorities.

Carboxyhaemoglobin levels in water-pipe and cigarette smokers.

UNLABELLED: Water-pipe smoking is growing in popularity, especially among young people, because of the social nature of the smoking session and the assumption that the effects are less harmful than those of cigarette smoking. It has however been shown that a single water-pipe smoking session produces a 24-hour urinary cotinine level equivalent to smoking 10 cigarettes per day. AIM: We aimed to measure carboxyhaemoglogin (COHb) blood levels before and after water-pipe and cigarette smoking sessions. METHOD: Self-confessed smokers older than 18 years (N=30) volunteered to smoke a water-pipe or a cigarette and have their blood COHb levels measured under controlled conditions. RESULTS: Mean baseline COHb levels were 2.9% for the 15 cigarette smokers and 1.0% for the 15 water-pipe smokers. Levels increased by a mean of 481.7% in water-pipe smokers as opposed to 39.9% in cigarette smokers. CONCLUSION: The study demonstrated that water-pipe smokers had significantly higher increases in blood COHb levels than cigarette smokers during a single smoking session.

Lung and respiratory muscle function in facioscapulohumeral muscular dystrophy.

Pulmonary dysfunction is not a well-recognized feature of facioscapulohumeral muscular dystrophy (FSHD). The aim of this study was to establish the prevalence and type of pulmonary and respiratory muscle dysfunction in FSHD. Sixteen patients with moderately advanced FSHD and 16 healthy controls were evaluated. Standard lung and respiratory muscle function tests were performed. Diaphragm muscle inspiratory action was evaluated with transdiaphragmatic pressure measurements. Lung function tests showed an increased residual volume in five patients. There was a significant difference in global respiratory muscle function in patients versus controls; weakness was mild, and it affected expiratory more than inspiratory muscles. There was no significant difference in the diaphragm inspiratory action of patients versus controls. The dystrophic process that underlies FSHD did not significantly involve the muscles of the diaphragm, but it caused mild global respiratory muscle weakness that affected expiratory more than inspiratory muscles. It is probably not necessary to routinely monitor respiratory muscle function in ambulant FSHD patients who lack symptoms or signs of respiratory impairment.