Risk factors for Nipah virus encephalitis in Bangladesh.

Nipah virus (NiV) is a paramyxovirus that causes severe encephalitis in humans. During January 2004, twelve patients with NiV encephalitis (NiVE) were identified in west-central Bangladesh. A case-control study was conducted to identify factors associated with NiV infection. NiVE patients from the outbreak were enrolled in a matched case-control study. Exact odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by using a matched analysis. Climbing trees (83% of cases vs. 51% of controls, OR 8.2, 95% CI 1.25-infinity) and contact with another NiVE patient (67% of cases vs. 9% of controls, OR 21.4, 95% CI 2.78-966.1) were associated with infection. We did not identify an increased risk for NiV infection among persons who had contact with a potential intermediate host. Although we cannot rule out person-to-person transmission, case-patients were likely infected from contact with fruit bats or their secretions.

Clinical presentation of nipah virus infection in Bangladesh.

BACKGROUND: In Bangladesh, 4 outbreaks of Nipah virus infection were identified during the period 2001-2004. METHODS: We characterized the clinical features of Nipah virus-infected individuals affected by these outbreaks. We classified patients as having confirmed cases of Nipah virus infection if they had antibodies reactive with Nipah virus antigen. Patients were considered to have probable cases of Nipah virus infection if they had symptoms consistent with Nipah virus infection during the same time and in the same community as patients with confirmed cases. RESULTS: We identified 92 patients with Nipah virus infection, 67 (73%) of whom died. Although all age groups were affected, 2 outbreaks principally affected young persons (median age, 12 years); 62% of the affected persons were male. Fever, altered mental status, headache, cough, respiratory difficulty, vomiting, and convulsions were the most common signs and symptoms; clinical and radiographic features of acute respiratory distress syndrome of Nipah illness were identified during the fourth outbreak. Among those who died, death occurred a median of 6 days (range, 2-36 days) after the onset of illness. Patients who died were more likely than survivors to have a temperature >37.8 degrees C, altered mental status, difficulty breathing, and abnormal plantar reflexes. Among patients with Nipah virus infection who had well-defined exposure to another patient infected with Nipah virus, the median incubation period was 9 days (range, 6-11 days). CONCLUSIONS: Nipah virus infection produced rapidly progressive severe illness affecting the central nervous and respiratory systems. Clinical characteristics of Nipah virus infection in Bangladesh, including a severe respiratory component, appear distinct from clinical characteristics reported during earlier outbreaks in other countries.

August 2003 heat wave in France: risk factors for death of elderly people living at home.

The August 2003 heat wave in France resulted in many thousands of excess deaths particularly of elderly people. Individual and environmental risk factors for death among the community-dwelling elderly were identified. We conducted a case-control survey and defined cases as people aged 65 years and older who lived at home and died from August 8 through August 13 from causes other than accident, suicide, or surgical complications. Controls were matched with cases for age, sex, and residential area. Interviewers used questionnaires to collect data. Satellite pictures provided profiles of the heat island characteristics around the homes. Lack of mobility was a major risk factor along with some pre-existing medical conditions. Housing characteristics associated with death were lack of thermal insulation and sleeping on the top floor, right under the roof. The temperature around the building was a major risk factor. Behaviour such as dressing lightly and use of cooling techniques and devices were protective factors. These findings suggest people with pre-existing medical conditions were likely to be vulnerable during heat waves and need information on how to adjust daily routines to heat waves. In the long term, building insulation and urban planning must be adapted to provide protection from possible heat waves.

[An epidemic of meningococcal meningitis in the region of Savanes in Togo in 1997: research and control strategies]. / Une épidémie de méningite à méningocoque dans la région des Savanes au Togo en 1997: investigation et stratégies de contrôle.

Neisseria meningitidis is responsible for high levels of morbidity and mortality in the developing countries of the African meningitis belt. There are frequent meningococcal meningitis epidemics in this region affecting almost 1,000 people in every 100,000 (1%). Epidemics generally occur during the dry season but the interval between epidemics is variable (between 2 and 25 years). The reasons for these recurrent epidemics are unclear. There is a safe and effective polysaccharide vaccine against meningococci A and C. Unfortunately, the immunity it provides decreases with time, especially in young children (aged less than 5 years) and it is thus not included in the Expanded Program on Immunization (EPI). WHO recommends mass vaccination using a threshold approach. This control strategy is effective if vaccination begins very soon after the threshold is crossed. There was an outbreak of group A meningococcal meningitis in the Savanes region of northern Togo in December 1996. The national surveillance system put out an alert and control measures were implemented. These involved improvement of the surveillance system, and containment immunization in villages for early cases followed by a mass immunization campaign in the entire region, distribution of oily chloramphenicol and decentralized case management. The target population for mass vaccination included everyone older than 6 months of age living in the Savanes region. The aim was to vaccinate at least 80% of the target population. There were 2,992 cases of meningitis reported in the Savanes region between December 1996 and May 1997 (in a population of about 500,000). This gives a cumulative incidence rate of 581 per 100,000 population. The epidemic was bimodal, with the first peak in the number of cases occurring at the end of January and the second peak in March. There were 60,700 vaccinations in two of the four districts of the region in December and January, as part of the containment strategy and 346,469 vaccinations in the four districts of the region during February, as part of the mass vaccination campaign. By the end of the mass campaign, 67.3% of the target population in the region as a whole had been vaccinated, with 61% vaccinated in the Kpendjal district and 78% in the Oti district. There was an increase in the number of cases 2 weeks after the end of the mass vaccination campaign. This was attributed to the inadequate level of vaccination achieved. Only 52% of the urban population of Dapaong were vaccinated. The national surveillance system put out an alert early in the epidemic. The intervention was planned and adapted according to the progression of the epidemic, and national and international efforts were well coordinated. This emphasizes the importance of a rapid reaction from the surveillance system and of the choice of strategy for dealing with meningitis epidemics in sub-Sahelian Africa.