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Source: World Health Organization (WHO)
Dengue and dengue haemorrhagic fever in MalaysiaMalaysia recorded 19,544 dengue cases in 1997, 37% higher than the number reported in 1996 and the highest recorded since the disease was made notifiable in 1973. Included were 806 cases of dengue haemorrhagic fever with 50 deaths. Cases were reported throughout the year but peaked in July. Although all states were affected, most cases were reported in urban areas with high population density. Of the 5,433 specimens submitted to the WHO Collaborating Centre for Arbovirus Reference and Research in Kuala Lumpur for laboratory confirmation 57% were positive serologically. The male:female ratio was 1.3:1 and the 21 to 25 years age group was the most affected. Of the 100 virus strains isolated, 64 were dengue 1, 33 were dengue 2 and 3 were dengue 3. The WHO Centre is intensifying its surveillance in 1998.
Diarrhoea in CameroonShigella dysenteriae type 1 (Sd1) has been confirmed as the organism responsible for the outbreak of bloody diarrhoea which started in Cameroon in November 1997. Since then 237 cases with 60 deaths have been reported. A team from the Ministry of Health has assessed the situation in collaboration with WHO. Stool samples were collected and analysed at the Pasteur Institutes in Cameroon and Paris, France. Blood samples were negative in tests for haemorrhagic fevers, including Ebola haemorrhagic fever. Antibiotic susceptibility testing showed the Sd1 strains were sensitive to quinolones and cephalosporins but resistant to antibiotics commonly recommended for treatment of shigella. Shigella dysenteriae type 1, also known as Shiga bacillus, is the most virulent of the four serogroups of Shigella and the only cause of epidemic dysentery. In Africa epidemic dysentery due to Sd1 appeared in eastern Democratic Republic of the Congo (former Zaire) in 1979 and has regularly affected more than 15 countries on the continent.
Meningitis in ChadDuring 1996 and 1997 many countries in the African meningitis belt experienced severe epidemics of meningococcal meningitis with 188,341 cases reported from Africa in 1996 and 69,518 case in 1997. So far 7,595 cases have been reported from the WHO African Region in 1998. However not all countries are experiencing this generally reduced level of activity. In recent weeks there has been a large outbreak in Chad. From 29 December 1997 to 22 March 1998 there were 2,835 cases and 239 deaths reported from Chad. This is more than twice the annual total number of cases reported in Chad in 1996 (1,079 cases) and 1997 (1,123 cases). Vaccination campaigns have been carried out in districts where the weekly attack rate has exceeded 5 cases per 100,000 population. The threat of epidemics of meningitis during the hot dry season from late December to early May means that the countries of the 'African meningitis belt' must continue to strengthen surveillance, reporting systems and rapid laboratory confirmation. Early detection is crucial to the ability to mount a response to control epidemics.
This article was published in Communicable Diseases Intelligence Vol 22 No 5, 14 May 1998.