Hospital-based surveillance for Japanese encephalitis at four sites in Bangladesh, 2003-2005.

We investigated the epidemiology and etiology of encephalitis at four tertiary hospitals in Bangladesh during 2003-2005. Patients who met a clinical case definition for acute encephalitis and had cerebrospinal fluid (CSF) pleocytosis were eligible for enrollment; a standardized sampling pattern was used to enroll eligible patients. Recent Japanese encephalitis virus (JEV) infection was defined by presence of IgM antibodies against JEV in CSF or serum. Twenty (4%) of 492 cases had laboratory evidence of recent JEV infection; two died. All JE cases occurred during May-December, and cases were identified among all age groups. All cases resided in rural areas. Fifteen patients were re-assessed 4-6 weeks after hospitalization; 5 (33%) patients had physical disabilities and 7 (47%) reported cognitive difficulties. Infection with JEV is clearly an etiology of encephalitis in Bangladesh. Population-based studies to quantify burden of disease could assess options for targeted immunization programs.

Etiologies of bacterial meningitis in Bangladesh: results from a hospital-based study.

We conducted a study at four hospitals from June 2003 to July 2005 to investigate the etiologies of bacterial meningitis in Bangladesh. A total of 2,609 patients met the clinical case definition, and 766 had cerebrospinal fluid tested by at least one of the following methods: latex agglutination, 16S rRNA gene sequencing, or real-time polymerase chain reaction for Neisseria meningitidis A and C, Streptococcus pneumoniae, and Haemophilus influenzae type b (Hib); culture results were noted from patient records. In total, 189 patients (24%) of those tested, representing all age groups, were diagnosed with bacterial meningitis; 136 (18%) had meningococcal, 23 (3%) had pneumococcal, and 25 (3%) had Hib infection. Twenty percent of patients with Hib meningitis (5/25) were > 15 years old. Case-fatality ratios were 10% for N. meningitidis, 22% for S. pneumoniae, and 24% for Hib. Bacterial meningitis from vaccine-preventable pathogens causes significant morbidity and mortality in Bangladesh in adults and children.

Failure of national guidelines to diagnose uncomplicated malaria in Bangladesh.

During the mid 1990s, national guidelines were established in accordance with World Health Organization recommendations for the diagnosis of uncomplicated malaria in Bangladesh. Based on simple clinical and epidemiologic criteria these guidelines were designed to be applied outside of tertiary care centers where microscopy was not feasible. We evaluated the positive predictive value (PPV) of these criteria using microscopic slide examinations as the gold standard in 684 subjects diagnosed and treated for malaria, sampling from eight subdistrict centers. The PPV for malaria was 32% with 19% for falciparum and 14% for Plasmodium vivax. Medical officers assigned to the study also gave their own clinical impression of whether cases could have been malaria. With the additional criteria of a medical officers' diagnosis, the PPV increased negligibly to 37% with 23% and 14% for falciparum and vivax, respectively. Since the PPV of diagnosis is low and cannot be improved on clinical grounds alone, we recommend the incorporation of laboratory diagnosis. This is especially important as we detect resistance to the first-line therapy chloroquine and require more expensive, potentially more toxic, regimens.