Evaluation of alternative diagnostic techniques for diagnosis of cerebral malaria in a tertiary referral hospital in Bangladesh.

Five alternative techniques for diagnosis of malaria were evaluated in 124 clinically diagnosed cerebral malaria cases admitted in a tertiary hospital in Bangladesh. Clinical diagnosis of cerebral malaria was done by WHO criteria. The tests were conventional routine malaria microscopy; prolonged microscopy; dipstick antigen capture assay (Para Sight TM-F test); pigments in peripheral leucocytes and routine microscopy repeated at 12 hours interval. First four tests were done at 0 hours of hospital admission and repeat routine microscopy was added at 12 hours interval. Diagnostic capability of the test was 64%, 65%, 69%, 27% and 63% respectively. None of the tests except pigments in peripheral leucocytes was superior at initial evaluation. Only the dipstick test added 5% more diagnostic possibility compared with routine microscopy as standard. Stratification of diagnostic capability in different ways improved diagnosis 15% and 11% in smear negative cases by dipstick and prolonged microscopy respectively. It was increased by 50% (5/10 patients) with dipstick test in the smear negative patients with history of anti-malarials prior to hospital admission.

Role of a large plasmid in mediation of multiple drug resistance in Salmonella typhi and paratyphi A in Bangladesh.

From 405 patients of suspected typhoid fever, 94 Salmonella typhi and 17 Salmonella paratyphi A, were isolated from blood and/or stool at the Institute of Postgraduate Medicine and Research, Dhaka during March 1992 to February 1993. Forty seven percent of the isolates were resistant to multiple drugs which included amoxicillin, ampicillin, chloramphenicol and co-trimoxazole. A large plasmid of 140 MDa was isolated from 73% of multidrug resistant (MDR) strains. However, no plasmid was isolated from any of the strains sensitive to above mentioned antibiotics. Majority of MDR Salmonella transferred resistance to E. coli K-12 (Lac+, F-, NxR.) by conjugation method. The transconjugants were similarly resistant to multiple drugs. All Salmonella were sensitive to ciprofloxacin and ceftriaxone.

Evaluation of co-agglutination (COA), counter immunoelectrophoresis (CIE), culture and direct microscopic (Dm) examination of cere-brospinal fluid (CSF) for detection of meningitis caused by common bacterial pathogens.

Cerebrospinal fluid from 260 children clinically diagnosed as meningitis were examined by Dm, culture, COA and CIE test. Dm revealed the presence of bacteria in 41 (15.8%) whereas culture showed growth of organism in 52 (20%) cases. COA and CIE test were done for the detection of antigen of H. influenzae, S. pneumoniae and N. meningitidis. Among the 3 methods viz. culture, COA and CIE test which were used for the detection of the above three organisms COA detected the maximum numbers (23.5%). COA test could detect antigen in both culture positive and culture negative CSF samples. COA test detected 100% of pneumococcal, 88.5% of H. influenzae and 66.7% of N. meningitidis antigens from CSF. Diagnosis by CIE in detecting H. influenzae and N. meningitidis antigens is inferior to culture and COA, whereas in detecting pneumococcal antigens CIE is superior to culture. So COA is a valuable, cheap, rapid and sensitive method for the diagnosis of meningitis caused by the above three organisms and when used along with culture 100% of cases can be diagnosed.