Bacterial meningitis in children admitted in hospitals within Nairobi.

Four hundred and ninety nine children (aged between one month and five years) admitted with clinical features of meningitis were recruited in cross-sectional survey of bacterial meningitis in hospitals within Nairobi. Lumbar punctures were done on all of them and the cerebrospinal fluid (CSF) analysed bacteriologically and serologically for the common causative organisms. Two hundred and fifty (50.1%) cases were diagnosed clinically as having meningitis. Of these, 132 (52.8%) had turbid CSF specimens, while 118 (47.2%) were clear. When turbid CSF specimens were cultured, 83 (62.8%) yielded three common bacterial micro-organisms namely; Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae in that order of frequency. The implications of these findings in paediatric meningitis together with the drug sensitivity patterns is presented and discussed.

Agglutinins for brucellae antigens in blood sera of an urban and rural population in Kenya.

The antibody titres for Brucella arbotus and Br. melitensis in 364 sera from healthy individuals in Nairobi and Naivasha are presented. A majority (96%) had no detectable agglutinins. Reactivity was markedly higher in the Naivasha serum samples, than in those from Nairobi. In Naivasha, seven per cent showed reactivity, whereas in Nairobi a larger majority (98%), showed no reactivity, with antibody titres ranging from 1:20-1:160. Age and sex were found to have no effect on antibody titre distribution in the two populations. The presence of brucellae antibodies in the healthy population screened (with titres upto 1:80) may be due to exposure to brucellae antigens, rather than denoting brucellosis, this titre could therefore be taken as the baseline in the healthy Kenyan population.

Meningococcal meningitis.

Meningococcal meningitis has been recognised as serious problem for almost 200 years. In Africa the disease occurs in epidemics periodically during the hot and dry weather in the "meningitis belt" and in east Africa, which is outside this belt the epidemics tend to occur during the cold and dry months. The infection is mainly transmitted from person to person by nasopharyngeal carriers in crowded places like refugee camps and army barracks. The rural/urban migration, the basic structural conditions of housing in squatter settlements and slums together with an overcrowded transport system have also contributed to the transmission of meningococcal meningitis. The earlier treatment of meningococcal meningitis was by the way of repeated CSF drainage. The first important advance in the treatment was intrathecal injection of antimeningococcal serum. A major break through in the treatment was the introduction of sulphonamides which was the preferred treatment until emergence of resistance to sulphonamides in mid 1960's. Penicillin remains the drug of choice currently. Mass immunisation of selected communities using polyvalent A and C polysaccharide vaccine is a useful control measure. Chemoprophylaxis is generally not recommended during epidemics. Given the current population densities and rural/urban migration together with financial constraints, future epidemic in Kenya may be more explosive unless strict surveillance programmes are maintained.

Salmonella typhi and Salmonella paratyphi antibodies in Kenya.

The distribution of Salmonella typhi, S. paratyphi A. and S. paratyphi C. agglutinins among 364 sera from a randomly selected group of healthy individuals in Nairobi and Naivasha (Kenya) were analysed in relation to bacteriologically confirmed cases of typhoid fever at the Kenyatta National Hospital (KNH). Out of these, 30% of the healthy individuals had no detectable Widal titres. Overall agglutinin titres obtained for the healthy population showed that 96% of the individuals had low level reactivity with titres < 1:80 for both H and O antigens of S. typhi, while 4% had titres of 1:160 or above. Agglutinins for S. paratyphi A and C were rarely present in the sera tested. Age and sex were found to have no effect on antibody titre distribution in the two populations but differences in the water source may have affected the percentage of positive tests recorded. In this typhoid endemic region titres upto 1:80 are not uncommon but both H and O titres of 1:160 and above found in conjunction with the clinical picture may be taken to be suggestive of typhoid fever.

Typhim Vi vaccine against typhoid fever: a clinical trial in Kenya.

Safety, tolerance and immunogenicity of the purified Vi polysaccharide vaccine (Typhim Vi) against typhoid fever was evaluated in primary school children aged 5-15 years. A total of 435 children were vaccinated, each with a single intramuscular injection in the left deltoid muscle. One hundred and ten children were randomly selected for blood samples on day 0 (pre vaccination) and day 30 (post vaccination). Vi antibodies studied by Radio immuno assay (RIA) on 97(88%) paired sera showed a seroconversion rate of 76.2% and seroprotection rate after vaccination was 74.2%, while 6.2% of children already had protective immunity before vaccination. The vaccine was well tolerated. Most commonly reported reactions were mild pain at site of injection (83%), and a few complained of mild swelling (4.6%), induration (1.1%), itching (1.1%) and headaches (1.4%). All reactions were of mild severity and disappeared within 24 to 48 hours.

Rat bite fever: a case report of a Kenyan.

Rat bite fever has not been reported from Kenya previously. A case of 17 year old Kenyan male who was diagnosed to have rat bite fever after a bite of domestic rat is described. The history, clinical features and demonstration of spirillum like organisms from a thick blood film suggest infection due to spirillum minus. The patient recovered completely after a course of penicillin and gentamicin.

Epidemic meningococcal disease in Nairobi, Kenya, 1989. The Kenya/Centers for Disease Control (CDC) Meningitis Study Group.

An epidemic of meningococcal disease occurred in Nairobi, Kenya, during 1989, outside the "meningitis belt" of sub-Saharan Africa. About 3800 cases occurred between April and November (250/100,000 population). The case-fatality rate was 9.4% among hospitalized patients. Areas that included Nairobi's largest slums had particularly high attack rates. The epidemic displayed an unusual age distribution, with high attack rates among those 20-29 years old. A vaccination campaign was conducted. By early January, the weekly case count had fallen to 25 from a high of 272 (in September). A case-control study estimated the vaccine efficacy to be 87% (95% confidence interval, 67%-95%). A model estimated that the vaccination campaign reduced the number of cases by at least 20%. Multilocus enzyme electrophoretic typing demonstrated that the strain responsible for this large epidemic is closely related to strains that caused other recent epidemics, documenting further spread of what may be a particularly virulent clonal complex of group A Neisseria meningitidis.

Tetracycline resistance genes in Kenyan hospital isolates of Salmonella typhimurium.

All 97 strains of Salmonella typhimurium isolated from patients at a hospital in Nairobi, Kenya, during 1988-90 were resistant to tetracycline. The minimum inhibitory concentration (MIC) showed a large distribution range from 1 microgram/ml to 128 micrograms/ml. The strains were heterogeneous with respect to plasmid content, but initially all strains possessed, in addition to other plasmids, a large 60-, 63- or 65-MDa plasmid. The tetracycline resistance genes were characterized using oligonucleotide probes, and 20% of the resistant strains possessed tetracycline type A (tetr A), 6% tetr B, and 4% tetrC genes. Three strains possessed both type A and B tetracycline resistance determinants, which were shown to be located on the large 65-MDa plasmid. There was no correlation between strains isolated from stools, blood, cerebrospinal or epidural fluids, pus, or urine, with respect to the tetracycline genotypes, MIC values or plasmid content.

Infection with HIV as a risk factor for adverse obstetrical outcome.

We carried out a case-control study to investigate the role of sexually transmitted diseases (STDs), including infection with HIV, as risk factors for adverse outcome of pregnancy. Overall, 1507 women were enrolled within 24 h of delivery. Cases (n = 796) were mothers of low-birthweight infants (less than 2500 g) or of stillborns. Low-birthweight infants were divided into preterms (n = 373) and neonates small for gestational age (n = 234). Stillborns were separated into intrauterine fetal deaths (n = 120), and intrapartum fetal deaths (n = 69). Controls were selected from mothers delivering a live baby of greater than or equal to 2500 g (n = 711). The maternal HIV seroprevalence in the control group was 3.1%. Prematurity was associated with maternal HIV antibody [8.6% seropositive; adjusted odds ratio (OR) 2.1; 95% confidence interval (CI) 1.1-4.0], as was being born small for gestational age (7.7% seropositive; adjusted OR 2.3; 95% CI 1.2-4.2). In mothers who delivered a stillborn baby, both intrauterine fetal death (11.7% seropositive; adjusted OR 2.7; 95% CI 1.3-5.5) and intrapartum fetal death (11.6% seropositive; adjusted OR 2.9; 95% CI 1.3-6.5) were independently associated with HIV seropositivity in the mother. Maternal syphilis was confirmed as an important risk factor for intrauterine fetal death (14.3% positive; adjusted OR 4.8; 95% CI 2.4-9.5). No significant association was found between other STDs, including gonococcal and chlamydial infection, and adverse obstetrical outcome. These results suggest an association between maternal HIV infection and adverse obstetrical outcome, defined as low birthweight and stillbirth.

Towards developing a diagnostic algorithm for Chlamydia trachomatis and Neisseria gonorrhoeae cervicitis in pregnancy.

C trachomatis and N gonorrhoeae are major causes of maternal and neonatal morbidity and mortality in developing countries. To identify characteristics predictive of cervical infection, we examined pregnant women attending an antenatal clinic in Nairobi, Kenya. C trachomatis was isolated from 14/178 (8%), and N gonorrhoeae from 17 (10%); cervical infection with either pathogen was present in 28 (16%). Two characteristics were independently predictive of cervical infection by logistic regression analysis; the presence of either endocervical mucopus or induced endocervical bleeding, relative risk 4.2 (95% confidence interval (CI) 2.2 to 8.0) and having more than one sexual partner during pregnancy, relative risk 3.3 (95% CI 1.4 to 7.6). A screening programme for cervical infection which tested women with one or both risk markers would have a sensitivity of 68% (95% CI 51 to 85%) and a positive predictive value of 0.35 (95% CI 0.22 to 0.47). In countries where resources are limited, diagnostic algorithms incorporating clinical signs and behavioural characteristics may be useful in identifying pregnant women at high risk of cervical infection.

PIP: Chlamydia trachomatis and Neisseria gonorrhoea are major causes of maternal and neonatal morbidity in developing countries. 178 pregnant women attending an antenatal clinic in Nairobi, Kenya, were therefore examined in the attempt to identify characteristics predictive of cervical infection. Chlamydia trachomatis was isolated from 14 (8%) and Neisseria gonorrhoea from 17 (10%); cervical infection with either pathogen was present in 28 (16%). Logistic regression analysis found that the presence of either endocervical mucopus or induced endocervical bleeding and having more than 1 sex partner during pregnancy were independently predictive of cervical infection. A screening program for cervical infection which tested women with 1 or both risk markers wold have a sensitivity of 68% and a positive predictive value of 0.35. The authors conclude that countries with limited resources may use diagnostic algorithms and incorporate clinical signs and behavioral characteristics to help identify pregnant women at high risk of cervical infection.

Salmonella typhimurium outbreak at Kenyatta National Hospital (1985).

A total of 560 Salmonellae species were isolated from Jan-Dec 1985. Of these, 347 (62%) were from blood cultures, 180 (32%) from stools and 33 (6%) were from cerebrospinal fluid (CSF) and other body aspirates. S. typhimurium were the highest isolated. These were, 291 (52%) from blood cultures, 94 (17%) from stool cultures and 32 (6%) from CSF. S. typhimurium was also multi-drug resistant. More than 50% strains of S. typhimurium were resistant to ampicillin, tetracycline, kanamycin and chloramphenicol. The need for coordination between the laboratory and clinical staff to prevent the spill-over of infection with S. typhimurium and its epidemic spread is discussed.

Salmonella septicaemias in Kenyan children.

In a 5-month study of Salmonella septicaemias in Kenyan children carried out during the annual peak infection period, Salmonella typhimurium septicaemias occurred seven times more frequently than typhoid or other non-typhoid infections. Salmonella typhimurium infections were predominantly community acquired, malnourished infants from rural malaria endemic areas with poor water supply were especially vulnerable. Typical clinical features of fever, diarrhoea, and severe anaemia resembled P. falciparum malaria which often co-existed. Mortality was 18 per cent. Isolates exhibited a wide range of multidrug resistance. Typhoid affected older children, was less severe and drug sensitive.

Microbiology of vaginal discharge in Nairobi, Kenya.

Among women attending a sexually transmitted disease (STD) clinic in Nairobi with vaginal discharge, Neisseria gonorrhoeae and Chlamydia trachomatis were isolated from the cervix in 32 (26%) of 122 and four (7%) of 58 women respectively. Infection with Trichomonas vaginalis, Candida albicans, Gardnerella vaginalis, and Mycoplasma spp were diagnosed in 42 of 122 (34%), 26 of 110 (24%), 75 of 100 (75%), and 42 of 89 (47%) women respectively. Mixed infections with at least two pathogens were found in 23 (26%) of 89 women examined for all microorganisms. Infection with N gonorrhoeae was significantly associated with abdominal pain.