Group B streptococcus colonisation in pregnant women at Dr. George Mukhari Hospital, South Africa

The aim of the study was to estimate group B streptococcus (GBS) colonisation in pregnant mothers using selective enrichment broth and solid media for culturing GBS. Vaginal and rectal swabs were collected from 413 pregnant women for GBS culture at recruitment stage. Direct plating and enrichment broth culture methods were compared by using the same swab samples. The swabs were cultured on colistin nalidixic agar (CNA) plate and incubated at 37°C and examined after 18-24 h. The samples which were culture negative on a CNA agar plate were then inoculated into a Todd-Hewitt enrichment broth to recover any GBS present that was not recovered on the solid agar. With the CNA agar plate, the samples were cultured separately to enable identification of colonised sites such as vaginal sites or rectal sites. Rectal and vaginal swabs were inoculated into Todd-Hewitt enrichment broth at the same time in the same tube. The GBS colonisation rate in pregnant women was 30.9% (128/413). The CNA agar plate recovered 45.3% (58/128) of the GBS isolates, whereas 54.7% (70/128) isolates were recovered from Todd-Hewitt broth. Pregnant women of various ages were found to be at risk of GBS colonisation. The colonisation rate was however highest among women of 25–29 age groups as compared with other age groups. Detection of group B streptococcus improved when both rectal and vaginal swabs were collected for laboratory analysis. The simultaneous use of Todd-Hewitt broth and CNA plate also improved the yield of group B streptococcus.

Streptococcus agalactiae (group B streptococcus (GBS)) colonisation and persistence, in pregnancy; a comparison of two diverse communities (rural and urban)

OBJECTIVE

To establish the extent of GBS colonisation, persistence of colonisation in pregnancy and influence of obstetric history in two diverse communities (rural and urban) in Zimbabwe.

DESIGN

Cross sectional survey.

SETTING

Rutsanana Clinic in Highfield, Harare (representing the urban area) and Chitsungo Mission Hospital in Lower Guruve, (representing the rural area).

SUBJECTS

300 and 100 pregnant women from the urban and rural areas respectively.

MAIN OUTCOME MEASURES

GBS colonisation and persistence rates for both urban and rural areas were established, together with pregnancy outcome.

RESULTS

Mother colonisation rate was significantly higher in the rural areas (60%) as compared to the urban areas (46%). GBS colonisation persistence was evidently more in rural (48%) that in urban women (12%). Baby colonisation was also more in the rural (23%) that in urban area (5%). In both the rural and urban areas, flu-like illness was a common feature and was equally reported by the subjects. Vaginal discharge requiring treatment, previous stillbirths and previous miscarriages were equally reported in both communities.

The putative R1 protein of Streptococcus agalactiae as serotype marker and target of protective antibodies

The streptococcal R1 protein was studied by means of anti-R1 antibodies prepared by appropriate cross-absorption of rabbit antiserum raised against the group B streptococcal (GBS) strain ATCC 12403 (D136C), serotype III/R1. The protein was a ladder-forming antigen according to banding patterns in immunoblotting, similar to several other GBS proteins, and was susceptible to digestion by both pepsin and trypsin. Antibody-based testing revealed that 10% of Norwegian GBS isolates expressed the R1 protein, most frequently capsular antigen type V strains (72%) and less frequently type III strains (3%). None of 132 GBS strains from Zimbabwe, including 39 type V strains, expressed the R1 protein. R1-specific rabbit antibodies showed protective activity in mice challenged with a GBS type V/R1 strain. The results show that the R1 protein is an important GBS serotype marker in strains from certain geographical areas, notably for the subtyping of capsular type V strains, and that this protein is a target of protective antibodies.

Antibodies against Streptococcus agalactiae proteins c(alpha) and R4 in sera from pregnant women from Norway and Zimbabwe

Group B streptococci (GBS) express strain-variable and surface-localized proteins, which are important serotype markers and targets of protective antibodies. These include the c(alpha) and R4 proteins, one or the other of which is expressed by approximately 75% of clinical GBS isolates. These proteins have been considered vaccine candidates. In this study, the c(alpha) and R4 proteins were extracted by trypsin digestion of GBS and purified by sequential precipitation with trichloroacetic acid and ammonium sulfate followed by gel filtration chromatography. The proteins were used as antigens in an indirect enzyme-linked immunosorbent assay (ELISA) to measure the levels of c(alpha)- and R4-reactive antibodies in sera from pregnant women from Norway (n = 100) and from Zimbabwe (n = 124). Antibody levels in the Norwegian group of women were significantly higher than in the Zimbabwean group, and a higher proportion of the Norwegian women contained appreciable levels of antibodies against both proteins. The antibodies traversed the placental barrier. With individual sera, a significant correlation between the anti-c(alpha) and anti-R4 antibody levels was observed and each of the two protein antigens effectively competed for human serum antibodies both against itself and against the other antigen. Inhibition ELISA results demonstrated specificity for each of the proteins of immune antibodies raised in rabbits. These results demonstrate that (i) the majority of women of childbearing age have antibodies against c(alpha) and R4, (ii) the levels of these antibodies differ among pregnant women in different parts of the world, and (iii) the normal human serum antibodies may target a common c(alpha) and R4 protein site, whereas immune antibodies targeted a different site(s) specific for each protein.

Susceptibility of Zimbabwean Streptococcus agalactiae (group B Streptococcus; GBS) isolates to four different antibiotics

OBJECTIVE

To establish the susceptibility of Zimbabwean GBS strains isolated from hospitalised patients to four antibiotics.

DESIGN

Cross sectional survey.

SETTINGS

Four regions of Zimbabwe (Bindura, Bulawayo, Harare, and Masvingo).

SUBJECTS

113 GBS isolates from hospitalised patients in Bindura, Bulawayo, Harare and Masvingo, of whom most were suffering from infectious diseases.

MAIN OUTCOME MEASURES

All isolates were tested for their susceptibility to clindamycin, erythromycin, penicillin and tetracycline.

RESULTS

All isolates were 100% sensitive to clindamycin, 98% to penicillin, 86% to erythromycin; 2% of the isolates showed intermediate susceptibility to penicillin and 100% showed resistance to tetracycline.

CONCLUSION

Penicillin is still the antibiotic of choice for treatment of GBS infections and for intrapartum chemoprophylaxis in Zimbabwe. For patients who are allergic to penicillin, clindamycin will be the drug of choice for both treatment and/or chemoprophylactic use in Zimbabwe.

Low risk and high risk human papillomaviruses (HPVs) and cervical cancer in Zimbabwe: epidemiological evidence

OBJECTIVE

To establish the prevalence of detectable low-risk and high-risk, oncogenic HPV types in cervical swabs of women with histologically proven cancer of the cervix.

DESIGN

Cross sectional study.

SETTING

Harare Central and Parirenyatwa Hospitals.

SUBJECTS

119 women with histologically proven cervical cancer of whom 63 had the degree of differentiation of the tumour reported.

MAIN OUTCOME MEASURES

Frequency of infection with high and low-risk human papillomaviruses.

RESULTS

The presence of HPV DNA was demonstrated in 63% (75/119) of cases. Low risk HPVs were present in 26% (31/119) and high-risk HPVs were demonstrated in 51% (61/119) of samples tested. Co-infection with both low-risk and high-risk HPVs was observed in 14% (17/119) of the specimens. High-risk HPVs were detected in 55% (21/38) of poorly differentiated tumours while 60% (15/25) of moderately and well-differentiated tumours showed the presence of high-risk HPVs.

CONCLUSION

High-risk human papillomaviruses are associated with cervical cancer. There was no significant difference in the frequency of high-risk HPV types in women with moderately to well-differentiated tumours and those with poorly-differentiated tumours.

Prevalence, capsular type distribution, anthropometric and obstetric factors of group B Streptococcus (Streptococcus agalactiae) colonization in pregnancy

OBJECTIVE

To establish the prevalence, serotype distribution, anthropometry and obstetric factors of Group B Streptococcus (GBS) colonization in pregnant women.

DESIGN

Cross sectional survey.

SETTING

Chinhoyi General Hospital.

SUBJECTS

206 pregnant women attending the antenatal clinic at Chinhoyi General Hospital were systematically randomly sampled.

MAIN OUTCOME MEASURES

All the isolates were serotyped on the basis of capsular polysaccharide (CHO) antigen designated, Ia, Ib, II, III, IV and V.

RESULTS

65 (31.6%) were carriers of GBS. The serotypes found were, type III (41.8%), type V (37.4%), type Ia (11.0%), type IV (3.3%), type Ib (3.3%) type II (1.0%) and 2.0% of the isolates were non-typable. All isolates were sensitive to penicillin and resistant to gentamycin. Colonization was more common in women with parity 0 to 2 (4.6%) and age group 20 to 24 years (43.1%). There was some evidence (p = 0.063) to suggest that GBS was more often isolated from the vagina (12.6%) than from the rectum (6.3%).

CONCLUSION

There was a high prevalence of GBS colonization among pregnant women in Chinhoyi. Types III and V were the most common serotypes found.

In-vitro disk diffusion sensitivity of meropenem against bacterial pathogens in Harare

OBJECTIVE

To compare the in-vitro sensitivity of meropenem with imipenem and other antibiotics against clinically significant bacteria.

DESIGN

A longitudinal survey.

SETTING

Department of Medical Microbiology, in a tertiary care university hospital.

SUBJECTS

Specimens obtained from patients attending various clinics at tertiary care and teaching hospital in Harare. Those submitted to the Public Health Bacteriology Laboratory were analysed.

MAIN OUTCOME MEASURES

Rates of resistance or susceptibility of the various bacteria to the antibiotics employed in the study.

RESULTS

There was excellent in-vitro bacterial activity of meropenem against virtually all clinically significant Gram positive and Gram negative isolates when compared with other antibiotics such as imipenem, ciprofloxacin, gentamicin, penicillin, ampicillin, fusidic acid, tetracyclines, erythromycin and clindamycin (p < 0.5). All isolates of Streptococcus pyogenes, Pseudomonas aeruginosa, Enterobacteriaceae, Neisseria meningitidis were susceptible to meropenem. Meropenem showed 99% overall in-vitro sensitivity against Gram positive and Gram negative bacteria. About 80% of staphylococci were resistant to penicillin whereas at least 20-25% of S. aureus, coagulase negative staphylococci, S. pyogenes showed resistance to ampicillin, erythromycin, gentamicin, tetracycline and clindamycin.

CONCLUSION

Meropenem is not included in the list of routinely tested antibiotics in our laboratory, a major tertiary laboratory in the country. As a result of the ultra-broad spectrum of activity, we recommend its inclusion in our routine antibiotic sensitivity testing and observe that there is a great potential for meropenem in the treatment of infections caused by several genera of bacteria in our environment.

Comparison of three different methods in monoclonal antibody-based detection of Streptococcus agalactiae protein serotype markers

Surface-exposed proteins are important serotype markers in Streptococcus agalactiae (group B streptococci; GBS). The proteins include the c proteins c(alpha) and c(beta), the R4 protein and a protein provisionally called P. For all of these markers, protein-specific monoclonal antibodies (MAbs) have been generated. We have compared whole-cell-based fluorescent antibody testing (FAT), ELISA, and dot blotting for MAb-based detection of these proteins by testing a panel of 52 GBS isolates of different capsular antigen types. Of a total of 208 observations with each of the tests, positive signalling in the dot assay was observed in 32.2%, with ELISA in 27.8%, and with FAT in 26.4% of the recordings. Discordant results were noted most frequently with the c(beta) and c(alpha) MAbs. In the case of c(alpha) the reason for the discordant test results was further examined and it appeared that this could be attributed to low level expression of the c(alpha) protein, although structural variations of c(alpha) proteins cannot be excluded. Our findings favour dot blotting as the method of choice although we consider all three methods acceptable for serotyping of GBS.

The relationship between malaria and HIV

OBJECTIVE

To determine if there is an association between HIV and malaria infection.

DESIGN

A cross sectional survey.

SETTING

Sanyati Rural District, a malarious endemic area of Zimbabwe.

SUBJECTS

338 volunteers aged 15 months to 76 years.

MAIN OUTCOME MEASURES

Prevalence of Malaria and HIV.

RESULTS

The prevalence of malaria and HIV was 26.6% and 26.3% respectively. There was no association between prevalence of HIV and malaria.

CONCLUSION

There is no association between malaria and HIV.

In-vitro activity of piperacillin and tazobactam combination against clinically significant bacteria

The in-vitro activity of piperacillin/tazobactum which is not among the routinely tested antibiotic at the Public Health Bacteriology Laboratory, Parirenyatwa Hospital, Harare, Zimbabwe was evaluated for its activity against bacterial pathogens using the Kirby-Bauer disk diffusion method. Piperacillin/tazobactum showed superior in-vitro activity against both gram positive and gram negative bacteria when compared with routinely tested antibiotics such as gentamicin, erythromycin, tetracycline, penicillin, chloramphenicol, fusidic acid and clindamycin and the difference was statistically significant (p < 0.05). Ciprofloxacin showed in-vitro activity comparable to that of tazobactam/piperacillin. Specifically, 96% of gram positive isolates (comprising Streptococcus pyogenes, Staphylococcus aureus, coagulase negative staphylococci and Streptococcus pneumoniae were sensitive to piperacillin/tazobactam. For gram negative organisms, 98% of Haemophilus influenzae Shigella spp, Klebsiella spp were also sensitive to the combination. The broad spectrum of activity of piperacillin/tazobactam shows that the potential of the drug combination for the treatment of infections caused by diverse microorganisms should not be underestimated. We recommend its inclusion in routine antibiotic sensitivity testing in our hospital.

HIV infection and HIV-1 clades among pregnant women in Harare, Zimbabwe

OBJECTIVE

To determine HIV-1 seropositivity and HIV-1 clades/subtypes among pregnant women attending different clinics in Harare, Zimbabwe.

DESIGN

A prospective study.

SUBJECTS

206 pregnant women attending Edith Opperman and Budiriro clinics in Harare.

MAIN OUTCOME MEASURES

Frequency distribution of the various HIV-1 clades and rate of HIV-1 seropositivity.

RESULTS

Results obtained showed that out of the 206 pregnant women screened, 60 (29.1%) were HIV-1 seropositive. The most predominant clade was HIV-1 clade C (66.6%) whereas HIV-1 clades A and B accounted for 48.3% and 33.3% of HIV-1 clades respectively. Results also revealed dual infections with clades A and C (45%), A and D (10%), B and C (30%) and multiple infections with A, B, C and D (6.6%) whereas two (3.3%) were non-reactive.

CONCLUSION

Finally, the data on HIV-1 clades are of immense immunological, molecular and epidemiological importance in Harare, Zimbabwe and should serve as base line data for future investigations in the country.

Subtypes of HIV-1 and the impact of dual infections of HIV-1 and measles virus on micronutrient levels of pregnant women in Harare, Zimbabwe

OBJECTIVE

To determine subtypes of HIV-1, simultaneous prevalence of HIV-1 and measles virus antibodies and their impact on micronutrient levels of pregnant women in Harare, Zimbabwe.

DESIGN

Cross sectional.

SETTING

Budiriro and Edith Opperman Antenatal Clinics Harare; Departments of Medical Microbiology, Medical Laboratory Technology and Institute of Food, Nutrition and Family Sciences, University of Zimbabwe.

SUBJECTS

Pregnant women attending antenatal clinics in Harare, Zimbabwe.

MAIN OUTCOME MEASURES

HIV-1 subtypes, measles virus seropositivities and levels of micronutrients among the pregnant women.

RESULTS

Results showed that 101 (22.7%) out of a total of 444 pregnant women screened were HIV-1 positive. A separate group of 238 (inclusive of the 444) were screened for measles antibody and 118 (49.5%) were positive, whereas 41 (17.2%) were HIV-1 positive. Thirty five (29.7%) were seropositive for both HIV-1 and measles virus (simultaneous infection). HIV-1 subtypes revealed subtype C (70.4%) as the predominant subtype. HIV-1 subtypes B, A and D accounted for 40.8%, 39.8% and 22.4% respectively whereas HIV-1 subtypes E and F were not detected. Dual infections showed that 37.7%, 36.7%, 7.1% and 4.4% harboured subtypes A and C; B and C; A and D and B and D respectively. Multiple infections with subtypes A, B, C and D (5.1%) were also recorded whereas 9.2% were non-reactive. Results on micronutrients portrayed that HIV-1 positive pregnant women had significantly lower zinc than the control but co-infection with measles virus did not cause further decrease. Infection by either HIV-1 or measles virus increased serum copper (p < 0.05) but co-infection by the two viruses reduced the copper level significantly (p < 0.05). HIV-1 seropositivity did not affect serum magnesium level but was lower (p < 0.05) in women positive for both HIV-1 and measles virus.

CONCLUSION

This is a single report on HIV-1 infection, HIV-1 subtypes, simultaneous prevalence of HIV-1 and measles virus antibodies and their impact on micronutrient levels of pregnant women in Harare, Zimbabwe. The study is of nutritional, clinico-epidemiologic importance.

A sero-epidemiology cross-sectional nationwide study of the prevalence of human immunodeficiency virus in Zimbabwe 1989-1991

Between 1989 and 1991 a nationwide cross-sectional study of 2837 voluntary subjects was performed in all nine provinces of Zimbabwe to estimate the prevalence of HIV by age, sex and residence (urban/rural). The study areas were 15 randomly selected districts from each of the nine provinces. All collection of blood samples was done at schools, clinics, factories and rural health centres and samples were tested for anti HIV 1 and 2 using both the Abbott Recombinant HIV l/2,3rd generation and the Wellcozyme HIV 1+2. The overall prevalence was 6.9% (95% confidence interval (CI): 6.8-7.0). It was significantly higher in females (8.2%) than in males (5.1%) (P = 0.002) and in urban (11.9%) as compared with rural areas (3.0%) (P=0.0005). Analysing the study as a case-referent study resulted in an odds ratio (OR) of 1.7 for females as compared with males and 4.3 for urban as compared with rural areas. The difference between urban and rural areas remained after standardisation for age, sex and year of data collection but on a lower level (OR=2). The prevalence was higher in provinces where a higher proportion of the subjects was classified as resident in urban areas with one exception (Masvingo province in the southern part of the country (20.8%) and highest an the capital Harare (12.5%). The differences between the provinces remained after standardisation for age, sex and year of data collection. The prevalence of HIV in Zimbabwe was high already in 1989 and increased rapidly between 1989 and 1991, especially in urban areas.

Stillbirths and intrauterine infection, histologic chorioamnionitis and microbiological findings

OBJECTIVE

To analyze whether placental inflammation is associated with stillbirth in Zimbabwe.

METHOD

Placentas from 66 stillbirths (> 22 weeks' gestation; patients with congenital malformations, diabetes or preeclampsia were excluded) and 66 term live births were studied for the presence and severity of chorioamnionitis. The morphological results were compared with earlier presented microbiological findings in the same material.

RESULTS

Chorioamnionitis was present in 79% of stillbirths and 30% of live births (O.R. 8.5, 95% C.I. 4.0-18). Nine percent of stillbirths but no live births presented vasculitis of the chorionic plate, which verified an inflammatory response from the infant (O.R. 14, 95% C.I. 2.8-72). The same types of microorganisms were isolated from stillbirths and liveborns, but Escherichia coli and group B streptococci were more frequent among stillbirths.

CONCLUSIONS

Morphological chorioamnionitis occurred 2.6 times more often in women with stillbirths than in women with live births. In 9% of stillbirths the infant showed an inflammatory response. Thus the infant was alive when the infection occurred and it is therefore reasonable to assume that infection was the cause of death.

Measles virus haemagglutination-inhibition antibodies among pregnant and non-pregnant women in the vaccine era in Harare, Zimbabwe

OBJECTIVES

To determine the prevalence of measles virus haemagglutination-inhibitive antibodies among pregnant and non-pregnant women born before 1963 (pre-vaccine era) and those born after 1963 (vaccine era) in Harare.

DESIGN

Prospective study of serum samples collected from pregnant and non-pregnant women born during the pre-vaccine era and vaccine era in Harare.

SETTING

A laboratory based study at the Virology Laboratory, Department of Medical Microbiology, University of Zimbabwe using serum samples of women from different communities in Harare.

SUBJECTS

546 pregnant and non-pregnant women.

MAIN OUTCOME MEASURES

Age, pregnant or not pregnant and the use of measles virus haemagglutination-inhibition antibody tests to determine prevalence rates or levels of antibodies to the measles virus.

RESULTS

The results showed that 158 (28.9pc) out of a total of 546 pregnant and non-pregnant women screened were positive for measles virus haemagglutination-inhibition antibodies (MVHIA) at titers ranging from 1:10 to 1:80.39.8pc and 18pc of pregnant women born before 1963 and after 1963 were respectively positive whereas 49pc and 27.3pc of non-pregnant women born before 1963 and after 1963 were also positive for MVHIA respectively. The mean age of women born before 1963 was 38 + 2 years (range 34 to 60 years, median 42 years) while those born after 1963 had a mean age of 22 + 2 years (range 10 to 28 years; median 23 years). Higher antibody titers (1:40 and 1:80) were most commonly observed in both pregnant and non-pregnant women born during the pre-vaccine era than those born during the vaccine era and the difference was of statistical significance (p < 0.01).

CONCLUSION

Finally results suggest that immunity acquired by exposure to wild measles virus (pre-vaccine era or natural immunity) is higher than immunity acquired following immunisation (vaccine era) and this may affect the duration of maternally derived immunity by children of mothers born during the different eras. Consequently, while we expect that this finding will be of value in immunisation schedules, we suggest a titer of 1:40 and above as the likely screening titer for routine identification of protected women in Zimbabwe.

Intrauterine death and infections during pregnancy

OBJECTIVE

To elucidate whether microbial infections are involved in the etiology of intrauterine death.

METHODS

One hundred four cases of stillbirth of unknown etiology and 96 age- and parity-matched referents with live births were analyzed with respect to microbial infection by cultures from the placenta, endocervix and internal organs of the fetuses, external sites of the babies and fetuses, and by serology for bacteria, viruses and Toxoplasma gondii.

RESULTS

In 17 cases in whom no other infectious agent was diagnosed, Escherichia coli was isolated from the placenta and one or more internal fetal organs. Tests for Treponema pallidum and Toxoplasma gondii were more frequently positive in cases than in referents (O.R. 8.3 and 3.9, respectively). There was no increased risk for intrauterine death in women with human immunodeficiency virus, cytomegalovirus, herpes simplex virus or rubella virus.

CONCLUSIONS

Our findings indicate that infections remain an important cause of intrauterine death in Zimbabwe.

Hospital-based study of sexually transmitted diseases at Murewa rural district hospital, Zimbabwe 1991-1992

BACKGROUND AND OBJECTIVES

In Zimbabwe, sexually transmitted diseases are highly prevalent and represent a significant amount of the workload for physicians.

GOAL OF THIS STUDY

To estimate the prevalence of sexually transmitted diseases and human immunodeficiency virus as well as symptoms related to sexually transmitted diseases.

STUDY DESIGN

This was a cross-sectional study of 500 volunteers (285 women and 215 men) attending an sexually transmitted disease clinic in the Murewa District, 100 km northeast of the capital, Harare. Information on background characteristics and symptoms were obtained with a standardized questionnaire, and samples were collected and immediately transported to the laboratory for examination.

RESULTS

The majority of the patients were 20-29 years old. Half of the men and 12% of the women had never been married, and 7.9% of the men and 12% of the women were divorced. Genital ulcers and dysuria were the most prevalent symptoms in men (64% and 62%, respectively). In women, the most prevalent symptoms were lower vaginal discharge and lower abdominal pain (91% and 79%, respectively). Almost 50% of the men and women were positive for human immunodeficiency virus-1 antibodies. The prevalence of Treponema pallidum and Neisseria gonorrhoeae was 15% and 18%, respectively, in men and 19% and 10%, respectively, in women. Chlamydia trachomatis showed the lowest prevalence (8%) in both sexes. No relationship was found between human immunodeficiency virus and other sexually transmitted diseases.

CONCLUSION

Women who enter a sexually transmitted disease clinic with vaginal discharge or lower abdominal pain should be tested for several sexually transmitted diseases and human immunodeficiency virus. Men with dysuria or urethral discharge who enter such clinics should at least be tested for Neisseria gonorrhoeae.

A cross-sectional sero epidemiological prevalence of polio virus antibodies post-immunization with three doses of TOPV

A cross-sectional sero epidemiological study to detect the presence of antibodies to polio virus types 1, 2 and 3 was undertaken. A total of 437 infants with an average of 40 subjects per province was enrolled in this study. All the subjects had completed the three doses of TOPV. Blood samples were aseptically collected by heel pricking on calibrated filter papers and immediately transported to the laboratory for processing. In the laboratory, standardized techniques were used to detect neutralizing antibodies to polio virus. Antibodies with a titre of > 1:32 were detected in all studied subjects. Some infants developed titres as high as 1:1024. However, polio virus type 3 showed a higher antibody titre than the other two types. Differences in titres were observed from province to province.

An incident case-referent study of stillbirths at Harare Maternity Hospital: socio-economic and obstetric risk factors

This incident case-referent study was conducted at Harare Maternity Hospital in 1989-1990 on 104 consecutive cases of stillbirth with unknown aetiology and 96 age- and parity-matched referents. Information was collected by interviewing the women following a standardized form and by review of antenatal cards. None of the women refused to participate. The most significant obstetric risk factors were prevalence of earlier stillbirths (odds ratio, OR = 6.1) and miscarriages (OR = 4.8). Low height and body mass index also increased the risk of having a stillborn baby significantly as well as a history of flue-like illness during pregnancy (OR = 4.6). The latter may have stimulated the women to book early causing the unexpectedly high OR for early booking among these cases. The pattern for the socio-economic risk factors was not easy to interpret. The most striking finding was the U-shaped relationship between socio-economic status and stillbirths with a higher risk among those with low and high status.

Comparison of four commercial enzyme-linked immunosorbent and one agglutination assays for the detection of HIV antibodies in sera from Zimbabwe

Sera from 871 AIDS and AIDS related complex patients were used to evaluate four ELISA and one agglutination assays. Commercial tests compared were Abbot, Wellcoyzyme, Biotest, Du Pont and Serodia. Wellcozyme and Serodia had the highest sensitivity (96.8 pc and 98.8 pc respectively) but the lowest specificity (53.3 pc and 46.5 pc respectively). Du Pont was the least sensitive test (89.1pc). Biotest and Abbot were comparable--Biotest had a higher sensitivity (93.2pc as compared with 90.6pc) but Abbot had a higher specificity (94.1 pc as compared with 89.1 pc). Thus, Abbott and Biotest both had a satisfactory high sensitivity and specificity and could thereby be recommended for use in screening of HIV-1 antibodies in south east Africa.

The interrelationship between HBV-markers and HIV antibodies in patients with hepatocellular carcinoma

To determine the interrelationship between hepatitis B viral markers (HBV), the human Immunodeficiency virus (HIV), and hepatocellular carcinoma (HCC) in HCC patients, a total of 282 subjects were included in the study. Out of 282 subjects, 182 were HCC patients as determined by raised alpha-feto-protein (AFP) of greater than 1,000 ng/ml. The other 100 control patients presented with other conditions and had detectable AFP of less than 1,000 ng/ml in their sera. On presentation, 10 ml of venous blood was drawn from each enrolled subject and taken to the laboratory. HBV markers were detected using commercial reagents; HIV antibodies were detected by the commercial ELISA tests and were confirmed by Western blot. AFP was detected using an RIA technique. Of 282 examined subjects 182 (64.5%) had detectable AFP of greater than 1,000 ng/ml. 113 (40.1%) and 103 (36.5%) had HBsAg and Anti-HBc respectively. However, HBeAg was found in 21 of 113 (18.6%) of the HBsAg positive only. Anti-HIV antibodies were present in 15 (5.3%) of the 282 tested individuals. Only 1 (1.0%) of the control group had detectable anti-HIV antibodies in the serum. Eleven percent and 4.0% of the same control group had HBsAg and anti-HBc in their sera respectively. The study shows a significant correlation between HCC and HBV-markers (P less than 0.0001). Similarly, a significant correlation between anti-HIV antibodies and HBV-markers, (P less than 0.0001) was found.

The detection of rotavirus antigen in faeces of asymptomatic children from two different communities in Zimbabwe

A study of the existence in Zimbabwe of Rotavirus asymptomatic infection was conducted. Rectal swabs were collected from children aged between one month and two years, who were attending health clinics at Chiweshe Hospital (rural area) and Rujeko (a Harare high density suburb) in Zimbabwe. These infants were tested for the presence of Rotavirus antigen, using the ELISA test. Out of 292 specimens collected during a period of one year, 6.9 pc were found positive for Rotavirus antigen although none of the infants had symptoms of Rotavirus infection. Our results show no significant difference (x2 = .357, P = .55) between the prevalence of Rotavirus in children, 1-12 months old from Rujeko and Chiweshe. Likewise, there was no significant difference (x2 = 1.52, P = .281) in the 13-14 months children. It was however shown that a significant difference (x2 = 9.28, P = 0.0096) appeared between winter months versus dry or wet months. We, therefore, conclude that Rotavirus antigen is prevalent in asymptomatic children, and that it is more frequent during winter months.

The incidence of rotavirus infection in children from two selected study areas in Zimbabwe

Five hundred and twenty faecal samples or rectal swabs, collected over one year from children mainly under 24 months, were tested for the presence of human rotavirus (HRV) in enzyme linked immunosorbent assays (ELISA). Fifty-three (23.6 pc) of 225 diarrhoea samples and 25 (8.5 pc) of 295 control samples were HRV positive. The association between diarrhoea and detection of HRV in stools was statistically significant with an overall odds ratio of diarrhoea patients of 3.32 (0.001 greater than p). No significant difference in the incidence of HRV infection between populations at a communal farming location and a high density suburb community was proved. The highest HRV incidence was found during the dry cool season in diarrhoea patients between four and 24 months of age. Overall proportions of 16.7 pc and 28.6 pc HRV positive in groups of 0-3 and 4-6 months old diarrhoea patients respectively was remarkably high, suggesting influence of close human contact, crowding in residences and insufficient sanitary facilities on the transmission of the HRV. Approximately 10 pc of 4-18 months old control patients were HRV positive.