AIDS: an international perspective.

The acquired immunodeficiency syndrome (AIDS) and infection with the human immunodeficiency virus type 1 (HIV-1) constitute a worldwide public health problem. Whereas in Europe and in most of the Americas transmission of HIV-1 has occurred predominantly among homosexual men and intravenous drug abusers, in Africa a distinct epidemiologic pattern has emerged that indicates that HIV-1 infection is mainly heterosexually acquired. Heterosexual transmission appears to be increasing in some parts of Latin America and the Caribbean, and possibly in the United States. In addition to HIV-1, at least one other human retrovirus, namely HIV-2, has been implicated as a cause of AIDS in Africa and Europe. Factors that influence heterosexual transmission of HIV-1 include genital ulcerations, early or late stages of HIV-1 infection in the index case, and possibly oral contraception and immune activation. The rate of perinatal transmission is enhanced when the mother's illness is more advanced. AIDS and HIV-1 infection may have a significant impact not only on public health, but also on the demography and socioeconomic conditions of some developing countries. Programs for the prevention and control of AIDS should be an immediate priority in all countries.

Burden of diseases in poor resource countries: meeting the challenges of combating HIV/AIDS, tuberculosis and malaria.

Poverty, ill health and ignorance are closely interlinked and each is a determinant of the other. HIV/AIDS, malaria and tuberculosis are by far the commonest causes of ill-health and death in the poorest countries of the world which happen to be in the tropics and temperate countries in Africa, Asia and South America. Morbidity and mortality from these three diseases have a major socio-economic impact on individuals, communities and nations, due to the vicious cycle of poverty, ill health and ignorance. In Tanzania morbidity due to HIV/AIDS, tuberculosis and malaria leads to irrecoverable losses in productivity, inadequately trained workforce due to absence from training by the sick, heavy health care budgets to treat these otherwise preventable diseases, less competitive economy, higher labour force turnovers and unstable national budgets. If not controlled continuing rise in incidence of HIV/AIDS, malaria and TB may threaten the survival of small enterprises and ability to attract foreign investments leading to a rise in unemployment. Thus, investments in the improvement of health including HIV/AIDS, malaria and TB if done well will bring substantial benefits for the national economy including an increase in productivity. In this paper a review of the impact of HIV/AIDS, TB and malaria in Tanzania is done with an attempt to propose how research can contribute to improved efforts towards more effective prevention and control efforts. The need for multidisplinary research efforts in addressing the three disease conditions is proposed.

Laboratory diagnosis of HIV-1 and HIV-2 in Africa.

PIP: It is well accepted that HIV is the cause of AIDS and that the virus is distributed widely throughout the world. Being able to diagnose infection with HIV through laboratory tests has done much to facilitate the early recognition of the severity and extent of the AIDS pandemic. Many laboratory techniques exist to detect infection with HIV-1 and HIV-2. In recent years, however, African countries have found it difficult to implement such diagnostic tests because the tests have been either ill-suited or too expensive for the developing country setting. This paper describes many of the HIV laboratory diagnostic techniques currently used in both diagnostic and research settings. The review of techniques is, however, neither all-inclusive nor globally applicable, but intended to be simply a view of available techniques from the African perspective. The opening general section on the detection of HIV-1 and HIV-2 is followed by discussion of screening tests, rapid tests, and confirmatory tests to detect HIV antibodies. Techniques to detect virus include viral isolation, the detection of viral antigen, and PCR. HIV testing algorithms are discussed. The authors stress in closing the importance of the effective laboratory diagnosis of HIV in the prevention and control of HIV/AIDS. Laboratory personnel must be trained, cost-effective laboratory techniques made available for the African setting, and test systems chosen which are best adapted to the prevailing epidemiologic, socioeconomic, and cultural contexts. These latter systems often will differ from the types of diagnostic tests and testing algorithms used in more developed countries.^ieng

Prevalence of HIV-1 infection and symptomatology of AIDS in severely malnourished children in Dar Es Salaam, Tanzania.

In Dar es Salaam, Tanzania, 200 children with severe malnutrition and controls matched for age, sex, and area of residence were screened for serological evidence of infection with the human immunodeficiency virus type 1 (HIV-1) over 5 months in 1988. The prevalence of HIV-1 antibodies in the malnourished group was 25.5% (51 of 200) compared with 1.5% (three of 200) in the controls. The seroprevalence rate was equally high in malnourished children above the age of 18 months (26 of 102; 25.5%), as in those below this age (25 of 98; 25.5%). The prevalence rate was higher in children with marasmus (38.2%) as compared to children with marasmic-kwashiorkor (12.3%) or kwashiorkor (12.2%). The prevalence of clinical features known to be associated with AIDS was higher in the HIV seropositive malnourished children as compared to the seronegative children. The modified World Health Organization clinical case definition of AIDS in children was also evaluated and found to have a low sensitivity and positive predictive value (62.8 and 57.1%, respectively) but a fairly high specificity (83.9%). It is recommended to routinely rule out HIV infection in malnourished children, especially those with marasmus.

Alternative confirmatory strategies in HIV-1 antibody testing.

Alternatives to confirmation of human immunodeficiency virus (HIV)-1 seropositivity by Western blot analysis were evaluated retrospectively using combinations of six anti-HIV-1 screening assays, including four enzyme-linked immunosorbent assays (ELISA) and two simple tests (a rapid dot immunoassay and an agglutination assay), according to an algorithm where sera are first screened by one assay and those repeatedly reactive on this assay are tested repeatedly by a second assay. Two panels of sera collected in Dar es Salaam, Tanzania, were used. Panel 1 was composed of 1,465 consecutive blood donor sera of which 99 (6.8%) were confirmed HIV-1 antibody positive, and panel 2 was composed of sera from 396 consecutively admitted patients at two medical wards of which 116 (29.3%) were confirmed HIV-1 antibody positive. Sera reactive on any of the six screening assays were also tested by a confirmatory Western blot assay. The sensitivity of the assays at the initial valid testing were as follows: Abbott 99.5%, Behring 99.5%, Organon 97.7%, Wellcozyme 100%, HIV CHEK-1 95.8%, and Serodia 95.8%. After repeat testing of sera that initially gave false-negative results all assays showed 100% sensitivity except HIV CHEK-1 (98.6%). The specificities after repeat testing were between 99.6 and 99.9% for all assays except for the Behring ELISA (98.1%). Several combinations of screening assays were found to give the same diagnostic accuracy as the screening assay followed by Western blot analysis. We conclude that an alternative confirmatory strategy can be fully satisfactory for some testing purposes.

Lymphocyte subset enumeration in HIV seronegative and HIV-1 seropositive adults in Dar es Salaam, Tanzania: determination of reference values in males and females and comparison of two flow cytometric methods.

The level of CD4(+) T-lymphocytes represents a useful marker with which to monitor the progression of HIV infection. Sex and geographical differences in the reference values of lymphocyte subsets have been reported. We have compared two flow cytometric methods (MultiSET and SimulSET) for the quantification of lymphocyte subsets using whole blood from 92 HIV seropositive and 241 seronegative adults, and determined the reference values of lymphocyte subsets in HIV seronegative Tanzanian subjects. In seronegative Tanzanian subjects, the percentages of CD3(+) and CD4(+) T-lymphocytes and the CD4(+):CD8(+) T-lymphocyte ratios were lower while the percentage of natural killer cells was higher compared to the levels of the corresponding parameters reported for Europeans. Seronegative Tanzanian females had significantly higher levels of CD3(+) and CD4(+) T-lymphocytes and CD4(+):CD8(+) T-lymphocyte ratios compared to seronegative males. The correlation coefficients of CD3(+), CD4(+) and CD8(+) T lymphocyte counts and percentages obtained by the two flow cytometric methods were high. The median values of the number of CD4(+) T-lymphocytes obtained by the two methods were not significantly different. In conclusion, determination of the reference values of lymphocyte subsets in HIV seronegative Tanzanian adults showed significant sex differences and differences in percentage values compared to those reported in certain other geographical areas. There was acceptable agreement in the levels of CD4(+) T-lymphocyte values obtained by the two flow cytometric methods.

Evaluation of the FACScount, TRAx CD4 and Dynabeads methods for CD4 lymphocyte determination.

A study to evaluate the performance of the FACScount, TRAx CD4 and Dynabeads methods for the determination of CD4+ T lymphocyte subset levels was conducted in Tanzania as part of a World Health Organization (WHO) collaborative multicenter field evaluation of alternative methodologies for the enumeration of CD4+ T lymphocytes. The objective was to compare the performance of these alternative methods in a developing country setting, against that of flow cytometry as the reference standard. T lymphocyte subset levels were determined in 91 HIV seronegative and 98 HIV-1 seropositive adults using the three alternative methods. CD4+ and CD8+ T lymphocyte counts were determined by all methods except for TRAx CD4 enzyme linked immunosorbent assay (ELISA) which measures CD4+ T lymphocyte levels only. Linear regression analysis was done to correlate the counts obtained by the alternative methods to those obtained by flow cytometry. The overall correlation coefficients of FACScount and Dynabeads CD4+ and CD8+ T lymphocyte counts with those of flow cytometry were high (r > 0.9). A lower correlation (r = 0.631) was obtained when TRAx CD4+ ELISA counts were compared to those of the reference method. These results show that two of these alternative methodologies are suitable for the determination of CD4+ and CD8+ T lymphocyte counts with the use of African blood samples. Since the methods are simpler and cheaper than flow cytometry, they provide an alternative option for the enumeration of T lymphocyte subsets in laboratories with limited facilities.

Affordable CD4+ T cell counts by flow cytometry. II. The use of fixed whole blood in resource-poor settings.

We tested the feasibility and precision of affordable CD4+ T cell counting in resource-poor settings using a recently standardised fixative, TransFix in whole blood (WB) by flow cytometry (FCM). The precision of the assays was established under optimal conditions for single-platform FCM such as the volumetric CytoronAbsolute and the bead-based FACSCan. Fresh WB samples from HIV-seropositive and seronegative patients were tested in Tanzania and South Africa, fixed and sent to the UK for reanalysis 7 days later. Correlation, bias and limits of agreements were analysed by linear regression and the Bland-Altman test. Absolute CD4+ T cell counts remained stable for at least 10 days when TransFix was added to WB in 1:10 dilution at 20-25 degrees C, and for 7 days when added in 1:10 or 1:5 dilution to samples stored to mimic 'tropical' conditions at 37 degrees C. Higher temperatures such as 42 degrees C were tolerated for only short periods since the recovery had decreased to 63% by day 3. The reproducibility of lymphocyte subset analysis remained unchanged by TransFix with coefficient of variations <6% for all T cell subsets. Absolute CD4+ T cell counts and CD4+ T cell % values on fixed samples in the UK showed a high correlation with the results using fresh samples in Tanzania (r=0.993 and 0.969, respectively) and with the samples handled in Johannesburg (r=0.991 and 0.981) with minimal bias. Primary CD4 gating using only a single CD4 antibody also remained accurate in TransFixed samples (r=0.999). Thus, TransFix permits optimal fixation and transport of WB samples in the developing world for FCM to local regional laboratories and for quality assurance in international centres. When used together with inexpensive primary CD4 gating, TransFix will allow reliable and affordable CD4+ T cell counting by FCM in resource-poor settings.

Antibodies to Yersinia enterocolitica in a healthy population in Tanzania.

A micro-agglutination technique was used for the detection of antibodies to Yersinia enterocolitica serogroups 03, 08 and 09 in sera from healthy individuals in Dar es Salaam, including 38 school children and 81 adults. Antibody titres greater than or equal to 128 to serogroup 03 were found in 2.6% of the children and 0.8% of the adults, and to serogroup 09 in 5.3% of the children and 2.5% of the adults. Antibody titres greater than or equal to 128 serogroup 08 were not detected.

Incidence of HIV-1 infection among adults in the Kagera region of Tanzania.

The results of a population-based follow-up study are presented. The baseline study which started in August 1987, was carried out to determine the prevalence of human immunodeficiency virus (HIV-1) infection in the Kagera region of Tanzania. A multistage cluster sampling technique was adopted in the selection of the study population. In the follow-up survey which started in June 1988, members of the same study population were revisited and studied in order to determine the incidence of HIV-1 infection among those who were HIV seronegative in the initial survey. HIV serology was conducted by using enzyme-linked immunosorbent assay and all positive sera were confirmed by the Western blot technique. A total population of 1316 adults aged 15-54 years was studied, constituting an average follow-up response rate of 69% in the rural areas and of 59% in the urban area. The overall incidence of HIV-1 infection among the adult population sample was 13.7 per 1000 person-years at risk with the highest incidence in the urban zone (47.5 per 1000 person-years at risk) and the lowest incidence in one of the three rural zones (4.9 per 1000 person-years at risk). The age-specific annual incidence was highest in the age group 25-34 years for males and in the age group 15-24 for females. From these results it was estimated that the number of newly infected adults in the region each year is about 8200 with a range between 5400 and 11,000 corresponding to the 95% confidence limits on the overall incidence.(ABSTRACT TRUNCATED AT 250 WORDS)

Infection with Streptococcus agalactiae in a London hospital.

Streptococcus agalactiae is presently the commonest beta-haemolytic streptococcus isolated from clinical material in this hospital. Between October 1974 and March 1975, 81 patients with such infections were seen. Seventeen had urinary tract infections, six had septicaemia, and one neonate had meningitis. Three of those with septicaemia were neonates and two died. The organism was also found to be a cause of pyogenic skin conditions in five patients. Isolates from throat swabs in 12 patients, from sputum in four, and from the female genital tract in 18 were considered part of the normal flora. Human strains of Str. agalactiae were found to be biochemically different from animal strains.

Immunological profile of endemic and epidemic Kaposi's sarcoma patients in Dar-es-Salaam, Tanzania.

Kaposi's sarcoma (KS) presents in four clinicopathological types namely classical/sporadic (CKS), endemic African (EKS), iatrogenic (IKS) and that associated with AIDS (AKS). Recently a putative herpes virus (HHV-8) was described and shown to be present in all four types of KS. The immunological status of patients with EKS has been conflicting. In this study total leucocyte counts, total lymphocyte counts and lymphocyte subsets of patients with EKS and AKS were determined by flow cytometry and compared to those of healthy HIV-1 seronegative controls. Results show that 50% of EKS lesions were of nodular type. Patients with EKS had significantly lower levels of CD4+ T- lymphocytes and CD4:CD8 ratio but significantly higher CD8+ T-lymphocytes compared to controls. Patients with AKS had significantly lower levels of CD4+ T-lymphocytes and also CD4:CD8 ratios but significantly higher percentage of CD8+ T-lymphocytes when compared with EKS patients. These findings indicate that in both forms of KS there is a certain degree of immunological disturbance which is more conspicuous in AKS because of HIV infection and suggests that HIV-1 acts synergistically with the aetiological agent (HHV-8) to cause a more aggressive type of KS.

Prevalence and incidence of syphilis and its association with HIV-1 infection in a population-based study in the Kagera region of Tanzania.

Population-based prevalence and incidence studies on HIV-1 infection were started in the Kagera region of Tanzania in 1987. The prevalence and incidence of infection with Treponema pallidum was studied to enable development of better strategies for STD control. Serological diagnosis of a past or treated infection with Troponema pallidum was made by seropositivity only to TPHA testing while active syphilis was diagnosed by seropositivity to both VDRL and TPHA tests. Seroconversion was measured in 1989 by finding TPHA serologically positive individuals during the follow-up period among the initially seronegative study population of 1987. The overall prevalence of active syphilis in the total sample of adults in the region was found to be 5.9% while that of past syphilis was 13.5%. The association between the prevalence of HIV-1 infection and syphilis of both types was found to be highly significant. However, the association between one pre-existing infection and seroconversion in the other was present but not statistically significant. The overall incidence of syphilis based on seroconversion in a cohort of adults in the region was found to be 11.6 per 1000 person-years at risk. In view of these findings, syphilis is a significant health problem in the region with a high level of transmission and efforts should be made to control it. Intervention studies should use these base-line data and monitor changes in syphilis incidence which may indicate changes in sexual behaviour. Such indicators could also be useful for evaluating the impact of interventions directed at reducing the transmission of HIV, syphilis and other STDs in the region.

PIP: Population-based prevalence and incidence studies on HIV-1 infection were started in the Kagera region of Tanzania in 1987. In 1989, a follow-up population-based serosurvey was conducted in the same population with the aim of determining the incidence of HIV-1 infection in the region. In 1987 multi-stage cluster sampling technique was employed to visit all the households selected and to choose at random 1 adult between 15 and 54 years old and 1 child under 15 years old. Syphilis serological examination was done on 2307 adults; 135 had active infection (both VDRL and TPHA positive), 1837 were negative, and 24 had false positive serology (VDRL positive and TPHA negative). The overall prevalence of active syphilis in the regional study sample was 5.9%, while that of past syphilis infection was 13.5%. The prevalence of past infection with syphilis in the rural areas (12.1%) was statistically significantly different from that in the urban area (17.8%, p 0.001). The prevalence of both types of infection increased with age in both rural and urban areas (p 0.001), except for active infection in the urban area (p 0.05). Analysis determining the association between HIV-1 infection and treponemal disease of both types found that there was a highly significant association between the 2 infections after controlling for the number of sexual partners in 3 categories of 0-1, 2-4, and 5 or more sexual partners an individual had had during the 8 years before 1987 (Mantel Haenszel weighted odds ratio 2.38). Between 1987 and 1989 the mean risk period for syphilis seroconversion of the 1133 individuals tested, was 1.82 years with a range between 1.20 and 2.49 years. The overall incidence was 11.6 per 1000 person-years at risk. The highest incidence was in the urban zone (15.4 per 1000 person-years at risk) and the lowest in the Karagwe rural zone (6.5 per 1000 person-years at risk). There was but a weak association between 1 pre-existing infection and seroconversion in the other as indicated by the risk ratios, which were more than unity.

Inter-relationships between HIV infection and other sexually transmitted diseases.

The HIV is a typical sexually transmitted disease (STD) agent which depends for its transmission through sex on contact between raw body tissues of infected and uninfected individuals independent of sexual inclination. The dynamics of HIV transmission and its control in a community can be inferred from studying the socio-cultural and epidemiological aspects of acute STD. There is strong evidence to suggest that the main cause of rampant heterosexual transmission of the HIV in sub-Saharan Africa in contrast to the rarer heterosexual HIV transmission in Europe and the USA is the high prevalence of ulcerative STD in Africa. Studying the trend and response to treatment of conventional acute STD are quick and indirect ways of assessing the impact of control measures against AIDS and HIV infection in an HIV endemic area. Further research is needed to determine the extent and detailed mechanism of interaction between HIV infection and other STDs as well as studying the efficacy of AIDS control through control of other STDs.

PIP: Having reviewed the interrelation between HIV infection and other STDs, the author concludes that enough evidence exists to designate some STDs -- especially genital ulcer diseases (GUD) -- as a risk factor for HIV transmission. Additionally, the evidence suggests that sub-Saharan Africa's rampant heterosexual transmission of HIV, which depends contact between raw body tissue of infected and uninfected individuals, is mainly due to the high prevalence of ulcerative STDs in the region. Studies have shown a connection between the presence of HIV and past history of STD. In one such study in Zaire, 50% of AIDS cases had a past history of STDs, compared to 14% of controls. In Tanzania and Rwanda, the prevalence of a pst STD history among AIDS cases were 35% and 70%, respectively. Unlike the US and Europe, where homosexual intercourse and intravenous drug use are the major risk factors for HIV, heterosexual intercourse is the major mode of HIV transmission in sub-Saharan Africa. While studies in the US show that male to female transmission of HIV occurs in 1 out of every 500 sexual exposures, the rate is far higher in sub-Saharan Africa. Researchers have identified various possible risk factors for heterosexual transmission of HIV, and the only contrasting difference between sub-Saharan Africa and the US and Europe is the high prevalence of STDs -- including IUDs -- in Africa. Not all STDs may facilitate HIV transmission. A study at a London STD clinic suggests that gonorrhea does not appear to act as a cofactor of HIV transmission. The author concludes that these findings indicate that AIDS control activities in Africa require corresponding STD control programs.

Antibiotic susceptibility of group A streptococci in a national consultant hospital in Dar es Salaam: a four year follow-up.

Seventy one Group A streptococcal strains isolated between 1992 and 1995 at Muhimbili Medical Centre in Dar es Salaam were found to be susceptible to penicillin G and cotrimoxazole. All except two strains, which showed intermediate susceptibility, were susceptible to erythromycin. Sixty five strains (91.5%) were resistant to doxycycline. The findings confirm continuing efficacy of penicillin G, erythromycin and contrimoxazole in treating Group A streptococci (GAS). The low prevalence of GAS with intermediate susceptibility to erythromycin and resistance to doxycycline by a majority of the GAS emphasise the need for regular monitoring of antibiotic susceptibility of GAS.

Antistreptolysin O and antideoxyribonuclease B titres in blood donors and in patients with features of nonsuppurative sequelae of group A streptococcus infection in Tanzania.

Antistreptolysin O (ASO) and antideoxyribonuclease B (ADN B) titres were determined on sera from blood donors in Dar es Salaam, Tanzania and from Bergen, Norway and were compared with titres in patients with features of postgroup A streptococcal diseases in Dar es Salaam. The upper limit of normal ASO titres in Dar es Salaam was 200 mu/ml and for ADN B it was 300 u/ml while in Bergen the upper limit of normal ASO titre was 250 u/ml and that of ADN B was 100 u/ml. Titres of ASO in Dar es Salaam and Bergen were consistent with those from sub-Saharan Africa and from other continents. Upper limit of normal ADN B titres in adults in Dar es Salaam were higher than those in Bergen probably due to higher frequencies of group A streptococcal skin infections in Dar es Salaam than in Bergen. Patients with features of postgroup A streptococcal diseases in Dar es Salaam had antibody titres above the upper limits of normal in 32.8% of the patients for ASO and in 45.9% for ADN B. ASO and ADN B titres or ASO and any other reliable test for antibody to group A streptococcus should be utilised together in providing strong evidence of recent infection with the group A streptococcus or of postgroup A streptococcal disease.

Human immunodeficiency virus infection and AIDS in east Africa: challenges and possibilities for prevention and control.

Human immunodeficiency infection and AIDS are a major recent microbial infection in east Africa with serious health and socioeconomic impacts in the region. At present HIV infection and AIDS account for more than 50% of adult medical admissions into some of the national and provincial hospitals as well as for 10-15% of paediatric admissions. AIDS is also at present the commonest cause of death among those aged 15-45 years. Tuberculosis, a closely associated disease to HIV infection, has increased more than three fold in some countries in the region. The prevalence of HIV infection currently ranges from 10-30% among adults in urban areas and from less than 1% to 25% in adults in rural areas; since this prevalence is still rising, the full impact of the AIDS problem in east Africa is yet to be realised. This is different from the situation in many developed countries where AIDS is no longer a priority health issue and where peak prevalences of the infection have been reached. The differences in HIV prevalences between east Africa and developed countries are due to poverty, ignorance, high prevalence of other STDs and associated cultural and traditional practices which prevail and facilitate HIV transmission in the region. While more than 80% of HIV infection in east Africa is transmitted through heterosexual intercourse, 5-15% of cases are perinatally transmitted and the remaining cases are transmitted through blood and blood products. While a lot of scientific advances have been made in immunopathology of AIDS, diagnostics and in social behavioural studies, we are still a long way towards getting curative therapy and or effective preventive vaccines. Recent discovery that use of zidovudine can significantly reduce perinatal HIV transmission is an additional breakthrough. While knowledge and tools for preventing HIV transmission are available in the world, prospects for AIDS control in east Africa appear gloomy unless major efforts are made in the reduction of poverty, ignorance and in the control of other common sexually transmitted diseases.

PIP: HIV/AIDS poses a major health and socioeconomic burden in east Africa. More than 50% of adults and 10-15% of children admitted to some of the national and provincial hospitals in the region have HIV/AIDS. AIDS is the leading cause of death among people aged 15-45. Tuberculosis, an opportunistic infection associated with HIV infection, has risen more than three times in some east African countries. 10-30% of adults in urban areas and from less than 1% to 25% of adults in rural areas are infected with HIV. In fact, HIV prevalence is still increasing; so the full impact of AIDS in eastern Africa has not yet occurred. Yet in many developed countries, HIV infection has peaked and HIV/AIDS is no longer a top priority. Poverty, ignorance, high prevalence of other sexually transmitted diseases (STDs), and associated cultural and traditional practices (e.g., inheritance of widows and polygamy), which abound and facilitate HIV transmission, account for the differences in HIV prevalence between east Africa and developed countries. Heterosexual intercourse accounts for more than 80% of HIV infections in east Africa. Perinatal transmission accounts for 5-15% of HIV cases. Blood and blood products transmitted HIV in the remaining cases. There have been considerable scientific advances in immunopathology of AIDS, diagnostics, and social behavioral studies; yet a cure and/or an effective vaccine is not in the near future. Recently, scientists have discovered that a mother's use of zidovudine during the last weeks of pregnancy and labor and zidovudine administered to the newborn significantly reduce perinatal HIV transmission. The knowledge and tools for preventing HIV transmission are available worldwide, but AIDS control in eastern Africa is apt to be for naught unless strong efforts are implemented toward the reduction of poverty, ignorance, and in the control of other common STDs.

Serological evidence of Lyme borreliosis in Africa: results from studies in Dar es Salaam, Tanzania.

Investigations were performed on sera from blood donors, pregnant women, patients with polyarthritis and from patients with clinical suspicion of syphilis in Dar es Salaam using Borrelia burgdorferi (Bb) flagellar antigen in a second generation ELISA test from DAKO A/S, Denmark, for specific IgM or IgG antibodies. An IgM and or IgG seropositivity rate of 30/100 (30%), 19/50 (7.2%), 10/20 (50%) and 11/20 (55%) was found in sera from the respective groups. These results compare with a Bb seroprevalence rate of 4/100 (4%), 1/52 (2%) and 363/5024 (7.2%) in blood donors, in pregnant women and in patients investigated serologically for Lyme borreliosis (Lb) respectively in Bergen, Norway, where cases of Lb are detected regularly. The high prevalence of antibodies to Bb flagellar antigen in Dar es Salaam, Tanzania where clinical conditions including erythema migrans, arthritis, mycocarditis and CNS diseases as well as tickbites are found call for further clinical, entomological and laboratory investigations.

High frequency of sexually transmitted diseases among pregnant women in Dar es Salaam, Tanzania: need for intervention.

In order to determine the prevalence and characteristics of sexually transmitted diseases (STDs) in pregnant women (PW) attending a primary health care antenatal clinic (ANC) in metropolitan Dar es Salaam, Tanzania, a randomly selected sample of PW in their second or third trimesters were invited to participate at their first visit. They were interviewed using a questionnaire and underwent genital examination. Genital swabs were obtained for microscopy and/or culture isolation of Candida albicans, Trichomonas vaginalis, and Neisseria gonorrhoeae. Blood specimens were also obtained for serological testing for syphilis and for antibodies to the human immunodeficiency virus (HIV). A total of 777 PW aged 14 to 40 years were seen. Parities ranged from 0 to 10. Prevalence of syphilis, trichomoniasis, gonorrhoea and HIV infection were 4.0%, 22.7%, 3.6% and 15.2%, respectively. At least one acute STD (excluding HIV infection) was found in 32.8% of the PW. The prevalence of multiple STDs (excluding HIV infection) was higher in teenagers (45.3%, 77/170) than in PW in other age groups (29.2%, 177/607) (p < 0.001). The prevalence of HIV infection in teenage PW was 10.0%. Most STDs were least prevalent in PW who were married monogamously. Of the 732 PW who had one or more genital infections (including infection with Candida species), 669 (91.4%) had one or more genital complaints. However, most of the genital complaints were not disease specific. Since this study has shown that the prevalences of acute STDs were high in PW, especially in teenagers, it is recommended that all PW in Tanzania should be screened for STDs syndromically including the use of appropriate clinical and laboratory examination whenever possible.

PIP: A survey of 777 randomly selected pregnant women attending an antenatal clinic in Dar es Salaam, Tanzania, in 1993 revealed a high prevalence of sexually transmitted diseases (STDs), particularly among teenagers. The median age of survey respondents was 23.6 years (range, 14-40 years); 170 women (22%) were teenagers and 439 (56.7%) were married. 320 women (41.2%) had 1 or more STDs (excluding human immunodeficiency virus (HIV) infection); in 32.7%, there was active infection. STD prevalence was 45.3% in teenagers compared with 29.2% in adults. In the overall sample, the prevalences of syphilis, trichomoniasis, gonorrhea, and HIV were 4.0%, 22.7%, 3.6%, and 15.2%, respectively. 80 women (10.3%) showed serologic evidence of past syphilis infection and 4% had active syphilis. Syphilis was most prevalent in pregnant women aged 35 years and above (13.8%), while trichomoniasis was most common in teenagers (34.3%). Of the 732 pregnant women with genital infections, 63 (8.6%) were asymptomatic; when symptoms did exist, they were generally not disease-specific. The most significant risk factor for STDs, including HIV, was single marital status. These findings suggest a need for the introduction of essential clinical and laboratory facilities for STD detection to antenatal clinics in Tanzania.

Antimicrobial susceptibility pattern of Vibrio cholerae O1 strains during two cholera outbreaks in Dar es Salaam, Tanzania.

OBJECTIVE: To determine and compare the antimicrobial susceptibility patterns of Vibrio cholerae 01 strains, which were isolated in two cholera epidemics in 1997 and 1999 in Dar es Salaam. METHODS: V. cholerae 01 strains isolated from patients with cholera in Dar es Salaam city during 1997 (94 isolates) and 1999 (87 isolates) were stored on nutrient agar slants at room temperature and antimicrobial susceptibility pattern was determined, using Kirby Bauer method. SETTING: Department of Microbiology and Immunology, Muhimbili Medical Centre, Dar es Salaam, Tanzania. RESULTS: A total of 181 V. cholerae 01 strains were studied during two epidemic periods when tetracycline or erythromycin was used for treatment of patients with severe disease. Among the 94 V. cholerae 01 strains isolated in 1997; 98.6%, 93.6%, 83%, 81.9%, 36.2%, 35.5%, 3.2% were sensitive to ciprofloxacin, tetracycline, ampicillin, erythromycin, nalidixic acid, chloramphenicol and trimethoprim/sulphamethoxazole, respectively. Among the 87 V. cholerae 01 isolates collected in 1999, 100%, 58.6%, 46.0%, 46%, 47.1%, 19.5%, 3.4% were sensitive to ciprofloxacin, tetracycline, ampicillin, erythromycin, chloramphenicol, nalidixic acid and trimethoprim/sulphamethoxazole, respectively. Between 1997 and 1999, there was a significant increase in the proportion of V. cholerae 01 isolates resistant to tetracycline, ampicillin, nalidixic acid and to erythromycin but there was no change for susceptibility to ciprofloxacin and trimethoprim/sulphamethoxazole. CONCLUSION: Significant proportion of V. cholerae 01 strains in Dar es Salaam were resistant to commonly used antimicrobial agents during the two years of the study. Therefore, there is a great need to control the utilisation of antimicrobial agents in cholera control, in addition to continuing carrying out surveillance of antimicrobial resistance as a guide to choice of antimicrobial treatment. Rotational use of the available drugs with regular monitoring of susceptibility may contribute to continuing usefulness of such drugs.