Schistosomiasis-related perceptions, attitudes and treatment-seeking practices in Magu district, Tanzania: public health implications.

A study on perceptions, attitudes and treatment-seeking practices related to schistosomiasis was conducted among the Wasukuma in the rural Magu district of Tanzania at the shore of Lake Victoria where Schistosoma haematobium and mansoni infections are endemic. The study applied in-depth interviews, focus group discussions and a questionnaire survey among adults and primary school children. The perceived symptoms and causes were incongruous with the biomedical perspective and a number of respondents found schistosomiasis to be a shameful disease. Lack of diagnostic and curative services at the government health care facilities was common, but there was a willingness from the biomedical health care services to collaborate with the traditional healers. Recommendations to the District Health Management Team were: that collaboration between biomedical and traditional health care providers should be strengthened and that the government facilities' diagnostic and curative capacity with regard to schistosomiasis should be upgraded. Culturally compatible health education programmes should be developed in collaboration with the local community.

The fibre-web blood sampling technique applied to serological diagnosis of schistosomiasis mansoni.

The fibre-web technique for sampling, storing and transport of venous or capillary blood has been evaluated, in 84 schoolchildren from the Mwanza region of Tanzania, with regard to diagnostic efficacy for determination of the schistosome circulating anodic antigen (CAA) under conditions similar to those prevailing in the field. Although the average concentrations determined in fibre-web eluates were only about half of those determined in serum, the prevalences of CAA-positive individuals for the 2 sample materials were approximately the same. The average coefficient of variation calculated on determination of CAA in venous-blood fibre-web eluates amounted to 7%. The study shows that the fibre-web technique is well suited for use under field conditions.

Diagnostic value of connective tissue metabolites in Schistosoma mansoni related liver disease.

Reliable non-invasive markers of hepatosplenic involvement in schistosomiasis are needed for determination of morbidity levels in endemic populations and for diagnosis and follow-up of affected individuals. Serum levels of connective tissue metabolites have been investigated as fibrosis markers in various hepatic disorders, but their accuracy in the detection of hepatosplenic schistosomiasis under endemic conditions has not been fully elucidated. 206 adult inhabitants of a Tanzanian village highly endemic for schistosomiasis mansoni (prevalence 88%) underwent clinical, parasitological and sonographic work-up; sera were tested for aminoterminal procollagen III-peptide (PIIIP), carboxyterminal procollagen IV peptide (NC1) and laminin. Connective tissue marker levels did not correlate with the presence or intensity of infection. NC1 levels were significantly correlated with periportal liver fibrosis (P < 0.001), splenomegaly (P < 0.002), portal vein dilatation (P < 0.004) and the presence of portosystemic collaterals (P < 0.001); for PIIIP and laminin, none of the respective relationships was significant. Due to wide overlap of NC1 levels between individuals with normal sonography findings and those with advanced periportal fibrosis and portal hypertension, the sensitivity and positive predictive value of this markers to detect these individuals were low (< 40%), although specificity and overall accuracy in the given setting were good (80-90%). It is concluded that PIIIP and laminin are not useful as diagnostic serum markers of hepatosplenic schistosomiasis at the community level; NC1 was significantly related to various indices of hepatosplenic involvement, but its low sensitivity precludes its use as a screening tool under endemic conditions.

Schistosoma mansoni-related morbidity on Ukerewe Island, Tanzania: clinical, ultrasonographical and biochemical parameters.

One thousand six hundred and ninety-five inhabitants of 3 rural villages on Ukerewe Island, Lake Victoria, Tanzania, were examined by clinical, parasitological, ultrasonographic and--in part--serological means to evaluate Schistosoma (S.) mansoni-related morbidity on a community level. Villagers frequently complained of typical colitis symptoms (abdominal pain 80.1%, bloody stools 43.1%, diarrhoea 35.1%); haematemesis, on the other hand, was rare (and reports doubtful in most cases). 16.9% of the population had been given praziquantel previously. Overall S. mansoni prevalence was 86.3%, with a median egg output of 176 eggs per gram (e.p.g.) and maximum output of 17,984 e.p.g. Children and adolescents were infected more severely than adults, men more severely than women. Pretreated individuals excreted significantly fewer ova (median 124 vs 192e.p.g., P < 0.001). Hepatomegaly (determined by ultrasonography) was present in 35%, splenomegaly in 80%. Organomegaly was significantly related to egg output. Pretreated persons had lower rates of splenomegaly and left lobe hepatomegaly. Low-degree periportal fibrosis was common, while severe grades of fibrosis (MANAGIL score II and III) were present in about 6%. About 10% had other abnormalities on liver sonography (irregular parenchymal texture and/or shape); these person passed significantly more S. mansoni ova than others. Clear sonographic signs of portal hypertension were seen in 2.1%. Serum procollagen-IV-peptide and gamma-glutamyl-transferase levels were increased in persons with severe periportal fibrosis, irregular liver texture of portofugal collateral vessels. Thus, S. mansoni infection in the western part of Ukerewe Island is frequent and often severe, leading to a high prevalence of gastrointestinal symptoms. Hepatosplenic involvement does occur, although symptomatic cases of portal hypertension were not identified beyond doubt. The overall level of schistosomal morbidity is thus considered intermediate. Serum procollagen-IV-peptide may be a promising marker of schistosomal liver disease. Our data suggest that S. mansoni infection may also be related to diffuse liver parenchyma alterations in this area.

A comparative study on specific antibodies and circulating antigen (CAA) in serum and parasitological findings for diagnosis of schistosomiasis mansoni in an endemic area in Tanzania.

A baseline study to evaluate the prevalence of Schistosoma mansoni infection as well as the diagnostic efficacy of serodiagnostic tests was performed in Kabaganga village, Kome island, Lake Victoria, Tanzania. A total of 1108 individuals were examined parasitologically and clinically. Egg excretion was demonstrated by one-sample Kato-Katz test. Specific IgG1 and IgG4 antibodies against S. mansoni adult worm (SAWA) and egg (SEA) antigens as well as circulating anodic antigen (CAA) were determined in serum samples from 250 of these subjects. As a control population 41 individuals from a non-endemic area were examined parasitologically, clinically and serologically. In the parasitologically examined Kabaganga population 45% were excreting eggs. The pattern of egg excretion was typical for an endemic area with a peak in the age group 10-14 years. Sixty-five percent of the serologically tested villagers were positive in the CAA test. A total of 80% were positive in either of the two tests, indicating an active infection. In 67-95% of these individuals the levels of isotype specific antibodies were increased. The prevalence of CAA positivity corresponded fairly well with that of Kato-Katz results in the age groups 10-29 years, but in the younger age groups a considerably greater number of individuals were positive in the CAA test than in the Kato-Katz test. The results obtained indicate that virtually all of the Kabaganga villagers, regardless of age, had an ongoing, active infection or had previously been infected with S. mansoni. This population, therefore, may be useful for evaluation of the diagnostic efficacy of various antibody tests. The highest degree of discrimination between the endemic and the non-endemic village populations was noted for anti-egg IgG4 antibodies. It is concluded that the combined determination of parasite eggs in faeces and CAA in serum provides high sensitivity as regards active infection. Increased levels of isotype-specific antibodies, particularly of the IgG4 subclass, is a sensitive indicator of past or present infection, and the prevalence of individuals with such increased levels may be a simple and reliable indicator of the frequency of schistosomiasis in a community.

HIV-1 incidence and HIV-1 associated mortality in a cohort of urban factory workers in Tanzania.

OBJECTIVE: To determine HIV-1 incidence and HIV-1 associated mortality in a prospective cohort study. To determine whether the cohort is suitable for studies aiming to determine the impact of interventions on HIV-1 incidence. METHODS: The study population was a cohort of 1772 urban factory workers (1478 men and 294 women) in northwest Tanzania. The study took place from October 1991 to September 1993. Outcome measures were HIV-1 seroconversion and death. RESULTS: HIV-1 incidence was 1.2 (95% CI 0.7-2.0) per 100 person-years (pyr). Crude annual mortality was 4.9 per 100 pyr in those with and 0.3 in those without HIV-1 infection, giving an age and sex adjusted mortality ratio of 12.9 (95% CI 5.4-30.7). Of all deaths, 62% were attributable to HIV-1 infection. CONCLUSION: HIV-1 infection was a major public health problem, being the major cause of death in this adult population. At an HIV-1 incidence of 1.2 per 100 pyr, a large cohort size would be required to evaluate the impact of interventions on HIV-1 incidence.

PIP: The objectives were to determine HIV-1 incidence and HIV-1 associated mortality in a prospective cohort study and to determine whether the cohort is suitable for studies attempting to determine the impact of interventions on HIV-1 incidence. The study population was a cohort of 2038 urban factory workers in northwest Tanzania of whom 1772 workers (1478 men or 87% and 294 women or 89%) had enrolled in the study during October 1991 to September 1993. 471 (27%) of the total study population were lost to follow-up by the end of the study period. Outcome measures were HIV-1 seroconversion and death. At intake, 153 of 1478 (10.4%) men and 52 of 294 (17.7%) women were infected with HIV-1. In the study period, 17 seroconversions took place in 1365.9 person years of follow-up giving an HIV-1 incidence rate of 1.2/100 person-years of follow-up. No association was found between seroconversion and age or sex. The crude annual mortality rate was 4.9/100 person-years in those with and 0.3/100 person-years in those without HIV-1 infection, giving an age- and sex-adjusted mortality ratio of 12.9. The age- and sex-adjusted population attributable risk was 0.5/100 person-years, and of all deaths, 62% were attributable to HIV-1 infection. Of the 14 HIV-1 infected people who died, 9 met the criteria of the 1987 revised Centers for Disease Control/World Health Organization AIDS case definition: one had cryptococcal meningitis and eight HIV wasting syndrome. Two others had had weight loss and fever, but the evidence was inadequate to make or reject the diagnosis of AIDS. The remaining three without an AIDS diagnosis had pulmonary tuberculosis, diarrhea, and pyomyositis, respectively. HIV-1 infection was a major cause of death in this adult population. At an HIV-1 incidence of 1.2/100 person-years, a large cohort size would be required to evaluate the impact of interventions on HIV-1 incidence.

Antimicrobial susceptibility, auxotype and plasmid content of Neisseria gonorrhoeae in northern Tanzania: emergence of high level plasmid mediated tetracycline resistance.

OBJECTIVE: To study the antimicrobial susceptibility, plasmid content, auxotype and serogroup of strains of Neisseria gonorrhoeae isolated from an urban population of STD clinic attenders in Northern Tanzania. METHODS: The minimum inhibitory concentrations of nine common antimicrobial agents were measured by the agar dilution method against 130 strains of Neisseria gonorrhoeae isolated in a free government STD clinic in Mwanza town. The auxotype, plasmid content and serogroup of these strains were also determined by conventional techniques. RESULTS: 65 strains (50%) were penicillinase producers (PPNG), and 34 (26%) exhibited chromosomally mediated resistance to penicillin. Seven (5%) were sensitive to tetracycline; 78 (60%) showed intermediate levels of resistance, and 45 (35%) had high level plasmid mediated resistance (TRNG), all of which carried a 25.2 MDa plasmid. 79 strains (61%) showed decreased sensitivity to trimethoprim-sulphamethoxazole, and five (4%) were resistant to this agent. All isolates were fully sensitive to spectinomycin, azithromycin, cefotaxime, cefuroxime, norfloxacin and ciprofloxacin. One hundred and one strains (78%) were of type W11/111, 22 type W1, and seven cross reacting strains. The W1 strains were significantly more likely to be carrying plasmid mediated resistance to both penicillin and tetracycline. Six different auxotypes were present, the major type requiring proline. Plasmid profiles showed the presence of both the 3.2 MDa and the 4.4 MDa beta-lactamase encoding plasmids. CONCLUSION: a high proportion of gonococcal isolates remain resistant to penicillin in this region, and most isolates are now also resistant to tetracycline, with the emergence of plasmic mediated tetracycline resistance. Trimethoprim-sulphonamide sensitivity is also decreasing. The population of strains is heterogeneous, and both African and Asian beta-lactamase encoding plasmids are present.

Sexual partner change and condom use among urban factory workers in northwest Tanzania.

OBJECTIVE: To describe sexual partner change and condom use at the intake of a cohort study of urban factory workers in Tanzania. METHODS: From October 1991 to March 1992, 926 male and 170 female factory workers were interviewed using a structured, pre-coded questionnaire. Questionnaire reliability was assessed by pre-testing and comparison with results of unstructured interviews and carrying out repeat questionnaires on a sub-sample. RESULTS: Almost half of both men and women had had sexual intercourse by their 17th birthday. The period of premarital sex had an interquartile range of 2 to 10 years in men and 0 to 2.5 years in women. Having had sexual intercourse in the past month with more than one partner was reported by 22% of the men and 5% of the women. Factors associated with multiple partners in men were being born in or near Mwanza Region, having low education and low income, and being married. Condoms had been used in the past month by 3% only, mainly with casual partners. Condom use in men was associated with being young, living in town, being born in Kagera Region, high education and high income, being circumcised, and having causal or steady (non- martial) partners. CONCLUSION: Information, education and communication (IEC) on sexual relationships and condom use should start at an early age, and include education at primary schools. Much sexual partner change appears to occur through steady (non-marital) partnerships, indicating the need for IEC to be expanded beyond groups such as commercial sex workers and their clients.

PIP: A cohort study of urban workers was initiated in a factory in Mwanza Municipality, Tanzania, October 1991 to March 1992, in order to identify risk factors for HIV-1 seroconversion and for contracting other STDs. All respondents were interviewed for 30-45 minutes in Kiswahili using a structured and pre-coded questionnaire that was slightly different for men and women. In the first 19 weeks 1096 workers (926 male, 170 female) were enrolled. Participants were more likely to be under 25 years old. By the 15th birthday 16% of male and 6% of female respondents reported having had sexual intercourse; by the 17th birthday these percentages were 44% and 33%, respectively. In those who had ever married, the median period of having had premarital sexual intercourse was 5 years (interquartile range 2-10 years) in men and 1 year (interquartile range 0-2.5 years) in women. Marriage survival was slightly longer for men than for women (0.05 p 0.1). 724/926 (78%) of male and 76/170 (45%) of the female factory workers were married and living together with their spouse. Of the 724 married men 45 (6%) had 2 wives, the others had 1 wife only. Among the married respondents 607/717 (85%) of the men and 71/76 (93%) of the women reported having had sex with their spouse in the past 4 weeks (men: median 4 times, women: median 5 times). Having had more than one sexual partner in the past month was reported by 205/926 (22%) of men and 8/170 (5%) of women. Factors associated with having had multiple sexual partners in the past month were: being born in Mwanza or the neighboring Mara or Shinyanga Regions, having had less education or having a low income, and being married. Having had more than one sexual partner in the past month was also associated with having ever had a genital discharge. Overall, 141/924 (15%) of men and 30/170 (18%) of women had ever used a condom. Only 28/924 (3%) of men and 5/170 (3%) of women had used a condom in the past month.

Intake of a cohort study of urban factory workers in northwest Tanzania. Risk factors for HIV-1 infection.

A cohort study has been started of urban factory workers and their spouses in Tanzania, in order to 1) identify risk factors for HIV-1 seroconversion, and 2) document changes over time in risk behaviour, in particular condom use and partner change, and determine whether these are associated with a reduced incidence of HIV-1 and other sexually transmitted diseases. We report findings at intake from October 1991 to March 1992. Study participants were interviewed, examined, and screened for HIV-1 and syphilis. HIV-1 prevalence was 91/926 (10%) in males and 36/217 (17%) in females. Statistically significant risk factors for HIV-1 infection in males were age group, region of birth, not being married for more than 5 years, being uncircumcised, having had a genital ulcer in the past four months, and having received injections from medical staff in the past four months. HIV-1 incidence in this group is expected to be between 1% and 2% per year. It is concluded that a longitudinal study is needed to assess the importance of partner change. This cohort appears to be suitable for such a study as HIV-1 incidence is expected to be fairly high, HIV-1 prevalence and risk factors are comparable to those of the general population and cooperation of the factory workers is good.

Kagera 1989 health survey: 1. Human immunodeficiency virus seroprevalence in adolescents.

One thousand four hundred and fifty five adolescents were surveyed for Human Immunodeficiency Virus (HIV) infection in an area experiencing AIDS epidemic. The study was done in order to estimate control measures. Among the 1455 adolescents serosurveyed, 47 (3.2%) were HIV infected, of whom 30 (63.8%) were all aged 10-15 years old. The male/female ratio was 1:1. Of all the adolescents examined 830 (57.1%) were attending school. Among the selected potential risk factors namely non-school enrollment, illicit injections, blood transfusion and sexually transmitted diseases none of these was significantly associated with HIV seropositivity. Special care should be taken when interviewing adolescents on sensitive issues like the ones associated with HIV infection. In this study potential risk factors for getting HIV infection were rarely reported, thus making it difficult to get significant association with the HIV infection.

PIP: 738 male and 717 female adolescents and young adults aged 10-19 years in Ishozi ward of Kagera rural community were surveyed for HIV infection. Only 36 males and 70 females admitted to having experienced sexual intercourse, with 29 of these experienced females being married. 3.2% of the sample was seropositive. 30 of these 47 with HIV, or 63.8%, were aged 10-15. In fact, subjects in the 10-12, 13-15,, and 16-19 year age groups were infected in almost equal proportions, as were males and females. Since customary laws prohibit sexual intercourse before marriage for both sexes, fear may have driven respondents to underreport the extent of their sexual activity. Some correlation may also exist between school enrollment and HIV infection, with teachers or other school workers being vectors of infection. No significant association with HIV seropositivity was, however, found with potential factors for infection such as non-school enrollment, illicit injections, blood transfusion, and sexually transmitted diseases. Special care should be taken when interviewing adolescents on sensitive issues such as those associated with HIV infection to elicit as much information as possible on potential risk factors which may be present for becoming infected with HIV.