Biomedical subjects

T Marufu

Publications and source records attributed to T Marufu.

15 recordsLinked to original sources

PubMed2001

Impact of multiple dose measles vaccination on measles transmission patterns in Gweru, Zimbabwe.

Multiple dose measles vaccination was applied in Gweru, Zimbabwe in 1990-1996. This included (a) a vaccine administered to children at 9 months of age and revaccination of the same children at any point between the ages of 12 and 23 months, and (b) a single mass vaccination campaign targeted at children aged 12-119 months (who were vaccinated irrespective of vaccination status or disease history) run in early 1990. This study describes the impact of this schedule on measles transmission patterns. Using measles disease surveillance data the study compared measles transmission patterns under single dose vaccination in 1983-1989 and under multiple dose vaccination in 1990-1996. Median measles incidence rates were 261.0 and 19.0/100000 population in 1983-1989 and 1990-1996, respectively, and these were different (p = 0.002). Vaccinated cases (vaccine failures) among children aged 10-119 months significantly increased from 49.6 to 70.4 per cent of all reported cases in 1983-1989 and had a median incidence rate of 480.4/100000. In 1990-1996 the median incidence rate was 12.8 and these incidence rates were different (p = 0.002). Cases aged 60-119 months significantly increased from 14.3 to 62.2 per cent of all reported cases in 1983-1989 and had a median incidence rate of 654.1/100000. In 1990-1996 the median incidence rate was 21.4 and these incidence rates were different (p = 0.004). It was concluded that under multiple dose vaccination, lower measles incidence rates occurred most likely due to reduction of both vaccine failures and cases aged 60-119 months.

Age Distribution↗

PubMed2001

Factors associated with measles complications in Gweru, Zimbabwe.

OBJECTIVE: To investigate factors associated with complications or death among measles cases. DESIGN: A cross-sectional study. SETTING: Health facilities in the city of Gweru, Zimbabwe. SUBJECTS: Six hundred and thirty seven measles cases randomly selected from measles surveillance data. MAIN OUTCOME MEASURES: (a) Associations of respiratory complications and diarrhoea with death among complicated cases; (b) associations of age at infection, gender of cases and vaccination status of cases with occurrence of either respiratory complications or diarrhoea or death among measles cases. RESULTS: Among cases with respiratory complications, twenty two (29%) had died, while five (5%) had died among those with diarrhoea (OR=7.06,95% CI=2.55-22.35, p<0.001). On rates of respiratory complications among cases, age groups 24-59 and 60+ months were protective by 57% (95% CI=11-79%) and 76% (95% CI=52-88%) respectively compared to the age group <24 months, and vaccination was protective by 42% (95% CI=2-65%) compared to those unvaccinated. Concerning rates of diarrhoea among cases, the age group 60+ months was protective by 80% (95% CI=62-89%) compared to age group <60 months, while vaccination was protective by 64% (95% CI=42-77%) compared to those unvaccinated. With respect to rates of mortality among cases, age was protective by six per cent (95% CI=3-9 %) for every year older. CONCLUSION: It was concluded that: (a) the risk of death was higher in cases with respiratory complications than diarrhoea; (b) the risk of complications and death was inversely related to age at infection and older age groups were protective against occurrence of complications or death; (c) the risk of complications was higher in unvaccinated cases and vaccination was protective against occurrence of complications.

Age Factors↗

PubMed2000

An outbreak of dysentery in a rural district of Zimbabwe: the role of personal hygiene at public gatherings.

OBJECTIVES: To characterize the nature and extent of the outbreak; to determine the risk factors associated with contracting shigellosis; and to institute disease control and preventive measures. DESIGN: Case control study. SETTING: Nyaure Ward, Goromonzi District, Mashonaland East Province, Zimbabwe. SUBJECTS: 52 cases and 52 controls. A case was defined as any resident of Nyaure Ward who presented with bloody diarrhoea (three or more loose stools/day) between 25 July and 25 October 1997. MAIN OUTCOME MEASURES: Frequencies of symptoms, types of treatment received, risk factors for contracting the illness. RESULTS: The median age was 17 (Q1 = 8, Q3 = 30) years for cases and 19 (Q1 = 7, Q3 = 28) years for controls. Prominent symptoms were abdominal cramps (96.2%), malaise and fever (92.3%), nausea and vomiting (50.0%). The median duration of diarrhoea was 13 (Q1 = 6, Q3 = 14) days. Eighteen (34.6%) cases were admitted and of these five were referred to a central hospital and two of them complicated with haemolytic uraemic syndrome. The case fatality rate was 1.6%. Twenty four(46.1%) of the cases had Shigella dysenteriae type I, sensitive to Nalidixic acid, Kanamycin, and Doxycycline but resistant to Metronidazole, isolated from the stool specimen. Water samples did not yield any pathogens. Significant risk factors associated with contracting dysentery were shared hand washing in the same standing water at gatherings[OR = 8.47, 95% CI: (2.43-31.33)] or within homes[OR = 60.43, 95% CI: (15.73 to 256.00)]. The use of Blair toilets was a protective factor[OR = 0.03, 95% CI: (0.01 to 0.11)]. CONCLUSION: The epidemiologic evidence implicated contamination of water used for shared hand washing before meals as the source of the infection. The common practice of shared hand washing in standing water should be discouraged at all gatherings and within households to avoid future outbreaks.

Case-Control Studies↗

PubMed1999

Risk awareness of HIV/AIDS among commercial farm workers in Zimbabwe.

OBJECTIVE: To determine levels of perceived risk of HIV infection and the determinants of these perceptions among commercial farm workers. DESIGN: Cross sectional. SETTING: Commercial farms in Manicaland, Mashonaland Central, Mashonaland West and Mashonaland East provinces of Zimbabwe. SUBJECTS: 406 male and 411 female adults. MAIN OUTCOME MEASURES: Perceived risk of HIV infection. RESULTS: Out of 33 female respondents aged less than 20 years, 19 (57.6%) reported that they had no chance of acquiring the HIV infection. The majority (15) of these 19 teenagers indicated that they had no chance of being HIV infected because they had sex only with their spouses. Of the respondents aged 20 years or more, 235 (64.6%) males and 182 (55.3%) females reported that they had no chance of being HIV infected (OR = 1.47, 95% CI 1.07 to 2.02, p = 0.016). Most males (57.0%) and females (59.9%) of age 20 years or more said that they had no chance of being HIV infected because they had sex with only their spouses. Among the respondents of age 20 years or more who indicated they had a moderate to high chance of being infected or were already infected, 35 (33.3%) of the males reported that they had multiple partners and 41 (40.6%) of the females reported that their spouses had multiple partners. CONCLUSION: In general, despite high seroprevalence rates in Zimbabwe, many individuals do not perceive themselves at risk. Future health education intervention studies should seek to increase the general perception of low risk so that adequate precaution can be taken against being infected.

Adolescent↗

PubMed1998

Secular changes in rates of respiratory complications and diarrhoea among measles cases.

It has been observed that the occurrence of respiratory complications and diarrhoea among measles cases has changed over time but this change has not been quantified. A study was carried out in the city of Gweru, Zimbabwe, to quantify these changes. Rates of respiratory complications and diarrhoea among measles cases were determined in each year for the period 1968-89. It was found that mean rates of respiratory complications and diarrhoea during 1968-78 were 17.2 per cent (95 per cent CI = 11.6-22.8) and 5.2 per cent (95 per cent CI = 0-11) respectively while during 1979-89, mean rates of respiratory complications and diarrhoea were 6.5 per cent (95 per cent CI = 1-12.1) and 16.4 per cent (95 per cent CI = 10.1-22.0) respectively. Analysis of variance (ANOVA) to determine the main effects and the interaction showed that the main effects were not statistically significant (F = 0.01, d.f.1,2 = 1,40, p = 0.935; and F = 0.13, d.f.1,2 = 1,40, p = 0.725 respectively) Meanwhile the interaction term of complications and period was statistically significant (F = 15.7, d.f.1,2 = 1,40, p < 0.001). It was concluded that a change in rates of respiratory complications and diarrhoea had occurred among measles cases. It is suggested that the increase in vaccination coverage in 1979-89 and the shift in age at infection to older age groups in the same period may have brought about this change through selective suppression of respiratory complications among measles cases.

Age Distribution↗

PubMed1998

Challenges posed by changes in measles transmission patterns.

OBJECTIVE: To quantify changes in measles transmission patterns. DESIGN: Analysis of measles surveillance data. SUBJECTS: All measles cases identified in 1988. MAIN OUTCOME MEASURES: Proportion of cases in age group 60 to 119 months, proportions of vaccinated and unvaccinated cases in age group 60 to 119 months, and occurrence of cases in schools. RESULTS: Measles vaccination coverage was 91%. Incidence rate of measles was 205 per 100,000 population. The age group 60 to 119 months accounted for 49% of all reported cases and 68% of cases in this age group were vaccinated. There were measles epidemics in schools and these were associated with occurrence of secondary cases in younger siblings in the community. Case fatality rate and mortality rate were 0.4% and one per 100,000 population respectively. CONCLUSION: High measles transmission in children of school going age could spill into the community through generation of secondary cases among younger siblings and this could result in high morbidity and mortality in this vulnerable group. It is recommended that either revaccination at school entry or mass vaccination campaigns be carried out in affected age groups at schools to reduce occurrence of epidemics.

Age Distribution↗

PubMed1998

Consultations at central hospitals: reasons and outcome of referrals from urban clinics in Bulawayo, Zimbabwe.

OBJECTIVE: To quantify the main reasons for referral from urban primary health care clinics to central hospitals and to assess the outcome of such referrals in Bulawayo. DESIGN: Descriptive cross sectional study. SETTING: Mpilo Central Hospital, a quaternary level hospital and referral centre for urban clinics. SUBJECTS: 914 patients referred by urban clinics who attended the hospital in April and May 1995. MAIN OUTCOME MEASURES: Frequency of referrals by referrer, reasons for referral, outcome of referrals, diagnosis of admitted referrals. RESULTS: Of 914 referrals studied, 863 (94%) were made by registered general nurses and 51 (6%) by medical officers. Four hundred and forty four (49%) referrals made by registered general nurses were for doctors to establish the diagnosis, and 341 (37%) were for treatment or operation. The other referrals were for specialists to take over management, for advice on management and referral back to the clinic, and for the hospital to carry out specific tests. Of all referrals, 844 (92%) were consulted by generalist medical officers (GMOs), and only 70 (8%) by specialists. A total of 148 (16%) patients were admitted. Of these, 84 (57%) were females and 47% of admissions were aged 15 years or more. Nine (18%) of 51 referrals made by medical officers were admitted compared to 139 (16%) of 863 by registered general nurses. The rate of admission was not different by referrer (p = 0.7). CONCLUSIONS: The main reasons for referral from urban clinics to central hospitals are for doctors to either establish the diagnosis or provide treatment. There is scope for reducing the number of referrals made primarily for these reasons if a secondary or tertiary level of care institution is availed to Bulawayo and/or if clinic operations are reorganized to make medical officers' advice more accessible to registered general nurses during working hours.

Adolescent↗

PubMed1997

Measles complications: the importance of their management in reducing mortality attributed to measles.

OBJECTIVE: To determine the effect of rates of complications among cases and management of complicated cases on measles case fatality rates. DESIGN: Measles disease surveillance. SETTING: City of Gweru, Department of Health. SUBJECTS: Children aged zero to 15 years. MAIN OUTCOME MEASURES: Case fatality rates. RESULTS: Measles case fatality rates declined from 47.6 in 1967 to zero in 1989. Between 1967 and 1978 respiratory infections were the predominant complications (66.5%), while after 1979 diarrhoea was the predominant complications (60.6%). A significant partial correlation coefficient was observed between rates of mortality among complicated cases and case fatality rates (r = 0.89, df = 20, p < 0.001). CONCLUSION: Good management of complicated cases may have contributed towards the decline in measles case fatality rates.

Adolescent↗

PubMed1997

Comparison of protection afforded by single measles vaccination and late revaccination schedules.

An intervention study compared the protection afforded vaccinees by single measles vaccination and late revaccination schedules in 1990-94. During the intervention a single revaccination (after initial vaccination at nine months of age) was applied to children at any point in time between 12 and 23 months of age. Cases of measles aged 10-23 months were identified through an active surveillance system and in this period 5, 11 and 11 cases of revaccinated, single vaccination and unvaccinated children were identified. Measles incidence rates were 392.2-415.6 (mean = 405.6, SD = 6.7), 75.4-112.1 (median = 91.7, SD = 13.3) and 12.8-15.2 (mean = 13.9, DS = 0.99) per 100,000 population in children who were unvaccinated, with single vaccination and revaccinated respectively. Relative risk of contracting measles in children who were unvaccinated or with single vaccination was 26.5-32.5 (mean = 29.4, SD = 2.3) and 5.8-8.8 (mean = 6.8, SD = 1.2) respectively compared with revaccinated children. Vaccine efficacies that were determined were 73-81% (mean = 77.2, SD = 2.9) and 96.2-96.9% (mean = 96.6, SD = 0.27) for single vaccination and late revaccination schedules respectively. It was concluded that late revaccination affords vaccinees better protection than single vaccination through improvement in vaccine.

Age Factors↗

PubMed1996

Diagnostic and cost comparisons of a questionnaire against a chemical reagent strip test in identifying high risk communities for Schistosoma haematobium infection in northern Zambia.

A comparative study was conducted in northern Zambia in order to compare both the economical and diagnostic performance of a questionnaire with that of the chemical reagent strip test in diagnosing urinary schistosomiasis with a view to replacing the more economically expensive reagent strip test with the questionnaire in the identification of high risk communities. A total of 57 schools participated in the study and each school was considered as a community. Among the symptoms and conditions of blood in urine, pain when passing urine and bilharzia for urinary schistosomiasis, blood in the urine was the best predictor for urinary schistosomiasis with 73.9 pc (95 pc CI 56.0 to 91.9 pc) sensitivity, 82.4 pc (95 pc CI 69.5 to 95.2 pc) specificity and 78.9 pc (95 pc CI 68.4 to 89.5 pc) diagnostic efficiency in the identification of schools with high levels of infection. A diagnostic questionnaire for urinary schistosomiasis was two times cheaper than the reagent strip test in economical terms. The questionnaire approach in identifying high risk communities for urinary schistosomiasis is promising and should be tried in other endemic areas.

Adolescent↗

PubMed1996

Measles vaccine efficacy in Masvingo district, Zimbabwe.

OBJECTIVE: To carry out a survey in Masvingo District to determine the efficacy of measles vaccine. DESIGN: A retrospective study, using existing health care facility records and interviews with care givers. SETTING: Using the standard WHO-EPI cluster sampling methodology, 30 clusters were randomly selected in Masvingo District. SUBJECTS: 14 or more children in each of the 30 clusters were selected. MAIN OUTCOME MEASURES: Occurrence of measles or lack of it among the children aged 12 to 23 months, age at vaccination, status, the age at which the child had measles and availability of a health card. RESULTS: In Masvingo District from 1987 to 1994, measles incidence remained very high, though mortality drastically declined. Using field survey data measles vaccine efficacy was estimated at 78.3pc (95pc CI 54.1; 89.8). Vaccine coverage was estimated to be 75pc. CONCLUSION: The efficacy results fall at the lower end, but within the normal limits, of those expected for measles vaccine as used in Zimbabwe. Steps to increase vaccine coverage are of the highest priority.

Humans↗

PubMed1995

Relationship of casual blood pressure to smoking, education and occupation in a high density town near Harare, Zimbabwe.

An analysis is presented on associations of smoking, education and occupation with blood pressure among residents of a high density town near Harare, Zimbabwe. A total of 973 persons aged five years and above were surveyed in 1993. Obesity was significantly (p < 0.001) correlated with blood pressure (systolic or diastolic). A significant linear relationship between blood pressure and age for each sex was observed (p < 0.001). Smoking was not associated with blood pressure in both sexes. There was little evidence to suggest that education was associated with systolic blood pressure in both sexes. Meanwhile, there was strong evidence to suggest that education was associated with diastolic blood pressure in males and not in females. Mean differences in diastolic blood pressure levels between unemployed females and females in formal employment (mean difference (MD) = -7.57; standard error (SE) = 3.15; p < 0.05), in self employment (MD = -10.28; SE = 3.27; p < 0.01) and in school (MD = -6.57; SE = 3.06; p < 0.05) were statistically significant. We suggest that further studies utilizing longitudinal data on the risk factors for hypertension be conducted.

Adolescent↗

PubMed1995

Questioning the level of efficacy of the measles vaccine in use in Zimbabwe.

A prospective study was carried out between 1987 and 1989 in the City of Gweru (Zimbabwe) to assess the efficacy of the measles vaccine. The vaccine efficacy assessment was carried out on an epidemiological basis by relating measles transmission in the vaccinated and unvaccinated children aged 10 to 23 months. Measles cases were identified on the basis of a standard case definition and data on occurrence of measles cases was collected through an active surveillance system. Efficacies of 73 pc, 82 pc and 77 pc were calculated for the years 1987, 1988 and 1989 respectively. Over the three year period mean efficacy was found to be 77 pc (95 pc confidence interval 75 to 79 pc). The vaccine efficacies found in this study were lower than 85 pc which is the officially accepted efficacy of the measles vaccine that is in use in Zimbabwe. The low vaccine efficacy found in this study is attributed to the fact that the measles vaccine is applied (at nine months of age) when probably 10 to 20 pc of children still have prenatally acquired maternal antibodies. It is suggested that further studies be carried out in Zimbabwe to enable the country to define the way forward.

Age Distribution↗

PubMed1995

Is the protection afforded measles vaccinees the same in children of all age groups?

A prospective study was carried out in the City of Gweru in 1988 to examine the relationship between age and protection afforded measles vaccinees by the measles vaccine. The age group 10 months to nine years accounted for 240 cases or 87 pc of the 276 measles cases reported in 1988. The disease had shifted towards older age groups with children aged 10 to 59 months accounting for 105 cases or 43.7 pc and those aged five to nine years accounting for 135 cases or 56.3 pc of the 240 measles cases reported in the age group 10 months to nine years. In all the sub-age groups of the age group 10 months to nine years i.e. 10 to 23 months, 24 to 35 months, 36 to 47 months etc. the proportion of vaccinated cases was more than that of unvaccinated cases and the incidence rates in the unvaccinated population were all higher than in the vaccinated population. A correlation of age and relative risk (relative risk was calculated for each sub-age group) showed a significant negative trend (correlation coefficient = -0.79; p = 0.012).

Age Distribution↗

PubMed1992

The changing age ecology of measles and its implications on measles control.

In the City of Gweru measles vaccination was commenced in 1971. With the advent of the Expanded Programme on Immunisation in 1981-82, measles vaccination coverage was increased, reaching over 80 pc in 1985 and after. Despite this vaccination effort measles morbidity rates have remained high and epidemics continue to occur periodically. It is argued that the shift of the disease from young age groups to older children, coupled with the fact that there are more vaccinees amongst cases with the disease, will mean that transmission will continue uninterrupted. Possible reasons for persistent transmission in older children are explored. It is concluded that measles revaccination is required to interrupt measles transmission.

Child↗