Effectiveness of typhoid conjugate vaccine in Zimbabwe used in response to an outbreak among children and young adults: A matched case control study

BackgroundZimbabwe suffers from regular outbreaks of typhoid fever (TF), worse since 2017. Most cases were in Harare and a vaccination campaign with Typhoid Conjugate Vaccine (TCV) was conducted in March 2019. The vaccine effectiveness (VE) was assessed against culture-confirmed S. Typhi in children six months to 15 years and in individuals six months to 45 years in Harare.MethodsA matched case-control study was conducted in three urban suburbs of Harare targeted by the TCV vaccination campaign. Suspected TF cases were enrolled prospectively in four health facilities and were matched to facility (1:1) and community (1:5) controls.FindingsOf 504 suspected cases from July 2019 to March 2020, 148 laboratory-confirmed TF cases and 153 controls confirmed-negative were identified. One hundred and five (47 aged six months to 15 years) cases were age, sex, and residence matched with 105 facility-based controls while 96 cases were matched 1:5 by age, sex, and immediate-neighbour with 229 community controls.The adjusted VE against confirmed TF was 75% (95%CI: 1–94, p = 0.049) compared to facility controls, and 84% (95%CI: 57–94, p < 0.001) compared to community controls in individuals six months to 15 years. The adjusted VE against confirmed TF was 46% (95%CI: 26–77, p = 0.153) compared to facility controls, and 67% (95%CI: 35–83, p = 0.002) compared to community controls six months to 45 years old.InterpretationThis study confirms that one vaccine dose of TCV is effective to control TF in children between six months and 15 years old in an African setting.     

Extreme hyperbilirubinaemia in Zimbabwean neonates: neurodevelopmental outcome at 4 months

As part of a prospective study of severely jaundiced Zimbabwean infants, the relationship between maximum total serum bilirubin (TSB) concentration in the neonatal period and neurodevelopmental outcome at the corrected age of 4 months was studied. Fifty infants with a TSB of >400 μmol/l (23.4 mg/dl) were enrolled and screened with a neonatal neurological examination (NNE). The cause of jaundice was low birth weight in 22 (44%), ABO incomptability in 8 (16%), sepsis in 8 (16%) and congenital syphilis (6%) in 3 infants. In 9 infants a cause could not be determined. At 4 months, 2 infants had died and 3 were lost to follow up, leaving 45 infants for the infant motor screen (IMS) at 4 months of age. Mean TSB in the neonatal period was 485 μmol/l (28.2 mg/dl), and 7 infants received an exchange transfusion. Mean TSB of the infants with an exchange transfusion was 637 μmol/l (37.2 mg/dl) (range 429–865 μmol/l (25–50.3 mg/dl)) and of the infants without transfusion 459 μmol/l (26.8 mg/dl) (range 400–740 μmol/l (23.4–43 mg/dl)) (P < 0.0001). The TSB was not associated with birth weight, gestational age, gender or head circumference of the baby. On the IMS, 6 of 45 (13.3%) infants scored abnormal, 6 (13.3%) suspect and 33 (73%) scored normal. Three of the six (50%) remaining infants who received an exchange transfusion scored abnormal on the IMS while only 3 of the 39 (8%) infants without exchange transfusion were abnormal. Conclusion More than 25% of infants with a TSB of >400 μmol/l (23.4 mg/dl) scored abnormal or suspect at 4 months of age and half of these infants already showed irreversible neurological symptoms. All infants who scored abnormal or suspect on the IMS with bilirubin levels between 400 and 500 μmol/l (23.4 and 29.2 mg/dl) had haemolytic disease or were premature. Received: 4 October 1996 / Accepted: 5 February 1997     

Zimbabwe's national AIDS levy: A case study

Background: We conducted a case study of the Zimbabwe National AIDS Trust Fund (‘AIDS Levy’) as an approach to domestic government financing of the response to HIV and AIDS.

Methods: Data came from three sources: a literature review, including a search for grey literature, review of government documents from the Zimbabwe National AIDS Council (NAC), and key informant interviews with representatives of the Zimbabwean government, civil society and international organizations.

Findings: The literature search yielded 139 sources, and 20 key informants were interviewed. Established by legislation in 1999, the AIDS Levy entails a 3% income tax for individuals and 3% tax on profits of employers and trusts (which excluded the mining industry until 2015). It is managed by the parastatal NAC through a decentralized structure of AIDS Action Committees. Revenues increased from inception to 2006 through 2008, a period of economic instability and hyperinflation. Following dollarization in 2009, annual revenues continued to increase, reaching US$38.6 million in 2014. By policy, at least 50% of funds are used for purchase of antiretroviral medications. Other spending includes administration and capital costs, HIV prevention, and monitoring and evaluation. Several financial controls and auditing systems are in place. Key informants perceived the AIDS Levy as a ‘homegrown’ solution that provided country ownership and reduced dependence on donor funding, but called for further increased transparency, accountability, and reduced administrative costs, as well as recommended changes to increase revenue.

Conclusions: The Zimbabwe AIDS Levy has generated substantial resources, recently over US$35 million per year, and signals an important commitment by Zimbabweans, which may have helped attract other donor resources. Many key informants considered the Zimbabwe AIDS Levy to be a best practice for other countries to follow.     

Salmonella enteritidis diarrhoea in Harare, Zimbabwe

The study was conducted to determine the prevalence of Salmonella enteritidis diarrhoea in an urban area in Zimbabwe. Stool specimens from people of all ages presenting at primary level health centres in Harare were investigated for S. enteritidis and other bacterial and parasitic enteric pathogens. The first 46 S. enteritidis isolates were phage-typed, and all isolates were tested for susceptibility to ampicillin (10 microg), chloramphenicol (30 microg), cotrimoxazole (25 microg), tetracycline (30 microg), gentamicin (10 microg), nalidixic acid (30 microg), ciprofloxacin (5 microg) and ceftriaxone (30 microg). S. enteritidis was isolated in 74 (1.8%) of 4155 stool specimens which represented 30.7% of all Salmonella species isolated. The most common S. enteritidis phage type was 4 (78.3%) followed by 7, 9 and 23 (8.7%, 2.2%, 2.2%, respectively) All S. enteritidis isolates were sensitive to gentamicin, ciprofloxacin and ceftriaxone. Less than 10% of the isolates were resistant to the other antimicrobials except ampicillin, to which 13.5% were resistant. One isolate was resistant to ampicillin, chloramphenicol, cotrimoxazole and nalidixic acid.     

Pleural tuberculosis in Harare, Zimbabwe: the relationship between human immunodeficiency virus, CD4 lymphocyte count, granuloma formation and disseminated disease

objective   To elucidate the relationship between HIV, CD4¹ count and pleural TB. method   In a prospective study, 94 patients presenting at two large Harare hospitals with clinically suspected pleural TB were enrolled over a 10-month period. All underwent standardized evaluation, closed pleural aspiration and biopsy. Patients receiving directly observed anti-TB therapy were followed-up. results   Pleural TB was diagnosed in 90 individuals (median age 33 years; range 18-65; 64 males); the seroprevalence of HIV was 85%. HIV-positive patients were older than HIV-negative individuals (median age 33 vs 23 years, P = 0.013) and had a significantly lower median CD4¹ count (191 vs 1106 × 10⁶/l respectively, P = 0.004). A CD4¹ count of <200 × 10⁶/l was associated with a length of illness >30 days (65% vs 37%; P = 0.05), a positive pleural fluid smear (37% vs 0%; P = 0.0006) and a positive pleural biopsy Ziehl-Neelsen stain (35% vs 7%; P = 0.021). However, a relationship between CD4¹ count and either pleural granuloma formation or radiological evidence of disseminated disease was not observed. conclusion   In sub-Saharan Africa, TB pleural effusions have become associated with older age, a chronic onset, and an increased mycobacterial load. These data emphasize the complex relationship between pleural TB, HIV infection and a low CD4¹ count.     

The effects of household wealth on HIV prevalence in Manicaland,Zimbabwe – a prospective household census and population-based open cohort study

Introduction

Intensified poverty arising from economic decline and crisis may have contributed to reductions in HIV prevalence in Zimbabwe.

Objectives

To assess the impact of the economic decline on household wealth and prevalent HIV infection using data from a population-based open cohort.

Methods

Household wealth was estimated using data from a prospective household census in Manicaland Province (1998 to 2011). Temporal trends in summed asset ownership indices for sellable, non-sellable and all assets combined were compared for households in four socio-economic strata (small towns, agricultural estates, roadside settlements and subsistence farming areas). Multivariate logistic random-effects models were used to measure differences in individual-level associations between prevalent HIV infection and place of residence, absolute wealth group and occupation.

Results

Household mean asset scores remained similar at around 0.37 (on a scale of 0 to 1) up to 2007 but decreased to below 0.35 thereafter. Sellable assets fell substantially from 2004 while non-sellable assets continued increasing until 2008. Small-town households had the highest wealth scores but the gap to other locations decreased over time, especially for sellable assets. Concurrently, adult HIV prevalence fell from 22.3 to 14.3%. HIV prevalence was highest in better-off locations (small towns) but differed little by household wealth or occupation. Initially, HIV prevalence was elevated in women from poorer households and lower in men in professional occupations. However, most recently (2009 to 2011), men and women in the poorest households had lower HIV prevalence and men in professional occupations had similar prevalence to unemployed men.

Conclusions

The economic crisis drove more households into extreme poverty. However, HIV prevalence fell in all socio-economic locations and sub-groups, and there was limited evidence that increased poverty contributed to HIV prevalence decline.     

The prevalence and management of central post-stroke pain at a hospital in Zimbabwe

BackgroundCentral post-stroke pain (CPSP) is a poorly diagnosed chronic pain. It is under-treated and usually mismanaged.ObjectiveTo establish the prevalence of CPSP and its management in stroke clinics at a tertiary hospital.MethodsThis was a cross-sectional design with stroke patients and health professionals from the stroke clinic at the tertiary hospital in Zimbabwe.ResultsOut of 166 stroke survivors, 8% had CPSP. Younger age (<60 years) was significantly associated with CPSP (P<0.003). Pain characteristics of CPSP were hyperaesthesia (10, 71%), electric shocks (9, 64%), temperature allodynia (9, 64%) and allodynia (12, 86%). Ten health professionals participated in the study: one (10%) reported using Douleur Neuropathique 4 (to diagnose neuropathic pain) and two (20%) reported using sensory tests. Four patients (44%) were on paracetamol (acetaminophen) and on weak opiates such as codeine. None of the patients were on anticonvulsants or antidepressants. Two medical doctors (50%) used weak opiates as second-line management. Five patients (36%) reported receiving a combination of massage, stretching, general exercise and moist heat or cryotherapy.ConclusionThe prevalence of CPSP in the study group is within international range. There is a need for appropriate management and use of tests and outcome measures for diagnosis of CPSP.     

Plants of Zimbabwe Used as Anti-Fertility Agents

Ethnomedicine has gained a lot of recognition in post-independence Zimbabwe and yet little research on anti-fertility medicines has been done. Information on plants used as anti-fertility medicines was obtained by interviewing women, men, traditional healers and traditional midwives in urban Harare and surrounding rural areas of Mvurwi, Seke and Chiweshe. The use of 31 species belonging to 17 families for antifertility purposes is described. This survey forms a basis to initiate a study into the efficacy and toxicology of plants used by Zimbabwean women as traditional anti-fertility medicines.     

Isometamidium concentrations in the sera of cattle maintained under a chemoprophylactic regime in a tsetse-infested area of Zimbabwe

An experiment was carried out to determine the concentrations of the trypanocidal drug isometamidium chloride in the sera of cattle maintained under a chemoprophylactic regimen at Rekomitjie, Zimbabwe, an area of high tsetse challenge in the Zambezi valley. In February 1993, 24 cattle at this site were treated intramuscularly with isometamidium chloride at a dose of 1.0 mg/kg body weight. Thereafter all animals were monitored regularly for 6 months for the presence of trypanosomes and sera were collected to determine the concentrations of isometamidium using an ELISA. Isometamidium treated cattle appeared to be protected against trypanosome infections for at least 18 weeks following treatment. Thereafter, three trypanosome infections were detected, between 20 and 22 weeks following treatment. In contrast, in 18 untreated control cattle at the same site, 9 trypanosome infections were detected over the first 18 weeks of the experiment. Quantification of the isometamidium concentration in sera from the drug treated cattle indicated that the apparent half‐life of iso‐metamidium in these animals was 23 days. This was similar to the half‐life observed previously in cattle treated under laboratory conditions. The isometamidium ELISA was shown to be capable of quantifying drug levels in 20 out of 23 cattle for at least 70 days after treatment. There was no evidence of drug resistant trypanosomes at this site.