Search

Background/objectives: The COVID-19 pandemic has significantly impacted global health, with varying vaccine effectiveness (VE) across different regions and vaccine platforms. In Africa, where vaccination rates are relatively low, inactivated vaccines like BBIP-CorV (Sinopharm) and Coronovac (Sinovac) have been widely used. This study evaluated the real-world effectiveness of licensed inactivated COVID-19 vaccines in Zimbabwe during a period dominated by Omicron variants., Methods: We conducted a prospective, test-negative, case-control study among symptomatic adults across six Zimbabwean provinces from November 2022 to October 2023. Participants were categorized based on vaccination status, and nasopharyngeal swabs were collected for SARS-CoV-2 PCR testing. Vaccine effectiveness was assessed using conditional logistic regression, adjusting for various covariates such as age, sex, and comorbidities., Results: Among 5175 participants, 701 tested positive for SARS-CoV-2 and 4474 tested negative. The overall adjusted VE against symptomatic COVID-19 was 31% (95% CI: 5.3-49.7%) among verified vaccinated individuals. Boosted individuals demonstrated a higher VE of 59.8% (95% CI: 40.3-72.9%). VE decreased significantly to 24% (95% CI: -4.1-44.8%) in individuals vaccinated over a year prior. Similar VE was observed for BBIP-CorV (36.8%, 95% CI: 11.4-54.9%) and Coronovac (38.1%, 95% CI: 16.3-54.2%)., Conclusions: This study indicates modest protection from inactivated COVID-19 vaccines against symptomatic Omicron infection, with significant enhancement following booster doses. These findings highlight the need for continued vaccine evaluation, particularly in resource-limited settings, to inform public health strategies and optimize vaccination programs.

Multimorbidity is an emerging challenge for health systems globally. It is commonly defined as the co-occurrence of two or more chronic conditions in one person, but its meaning remains a lively area of academic debate, and the utility of the concept beyond high-income settings is uncertain. This article presents the findings from an interdisciplinary research initiative that drew together 60 academic and applied partners working in 10 African countries to answer the questions: how useful is the concept of multimorbidity within Africa? Can the concept be adapted to context to optimise its transformative potentials? During a three-day concept-building workshop, we investigated how the definition of multimorbidity was understood across diverse disciplinary and regional perspectives, evaluated the utility and limitations of existing concepts and definitions, and considered how to build a more context-sensitive, cross-cutting description of multimorbidity. This iterative process was guided by the principles of grounded theory and involved focus- and whole-group discussions during the workshop, thematic coding of workshop discussions, and further post-workshop development and refinement. Three thematic domains emerged from workshop discussions: the current focus of multimorbidity on constituent diseases; the potential for revised concepts to centre the priorities, needs, and social context of people living with multimorbidity (PLWMM); and the need for revised concepts to respond to varied conceptual priorities amongst stakeholders. These themes fed into the development of an expanded conceptual model that centres the catastrophic impacts multimorbidity can have for PLWMM, families and support structures, service providers, and health systems., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Dixon et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The rapid development of vaccines in response to the COVID-19 pandemic has provided an effective tool for the management of COVID-19. However, in many African countries there has been a poor uptake of COVID-19 vaccines with only 32.5% first vaccine dose coverage compared to the WHO global target of 70%. As vaccine access improves, one of the important drivers of low uptake has been vaccine hesitancy, driven by levels of confidence, convenience, and complacency. Between 4 January-11 February 2022, we conducted a survey of vaccine late adopters to assess factors that influenced adults in Harare, Zimbabwe to present for their first COVID-19 vaccine dose almost 12 months after the vaccination program began. Of the 1016 adults enrolled, 50% were female and 12.4% had HIV co-infection. Binary logistic regression models were developed to understand factors associated with vaccine confidence. Women were more likely to have negative views about the COVID-19 vaccine compared to men (OR 1.51 (95%CI 1.16, 1.97, p = 0.002). Older adults (≥40 years) compared with youth (18-25 years) were more likely to have 'major concerns' about vaccines. When asked about their concerns, 602 (59.3%) considered immediate side effects as a major concern and 520 (52.1%) were concerned about long-term health effects. People living with HIV (PLWH) were more likely to perceive vaccines as safe (OR 1.71 (95%CI: 1.07, 2.74, p = 0.025) and effective (1.68 (95%CI: 1.07, 2.64, p = 0.026). Internet users were less likely to perceive vaccines as safe (OR 0.72 (95% CI: 0.55, 0.95, p = 0.021) compared to non-Internet users; and social media was a more likely source of information for youth and those with higher education. Family members were the primary key influencers for 560 (55.2%) participants. The most important reason for receiving the COVID-19 vaccine for 715 (70.4%) participants was the protection of individual health. Improving vaccine coverage will need targeted communication strategies that address negative perceptions of vaccines and associated safety and effectiveness concerns. Leveraging normative behavior as a social motivator for vaccination will be important, as close social networks are key influences of vaccination., Competing Interests: The authors declare no conflict of interest.

Vaccination is one of the most effective methods for preventing morbidity and mortality from COVID-19. Vaccine hesitancy has led to a decrease in vaccine uptake; driven by misinformation, fear, and misperceptions of vaccine safety. Whole inactivated vaccines have been used in one-fifth of the vaccine recipients in Africa, however there are limited real-world data on their safety. We evaluated the reported adverse events and factors associated with reported adverse events following vaccination with whole inactivated COVID-19 vaccines-BBiBP-CorV (Sinopharm) and CoronaVac (Sinovac). A quantitative survey evaluating attitudes and adverse events from vaccination was administered to 1016 adults presenting at vaccination centers. Two follow-up telephone interviews were conducted to determine adverse events after the first and second vaccination dose. Overall, the vaccine was well tolerated; 26.0% and 14.4% reported adverse events after the first and second dose, respectively. The most frequent local and systemic adverse events were pain at the injection site and headaches, respectively. Most symptoms were mild, and no participants required hospitalization. Participants who perceived COVID-19 vaccines as safe or had a personal COVID-19 experience were significantly less likely to report adverse events. Our findings provide data on the safety and tolerability of whole inactivated COVID-19 vaccines in an African population, providing the necessary data to create effective strategies to increase vaccination and support vaccination campaigns.

Despite sufficient supply, <25% of the population in sub-Saharan Africa has received at least one dose of COVID-19 vaccine. Vaccine mandates have previously been effective in increasing vaccine uptake. Attitudes to COVID-19 vaccine mandates and vaccines for children in African populations are not well understood. We surveyed late-adopters presenting for COVID-19 vaccination one year after program initiation in Zimbabwe. Logistic regression models were developed to evaluate factors associated with attitudes to mandates. In total, 1016 adults were enrolled; 690 (67.9%) approved of mandating vaccination for use of public spaces, 686 (67.5%) approved of employer mandates, and 796 (78.3%) approved of mandating COVID-19 vaccines for schools. Individuals of lower economic status were twice as likely as high-income individuals to approve of mandates. Further, 743 (73.1%) participants indicated that they were extremely/very likely to accept vaccines for children. Approval of vaccine mandates was strongly associated with perceptions of vaccine safety, effectiveness, and trust in regulatory processes that approved vaccines. Vaccine hesitancy is an important driver of low vaccine coverage in Africa and can be mitigated by vaccine mandates. Overall, participants favored vaccine mandates; however, attitudes to mandates were strongly associated with level of education and socioeconomic status.

Background: Healthcare workers are disproportionately affected by COVID-19. In low- and middle- income countries, they may be particularly impacted by underfunded health systems, lack of personal protective equipment, challenging working conditions and barriers in accessing personal healthcare., Methods: In this cross-sectional study, occupational health screening was implemented at the largest public sector medical centre in Harare, Zimbabwe, during the "first wave" of the country's COVID-19 epidemic. Clients were voluntarily screened for symptoms of COVID-19, and if present, offered a SARS-CoV-2 nucleic acid detection assay. In addition, measurement of height, weight, blood pressure and HbA1c, HIV and TB testing, and mental health screening using the Shona Symptom Questionnaire (SSQ-14) were offered. An interviewer-administered questionnaire ascertained client knowledge and experiences related to COVID-19., Results: Between 27th July and 30th October 2020, 951 healthcare workers accessed the service; 210 (22%) were tested for SARS-CoV-2, of whom 12 (5.7%) tested positive. Clients reported high levels of concern about COVID-19 which declined with time, and faced barriers including lack of resources for infection prevention and control. There was a high prevalence of largely undiagnosed non-communicable disease: 61% were overweight or obese, 34% had a blood pressure of 140/90mmHg or above, 10% had an HbA1c diagnostic of diabetes, and 7% had an SSQ-14 score consistent with a common mental disorder. Overall 8% were HIV-positive, with 97% previously diagnosed and on treatment., Conclusions: Cases of SARS-CoV-2 in healthcare workers mirrored the national epidemic curve. Implementation of comprehensive occupational health services during a pandemic was feasible, and uptake was high. Other comorbidities were highly prevalent, which may be risk factors for severe COVID-19 but are also important independent causes of morbidity and mortality. Healthcare workers are critical to combatting COVID-19; it is essential to support their physical and psychological wellbeing during the pandemic and beyond., Competing Interests: The authors have declared that no competing interests exist.

Introduction: Individuals recruited into clinical trials for life-threatening illnesses are particularly vulnerable. This is especially true in low-income settings. The decision to enrol may be influenced by existing inequalities, poor healthcare infrastructure and fear of death. Where patients are confused or unconscious the responsibility for this decision falls to relatives. This qualitative study is nested in the ongoing AMBIsome Therapy Induction OptimisatioN (AMBITION) Trial. AMBITION is recruiting participants from five countries in sub-Saharan Africa and is trialling a novel treatment approach for HIV-associated cryptococcal meningitis, an infection known to affect brain function. We aim to learn from the experiences of participants, relatives and researchers involved in AMBITION., Methods and Analysis: We will collect data through in-depth interviews with trial participants and the next of kin of participants who were confused at enrolment and therefore provided surrogate consent. Data will be collected in Gaborone, Botswana; Kampala, Uganda and Harare, Zimbabwe. Interviews will follow a narrative approach including participatory drawing of participation timelines. This will be supplemented by direct observation of the research process at each of the three recruiting hospitals. Interviews will also take place with researchers from the African and European institutions that form the partnership through which the trial is administered. Interviews will be transcribed verbatim, translated (if necessary) and organised thematically for narrative analysis., Ethics and Dissemination: This study has been approved by the Health Research Development Committee, Gaborone (Reference: HPDME:13/18/1); Makerere School of Health Sciences Institutional Review Board, Kampala (Reference: 2019-061); University of Zimbabwe Joint Research Ethics Committee, Harare (Reference: 219/19), and the London School of Hygiene and Tropical Medicine (Reference: 17957). Study findings will be shared with research participants from the sites, key stakeholders at each research institution and ministries of health to help inform the development and implementation of future trials. The findings of this study will be published in journals and presented at academic meetings., Trial Registration: Registered at www.clinicaltrials.gov:NCT04296292., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY. Published by BMJ.)

Introduction: Routine viral load (VL) testing among persons living with Human Immunodeficiency Virus (PLHIV) enables earlier detection of sub-optimal antiretroviral therapy (ART) adherence and for appropriate management of treatment failure. Since adoption of this policy by Zimbabwe in 2016, the extent of implementation is unclear. Therefore we set out to determine among PLHIV ever enrolled on ART from 2004-2017 and in ART care for ≥12 months at health facilities providing ART in Zimbabwe: numbers (proportions) with VL testing uptake, VL suppression and subsequently switched to 2nd-line ART following confirmed virologic failure., Materials and Methods: We used retrospective data from the electronic Patient Monitoring System (ePMS) in which PLHIV on ART are registered at 525 public and 4 private health facilities., Results: Among the 392,832 PLHIV in ART care for ≥12 months, 99,721 (25.4%) had an initial VL test done and results available of whom 81,932 (82%) were virally suppressed. Among those with a VL>1000 copies/mL; 6,689 (37.2%) had a follow-up VL test and 4,086 (61%) had unsuppressed VLs of whom only 1,749 (42.8%) were switched to 2nd-line ART. Lower age particularly adolescents (10-19 years) were more likely (ARR 1.34; 95%CI: 1.25-1.44) to have virologic failure., Conclusion: The study findings provide insights to implementation gaps including limitations in VL testing; low identification of high- risk PLHIV in care and lack of prompt utilization of test results. The use of electronic patient-level data has demonstrated its usefulness in assessing the performance of the national VL testing program. By end of 2017 implementation of VL testing was sub-optimal, and virological failure was relatively common, particularly among adolescents. Of concern is evidence of failure to act on VL test results that were received. A quality improvement initiative has been planned in response to these findings and its effect on patient management will be monitored., Competing Interests: The authors have declared that no competing interests exist.

Background: Acute kidney injury (AKI) is predominantly a disease of low and middle-income countries. Despite this, there is a particular paucity of data regarding AKI in Africa. Most published studies were conducted prior to the most recent Kidney Disease: Improving Global Outcomes (KDIGO) definition of AKI. This prospective, observational, cohort study examines AKI amongst newly admitted acute medical inpatients in a large, urban, tertiary hospital in Harare, Zimbabwe., Methods: All newly admitted, adult, medical patients in separate, randomly selected, 24-hour periods were included. Baseline demographic information, comorbidities, nephrotoxic medication use, and reason for admission were recorded on a standardised data capture record. A serum creatinine measurement was performed on all patients at the time of admission and again after 48 hours. Estimated glomerular filtration rate was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and AKI was defined using the most recent KDIGO definition as an increase in the serum creatinine of greater than 26.5μmol/L within 48 hours, with admission creatinine used as a baseline measurement., Results: 253 patients were included in the analysis; 137 patients (54.2%) were female; 100 patients (39.5%) had HIV infection. 36 patients (14.2%) met the KDIGO criteria for AKI during the 48-hour follow-up period. AKI was more common among males (19.8% vs 9.5%; p = 0.019). The AKI group had a higher serum creatinine at presentation than those without AKI (296.5μmol/L vs 91.0μmol/L; p<0.001) and at 48 hours (447.7μmol/L vs 77.1μmol/L; p<0.001). In logistic regression, AKI was related negatively to female sex (OR 0.461, 95% CI 0.211, 1.003; p = 0.051) and positively predicted by the presence of comorbid hypertension (OR 3.292, 95% CI 1.52, 7.128; p = 0.003) and chronic kidney disease (OR 6.034, 95% 1.792, 20.313; p = 0.004)., Conclusions: KDIGO-defined AKI was common in hospitalised patients in Sub-Saharan Africa and was predicted by male sex, a history of comorbid hypertension and a history of comorbid chronic kidney disease., Competing Interests: The authors have declared that no competing interests exist.

Background: Co-infections have become significant causes of morbidity and mortality in Human Immunodeficiency Virus (HIV) infected people. Due to shared routes of transmission, co-infection of HIV with Hepatitis B (HBV) and/or Hepatitis C (HCV) should be expected. In Zimbabwe, screening for both viruses in HIV infected people prior to treatment is not routinely practised despite the World Health Organisation (WHO) guidelines (2013) prioritising treatment where these co-infections exist., Objective: To determine the prevalence of HBV and HCV infection in HIV infected adults at a public sector HIV clinic in Zimbabwe and to determine risk factors associated with these infections., Design and Setting: An analytical cross-sectional survey carried out among systematically randomly sampled HIV infected patients coming for treatment between March and July 2012 at Parirenyatwa Hospital Opportunistic Infection Clinic., Materials and Methods: Blood samples were tested for hepatitis B surface antigen (HBsAg) and hepatitis C virus antibodies (anti-HCV). Demographic data and exposure to risk factors were collected., Results: 228 antiretroviral therapy (ART) naive adults were enrolled. 7.9% (18/228) were HBsAg positive and 0.9% (2/228) were anti-HCV positive. None of the participants were infected with both viruses., Conclusions: The prevalence of HBV has not changed during this HIV era and there is no significant HCV infection in this public sector clinic which serves quite a large sector of the population that lives in Harare, Zimbabwe. Based on these results, there is no need for HCV screening but HBV screening prior to ART initiation may be required. -

Background: The prevalence and determinants of renal dysfunction among HIV infected adults in the outpatient in Zimbabwe setting is unknown., Objective: To determine the proportion of patients with evidence of renal dysfunction among anti-retroviral treatment naive HIV infected patients in a tertiary outpatient setting., Design: Cross sectional study., Setting: HIV outpatients' clinic (Family Care Centre) at Parirenyatwa hospital., Subjects: 159 Anti-retroviral therapy (ART) naive HIV infected adults., Methods: A cross-sectional study was carried out on ART-naive HIV infected willing adult participants, > or = 18 years old. WHO clinical staging was conducted on all participants. Urine was examined using urinary dipsticks and proteinuria quantification by calculating its protein: creatinine ratio. Serum creatinine and CD4 cell counts were measured. Creatinine clearance (CrCl) was calculated using the Cockcroft-Gault formula., Main Outcome Measures: The primary endpoint was renal dysfunction defined as CrCl < 60 ml/min. Protenuria, defined as > or = + dipstick positive and/or protein to creatinine ratio > 20 mg/mg was a secondary outcome., Results: Renal dysfunction defined as CrCl < 60 ml/min was found in 7.5% [95% CI 3.4-11.7] (12/159) of the participants. Risk factors for renal dysfunction were age [OR 1.14, (95% CI 1.06-1.22)], BMI [OR 0.77 (95% CI 0.61-0.94)] andproteinuria [OR 7.45 (95% CI 1.58-35.26)]. Proteinuria was common, occurring in 45.9% of the participants., Conclusions: [corrected] A high prevalence of proteinuria (45.9%) was found in this study, while the prevalence of reduced creatinine clearance was relatively low (7.5%). Screening for proteinuria is strongly recommended in ART naive HIV infected patients and should be complemented by measurement of serum creatinine and calculation ofcreatinine clearance.

Objective: The objective of this study was to determine the prevalence of diabetic nephropathy in a diabetic clinic in a tertiary hospital setting in Zimbabwe., Design: Descriptive cross sectional study., Setting: Diabetic clinic in a tertiary hospital., Subjects: 75 insulin dependent diabetic consenting adults aged over 18 years., Methods: Consecutive sampling of 75 insulin dependent consenting subjects presenting at the Parirenyatwa Diabetic Clinic was conducted over a four month period. Patients were tested for proteinuria using dipsticks and were divided into dipstick positive and dipstick negative. The dipstick positive samples were sent to the laboratory for protein quantification. The dipstick negative samples were tested for microalbuminuria. Urine albumin creatinine ratios were utilised to quantify the proteinuria., Main Outcome Measures: Prevalence of overt proteinuria and the prevalence of microalbuminuria., Results: Overt proteinuria was found in 16 (21%) patients. Microalbuminuria was found in 9 (12%) of the patients. Nephropathy was, therefore, found in 25 (33%)., Conclusion: There is a high prevalence of diabetic nephropathy in adult patients with insulin dependent diabetis mellitus attending Parirenyatwa Diabetic Clinic.

Objective: To rank health problems contributing most to the burden of disease in Zimbabwe using disability-adjusted life years as the population health measure., Methods: Epidemiological information was derived from multiple sources. Population size and total number of deaths by age and sex for the year 1997 were taken from a nationwide census. The cause of death pattern was determined based on data from the Vital Registration System, which was adjusted for under-reporting of human immunodeficiency virus (HIV) and reallocation of ill-defined causes. Non-fatal disease figures were estimated based on local disease registers, surveys and routine health service data supplemented by estimates from epidemiological studies from other settings if no Zimbabwean sources were available. Disease and public health experts were consulted about the identification of the best possible sources of information, the quality of these sources and data adjustments made., Results: From the information collected, HIV infection emerged as the single most serious public health problem in Zimbabwe responsible for 49% of the total disease burden. A quarter of the total burden of disease was attributed to morbidity rather than premature mortality. The share of the disease burden was similar in females and males., Conclusion: Using local sources of information to a large extent, it was possible to develop plausible estimates of the size and the relative significance of the major health problems in Zimbabwe. The disease pattern of Zimbabwe differed substantially from regional estimates for sub-Saharan Africa justifying the need for countries to develop their own burden of disease estimates.

This is a report of a sudden death which turned out to be an unexpected case of neurocysticercosis. Most doctors nowadays expect cerebral cysticercosis to present with seizures and have forgotten its other clinical manifestations.

Primary infections, protein malnutrition or simply poor food intake which decrease albumin synthesis often prevail in rural Zimbabwe. Therefore, we postulated that serum albumin levels in rural folk may not compare with published values. To investigate this, blood samples were collected from 1,502 consenting participants aged between 16 and 90 years from randomly selected rural areas in Mashonaland West, Midlands, Matebeleland South and Matebeleland North provinces in Zimbabwe. The effects of smoking, alcohol consumption and pregnancy on serum albumin levels were also investigated. The mean age in years did not differ significantly between females and males (32.5 +/- 0.44, n = 943 vs 33.84 +/- 0.62, n = 559). Serum preserved with sodium azide at -4 degrees C was analyzed for albumin using a Quick Lab 2 Analyzer (Ames Quick Lab) by the bromocresol green dye binding method. Only small differences of albumin concentrations (means +/- S.E.M.) were noted for each studied area and results were pooled. The normal serum albumin ranges were 27 to 52 g/L for females and 26 to 52 g/L for males and were different from those reported for developed countries. The albumin levels in females were significantly (p < 0.01) lower than in males (39.29 +/- 0.20 g/L, n = 943 vs 40.09 +/- 0.25 g/L, n = 559). However, the concentrations of the protein in males who smoked (38.66 +/- 0.38 g/L, n = 174) were significantly low (p < 0.01) by comparison with non smokers. Smoking did not alter albumin levels in females (38.27 +/- 0.53 g/L, n = 87) perhaps because they smoked fewer cigarettes.(ABSTRACT TRUNCATED AT 250 WORDS)

The possibility of an interaction between oxytocin and aldosterone to influence renal Na+ excretion was investigated in Inactin-anaesthetized male Sprague-Dawley rats. Endogenous plasma concentrations of aldosterone were suppressed by either adrenalectomy or bicarbonate infusion. The effects of 2 h intravenous administration of oxytocin (0.04 pmol/min) and/or aldosterone (42 pmol/min) on renal Na+ handling were studied in 0.077 M NaCl-infused adrenalectomized (Adx) rats and groups of intact animals that were infused with 0.077 M NaHCO3. Aldosterone alone significantly (P < 0.01) reduced Na+ excretion from pretreatment peak value of 5.0 +/- 1.0 to 1.5 +/- 0.4 mumol/min in Adx animals (n = 8) and 9.2 +/- 1.2 to 5.2 +/- 1.2 mumol/min in NaHCO3-infused rats (n = 8) by 2 h after the start of administration. However, combined administration of aldosterone and oxytocin was associated with a significantly (P < 0.01) increased Na+ excretion rate from a peak pretreatment value of 6.8 +/- 0.7 mumol/min to a peak value of 11.5 +/- 1.1 mumol/min by 1 h 40 min after the start of treatment in Adx rats (n = 7). In bicarbonate-infused rats (n = 8) Na+ excretion rose within 20 min of the start of treatment from a pretreatment peak of 9.0 +/- 0.8 mumol/min to a peak value of 13.5 +/- 0.8 mumol/min in response to combined hormone administration. In conclusion, we have shown that concomitant administration of aldosterone and oxytocin increased the rate of excretion of Na+ in two different preparations, which supports the idea of an interaction between the steroid and oxytocin to promote Na+ loss.

The effect of a 2-hour intravenous chloroquine infusion (0.015, 0.030 and 1.25 micrograms min-1) on renal fluid and electrolyte handling was investigated in the saline infused, Inactin anaesthetized rat. Blood pressure and glomerular filtration rate were not affected by chloroquine administration, remaining around 128 mmHg and 2.4 ml min-1, respectively throughout the 5-hour post-equilibration period. Chloroquine produced an increase in Na+ and Cl- excretion without affecting the urine flow. By 1 hour after the start of treatment (0.03 micrograms chloroquine min-1) the Na+ excretion rate had increased to 14.5 +/- 2.1 mumol min-1 (n = 6), and was significantly (P < 0.01) greater than in control animals (8.6 +/- 1.0 mumol min-1) at the corresponding time. Parallel but lesser increases in Cl- excretion rates were also observed. The plasma aldosterone and corticosterone levels following either 10, 30 or 120 minutes infusion of chloroquine at 0.03 micrograms min-1 did not differ statistically from each other or from control values. It is concluded that acute chloroquine administration induces an increase in Na+ excretion. The mechanism of this natriuresis cannot be established from the present study, but is likely to involve altered tubular handling of Na+.