Survival analysis of patients with cholera admitted to treatment centres in Lusaka, Zambia
Authors: Nyuma Mbewe, Kelvin Mwangilwa, John Tembo, Martin P Grobusch, Nathan Kapata
Journal: The Lancet Infectious Diseases (2024)

Cholera remains a global threat to health security, particularly in sub-Saharan Africa where outbreaks have become frequent, with increased magnitude and fatalities.1WHOCholera in the WHO African region. Weekly regional cholera bulletin 1 April 2024.https://iris.who.int/bitstream/handle/10665/376526/AFRO%20Cholera%20Bulletin.58.pdfDate: March 31, 2024Date accessed: June 3, 2024Google Scholar, 2Kanungo S Azman AS Ramamurthy T Deen J Dutta S Cholera.Lancet. 2022; 399: 1429-1440Summary Full Text Full Text PDF PubMed Scopus (54) Google Scholar While the world is preparing for the next pandemic, we explored clinical outcomes and patient survival if admitted at any treatment centre during the cholera outbreak in Lusaka between Jan 1, 2024 and April 30, 2024. By April 1, 2024, 18 countries in the WHO African Region were reporting outbreaks with over 62 000 cases reported on the continent in 2024 already.1WHOCholera in the WHO African region. Weekly regional cholera bulletin 1 April 2024.https://iris.who.int/bitstream/handle/10665/376526/AFRO%20Cholera%20Bulletin.58.pdfDate: March 31, 2024Date accessed: June 3, 2024Google Scholar As of March 1, 2024, a total of 20 577 cumulative cases had been recorded across the country with 699 deaths. 60% of these deaths were in the community to quote the ministerial statement of the same date.3Zambia Ministry of HealthMinisterial statement on the cholera outbreak in Zambia.https://www.moh.gov.zm/?p=3549Date: March 1, 2024Date accessed: June 3, 2024Google Scholar The outbreak is yet to be declared over, with sporadic cases still being reported in some localities, although the overall attack rate has reduced following the administration of over two million oral cholera vaccination doses in February, 2024 to the hotspot areas of Lusaka in a reactive campaign. We studied a cohort of patients with cholera admitted in Lusaka, which has a population of 3 324 000 people. Lusaka is administratively divided into seven subdistricts, each with a district administration and first-level hospital managing patients with cholera from the onset of the outbreak. In January, during the rapid escalation of cases and deaths in the subdistricts, an executive decision was made to switch to a centralised patient management approach, with the opening of rooms in the national football stadium as a cholera treatment centre with a bed capacity exceeding 1000. All patients with moderate (plan B) or severe (plan C) dehydration were transferred immediately to the stadium, with a number of staff and specialists from across the district. Patients with comorbidities requiring specialised care (eg, pregnancy or childhood malnutrition) were referred to one of the other tertiary hospitals, while other patients who were too sick to be transferred were maintained at the first-level hospital until stabile. Standard case record forms were introduced, and available patient records were digitised and documented in RedCap for further analysis creating an electronic medical record system for 11 110 patients admitted in any of the seven treatment centres in Lusaka. Medical records for 1529 patients treated between between Jan 10 and March 31, 2024, which contain demographic data, such as age, sex, and final outcome were analysed using R software with a p value of 0·05. Cholera case management is usually conducted with a decentralised model as close to the patients as possible. Community-centric cholera case management models are encouraged to reduce community deaths and stigma associated with being treated in tents, stadiums, and other makeshift structures. The survival analysis was done to ascertain that centralising care to the football stadium did not adversely affect patient outcomes when compared with those who remained in their primary care levels. Cox proportional hazard models were used to assess survival probabilities and identify predictors of mortality. The overall survival rate was 97%, with the highest mortality reported within the first 24 hours of admission. The median survival from death was 2 days (IQR 1–3) and the total person time at risk was 3246 days. Previous oral cholera vaccination reduced mortality by about 88% (adjusted hazard ratio 0·12, 95% CI 0·02–0·85; appendix p 1). Hydration status was assessed by the admitting clinician by the presence of sunken eyes, consciousness, irritability, skin turgor, and thirst in line with the clinical guidelines from the Global Taskforce for Cholera Control (GTFCC). Patients who were admitted with severe dehydration had the highest risk of mortality during admission (p<0·001). Treatment plans were similarly ascribed based on the GTFCC guidance, with plan C being reserved for patients with severe dehydration and being prescribed rapid intravenous fluid resuscitation. Plan B was for patients with moderate dehydration and hence prescribed a fixed volume of oral rehydration solution over 4–6 hours, while plan A is for those with no dehydration being prescribed oral rehydration solution to replace ongoing severe and life-threatening fluid losses due to the acute watery stool and short observation. It was postulated that a higher number of patients received plan A due to previous resuscitation efforts en route to the treatment centres. An incorrect prescription of fluids, resulting from an erroneous classification of dehydration status, could have contributed to an increased mortality rate (p<0·001). The age group of 41–60 years had the highest hazard ratios for death (p<0·001; appendix p 2), highlighting the detrimental effects of middle age, male sex, and clinical dehydration on admission. Pateintes aged 41–60 years were most likely to present with hypertension, diabetes, or other comorbidities (appendix p 3). HIV testing was offered as an opt-in, with 109 patients living with HIV and 83 of them on treatment. Living with HIV was significantly associated with death, but again, this was linked to the occurrence of comorbid conditions such as tuberculosis or AIDS defining malignancy. CD4 count and viral load testing were offered based on the clinician's discretion, and often results were not available for analysis due to the brevity of admission. Understanding the factors influencing survival outcomes among patients with cholera is crucial for improving clinical management and informing public health interventions. Oral cholera vaccinations have been shown to be protective during and after cholera outbreaks.4Bugeme P Xu H Hutchins C et al.Cholera deaths during outbreaks in Uvira, Eastern Democratic Republic of Congo, 10–35 months after mass vaccination.Open Forum Infect Dis. 2024; 11ofae058Crossref PubMed Scopus (0) Google Scholar However, there is a dearth of information on the appropriate case management of patients with cholera and comorbid conditions.5Pampaka D Ciglenecki Z Alberti K Olson D Risk factors of cholera mortality: a scoping review.https://www.gtfcc.org/wp-content/uploads/2023/02/gtfcc-risk-factors-of-cholera-mortality.pdfDate: February, 2022Date accessed: June 3, 2024Google Scholar Our findings suggest that rapid fluid resuscitation necessary in patients with cholera might be complicated without strict quantitative monitoring of hydration status (particularly in patients with hypertension) and worsen patient outcomes. Further work would be needed to ascertain quantitative bedside assessments for fluid status and supportive point-of-care testing for better patient outcomes. We declare no competing interests. Download .pdf (.79 MB) Help with pdf files Supplementary appendix