Risk of COVID-19 death for people with a pre-existing cancer diagnosis prior to COVID-19-vaccination: A systematic review and meta-analysis

While previous reviews found a positive association between pre-existing cancer diagnosis and COVID-19-related death, most early studies did not distinguish long-term cancer survivors from those recently diagnosed/treated, nor adjust for important confounders including age. We aimed to consolidate higher-quality evidence on risk of COVID-19-related death for people with recent/active cancer (compared to people without) in the pre-COVID-19-vaccination period. We searched the WHO COVID-19 Global Research Database (20 December 2021), and Medline and Embase (10 May 2023). We included studies adjusting for age and sex, and providing details of cancer status. Risk-of-bias assessment was based on the Newcastle-Ottawa Scale. Pooled adjusted odds or risk ratios (aORs, aRRs) or hazard ratios (aHRs) and 95% confidence intervals (95% CIs) were calculated using generic inverse-variance random-effects models. Random-effects meta-regressions were used to assess associations between effect estimates and time since cancer diagnosis/treatment. Of 23 773 unique title/abstract records, 39 studies were eligible for inclusion (2 low, 17 moderate, 20 high risk of bias). Risk of COVID-19-related death was higher for people with active or recently diagnosed/treated cancer (general population: aOR = 1.48, 95% CI: 1.36-1.61, I2  = 0; people with COVID-19: aOR = 1.58, 95% CI: 1.41-1.77, I2  = 0.58; inpatients with COVID-19: aOR = 1.66, 95% CI: 1.34-2.06, I2  = 0.98). Risks were more elevated for lung (general population: aOR = 3.4, 95% CI: 2.4-4.7) and hematological cancers (general population: aOR = 2.13, 95% CI: 1.68-2.68, I2  = 0.43), and for metastatic cancers. Meta-regression suggested risk of COVID-19-related death decreased with time since diagnosis/treatment, for example, for any/solid cancers, fitted aOR = 1.55 (95% CI: 1.37-1.75) at 1 year and aOR = 0.98 (95% CI: 0.80-1.20) at 5 years post-cancer diagnosis/treatment. In conclusion, before COVID-19-vaccination, risk of COVID-19-related death was higher for people with recent cancer, with risk depending on cancer type and time since diagnosis/treatment.

Efficacy of typhoid vaccines against culture-confirmed Salmonella Typhi in typhoid endemic countries: a systematic review and meta-analysis

BACKGROUND

Typhoid is a serious public health threat in many low-income and middle-income countries. Several vaccines for typhoid have been recommended by WHO for typhoid prevention in endemic countries. This study aimed to review the efficacy of typhoid vaccines against culture-confirmed Salmonella enterica serovar Typhi.

METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, and Embase for studies published in English between Jan 1, 1986 and Nov 2, 2023. We included randomised controlled trials (RCTs) comparing typhoid vaccines with a placebo or another vaccine. This meta-analysis evaluated the efficacy and safety of several typhoid vaccines, including live attenuated oral Ty21a vaccine, Vi capsular polysaccharide (Vi-PS), Vi polysaccharide conjugated to recombinant Pseudomonas aeruginosa exotoxin A vaccine (Vi-rEPA), and Vi-tetanus toxoid conjugate vaccine (TCV). The certainty of evidence for key outcomes was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations methodology. The outcome of interest was typhoid fever confirmed by the isolation of Salmonella enterica serovar Typhi in blood and adverse events following immunisation. This study is registered with PROSPERO (CRD42021241043).

FINDINGS

We included 14 RCTs assessing four different vaccines (Ty21a: four trials; Vi-PS: five trials; Vi-rEPA: one trial; TCV: four trials) involving 585 253 participants. All trials were conducted in typhoid endemic countries and the age of participants ranged from 6 months to 50 years. The pooled efficacy against typhoid fever was 45% (95% CI 33-55%; four trials; 247 649 participants; I2 59%; moderate certainty) for Ty21a and 58% (44-69%; five trials; 214 456 participants; I2 34%; moderate certainty) for polysaccharide Vi-PS. The cumulative efficacy of two doses of Vi-rEPA vaccine at 2 years was 91% (88-96%; one trial; 12 008 participants; moderate certainty). The pooled efficacy of a single shot of TCV at 2 years post-immunisation was 83% (77-87%; four trials; 111 130 participants; I2 0%; moderate certainty). All vaccines were safe, with no serious adverse effects reported in the trials.

INTERPRETATION

The existing data from included trials provide promising results regarding the efficacy and safety of the four recommended typhoid vaccines. TCV and Vi-rEPA were found to have the highest efficacy at 2 years post-immunisation. However, follow-up data for Vi-rEPA are scarce and only TCV is pre-qualified by WHO. Therefore, roll-out of TCV into routine immunisation programmes in typhoid endemic settings is highly recommended.

FUNDING

There was no funding source for this study.

Post dural puncture headache in obstetric patients: experience from a West African teaching hospital

BACKGROUND

This prospective, non-randomised study examined the frequency and severity of post dural puncture headache in 96 Ghanaian women who consented to spinal anaesthesia for caesarean section at the Korle Bu Teaching Hospital, Accra, Ghana.

METHOD

Spinal anaesthesia was performed using 22-gauge (n = 22), 25-gauge (n = 46) or 26-gauge (n = 38) Quincke needles. Patients were followed up to determine the incidence and severity of post spinal headache.

RESULT

The overall incidence of post dural puncture headache was 8.3%, but was significantly higher (33%) in patients in whom 22-gauge Quincke needles were used than in the other two groups (4% and 5% respectively: P = 0.003). Most patients rated their headache as mild to moderate on a 10-cm visual analogue scale.

CONCLUSIONS

In view of the high incidence of headache and the need for treatment associated with the use of the 22-gauge Quincke needle, we recommend that this should not be used in the obstetric population. We are also aware that the incidence of post dural puncture headache could be further reduced by the use of small calibre pencil-point needles but these are currently very expensive and many obstetric units in developing countries may not be able to afford them.

Anaesthetic dilemma: spinal anaesthesia in an eclamptic patient with mild thrombocytopenia and an “impossible” airway

We present our anaesthetic management of a 27-year-old woman with antepartum eclampsia, mild thrombocytopenia, difficult airway and clinical evidence of impending upper airway obstruction. She required urgent delivery by caesarean section, which was conducted uneventfully under spinal anaesthesia. We discuss the management conundrums presented by this case and why we chose spinal anaesthesia over other anaesthetic options.