Tissue microarray validation in cervical carcinoma studies. A methodological approach.

Tissue microarrays (TMAs) are a cost-effective tool to study biomarkers in clinical research. Cervical cancer (CC) is one of the most prevalent in women worldwide, with the highest prevalence in low-middle-income countries due to a lack of organized screening. CC is associated with persistent high-risk human papillomavirus infection. Several biomarkers have been studied for diagnostic, therapeutic, and prognostic purposes. We aimed to evaluate and validate the effectiveness of TMA in CC compared to whole slide images (WSs). We selected and anonymized twenty cases of CC. P16, cytokeratin 5 (CK5), cytokeratin 7 (CK7), programmed death-ligand 1 (PD-L1), and CD8 expression were immunohistochemically investigated. All WS were scanned and 10 representative virtual TMA cores with 0.6 mm diameter per sample were selected. Ten random combinations of 1-5 cylinders per case were assessed for each biomarker. The agreement of scoring between TMA and WS was evaluated by kappa statistics. We found that three cores of 0.6 mm on TMA can accurately represent WS in our setting. The Kappa value between TMA and WS varied from 1 for p16 to 0.61 for PD-L1. Our study presents an approach to address TMA sampling that could be generalized to TMA-based research, regardless of the tissue and biomarkers of interest.

PD-L1 expression in squamous cervical carcinomas of Mozambican women living with or without HIV.

Programmed death-ligand 1 (PD-L1) is overexpressed in squamous cervical cancer (SCC) and can be used for targeted immunotherapy. The highest mortality rates of SCC are reported in sub-Saharan Africa, where Human immunodeficiency virus (HIV) prevalence is high. In Mozambique most SCC patients present at advanced stages. Thus, there is a need to introduce new treatment options. However, immunocompromised patients were frequently excluded in previous clinical trials. Our aim was to determine if PD-L1 expression in SCC is as prevalent among women living with HIV (WLWH) as among other patients. 575 SCC from Maputo Central Hospital were included. HIV status was available in 266 (46%) cases PD-L1 expression was scored through tumour proportion score (TPS) and combined positive score (CPS). PD-L1 was positive in 20.1% of the cases (n = 110), TPS (score ≥ 25%) and in 26.3% (n = 144), CPS (score ≥ 1). Stratifying according to the HIV status, WLWH were TPS positive in 16.7%, compared to 20.9%, p = 0.43, and concerning CPS 21.1% versus 28.7%, p = 0.19, respectively. PD-L1 status was not influenced by stage, Ki-67 or p16, CD8 expression influenced only CPS status. Our data indicates that the documented effect of PD-L1 therapy on SCC should be confirmed in randomized clinical trials in an HIV endemic milieu.

Cervical cancer in Mozambique: Clinical characteristics, treatment and survival of incident cases admitted to the Oncology Service of Maputo Central Hospital in 2016-2018.

In Mozambique, cervical cancer is the most frequent cancer in women. However, studies about cervical cancer treatment and prognosis are scarce. We describe the clinical characteristics, treatment and survival of patients with cervical cancer admitted to Maputo Central Hospital (MCH) in 2016 to 2018. Sociodemographic, clinical and cancer-related data were retrieved from clinical records of patients admitted to the Oncology Service of the MCH with an incident cervical cancer in 2016 to 2018 (n = 407). The Pathology Service database was used to obtain information regarding pathological diagnosis. Survival data was obtained through the MCH Cancer Registry and clinical records. Odds ratios for the association between patients' characteristics and the diagnosis of advanced stage cancer were computed using logistic regression. Survival analyses were performed using the Kaplan-Meier estimator. A total of 91.2% of the patients were diagnosed with advanced disease (stage IIB-IV) and squamous cell carcinoma was the predominant histological subtype. Most of the patients underwent chemotherapy (93.1%) but <7% were submitted to surgery, radiotherapy or brachytherapy. Those living with HIV had 3.4-fold higher odds of advanced disease. Overall survival was 72.7% (95% confidence interval [CI]: 67.9-77.0) at 1-year and 51.0% (95%CI: 45.3-56.3) at 2-years. Those with early stage (IA-IIA) and asymptomatic at diagnosis had a significantly higher 2-year overall survival. In Mozambique, cervical cancer is diagnosed mostly in advanced stages, resulting in poor prognosis. This highlights the importance of HPV vaccination and screening, to decrease the burden of cervical cancer in this context.

Differential etiopathogenic features of vulvar squamous cell carcinomas in sub-Saharan Africa and Europe.

Two pathways have been described for vulvar squamous cell carcinomas (VSCC), one associated with human papillomavirus (HPV), and the other HPV-independent. We compared the etiopathogenic features of a series of VSCC from Mozambique, a sub-Saharan country with high prevalence of HPV and HIV, with those of Spain, a European country with low prevalence of HPV and HIV. All VSCC diagnosed at the two institutions from January 2018 to December 2020 were included (n = 35 and n = 41, respectively). HPV DNA detection and genotyping, and immunohistochemistry for p16 and p53 were performed. Tumors showing p16 positive staining and/or HPV DNA positivity were considered HPV-associated. 34/35 tumors (97%) from Mozambique and 8/41 (19%) from Spain were HPV-associated (P < .001). Mean age of the patients from Mozambique and Spain was 45 ± 12 and 72 ± 14, respectively (P < .001). No differences were found in terms of HPV genotypes or multiple HPV infection rates. 1/35 tumors (3%) from Mozambique and 29/41 (70%) from Spain showed abnormal p53 immunostaining (P < .001). In contrast with the predominance of HPV-independent VSCC affecting old women in Europe, most VSCC in sub-Saharan Africa are HPV-associated and arise in young women. This data may have important consequences for primary prevention of VSCC worldwide.

Penile Squamous Cell Carcinomas in Sub-Saharan Africa and Europe: Differential Etiopathogenesis.

Penile squamous cell carcinomas (PSCC) are classified by the World Health Organization into two categories based on their relationship with the human papillomavirus (HPV): HPV-associated and HPV-independent. We compared a cohort of PSCC from Mozambique, a sub-Saharan country in southeast Africa with a high prevalence of HPV and HIV infection, and Spain, a country in southwestern Europe with a low prevalence of HPV and HIV, to study the distribution of the etiopathogenic categories of these tumors in both sites. A total of 79 PSCC were included in the study (28 from Mozambique and 51 from Spain). All cases underwent HPV-DNA polymerase chain reaction (PCR) testing, genotyping, and immunohistochemistry for p16 and p53. Any PSCC showing either p16 overexpression or HPV-DNA in PCR analysis was considered HPV-associated. Overall, 40/79 (50.6%) tumors were classified as HPV-associated and 39 (49.4%) as HPV-independent. The two sites showed marked differences: 25/28 (89.3%) tumors from Mozambique and only 15/51 (29.4%) from Spain were HPV-associated (p < 0.001). HPV16 was the most frequent HPV type identified in 64.0% (16/25) of the HPV-associated tumors from Mozambique, and 60.0% (9/15) from Spain (p = 0.8). On average, patients from Mozambique were almost two decades younger than those from Spain (mean age 50.9 ± 14.9 and 69.2 ± 13.3, respectively [p < 0.001]). In conclusion, significant etiopathogenic differences between PSCC in Mozambique and Spain were observed, with a remarkably high prevalence of HPV-associated tumors in Mozambique and a relatively low prevalence in Spain. These data may have important consequences for primary prevention of PSCC worldwide.

High within-host diversity found from direct genotyping on post-mortem tuberculosis specimens in a high-burden setting.

OBJECTIVES: To characterize the clonal complexity in Mycobacterium tuberculosis (MTB) infections considering factors that help maximize the detection of coexisting strains/variants. METHODS: Genotypic analysis by Mycobacterial Interspersed Repetitive-Unit-Variable-Number Tandem-Repeats (MIRU-VNTR) was performed directly on 70 biopsy specimens from two or more different tissues involving 28 tuberculosis cases diagnosed post-mortem in Mozambique, a country with a high tuberculosis burden. RESULTS: Genotypic data from isolates collected from two or more tissues were obtained for 23 of the 28 cases (82.1%), allowing the analysis of within-patient diversity. MIRU-VNTR analysis revealed clonal diversity in ten cases (35.7%). Five cases showed allelic differences in three or more loci, suggesting mixed infection with two different strains. In half of the cases showing within-host diversity, one of the specimens associated with clonal heterogeneity was brain tissue. CONCLUSIONS: Direct MTB genotyping from post-mortem tissue samples revealed a frequent within-host Mycobacterium tuberculosis diversity, including mixed and polyclonal infections. Most of this diversity would have been overlooked if only standard analysis of respiratory specimens had been performed.

Accuracy of verbal autopsy, clinical data and minimally invasive autopsy in the evaluation of malaria-specific mortality: an observational study.

BACKGROUND: Global malaria mortality estimates are hindered by the low reliability of the verbal autopsy (VA) and the clinical records, the most common sources of information used to estimate malaria-specific mortality. We aimed to determine the accuracy of these tools, as well as of the minimally invasive autopsy (MIA), a needle-based postmortem sampling method, to identify malaria-specific mortality in a large series of deceased patients from Mozambique, using complete autopsy as the gold standard. METHODS: Observational study that included 264 deaths, occurring at a tertiary level hospital in Mozambique, from 1 November 2013 to 31 March 2015 (17 months-long period). Clinical data were abstracted, a computer coded VA was completed using the clinical data as source of information, and an MIA followed by a complete autopsy were performed. Screening for malaria infection was conducted postmortem to all participants using molecular and histological techniques (PCR and immunohistochemistry). FINDINGS: Malaria infection was considered the cause of death in 6/264 (2.3%) cases: 2/54 children (3.7%, both less than 5 years old) and 4/57 (7.0%) maternal deaths. The sensitivity and specificity of the VA, the clinical data and the MIA to identify malaria-specific deaths were 33.3% and 96.1%, 66.7% and 96.1%, and 100% and 100%, respectively. In addition, malaria was identified as a possible contributor in 14 additional patients who died of other diseases. These cases were also accurately identified by the MIA (sensitivity 82.4%, specificity 100%). INTERPRETATION: The high sensitivity and specificity of the MIA in identifying malaria may help to improve current estimates of malaria-specific mortality in endemic areas.

Gestational gigantomastia with fatal outcome.

Gigantomastia is a rare disease defined by an extreme and rapid enlargement of the breast, generally bilateral. The majority of cases are reported in pregnant women. Ninety-eight cases of gestational gigantomastia have been identified in electronic databases, and those with fatal outcomes comprised only 2 cases (2%). Despite its benign nature, it can lead to severe complications and even death. Its etiology has not been fully elucidated, but it has been speculated that a hormonal component may play a role in the pathogenesis. Currently, treatment options are limited, and surgery is gaining importance, but it is often not feasible in low-resource settings. Herein, we describe a case of a 30-year-old HIV-positive female with no relevant past medical history, who died due to the complications of gestational gigantomastia at the Maputo Central Hospital, in Mozambique.

Gestational gigantomastia with fatal outcome

Gigantomastia is a rare disease defined by an extreme and rapid enlargement of the breast, generally bilateral. The majority of cases are reported in pregnant women. Ninety-eight cases of gestational gigantomastia have been identified in electronic databases, and those with fatal outcomes comprised only 2 cases (2%). Despite its benign nature, it can lead to severe complications and even death. Its etiology has not been fully elucidated, but it has been speculated that a hormonal component may play a role in the pathogenesis. Currently, treatment options are limited, and surgery is gaining importance, but it is often not feasible in low-resource settings. Herein, we describe a case of a 30-year-old HIV-positive female with no relevant past medical history, who died due to the complications of gestational gigantomastia at the Maputo Central Hospital, in Mozambique.

Standardization of Minimally Invasive Tissue Sampling Specimen Collection and Pathology Training for the Child Health and Mortality Prevention Surveillance Network.

BACKGROUND: Minimally invasive tissue sampling (MITS) is a simplified postmortem examination technique that has shown to be an adequate approach for cause of death investigation in low-resource settings. It requires relatively low level of infrastructures and can be performed by health professionals with no background in pathology. A training program has been developed for the Child Health and Mortality Prevention Surveillance (CHAMPS) network to guarantee standardization of specimen collection techniques, procedures, and laboratory methods. METHODS: The training program has included assessment of the site capacities and training on a standardized protocol of MITS sampling and histological processing. The project has also introduced a program of training for trainers for the personnel from Mozambique. To guarantee the adequacy of the procedure in each site, a trainer accompanied the local teams when the activities started. Training outcomes were assessed by evaluating the quality of the samples obtained and the quality of the slides produced locally. RESULTS: Between June 2016 and October 2018, the laboratories of 7 sites (Bangladesh, Ethiopia, Kenya, Mali, Mozambique, Sierra Leone, and South Africa) have been evaluated and upgraded. Training has been delivered to 63 staff members from all sites. More than 600 MITS procedures have been performed. The quantity of tissue obtained in the MITS by the local teams was sufficient or abundant in 73%, and 87% of the slides were considered as technically acceptable or excellent. CONCLUSIONS: Satisfactory standardization of MITS and histology procedures has been achieved across all CHAMPS sites through organized capacity-building plans.

Clinico-pathological discrepancies in the diagnosis of causes of death in adults in Mozambique: A retrospective observational study.

BACKGROUND: Clinico-pathological discrepancies are more frequent in settings in which limited diagnostic techniques are available, but there is little information on their actual impact. AIM: We assessed the accuracy of the clinical diagnoses in a tertiary referral hospital in sub-Saharan Africa by comparison with post-mortem findings. We also identified potential risk factors for misdiagnoses. METHODS: One hundred and twelve complete autopsy procedures were performed at the Maputo Central Hospital (Mozambique), from November 2013 to March 2015. We reviewed the clinical records. Major clinico-pathological discrepancies were assessed using a modified version of the Goldman and Battle classification. RESULTS: Major diagnostic discrepancies were detected in 65/112 cases (58%) and were particularly frequent in infection-related deaths (56/80 [70%] major discrepancies). The sensitivity of the clinical diagnosis for toxoplasmosis was 0% (95% CI: 0-37), 18% (95% CI: 2-52) for invasive fungal infections, 25% (95% CI: 5-57) for bacterial sepsis, 34% (95% CI: 16-57), for tuberculosis, and 46% (95% CI: 19-75) for bacterial pneumonia. Major discrepancies were more frequent in HIV-positive than in HIV-negative patients (48/73 [66%] vs. 17/39 [44%]; p = 0.0236). CONCLUSIONS: Major clinico-pathological discrepancies are still frequent in resource constrained settings. Increasing the level of suspicion for infectious diseases and expanding the availability of diagnostic tests could significantly improve the recognition of common life-threatening infections, and thereby reduce the mortality associated with these diseases. The high frequency of clinico-pathological discrepancies questions the validity of mortality reports based on clinical data or verbal autopsy.

Clinico-pathological discrepancies in the diagnosis of causes of death in adults in Mozambique: A retrospective observational study

Background Clinico-pathological discrepancies are more frequent in settings in which limited diagnostic techniques are available, but there is little information on their actual impact. Aim We assessed the accuracy of the clinical diagnoses in a tertiary referral hospital in sub-Saharan Africa by comparison with post-mortem findings. We also identified potential risk factors for misdiagnoses. Methods One hundred and twelve complete autopsy procedures were performed at the Maputo Central Hospital (Mozambique), from November 2013 to March 2015. We reviewed the clinical records. Major clinico-pathological discrepancies were assessed using a modified version of the Goldman and Battle classification. Results Major diagnostic discrepancies were detected in 65/112 cases (58%) and were particularly frequent in infection-related deaths (56/80 [70%] major discrepancies). The sensitivity of the clinical diagnosis for toxoplasmosis was 0% (95% CI: 0­37), 18% (95% CI: 2­52) for invasive fungal infections, 25% (95% CI: 5­57) for bacterial sepsis, 34% (95% CI: 16­57), for tuberculosis, and 46% (95% CI: 19­75) for bacterial pneumonia. Major discrepancies were more frequent in HIV-positive than in HIV-negative patients (48/73 [66%] vs. 17/39 [44%]; p = 0.0236). Conclusions Major clinico-pathological discrepancies are still frequent in resource constrained settings. Increasing the level of suspicion for infectious diseases and expanding the availability of diagnostic tests could significantly improve the recognition of common life-threatening infections, and thereby reduce the mortality associated with these diseases. The high frequency of clinico-pathological discrepancies questions the validity of mortality reports based on clinical data or verbal autopsy.

Unmasking the hidden tuberculosis mortality burden in a large post mortem study in Maputo Central Hospital, Mozambique.

Sensitive tools are needed to accurately establish the diagnosis of tuberculosis (TB) at death, especially in low-income countries. The objective of this study was to evaluate the burden of TB in a series of patients who died in a tertiary referral hospital in sub-Saharan Africa using an in-house real time PCR (TB-PCR) and the Xpert MTB/RIF Ultra (Xpert Ultra) assay.Complete diagnostic autopsies were performed in a series of 223 deaths (56.5% being HIV-positive), including 54 children, 57 maternal deaths and 112 other adults occurring at the Maputo Central Hospital, Mozambique. TB-PCR was performed in all lung, cerebrospinal fluid and central nervous system samples in HIV-positive patients. All samples positive for TB-PCR or showing histological findings suggestive of TB were analysed with the Xpert Ultra assay.TB was identified as the cause of death in 31 patients: three out of 54 (6%) children, five out of 57 (9%)maternal deaths and 23 out of 112 (21%) other adults. The sensitivity of the main clinical diagnosis to detect TB as the cause of death was 19.4% (95% CI 7.5-37.5) and the specificity was 97.4% (94.0-99.1) compared to autopsy findings. Concomitant TB (TB disease in a patient dying of other causes) was found in 31 additional cases. Xpert Ultra helped to identify 15 cases of concomitant TB. In 18 patients, Mycobacterium tuberculosis DNA was identified by TB-PCR and Xpert Ultra in the absence of histological TB lesions. Overall, 62 (27.8%) cases had TB disease at death and 80 (35.9%) had TB findings.The use of highly sensitive, easy to perform molecular tests in complete diagnostic autopsies may contribute to identifying TB cases at death that would have otherwise been missed. Routine use of these tools in certain diagnostic algorithms for hospitalised patients needs to be considered. Clinical diagnosis showed poor sensitivity for the diagnosis of TB at death.

Mortality due to Cryptococcus neoformans and Cryptococcus gattii in low-income settings: an autopsy study.

Cryptococcosis is a major opportunistic infection and is one of the leading causes of death in adults living with HIV in sub-Saharan Africa. Recent estimates indicate that more than 130,000 people may die annually of cryptococcal meningitis in this region. Although complete diagnostic autopsy (CDA) is considered the gold standard for determining the cause of death, it is seldom performed in low income settings. In this study, a CDA was performed in 284 deceased patients from Mozambique (n = 223) and Brazil (n = 61). In depth histopathological and microbiological analyses were carried out in all cases dying of cryptococcosis. We determined the cryptococcal species, the molecular and sero-mating types and antifungal susceptibility. We also described the organs affected and reviewed the clinical presentation and patient management. Among the 284 cases included, 17 fatal cryptococcal infections were diagnosed. Cryptococcus was responsible for 16 deaths among the 163 HIV-positive patients (10%; 95%CI: 6-15%), including four maternal deaths. One third of the cases corresponded to C. gattii (VGI and VGIV molecular types, Bα and Cα strains) and the remaining infections typed were caused by C. neoformans var. Grubii (all VNI and Aα strains). The level of pre-mortem clinical suspicion was low (7/17, 41%), and 7/17 patients (41%) died within the first 72 hours of admission. Cryptococcosis was responsible for a significant proportion of AIDS-related mortality. The clinical diagnosis and patient management were inadequate, supporting the need for cryptococcal screening for early detection of the disease. This is the first report of the presence of C. gattii infection in Mozambique.

Contribution of the clinical information to the accuracy of the minimally invasive and the complete diagnostic autopsy

Embora o diagnóstico de autópsia inclua rotineiramente uma avaliação completa de todos os resultados patológicos disponíveis e também de qualquer dado clínico disponível, a contribuição dessas informações clínicas para o rendimento diagnóstico da autópsia não foi analisada. Nosso objetivo foi determinar em que medida o uso de dados clínicos melhora a acurácia diagnóstica da autópsia diagnóstica completa (ACD) e da autópsia minimamente invasiva (MIA), um procedimento patológico simplificado post-mortem projetado para locais de baixa renda. Um total de 264 procedimentos acoplados MIA e CDA (112 adultos, 57 mortes maternas, 54 crianças e 41 neonatos) foram realizados no Hospital de Maputo, Moçambique. Comparamos os diagnósticos obtidos pelo MIA cego para dados clínicos (MIAb), o MIA adicionando a informação clínica (MIAc) e o CDA cego para informação clínica (CDAb), com os resultados do padrão-ouro, o CDA com dados clínicos, comparando a Classificação Internacional de Doenças, códigos da Décima Revisão e as principais classes diagnósticas obtidas com cada estratégia de avaliação (MIAb, MIAc, CDAb, CDAc). Os dados clínicos aumentaram a coincidência diagnóstica com o MIAb com o padrão-ouro em 30 (11%) de 264 casos e modificaram o diagnóstico CDAb em 20 (8%) de 264 casos. O aumento da concordância entre MIAb e MIAc com o padrão-ouro foi significativo nos óbitos neonatais (κ aumentando de 0,404 para 0,618, P = .0271), adultos (κ aumentando de 0,732 para 0,813, P = .0221) e maternos (κ aumentando de 0,485 para 0,836, 0.; P < .0001). Em conclusão, o uso de informações clínicas aumenta a precisão do MIA e do CDA e pode fortalecer o desempenho do MIA em ambientes com recursos limitados.

Contribution of the clinical information to the accuracy of the minimally invasive and the complete diagnostic autopsy.

Although autopsy diagnosis includes routinely, a thorough evaluation of all available pathological results and also of any available clinical data, the contribution of this clinical information to the diagnostic yield of the autopsy has not been analyzed. We aimed to determine to which degree the use of clinical data improves the diagnostic accuracy of the complete diagnostic autopsy (CDA) and the minimally invasive autopsy (MIA), a simplified pathological postmortem procedure designed for low-income sites. A total of 264 coupled MIA and CDA procedures (112 adults, 57 maternal deaths, 54 children, and 41 neonates) were performed at the Maputo Hospital, Mozambique. We compared the diagnoses obtained by the MIA blind to clinical data (MIAb), the MIA adding the clinical information (MIAc), and the CDA blind to clinical information (CDAb), with the results of the gold standard, the CDA with clinical data, by comparing the International Classification of Diseases, Tenth Revision codes and the main diagnostic classes obtained with each evaluation strategy (MIAb, MIAc, CDAb, CDAc). The clinical data increased diagnostic coincidence to the MIAb with the gold standard in 30 (11%) of 264 cases and modified the CDAb diagnosis in 20 (8%) of 264 cases. The increase in concordance between MIAb and MIAc with the gold standard was significant in neonatal deaths (κ increasing from 0.404 to 0.618, P = .0271), adult deaths (κ increasing from 0.732 to 0.813, P = .0221), and maternal deaths (κ increasing from 0.485 to 0.836, 0.;P < .0001). In conclusion, the use of clinical information increases the precision of MIA and CDA and may strengthen the performance of the MIA in resource-limited settings.

Postmortem Interval and Diagnostic Performance of the Autopsy Methods.

Postmortem studies, including the complete diagnostic autopsy (CDA) and the minimally invasive autopsy (MIA), an innovative approach to post-mortem sampling and cause of death investigation, are commonly performed within 24 hours after death because the quality of the tissues deteriorates over time. This short timeframe may hamper the feasibility of the procedure. In this study, we compared the diagnostic performance of the two postmortem procedures when carried out earlier and later than 24 hours after death, as well as the impact of increasing postmortem intervals (PMIs) on the results of the microbiological tests in a series of 282 coupled MIA/CDA procedures performed at the Maputo Central Hospital in Mozambique between 2013 and 2015. 214 procedures were conducted within 24 hours of death (early autopsies), and 68 after 24 hours of death (late autopsies). No significant differences were observed in the number of non-conclusive diagnoses (2/214 [1%] vs. 1/68 [1%] p = 0.5645 for the CDA; 27/214 [13%] vs. 5/68 [7%] p = 0.2332 for the MIA). However, increasing PMIs were associated with a raise in the number of bacteria identified (rate: 1.014 per hour [95%CI: 1.002-1.026]; p = 0.0228). This increase was mainly due to rising numbers of bacteria of the Enterobacteriaceae family and Pseudomonas genus strains. Thus, performing MIA or CDA more than 24 hours after death can still render reliable diagnostic results, not only for non-infectious conditions but also for many infectious diseases, although, the contribution of Enterobacteriaceae and Pseudomonas spp. as etiological agents of infections leading to death may be overestimated.

Postmortem interval and diagnostic performance of the autopsy methods

Postmortem studies, including the complete diagnostic autopsy (CDA) and the minimally invasive autopsy (MIA), an innovative approach to post-mortem sampling and cause of death investigation, are commonly performed within 24 hours after death because the quality of the tissues deteriorates over time. This short timeframe may hamper the feasibility of the procedure. In this study, we compared the diagnostic performance of the two postmortem procedures when carried out earlier and later than 24 hours after death, as well as the impact of increasing postmortem intervals (PMIs) on the results of the microbiological tests in a series of 282 coupled MIA/CDA procedures performed at the Maputo Central Hospital in Mozambique between 2013 and 2015. 214 procedures were conducted within 24 hours of death (early autopsies), and 68 after 24 hours of death (late autopsies). No significant differences were observed in the number of non-conclusive diagnoses (2/214 [1%] vs. 1/68 [1%] p = 0.5645 for the CDA; 27/214 [13%] vs. 5/68 [7%] p = 0.2332 for the MIA). However, increasing PMIs were associated with a raise in the number of bacteria identified (rate: 1.014 per hour [95%CI: 1.002-1.026]; p = 0.0228). This increase was mainly due to rising numbers of bacteria of the Enterobacteriaceae family and Pseudomonas genus strains. Thus, performing MIA or CDA more than 24 hours after death can still render reliable diagnostic results, not only for non-infectious conditions but also for many infectious diseases, although, the contribution of Enterobacteriaceae and Pseudomonas spp. as etiological agents of infections leading to death may be overestimated.

Validity of a minimally invasive autopsy for cause of death determination in maternal deaths in Mozambique: An observational study.

BACKGROUND: Despite global health efforts to reduce maternal mortality, rates continue to be unacceptably high in large parts of the world. Feasible, acceptable, and accurate postmortem sampling methods could provide the necessary evidence to improve the understanding of the real causes of maternal mortality, guiding the design of interventions to reduce this burden. METHODS AND FINDINGS: The validity of a minimally invasive autopsy (MIA) method in determining the cause of death was assessed in an observational study in 57 maternal deaths by comparing the results of the MIA with those of the gold standard (complete diagnostic autopsy [CDA], which includes any available clinical information). Concordance between the MIA and the gold standard diagnostic categories was assessed by the kappa statistic, and the sensitivity, specificity, positive and negative predictive values and their 95% confidence intervals (95% CI) to identify the categories of diagnoses were estimated. The main limitation of the study is that both the MIA and the CDA include some degree of subjective interpretation in the attribution of cause of death. A cause of death was identified in the CDA in 98% (56/57) of cases, with indirect obstetric conditions accounting for 32 (56%) deaths and direct obstetric complications for 24 (42%) deaths. Nonobstetric infectious diseases (22/32, 69%) and obstetric hemorrhage (13/24, 54%) were the most common causes of death among indirect and direct obstetric conditions, respectively. Thirty-six (63%) women were HIV positive, and HIV-related conditions accounted for 16 (28%) of all deaths. Cerebral malaria caused 4 (7%) deaths. The MIA identified a cause of death in 86% of women. The overall concordance of the MIA with the CDA was moderate (kappa = 0.48, 95% CI: 0.31-0.66). Both methods agreed in 68% of the diagnostic categories and the agreement was higher for indirect (91%) than for direct obstetric causes (38%). All HIV infections and cerebral malaria cases were identified in the MIA. The main limitation of the technique is its relatively low performance for identifying obstetric causes of death in the absence of clinical information. CONCLUSIONS: The MIA procedure could be a valuable tool to determine the causes of maternal death, especially for indirect obstetric conditions, most of which are infectious diseases. The information provided by the MIA could help to prioritize interventions to reduce maternal mortality and to monitor progress towards achieving global health targets.