Redefining pandemic preparedness: Multidisciplinary insights from the CERP modelling workshop in infectious diseases, workshop report

In July 2023, the Center of Excellence in Respiratory Pathogens organized a two-day workshop on infectious diseases modelling and the lessons learnt from the Covid-19 pandemic. This report summarizes the rich discussions that occurred during the workshop. The workshop participants discussed multisource data integration and highlighted the benefits of combining traditional surveillance with more novel data sources like mobility data, social media, and wastewater monitoring. Significant advancements were noted in the development of predictive models, with examples from various countries showcasing the use of machine learning and artificial intelligence in detecting and monitoring disease trends. The role of open collaboration between various stakeholders in modelling was stressed, advocating for the continuation of such partnerships beyond the pandemic. A major gap identified was the absence of a common international framework for data sharing, which is crucial for global pandemic preparedness. Overall, the workshop underscored the need for robust, adaptable modelling frameworks and the integration of different data sources and collaboration across sectors, as key elements in enhancing future pandemic response and preparedness.

Experimental determination of a procedure for casting a solid coloured emulsion

The aim of this study was to determine the experimental procedure for casting a solid water/oil (W/O) emulsion foundation. This process will enable us to preserve the organoleptic qualities of the foundation (hardness, surface appearance and cosmetic sensation) as well as maintaining the percentage of water contained in the formula. Two different industrial parameters were studied: * Influence of the temperature used to cast the bulk in the mould. * Influence of the type of cooling used for the mould, once full. For each trial, the hardness and the melting point were measured. The optimum results for this process were as follows: * Casting temperature: 65 degrees C. * Cooling temperature: 4 degrees C.

Accuracy of visual screening for cervical neoplasia: Results from an IARC multicentre study in India and Africa

Visual inspection-based screening tests, such as visual inspection with 4% acetic acid (VIA) and with Lugol's iodine (VILI), have been proposed as alternatives to cytology in mass screening programs. To date, there is only limited information on the accuracy of these tests in detecting High-grade Squamous Intraepithelial Lesions (HSIL). Eleven cross-sectional studies involving 56,939 women aged 25-65 years were conducted in Burkina Faso, Congo, Guinea, India, Mali and Niger to evaluate the accuracy of VIA and VILI performed by health workers. A common protocol and questionnaire was used. For final diagnosis, all women were investigated with colposcopy and biopsies were taken when necessary. Data from the studies were pooled to calculate sensitivity, specificity and predictive values of the tests for the detection of HSIL. Of the screened women, 16.1% and 16.4% were positive on examination using, respectively, VIA and VILI; 1,063 were diagnosed with HSIL. The pooled sensitivity, specificity, positive and negative predictive values for VIA were 76.8% (95% CI: 74.2-79.4%), 85.5% (95% CI: 85.2-85.8%), 9.4% (95% CI:8.8-10.8%) and 99.5% (95% CI:99.4-99.6%), respectively. The values were 91.7% (95% CI: 89.7-93.4%), 85.4% (95% CI: 85.1-85.7%), 10.9% (95% CI: 10.2-11.6%) and 99.8% (95% CI:99.7-99.9%), respectively for VILI. The range of sensitivity and specificity for VIA was 56.1-93.9% and 74.2-93.8%, respectively, between studies and were 76.0-97.0 % and 73.0-91.3% for VILI. VILI had a significantly higher sensitivity than VIA in detecting HSIL, but specificity was similar. VILI appears to be a more accurate visual test for use in screening and treatment programs in low-resource settings.

Correlation between the DNA global methylation status and progesterone receptor expression in normal endometrium, endometrioid adenocarcinoma and precursors

Endometrial carcinomas are the most common malignancy of the female genital tract and the third most common cancer in women. Progesterone and oestrogen receptors (PRs, ERs) are the most widely documented prognostic and predictive factors in endometrioid adenocarcinoma. Besides the hormonal pathway involved in the progression of preneoplastic and neoplastic lesions, alterations of the DNA methylation status have been shown to be an early signal of tumorigenesis. In this study, we show that in normal endometrium, during the proliferative phase, DNA methylation and PR expression are high, with a significant decline towards the end of the secretory phase and a gradual increase in non-atypical and atypical endometrial hyperplasia; they reach their highest level in grade I, then decrease significantly in grade-II and grade-III endometrioid adenocarcinomas. During each stage, a significant positive correlation is observed between DNA methylation and PR (P<0.0001). The strong parallelism between DNA methylation and PR expression precludes establishing a precise determination regarding the timing of these events, clearly involved in the genesis of endometrioid adenocarcinoma.

Accuracy of human papillomavirus testing in primary screening of cervical neoplasia: Results from a multicenter study in India

The knowledge that cervical neoplasia are caused by human papillomavirus (HPV) infection has led to the evaluation of its role in screening. We evaluated the accuracy of HPV testing by Hybrid capture II (HC II) method in detecting cervical intraepithelial neoplasia grade 2 and 3 (CIN 2 and 3) lesions in 4 cross-sectional studies with common protocol and questionnaire in 3 different locations (Kolkata, Mumbai and Trivandrum) in India. These studies involved 18,085 women aged 25-65 years. The reference standard for final diagnosis was a combination of colposcopy/biopsy. All women were investigated with colposcopy and 3,116 received directed biopsy. The sensitivity of HPV testing for detecting CIN 2-3 lesions varied from 45.7% to 80.9% across the study sites; the specificity varied from 91.7% to 94.6% and the positive predictive value from 6.7% to 13.7%. Retesting of 298 randomly chosen denatured samples in France revealed an agreement rate of 85.9% and a kappa-value of 0.72. Although HPV testing seems to be a promising approach for cervical cancer prevention, a large range in sensitivity was observed in our study, possibly due to variations in the quality of specimen collection and reference standards. A higher sensitivity was associated with the center performing the test well. Further developments in terms of more reproducible, less expensive and less sophisticated testing are essential to make the test feasible and effective in low-resource settings.

HIV-1 epidemic trends in rural south-west Uganda over a 10-year period

The objective of this study was to examine the epidemic trends of HIV-1 infection in a rural population cohort in Uganda followed for 10 years. The methods used were to assess incidence and prevalence trends in adults in this longitudinal cohort study. The results showed that incidence of infection has fallen significantly in all adults, and separately in males, females, young adults and older adults over the course of the study period. There was also a reduction in prevalence, especially in young men and women. There was some evidence of a cohort effect in women. The conclusions are that this study provides the first evidence of a falling incidence in a rural general population in Africa. This was an observational cohort exposed to national health education messages, giving hope that similar campaigns elsewhere in Africa could be used effectively in efforts to control the HIV epidemic.

Generalizability of population-based studies on AIDS: a comparison of newly and continuously surveyed villages in rural southwest Uganda

BACKGROUND

Population-based studies are thought to provide generalizable epidemiological data on the human immunodeficiency virus type 1 (HIV-1) epidemic. However, longitudinal studies are susceptible to bias from added attention caused by study activities. We compare HIV-1 prevalence in previously and newly surveyed villages in rural southwest Uganda.

METHODS

The study population resided in 25 neighbouring villages, of which 15 have been surveyed for 10 years. Respondents (>/=13 years) provided socio-demographic and sexual behaviour data and a blood sample for HIV-1 serology in private after informed consent. We tested the independent effect of residency: (1) original versus new villages; (2) proximity to main road; and (3) proximity to trading centre on HIV-1 serostatus of respondents using multivariate logistic regression.

RESULTS

There were 8,990 adults censused, 68.3% were from the original villages, 48.2% were males and 6111 (68.0%) were interviewed and had definite HIV-1 serostatus. The HIV-1 prevalence was 6.1% overall, 5.7% in the new, and 6.4% in the original villages (P = 0.25). Residency in the new or original villages did not independently predict HIV-1 serostatus of respondents (P = 0.46). Independent predictors of HIV-1 serostatus were education (primary or higher, odds ratio [OR] = 1.7 and 1.4, respectively), being separated or widowed OR = 4.2, reported previous use of a condom OR = 1.8, or reported genital ulceration OR = 3.3, and age group 25-34 and 35-44 years OR = 5.8 and OR = 4.8 (all P </= 0.001).

CONCLUSIONS

In the context of rural Uganda where there has been considerable health education about AIDS, the additional attention to HIV infection caused by this longitudinal study does not appear to have appreciably affected the prevalence of HIV-1 infection.

Prediction of the long-term survival in breast cancer patients according to the present oncological status

After a breast cancer diagnosis, single or multiple events can occur during follow-up (recurrence, metastasis, and death). An analysis of long-term survival should take into account not only the initial characteristics of the patient, but also her oncological status (that is, her history) after surgery. For this purpose, we used a technique proposed by Klein, Keiding and Copelan (1994), to predict the probability of a patient being alive 20 years after surgery for a breast cancer, based on data concerning her oncological status at time t. The first step of the model was to estimate the hazard function for each event of interest (recurrence, metastasis, and death) in a Cox model including initial patient characteristics (age, tumour size, number of involved axillary lymph nodes and the Scarff, Bloom and Richardson (SBR) histo-prognostic grade) and time-dependent covariates representing the occurrence of intermediate events (recurrence and metastasis). The second step was to use these estimations to calculate the conditional probability of being alive 20-t years later for a patient, given her oncological status at time t (t<10 years). In this second step, the method presented by Klein, Keiding and Copelan was extended to include non-proportional hazards. This model has been applied to a population of 3180 patients operated on for a breast cancer at the Institut Gustave Roussy between 1 January 1954 and 31 December 1983. At the time of surgery, the probability of survival at 20 years is 0.78 for all patients. Ten years after surgery, if no recurrence or metastasis are observed, the probability of survival at 20 years will rise to 0.89. If only a recurrence is observed, the probability of a patient being alive at 20 years will drop to 0.72. If a metastasis and no recurrence is observed, the probability of survival at 20 years will be only 0.18. If both recurrence and metastasis are observed the probability of survival at 20 years will be equal to 0.09. In conclusion, the model used dynamically appraises the prognosis and represents a new approach for studying the outcome of breast cancer patients having undergone surgery.

Radio-frequency tissue ablation of the liver: effects of vascular occlusion on lesion diameter and biliary and portal damages in a pig model

The aim of this study was to assess the effect of vascular occlusion on radio-frequency (RF) lesion size and on potential associated biliary and portal lesions. Radio-frequency lesions using a 1-cm exposed-tip cooled electrode were created in pig liver. Liver perfusion was modified by arterial embolization (n=2), left portal clamping (n=2), and both (n=2). Two pigs were used as controls. Two weeks after, control portography was performed, animals were killed, and ex-vivo cholangiography was carried out. Pathological studies evaluated the lesion surface and associated portal and biliary damages. A mathematical regression model showed that portal occlusion increased by 43 mm2 (+40%) the surface of RF lesions, arterial occlusion by 135 mm2 (+126%), and associated occlusion by 466 mm2 (+435%). Biliary stenoses were found in 4 cases (two arterial occlusions, one portal occlusion, and one associated occlusion). One case of partial portal vein thrombosis was found in one case of portal occlusion and resolved at 2 weeks. Ischemic damages adjacent to RF lesions were found in cases of combined occlusions. The reduction of liver perfusion increases significantly the size of RF lesions but is associated with a risk of biliary, portal, or parenchymal complications.

Declining HIV-1 incidence and associated prevalence over 10 years in a rural population in south-west Uganda: a cohort study

BACKGROUND

In Uganda, there have been encouraging reports of reductions in HIV-1 prevalence but not in incidence, which is the most reliable measure of epidemic trends. We describe HIV-1 incidence and prevalence trends in a rural population-based cohort between 1989 and 1999.

METHODS

We surveyed the adult population of 15 neighbouring villages for HIV-1 infection using annual censuses, questionnaires, and serological surveys. We report crude annual incidence rates by calendar year and prevalence by survey round.

FINDINGS

6566 HIV-1 seronegative adults were bled two or more times between January, 1990, and December, 1999, contributing 31984 person years at risk (PYAR) and 190 seroconversions. HIV-1 incidence fell from 8.0 to 5.2 per 1000 PYAR between 1990 and 1999 (p=0.002, chi(2) for trend). Significant sex-specific and age-group-specific reductions in incidence were evident. Incidence was 37% lower for 1995-99 than for 1990-94 (p=0.002, t-test). On average, 4642 adult residents had a definite HIV-1 serostatus at each yearly survey round. HIV-1 prevalence fell significantly between the first and tenth annual survey rounds (p=0.03, chi(2) for trend), especially among men aged 20-24 years (6.5% to 2.2%) and 25-29 years (15.2% to 10.9%) and women aged 13-19 years (2.8% to 0.9%) and 20-24 years (19.3% to 10.1%) (all p<0.001, chi(2) for trend).

INTERPRETATION

Our findings of a significant drop in adult HIV-1 incidence in rural Ugandans give hope to AIDS control programmes elsewhere in sub-Saharan Africa where rates of HIV-1 infection remain high.

Absence of a recognizable seroconversion illness in Africans infected with HIV-1

It is difficult to assess the proportion of individuals who experience an acute seroconversion illness after infection with HIV-1. We found that five out of 27 recent HIV-1 seroconverters (18.5%) in a population-based cohort in rural Uganda and four out of 22 HIV-negative controls (18.2%) reported a flu-like illness. More symptoms were reported by seroconverters, but the duration of illness was similar in both groups. We found no association between symptoms and infection with HIV-1 subtype A or D.

Genital ulceration in rural Uganda: sexual activity, treatment-seeking behavior, and the implications for HIV control

BACKGROUND

Genital ulcer disease (GUD) is documented as a significant risk factor for HIV acquisition. Its prompt recognition and effective treatment are important components of HIV control in sub-Saharan Africa.

GOALS

To determine the rate and risk factors for GUD, and to describe sexual and treatment-seeking behavior.

STUDY DESIGN

A longitudinal follow-up study of 525 individuals, both those infected with HIV and those uninfected, was conducted in a population-based, clinical cohort over 9 years.

RESULTS

The rate of GUD in this population was 16/100 person years, and 30% of the participants reported an episode during the follow-up period. The rates were almost four times higher in participants infected with HIV than in those who were HIV-negative. Half of the participants with a regular sexual partner reported engaging in sex while symptomatic, and only 16% informed their partner. Treatment was sought for only 12% of the genital ulcer disease episodes, despite open access to doctors at a free clinic. A self-diagnosis of genital herpes did not affect treatment-seeking or sexual behavior.

CONCLUSIONS

Genital ulcer disease is very common in this rural population, especially among those infected with HIV. Few seek treatment, and many continue sexual activity despite symptoms without informing their partners. The implications of these findings for HIV control are a cause for concern.

Herpes zoster and HIV-1 infection in a rural Ugandan cohort

OBJECTIVE

To compare the rates and clinical features of herpes zoster in HIV-positive and HIV-negative individuals in a cohort in rural Uganda; to report the incidence of herpes zoster in the HIV-positive group in relation to seroconversion and CD4 cell counts and to determine whether it is indicative of a more rapid progression to death.

DESIGN

A prospective population-based cohort.

METHODS

The cohort comprised 107 prevalent and 144 incident (with documented dates of seroconversion) participants with HIV infection and 231 HIV-negative controls who were reviewed routinely every 3 months.

RESULTS

The mean rate of herpes zoster was 53.6/1000 person-years in HIV-positive and 4.4 in HIV-negative participants. The cumulative incidence of a first episode of herpes zoster was 7.6% at 2 years, 12.6% at 4 years and 24.0% at 6 years after seroconversion; the incidence rate was 35.6/1000 person-years. There was no evidence of a significant effect of age, gender, period from seroconversion or CD4 cell count on this incidence rate. Herpes zoster was an indicator of HIV-1 infection in this population but not an indicator of more rapid progression to death after adjusting for CD4 cell count and age.

CONCLUSIONS

The rates, including the cumulative incidence after seroconversion and the clinical presentation of herpes zoster, were similar to those reported from industrialized countries. Although an indicator of HIV-1 infection in this population, herpes zoster was unrelated to CD4 cell count or period from seroconversion and did not lead to a faster disease progression.

Attributable morbidity and mortality of catheter-related septicemia in critically ill patients: a matched, risk-adjusted, cohort study

OBJECTIVE

To determine the attributable risk of death due to catheter-related septicemia (CRS) in critically ill patients when taking into account severity of illness during the intensive-care unit (ICU) stay but before CRS.

DESIGN

Pairwise-matched (1:2) exposed-unexposed study.

SETTING

10-bed medical-surgical ICU and an 18-bed medical ICU.

PATIENTS

Patients admitted to either ICU between January 1, 1990, and December 31, 1995, were eligible. Exposed patients were defined as patients with CRS; unexposed controls were selected according to matching variables.

METHODS

Matching variables were diagnosis at ICU admission, length of central catheterization before the infection, McCabe Score, Simplified Acute Physiologic Score (SAPS) II at admission, age, and gender. Severity scores (SAPS II, Organ System Failure Score, Organ Dysfunction and Infection Score, and Logistic Organ Dysfunction System) were calculated four times for each patient: the day of ICU admission, the day of CRS onset, and 3 and 7 days before CRS. Matching was successful for 38 exposed patients. Statistical analysis was based on nonparametric tests for epidemiological data and on Cox's models for the exposed-unexposed study, with adjustment on matching variables and prognostic factors of mortality.

RESULTS

CRS complicated 1.17 per 100 ICU admissions during the study period. Twenty (53%) of the CRS cases were associated with septic shock. CRS was associated with a 28% increase in SAPS II. Crude ICU mortality rates from exposed and unexposed patients were 50% and 21%, respectively. CRS remained associated with mortality even when adjusted on other prognostic factors at ICU admission (relative risk [RR], 2.01; 95% confidence interval [CI95], 1.08-3.73; P=.03). However, after adjustment on severity scores calculated between ICU admission and 1 week before CRS, the increased mortality was no longer significant (RR, 1.41; CI95, 0.76-2.61; P=.27).

CONCLUSION

CRS is associated with subsequent morbidity and mortality in the ICU, even when adjusted on severity factors at ICU admission. However, after adjustment on severity factors during the ICU stay and before the event, there was only a trend toward CRS-attributable mortality. The evolution of patient severity should be taken into account when evaluating excess mortality induced by nosocomial events in ICU patients.

Haemoglobin disorders among Southeast-Asian refugees in France

Haemoglobin disorders were studied among Southeast-Asian refugees (Vietnamese, Cambodians and Laotians). Phenotypic haemoglobin investigations and genotypical studies concerning the alpha loci were carried out. Most of the observed cases of microcytosis were related to a thalassaemic defect. High prevalence of Hb E and alpha-thalassaemia were found.