Correction to: First COVID-19 infections in the Philippines: a case report.

[This corrects the article DOI: 10.1186/s41182-020-00203-0.]

Diagnostic Accuracy of Recombinant Immunoglobulin-like Protein A-Based IgM ELISA for the Early Diagnosis of Leptospirosis in the Philippines

Background Leptospirosis is an important but largely under-recognized public health problem in the tropics. Establishment of highly sensitive and specific laboratory diagnosis is essential to reveal the magnitude of problem and to improve treatment. This study aimed to evaluate the diagnostic accuracy of a recombinant LigA protein based IgM ELISA during outbreaks in the clinical-setting of a highly endemic country. Methodology/Principal Findings A prospective study was conducted from October 2011 to September 2013 at a national referral hospital for infectious diseases in Manila, Philippines. Patients who were hospitalized with clinically suspected leptospirosis were enrolled. Plasma and urine were collected on admission and/or at discharge and tested using the LigA-IgM ELISA and a whole cellbased IgM ELISA. Sensitivity and specificity of these tests were evaluated with cases diagnosed by microscopic agglutination test (MAT), culture and LAMP as the composite reference standard and blood bank donors as healthy controls: the mean+3 standard deviation optical density value of healthy controls was used as the cut-off limit (0.062 for the LigA-IgM ELISA and 0.691 for the whole cell-based IgM ELISA). Of 304 patients enrolled in the study, 270 (89.1%) were male and the median age was 30.5 years; 167 (54.9%) were laboratory confirmed. The sensitivity and ROC curve AUC for the LigA-IgM ELISA was significantly greater than the whole cell-based IgM ELISA (69.5% vs. 54.3%, p<0.01; 0.90 vs. 0.82, p<0.01) on admission, but not at discharge. The specificity of LigA-IgM ELISA and whole cell-based IgM ELISA were not significantly different (98% vs. 97%). Among 158 MAT negative patients, 53 and 28 were positive by LigA- and whole cell-based IgM ELISA, respectively; if the laboratory confirmation was re-defined by LigA-IgM ELISA and LAMP, the clinical findings were more characteristic of leptospirosis than the diagnosis based on MAT/ culture/LAMP. Conclusions/Significance The newly developed LigA-IgM ELISA is more sensitive than the whole cell-based IgM based ELISA. Although the final diagnosis must be validated by more specific tests, LigAIgM ELISA could be a useful diagnostic test in a real clinical-setting, where diagnosis is needed in the early phase of infection

Epidemiological and clinical characteristics of patients with suspected COVID-19 admitted in Metro Manila, Philippines

Background: Coronavirus disease 2019 (COVID-19) has spread to almost every region and country in the world, leading to widespread travel restrictions and national lockdowns. Currently, there are limited epidemiological and clinical data on COVID-19 patients from low and middle-income countries. We conducted a retrospective single-center study of the first 100 individuals with suspected COVID-19 (between Jan. 25 and Mar. 29, 2020) admitted to San Lazaro Hospital (SLH), the national infectious diseases referral hospital in Manila, Philippines. Results: Demographic data, travel history, clinical features, and outcomes were summarized and compared between COVID-19 confirmed and non-confirmed cases. The first two confirmed cases were Chinese nationals, admitted on Jan. 25. The third confirmed case was a Filipino, admitted on Mar. 8. Trends toward confirmed COVID-19 cases not reporting international travel and being admitted to SLH from the densely populated area of Manila city were observed during Mar. 8-29. All 42 of the 100 confirmed COVID-19 cases were adults, 40% were aged 60 years and above and 55% were male. Three were health workers. Among individuals with suspected COVID-19, confirmed cases were more likely to be older, Filipino, not report international travel history and have at least one underlying disease,particularly diabetes, report difficulty in breathing, and a longer duration of symptoms. In over 90% of non-COVID-19 cases, the alternative diagnosis was respiratory. Nine (21%) confirmed cases died. The median duration from symptoms onset to death was 11.5 (range: 8-18) days. Conclusions: Imported COVID-19 cases have reduced but local transmission persists and there is a trend toward cases being admitted to SLH from densely populated areas. This study highlights the difficulty in diagnosing COVID-19 on clinical grounds and the importance of diagnostic capacity in all settings. Difficulty of breathing was the only symptom associated with COVID-19 infection and should alert clinicians to the possibility of COVID-19. Clinical characteristics of confirmed COVID-19 cases and a hospital case fatality rate of 21% are comparable with other settings

Lagged relationships between rainfall and leptospirosis.

<p>(A) Mean fitted relative risk surface over lag and weekly rainfall (flood-unadjusted model), (B) Cross-sectional plots of Fig 3(A) at constant lag / rainfall values with relative risk (RR) (solid red line) and 95% CIs (gray area) and (C) Cross-sectional plots at constant lag / rainfall values (flood-adjusted model) with relative risk (RR) (dotted blue line) and 95% CIs (gray area).</p

Weekly number of admitted leptospirosis cases, cumulative rainfall, mean temperature and flood events.

<p>(upper panel) Time series of the number of leptospirosis cases per week admitted to San Lazaro Hospital. (lower panel) Weekly cumulative rainfall (mm) (vertical bars), weekly mean temperature (°C) (solid line) and flood events (tick marks at the top).</p

Assumed causal relationships among rainfall, flood and leptospirosis and other environmental factors.

<p>Assumed causal relationships among rainfall, flood and leptospirosis and other environmental factors.</p

The relationship between flood occurrence and leptospirosis at lags 0 to 7 weeks.

<p>The relationship between flood occurrence and leptospirosis at lags 0 to 7 weeks.</p

Summary statistics of the weekly number of leptospirosis cases admitted to San Lazaro Hospital in Manila, the Philippines in 2001–2012.

<p>Summary statistics of the weekly number of leptospirosis cases admitted to San Lazaro Hospital in Manila, the Philippines in 2001–2012.</p

Comparison of sensitivity of diagnostic examination and day of illness among laboratory confirmed cases (N = 153).

<p>This figure included pair serum results of MAT and LigA / Patoc-based IgM ELISA. 11 plasma samples and 12 urine samples were not included in this analysis due to a lack of information. Vertical bars indicate 95% confidence intervals.</p

Comparison of sensitivity between serovars (N = 134).

<p>Vertical bars indicate 95% confidence intervals.</p