Investigation and contact tracing of the first eight cases of COVID-19 in Mozambique, 2020

Introduction: contact tracing is an important strategy to interrupt the spread of infectious disease and prevent new cases. After the confirmation of the first positive case of COVID-19 in Mozambique on March 22, 2020, case investigation and contact tracing were immediately initiated, which included clinical and laboratory monitoring of cases and contacts throughout the quarantine period. We aim to describe the methodology and impact of early investigation and contact tracing. Methods: in the context of implementation of the national COVID�19 preparedness and response plan, guidelines and forms for contact tracing were adapted from the existing World Health Organization (WHO) and The Centers for Disease Control and Prevention (CDC) guidelines. The case definition used was “patient with travel or residency history in a country reporting local transmission of COVID-19 during the 14 days prior to the onset of symptoms”. The cases interviews were face to face and contacts were followed up daily by phone calls for 14 consecutive days: using a structured questionnaire. Data were entered in an electronic Excel database. We collected samples for diagnosis of those who developed symptoms and provided quarantine follow up. Results: a total of 8 cases were confirmed, of which 6 (75%) were male. The average age of the cases was 51, median 44 (range: 31 to 80) years old. The majority of cases presented common symptoms of COVID-19, including headaches (50%), cough (37.5%), and fever (25%). Our case series included the country´s index case, two close positive contacts, and 5 additional cases that were not epidemiologically linked to the others and identified by the COVID-19 national surveillance system. All of them were identified in Maputo City from March 22 to March 28. Cases had a total of 123 contacts and all of them were tracked; 79 were contacts of the first case. From all the contacts in follow up, two had laboratory confirmed COVID-19. All cases and contacts were quarantined and none of them developed severe symptoms or required hospitalization. Conclusion: timely case identification and systematic contact tracing can be effective in breaking the chain of COVID-19 transmission when there is strong collaboration between epidemiological, laboratory surveillance and case management

Effects of an urban sanitation intervention on childhood enteric infection and diarrhea in Maputo, Mozambique: A controlled before-and-after trial.

We conducted a controlled before-and-after trial to evaluate the impact of an onsite urban sanitation intervention on the prevalence of enteric infection, soil transmitted helminth re-infection, and diarrhea among children in Maputo, Mozambique. A non-governmental organization replaced existing poor-quality latrines with pour-flush toilets with septic tanks serving household clusters. We enrolled children aged 1-48 months at baseline and measured outcomes before and 12 and 24 months after the intervention, with concurrent measurement among children in a comparable control arm. Despite nearly exclusive use, we found no evidence that intervention affected the prevalence of any measured outcome after 12 or 24 months of exposure. Among children born into study sites after intervention, we observed a reduced prevalence of Trichuris and Shigella infection relative to the same age group at baseline (<2 years old). Protection from birth may be important to reduce exposure to and infection with enteric pathogens in this setting

Effect of an onsite shared sanitation intervention on markers of environmental enteric dysfunction in children living in Maputo, Mozambique

The relationship between enteric pathogen exposure and long-term health effects like stunting and cognitive deficiencies may be mediated, in part, by environmental enteric dysfunction (EED). We aimed to assess whether access to a shared sanitation intervention affected the concentration of biomarkers of intestinal inflammation and permeability in the stool of young children living in Maputo, Mozambique. The Maputo Sanitation trial was a controlled before-and-after study of a shared onsite sanitation intervention in low-income, unplanned urban neighborhoods of Maputo, Mozambique. We collected data and stool specimens at baseline (pre-intervention) and 12- and 24-months post-intervention and measured the concentration of four biomarkers of EED: alpha-1-antitrypsin, neopterin, myeloperoxidase, and calprotectin. We assessed the effect of the intervention at 12- and 24-months post-intervention among all children, as well as among sub-groups of children with longitudinal data and children who were born into study sites post-intervention. After 12-months, the concentration of neopterin was higher among intervention children compared with controls (mean difference 0.39 log nmol/L, 95% CI: 0.15 - 0.62). Concentrations of calprotectin (mean difference 0.43 log ng/mL, 95% CI: 0.041 - 0.82) and neopterin (mean difference 0.38 nmol/L, 95% CI: 0.0079, 0.76), both measures of intestinal inflammation, were also higher among children born into intervention sites by the 24-month follow-up visit. The intervention did not a have statistically significant effect on the concentration of alpha-1-antitrypsin, the only marker of intestinal permeability. The intervention did not reduce the concentration of EED biomarkers after 12- and 24-months of exposure. The etiology and pathophysiologic mechanisms underlying EED have not been fully described, complicating its measurement. The lack of a formal case definition and of representative healthy reference concentrations for common EED biomarkers makes interpretation of effect estimates, including their potential clinical significance, complex. Our results highlight the importance of filling these evidence gaps so we may begin designing and implementing sanitation interventions that prevent, or at least delay, the onset of EED