Page 18 of Outbreak Protocol

CHAPTER ELEVEN

FELIX

"Patient zero." I tap the conference room whiteboard where Erik has mapped transmission networks with surgical precision.

Red lines connect cases like blood vessels, flowing backward through time toward an empty circle labelled "Index Case.

" "Every outbreak has one. The person who brought this pathogen into Hamburg. "

Erik adjusts his reading glasses, studying the network diagram with focused intensity. "Thirty-seven primary transmission clusters identified. Earliest documented case is Greta Petersen on January fifteenth, but symptom onset suggests infection occurred January eighth or ninth."

"So our index case was symptomatic around January sixth, possibly earlier." I trace the red lines with my finger, watching them converge toward that blank space. "Someone we haven't identified yet."

Sarah looks up from her laptop. "Genetic sequencing confirms all Hamburg isolates share common ancestor—single introduction event, not multiple importations."

"Which means systematic backward tracing will find them," Erik states with characteristic certainty. "Mathematical probability approaches one hundred per cent with sufficient data collection."

The investigation feels different this morning.

More focused. Personal tragedy still shadows every conversation—Anna remains unconscious in Ward Seven while Emma stays with a friend so we can work—but Erik and I have found a professional rhythm that channels grief into determined action.

We're hunting patient zero like epidemiological detectives, following transmission chains through Hamburg's urban landscape.

"Contact interviews first," I suggest. "Start with Greta Petersen's family, work backward through her movements."

Erik nods, gathering his laptop and case files. "I'll map geographic distribution while you conduct interviews. Combined approach should maximize data yield."

We've developed seamless collaboration; my clinical experience helps witnesses remember crucial details about their loved ones' final days, while Erik's analytical framework organizes scattered information into coherent patterns.

The partnership feels essential—neither of us could accomplish this alone.

Stepping outside Hamburg University Medical Centre, the morning air carries not only the salt tang from the harbour but also an acrid mix of disinfectants and exhaust fumes.

The once vibrant streets are now peppered with makeshift medical tents where weary doctors and nurses move with grim determination, their faces obscured by masks, trying to tend to the sick and injured.

Crying children clutch at their parents while sick individuals, some barely able to stand, wait for help – their eyes filled with fear and confusion. The atmosphere buzzes with an unsettling tension; every siren that wails nearby sends a ripple of anxiety through the throng .

NATO personnel in fatigues patrol the area, their presence a constant reminder of the unfolding crisis, as government officials try to maintain order amidst the chaos.

Though a few people still attempt to cling to normalcy, walking dogs or rushing to catch buses, the sense of routine feels like a bizarre illusion against the backdrop of this unravelling disaster.

The stark contrast between ordinary life and the dire reality unfolds with every step, creating a dissonance that Erik and I navigate together—one that weighs heavily in the air, suffocating our resolve.

"Petersen apartment first?" Erik asks, consulting his tablet where he's mapped case locations across Hamburg's districts.

"Friedrichsberg," I confirm. "Greta lived alone but had regular visitors—daughter in Eimsbüttel, neighbour who checked on her daily, cleaning lady twice weekly."

The U-Bahn ride takes twenty minutes through Hamburg's underground arteries.

Erik reviews case timelines on his laptop while I watch fellow passengers, noting coughs and exhausted faces that might indicate illness.

Paranoia, probably, but outbreak investigation heightens awareness of every potential symptom.

Greta Petersen's apartment building sits on a quiet residential street lined with chestnut trees. Five stories of red brick, built in the 1960s with practical German efficiency. Erik photographs the entrance while I review interview notes from Greta's daughter Ingrid.

"Building has eighteen units," Erik murmurs, consulting his tablet. "No other cases reported among residents. Suggests infection occurred elsewhere."

The superintendent, Herr Franke, meets us in the lobby. An elderly man with calloused hands and a suspicious expression that softens when I explain our medical investigation.

"Poor Greta," he sighs, unlocking her apartment door. "Quiet lady, very particular about cleanliness. Hard to believe she caught something so terrible. "

The apartment reveals a meticulous personality—spotless kitchen, organized bookshelves, family photographs arranged with geometric precision. Erik documents the layout while I search for clues about Greta's final week.

"She went to market every Tuesday," Herr Franke explains. "Always the same route—Edeka for groceries, pharmacy for medications, sometimes the flower shop."

"Did she mention feeling unwell?" I ask gently.

"Complained about headaches Thursday, Friday. Thought it was the weather changing." His weathered face creases with regret. "I should have insisted she see the doctor. Maybe if I had, she'd still be with us."

Erik appears from the bedroom, holding a small notebook. "Appointment calendar. Last entries show market visit January eighth, coffee with friend January ninth, cleaning lady January tenth."

I copy the information while Erik photographs relevant pages. The timeline places Greta's infection around January seventh or eighth—consistent with symptom onset three days later.

"The friend she had coffee with," I ask Herr Franke. "Local person?"

"Christa Schneider, lives in Altona. They met at the community centre for senior activities."

Erik makes a note, adding Christa Schneider to our contact list. We thank Herr Franke and head back toward the U-Bahn, each clutching pieces of Greta's final week.

"Market investigation next?" Erik suggests.

"Definitely. If she was infected January eighth during routine shopping, other customers might show a similar timeline."

The Edeka supermarket occupies a corner position on a busy Friedrichsberg street. The manager, Frau Klein, greets us with barely concealed anxiety that suggests media coverage has reached the neighbourhood level.

"We've followed all health protocols," she insists before we've asked anything. "Disinfection procedures, employee health monitoring, everything recommended."

"We're not investigating violations," I reassure her. "Just trying to understand one of your customer's movements during a specific timeframe."

Erik spreads his tablet on the small office desk, displaying Greta Petersen's photograph alongside our medical credentials. "January eighth, Tuesday morning. Regular customer, always shopped the same day each week."

Frau Klein relaxes slightly, consulting employee schedules. "That would be the morning shift. Klaus handles produce, Maria works checkout, Stefan manages the dairy section."

We interview each employee systematically.

Klaus remembers Greta selecting apples with characteristic care, spending extra time choosing perfect specimens.

Maria recalls a friendly conversation about the weather, nothing unusual.

Stefan mentions Greta purchasing yogurt and asking about expiration dates.

"Anyone else seem ill that week?" I ask. "Customers coughing, employees calling in sick?"

"Actually, yes," Maria says thoughtfully. "Strange week for illness. Three regular customers mentioned flu symptoms, two employees went home early with fevers."

Erik immediately opens his laptop, beginning contact trace documentation. "Names and contact information for sick employees and customers?"

"Personnel records are confidential," Frau Klein objects.

I lean forward with practiced empathy. "We're doctors investigating a disease outbreak. Patient confidentiality allows information sharing for public health protection."

Twenty minutes later, we've identified five additional cases connected to the supermarket during Greta's shopping timeframe. Erik maps their residential addresses while I collect symptom descriptions and timeline details.

"Clustering pattern suggests common source exposure," Erik observes, studying the geographic distribution. "All five live within a two-kilometre radius."

"Or they infected each other through brief contact in the store," I counter. "Respiratory transmission in a confined space with poor air circulation."

"Both possibilities require investigation."

The afternoon progresses through systematic contact tracing.

We visit apartments and workplaces, conducting interviews with families and colleagues of early cases.

Each conversation reveals fragments of information—a cough overheard on public transport, a neighbour who seemed unwell, a coworker who left early with symptoms.

Erik's analytical mind recognizes patterns that my clinical training might miss. Geographic clustering around specific transit routes. Temporal correlation between cases attending the same community events. Age distribution suggesting exposure at locations frequented by older adults.

My empathy helps witnesses remember details they might dismiss as unimportant. The way their sick relative's voice changed during their last phone conversation. Unusual fatigue that preceded fever by several days. Small behavioural changes that preceded obvious illness.

"You have a gift for this," Erik tells me as we walk between interviews. "Making people comfortable enough to share painful memories."

"Years of emergency medicine," I reply. "Reading fear, offering comfort, extracting crucial information under pressure."