my test problem colaboration

using System;
using System.Collections.Generic;
using System.Linq;

namespace testingdotnet
{
    class Program
    {
        static void Main(string[] args)
        {
            var world = new string[,] { { "H", "H", "H" }, { "H", "I", "H" }, { "H", "H", "H" } };
            var firstInfected = new int[2] { 1, 1 };

            string report = SurviveTheSpread(world,firstInfected);
            Console.WriteLine(report);
        }
        public static string SurviveTheSpread(string[,]world,int[] firstInfected)
        {
            var people = FillPeople(world, firstInfected);
            bool peopleGotIll = true;
            int totalDays = 1;

            while (peopleGotIll)
            {

                UpdateQuarantines(people);
                var currentInfected = people.Where(x => x.Value.Status == "I")
                    .OrderBy(x=>x.Key.Row)
                    .Select(x=>x.Key).ToList();
                peopleGotIll = SpreadDesease(people, currentInfected);
                totalDays++;
            }
            int infected = people.Values.Where(x=>x.Status=="I").Count();
            int recovered = people.Values.Where(x => x.Status == "R").Count();
            int uninfected = people.Values.Where(x => x.Status == "H").Count();

            var results = new int[]
            {
                totalDays,infected,recovered,uninfected
            };

            return string.Join(" ",results);
        }

        public static void UpdateQuarantines(Dictionary<Address,Occupant>people)
        {
           var infectedAdresses = people.Where(x=>x.Value.Status=="I").Select(x=>x.Key);
           foreach (var address in infectedAdresses)
           {
               var healed = people[address].Quarantine;
               people[address].Quarantine++;
               people[address].Status= healed==3?"R":"I";
           }
        }

        public static bool SpreadDesease(Dictionary<Address,Occupant>people,List<Address>currentInfected)
        {
             bool newInfected= false;
            foreach (var current in currentInfected)
            {
                var result = Infect(people,current);
                if(!newInfected && result)
                    newInfected =true;

            }

            return newInfected;
        }

        public static bool Infect(Dictionary<Address,Occupant>people,Address address)
        {
            var possibleInfected = new List<Address>
            {
                new Address
                {
                    Col=address.Col,
                    Row=address.Row+1
                },
                new Address
                {
                    Col =address.Col-1,
                    Row = address.Row
                },
                new Address
                {
                    Col=address.Col,
                    Row=address.Row-1
                },
                new Address
                {
                    Col=address.Col+1,
                    Row= address.Row
                }
            };
            foreach (var shouldBeInfected in possibleInfected)
            {
                if(CanBeInfected(people,shouldBeInfected))
                {
                    var adressToGetInfected = people.Keys.First(x => x.Col == shouldBeInfected.Col && x.Row == shouldBeInfected.Row);
                    people[adressToGetInfected].Status = "I";
                    people[adressToGetInfected].Quarantine = 1;
                    return true;
                }
            }
            return false;
        }
        public static bool CanBeInfected(Dictionary<Address,Occupant>people,Address address)
        {
            return people.Any(x => x.Key.Col == address.Col && x.Key.Row == address.Row && x.Value.Status =="H");
        }

        public static Dictionary<Address, Occupant> FillPeople(string[,] world, int[] firstInfected)
        {
            var startingPoing = new Dictionary<Address, Occupant>();
            for (int i = 0; i < world.GetLength(0); i++)
            {
                for (int j = 0; j < world.GetLength(1); j++)
                {
                    string status = (i == firstInfected[0] && j == firstInfected[1]) ? "I" : world[i, j];
                    int quarantine = status == "I" ? 1 : 0;
                    var currentAddress = new Address
                    {
                        Row = i,
                        Col = j
                    };
                    var occupant = new Occupant
                    {
                        Quarantine = quarantine,
                        Status = status
                    };
                    startingPoing.Add(currentAddress, occupant);
                }
            }
            return startingPoing;
        }
    }
    public class Address
    {
        public int Row { get; set; }
        public int Col { get; set; }
    }
    public class Occupant
    {
        public string Status { get; set; }
        public int Quarantine { get; set; }
    }
}