( CNN ) -- Worries about high tides overwhelming parts of Thailand in recent days have morphed into fears about water- and insect-borne diseases in the flood-ravaged country . Bangkok 's central business district has avoided major flooding so far , but outlying areas are chest- or waist-deep in water . `` The water in those parts is a filthy black color containing sewage , garbage and dead animals with a nasty smell . Mosquitoes are also breeding rapidly , '' said Igor Prahin of Bangkok . More than 370 people have died since the flooding began after heavy monsoon rains . U.S . Ambassador to Thailand Kristie A. Kenney said Monday that `` the worst may be over for central Bangkok , '' but about 2 million people are still affected by the flooding . The United States has pledged a total of $ 1.1 million in aid . CNNGo : Updated travel information for tourists . Charities working in the country have warned of diseases such as diarrhea , dengue fever and malaria in the coming days and weeks . `` There are places on the outskirts of Bangkok and in other parts of the country which have been flooded for nearly two weeks , '' said Matthew Cochrane of the International Federation of Red Cross and Red Crescent Societies . `` The country 's prime minister has said that the city has 'dodged a bullet ' -- the economic impact of central Bangkok being flooded would have been huge , and thankfully that did not happen -- but a huge part of the country is still under water , '' Cochrane said . `` Outside the city it is certainly a humanitarian crisis , because there are people who have been cut off for weeks without any aid , supplies or food . '' UNICEF said it was providing 20,000 mosquito nets and handing out 20,000 pamphlets explaining how to stay safe and healthy in flood-stricken regions . Supatra ( Jenstitvong ) Assavasuke , who lives east of central Bangkok , took in two friends whose house on the west side of the city is submerged under 1 to 2 meters ( 3 to 7 feet ) of water . It 's unclear how long they will need to stay . She and her family have helped donate about 3,000 liters ( almost 800 gallons ) of drinking water to those in worse-off areas . `` Those who got affected , they lose their houses , they lose their jobs , their cars -- many things , '' she said . But even those in the capital faced possible shortages of water . The Metropolitan Waterworks Authority said it had reduced the amount of tap water processed for residents from 900,000 to 400,000 cubic meters per day , because of high algae counts at one of its plants . Prime Minister Yingluck Shinawatra said authorities would speed up the process of draining water into Bangkok 's canals and into the sea , raising hopes that water levels in the city could start to sink . However , the government has warned it may take more than a month for the floods to recede . Already , the flooding has caused an estimated $ 6 billion in damages , the Thai Finance Ministry has said . The Thai government has set up more than 1,700 shelters across the country , where more than 113,000 people have taken refuge . Yet many are trying to push through with their daily routines . In Bangkok 's Chinatown area , a food vendor up to her knees in murky water continued to serve patrons at her small cart . One resident traveled down a street by row boat as a nearby bicyclist pedaled through thigh-deep flooding . And a man walked his dog near Bangkok 's Grand Palace , the dog chest-deep in water . CNN 's Bryony Jones , Kocha Olarn and Germain Perez contributed to this report .
2 million people are affected by the flooding , a U.S. diplomat to Thailand says . Bangkok resident : " I'm not sure if this is true or not Places outside Bangkok cut off from supplies endure a humanitarian crisis . Charities working in the country warn about diarrhea , dengue fever and malaria in the coming weeks .