Category Archives: water microbiology

Venezuela – Salmonella outbreak continues with close to 500 sick

Food Safety News

About 500 people have fallen ill in a Salmonella outbreak in a Venezuelan state.

The Anzoatiguense Institute of Health (Saludanz) reported 480 people had tested positive for Salmonella, mostly from the El Carmen and San Cristóbal area of the Simón Bolívar municipality.

In mid-December 2020, the agency revealed 240 children and adults had been affected and seen at different health centers after a significant increase in salmonellosis during the previous month.

Investigations so far have pointed to contaminated water as the source of infection but officials have not ruled out a type of Brazilian sausage being behind some cases in the outbreak. They urged the public to buy food and water from hygienic places that comply with the necessary permits.

Research – A Methodology for Classifying Root Causes of Outbreaks of Legionnaires’ Disease: Deficiencies in Environmental Control and Water Management


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We piloted a methodology for collecting and interpreting root cause—or environmental deficiency (ED)—information from Legionnaires’ disease (LD) outbreak investigation reports. The methodology included a classification framework to assess common failures observed in the implementation of water management programs (WMPs). We reviewed reports from fourteen CDC-led investigations between 1 January 2015 and 21 June 2019 to identify EDs associated with outbreaks of LD. We developed an abstraction guide to standardize data collection from outbreak reports and define relevant parameters. We categorized each ED according to three criteria: ED type, WMP-deficiency type, and source of deficiency. We calculated the prevalence of EDs among facilities and explored differences between facilities with and without WMPs. A majority of EDs identified (81%) were classified as process failures. Facilities with WMPs (n = 8) had lower prevalence of EDs attributed to plumbed devices (9.1%) and infrastructure design (0%) than facilities without WMPs (n = 6; 33.3% and 24.2%, respectively). About three quarters (72%) of LD cases and 81% of the fatalities in our sample originated at facilities without a WMP. This report highlights the importance of WMPs in preventing and mitigating outbreaks of LD. Building water system process management is a primary obstacle toward limiting the root causes of LD outbreaks. Greater emphasis on the documentation, verification, validation, and continuous program review steps will be important in maximizing the effectiveness of WMPs. View Full-Text

USA – Legionnaires’ disease outbreak in Portland: 1 dead; 4 hospitalised

Outbreak News Today

A bacterial pneumonia outbreak, known as Legionnaires’ disease has hit a Portland-based senior housing complex, leaving 1 dead and 4 hospitalized as more than 100 residents were evacuated from the housing complex.

A report released by the Multnomah County Health Department said that the outbreak is caused by contaminated water that has entered the Rosemont Court senior living complex. Health authorities further say that people that have increased risk, including senior members of the community, have a greater risk for Legionnaires disease, albeit being not contagious in nature.

Research – Living with Legionella and Other Waterborne Pathogens


Legionella spp. and other opportunistic premise plumbing pathogens (OPPPs), including Pseudomonas aeruginosaMycobacterium aviumStenotrophomonas maltophilia, and Acinetobacter baumannii, are normal inhabitants of natural waters, drinking water distribution systems and premise plumbing. Thus, humans are regularly exposed to these pathogens. Unfortunately, Legionella spp. and the other OPPPs share a number of features that allow them to grow and persist in premise plumbing. They form biofilms and are also relatively disinfectant-resistant, able to grow at low organic matter concentrations, and able to grow under stagnant conditions. Infections have been traced to exposure to premise plumbing or aerosols generated in showers. A number of measures can lead to reduction in OPPP numbers in premise plumbing, including elevation of water heater temperatures.

India – Kerala health minister on Shigella outbreak: ‘Everything is under control’

Outbreak News Today

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After a suspected Shigella outbreak that claimed the life of an 11-year old child in the city of Kozhikode, Kerala health prime minister KK Shailaja has stated that the aforementioned outbreak has been ‘under control’ by health authorities.

“An 11-year-old child died last week in Kozhikode. After that tests have been done for about fifty suspected cases and six have been infected. Now, only two are in the hospital while others have been discharged,” she said.

She further added that the Shigella bacteria is prevalent in densely populated areas, through contaminated water.

The health department has conducted an awareness campaign and set up medical camps. Wells in the area were chlorinated,” Shailaja commented, while stressing health authority directives that people should first boil their water before consuming.

USA – Estimate of Burden and Direct Healthcare Cost of Infectious Waterborne Disease in the United States


Provision of safe drinking water in the United States is a great public health achievement. However, new waterborne disease challenges have emerged (e.g., aging infrastructure, chlorine-tolerant and biofilm-related pathogens, increased recreational water use). Comprehensive estimates of the health burden for all water exposure routes (ingestion, contact, inhalation) and sources (drinking, recreational, environmental) are needed. We estimated total illnesses, emergency department (ED) visits, hospitalizations, deaths, and direct healthcare costs for 17 waterborne infectious diseases. About 7.15 million waterborne illnesses occur annually (95% credible interval [CrI] 3.88 million–12.0 million), results in 601,000 ED visits (95% CrI 364,000–866,000), 118,000 hospitalizations (95% CrI 86,800–150,000), and 6,630 deaths (95% CrI 4,520–8,870) and incurring US $3.33 billion (95% CrI 1.37 billion–8.77 billion) in direct healthcare costs. Otitis externa and norovirus infection were the most common illnesses. Most hospitalizations and deaths were caused by biofilm-associated pathogens (nontuberculous mycobacteria, PseudomonasLegionella), costing US $2.39 billion annually.

At the beginning of the 20th century, diseases commonly transmitted by water, such as cholera and typhoid, were major causes of death in the United States (1). Reliable provision of treated, safe drinking water dramatically reduced the burden of these diseases and has been recognized as one of the greatest public health achievements of the 20th century (2). Despite this achievement, waterborne disease in the United States persists (35).

In the United States, outbreaks associated with large public drinking water systems have sharply declined in the past 40 years (3,6), likely the result of improvements in regulation and operation. However, transmission of disease via drinking water systems still occurs, often attributable to aging infrastructure, operational challenges, and the private or unregulated water systems (e.g., private wells) that serve an estimated 43 million persons (7). At the same time, the complexity and scope of water use has increased; drinking, sanitation, hygiene, cooling, and heating needs are supported by 6 million miles of plumbing inside US buildings (i.e., premise plumbing) (8,9). Premise plumbing water quality can be compromised by long water residency times, reduced disinfectant levels, and inadequate hot water temperatures, creating environments where pathogens (e.g., nontuberculous mycobacteria [NTM], Pseudomonas, and Legionella) can amplify in biofilms (10). People can be exposed to these pathogens through contact, ingestion, or inhalation of aerosols (e.g., from showerheads, building cooling towers, or decorative fountains).

As leisure time has increased, swimming pools, waterparks, water playgrounds, and hot tubs have proliferated (5). These venues rely largely on chlorination as the major barrier against disease transmission. Cryptosporidium has emerged as the major cause of outbreaks associated with treated aquatic venues because it is extremely chlorine resistant and has a low infectious dose (5,11,12). Warmer oceans have led to Vibrio-associated wound infections farther north than previously documented (13).

Estimates of the overall burden of foodborne disease in the United States, including both known and unknown agents, have been useful in directing prevention activities and setting public health goals (14,15). Quantifying the burden of infectious waterborne disease in the United States would also be beneficial.

Previous studies have attempted to estimate the burden of gastrointestinal illness (16,17) or all illness associated with drinking water (18) and untreated recreational water (19) in the United States, but the burden of disease from all water sources (drinking, recreational, environmental) and exposure routes (ingestion, contact, inhalation) has not been estimated. We present an estimate of the burden of waterborne disease in the United States that includes gastrointestinal, respiratory, and systemic disease; accounts for underdiagnosis; and includes all water sources and exposure routes.

Research – Inhibitory Activity of Essential Oils against Vibrio campbellii and Vibrio parahaemolyticus


Vibriosis, caused by Vibrio strains, is an important bacterial disease and capable of causing significant high mortality in aquatic animals. Essential oils (EOs) have been considered as an alternative approach for the treatment of aquatic bacterial diseases. In this study, we evaluated the antibacterial activity of essential oils (= 22) or essential oil components (EOCs, = 12) against Vibrio strains belonging to the harveyi clade. It was verified by three different approaches, e.g., (i) a bacterial growth assay, comparing Vibrio growth with or without EO(C)s at various concentrations; (ii) a vapor-phase-mediated susceptibility assay, comparing the effect of EO(C)s on bacterial growth through the vapor phase; and (iii) a quorum sensing-inhibitory assay, based on specific inhibition of quorum sensing-regulated bioluminescence. The results showed that, in the bacterial growth assay, EOs of Melaleuca alternifolia and Litsea citrata at 0.0001%, Eucalyptus citriodora at 0.01% can inhibit the growth of Vibrio campbellii BB120. These EOs can also prevent the growth of V. parahaemolyticus strains but need to be present at a higher concentration (0.1%). Moreover, in the vapor-phase-mediated susceptibility assay, EOs of M. alternifoliaL. citrata and E. citriodora can inhibit the growth of V. campbellii BB120 through their vapor phase. However, V. parahaemolyticus strains (CAIM170, LMG2850 and MO904) cannot be inhibited by these EOs. Additionally, in the quorum sensing-inhibitory assay, EOs of Mentha pulegiumCuminum cyminumZingiber officinalis, and E. citriodora, all at 0.001%, have quorum sensing-inhibitory activity in V. campbellii BB120. Taken together, our study provides substantial evidence that usage of the major components, individually or in combination, of the tested commercial EOs (extracted from M. alternifoliaL. citrata, and E. citriodora) could be a promising approach to control V. campbellii BB120.

Portugal – Legionnaires’ disease update: Additional cases/death recorded

Outbreak News Today

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In a follow-up on the Legionnaires’ disease outbreak in northern Portugal region of Greater Porto, officials report from October 29 through November 29, 88 registered cases, including 10 deaths.

The outbreak, which has affected the cities of Matosinhos, Vila do Conde and Póvoa de Varzim, has decreased after the cooling towers of an industry in Matosinhos were disconnected where the bacteria was detected.

“Since the operation of the aforementioned cooling towers was suspended, there has been a marked decrease in the number of cases of Legionnaires’ disease in the aforementioned geographical area,” ARS / Norte said in a statement this Sunday.

Singapore – Recall of Meadows Bottled Drinking Water Due to Presence of Pseudomonas aeruginosa


The Singapore Food Agency (SFA) has detected the presence of Pseudomonas aeruginosa in “Meadows” bottled drinking water during a routine sampling of the product. The product was imported from Malaysia by Cold Storage Singapore (1983) Pte Ltd. SFA has directed the importer to recall all the implicated products. The recall has been completed.

Consumers who have purchased the implicated product are advised not to consume it. Those who have consumed the implicated product and have concerns about their health should seek medical advice. Consumers may contact their point of purchase for enquiries or refund
.Details of the products are as follows.

Implicated product: Meadows Pure Drinking Water
Expiry Date: 9/11/2022
Packing Size: 1.5L
Country of origin: Malaysia
Issued by the Singapore Food Agency
3 December 2020

Portugal – Portugal Legionnaires’ disease outbreak sickens dozens, kills 9

Outbreak News Today

CDC legionella

Public health authorities in Portugal are reporting a Legionnaires’ disease outbreak in the Greater Porto region of the northern region of the country.

Three counties have been affected–Póvoa de Varzim, Vila do Conde and Matosinhos.

The number of legionella cases diagnosed since the outbreak began on Oct. 29 is 85, including nine deaths due to complications associated with the disease.

According to the ECDC, an epidemiological investigation is ongoing, including clinical and environmental assessment and sampling for subsequent subtyping and isolate comparison. Two cooling towers have been closed.