2011

Through this epidemiological alert the Pan American Health Organization is reporting the current dengue situation in the Region and recommending to its Member States to continue and reinforce the actions of prevention and control that involve all government actors and/or non gubernamental and above all, the community.

PAHO also recommends that any resident of the Americas planning to travel to other regions of the world should be protected against measles and rubella prior to departing on their trip. Travelers who have not been vaccinated against measles and rubella are at risk of contracting these diseases when visiting countries where the viruses are currently circulating. Special efforts should be made to ensure vaccination for women of childbearing age in order to prevent possible infections caused by the rubella virus during pregnancy.

Since the beginning of 2011, in the region of the Americas, there have been significant outbreaks of influenza A (H1N1) 2009, that while geographically limited, have generated a significant demand on health services. This situation is not unexpected. Since the end of the pandemic (2009-2010), the influenza A (H1N1) 2009 virus, continues to circulate on a global level like a seasonal strain, periodically causing important outbreaks in various continents. Considering the possibility of outbreaks occurring on account of the influenza A (H1N1) 2009 virus in the countries of the Region, national authorities should be prepared to mitigate the resulting impact.

In light of the identification by scientific communities of a strain of gonorrhea resistant to all microbial treatments available for sexually transmitted infections (STIs), the Pan American Health Organization recommends informing health workers, institutions, and nongovernmental organizations that work in the prevention and control of STIs about the risk of resistance in this strain, and in particular strengthen the surveillance in each country regarding the appearance of strains with an unusual profile. The Organization also recommends promoting the use of STI prevention methods.

New Case Definition

Starting 8 June 2011, European Union (EU) Members States are reporting case according to a new case-definition.

Possible Epidemic Case: Any person who developed in or after 1 May 2011;

• STEC diarrhea defined as acute inset of diarrhea or bloody diarrhea AND at least one of the following criteria:

1. Isolation of an E coli strain that produces Shiga toxin 2 (Stv2) or stx2 gene.
2. Direct detection of stx2 gene nucleic acid in feces without strain isolation.

• STEC HUS defined as hemolytic uremic syndrome (HUS) defined as acute renal failure and at least one of the following clinical criteria

1. Microangiopatic hemolytic anemia
2. Thrombocytopenia

Probable Epidemic Case Any possible epidemic case of STEC diarrhea or STEC HUS AND during the exposure period of 14 days before the onset of illness, meeting at least one of the following epidemiological criteria:

• Stay in Germany or any other country where a confirmed case has probably acquired infection;
• Consumption of food product obtained from Germany;
• Close contact (e.g., in a household) with a confirmed epidemic case.

Confirmed Epidemic Case Any person meeting the criteria for a possible case, AND Isolation of a STEC strain of serotype O104:H4

OR isolation of a STEC strain of serotype O104 AND fulfilling epidemiological criteria for a probable case. EU Members States are reporting number of probable and confirmed cases and deaths.

Developed by the Robert Koch Institute to be applied to HUS-cases associated with the 2011 Germany outbreak.

HUS Clinical criteria: A clinical picture of acute enteropathogenic HUS is defined by the presence of at least two of the following three criteria:
1. Hemolytic anemia
2. Thrombocytopenia ≤ 150,000 cells/mm3,
3. Renal dysfunction

Laboratory confirmed cases: Positive result in at least one of the following tests:

Detection of Shigatoxin

1. Culture of the pathogen and isolation only from stool AND detection of Shigatoxin Stx2 using ELISA on the E. coli culture,
2. Mixed culture of the pathogen, enriched stool cultures or isolation of E. coli AND nucleic acid amplification test (e.g. PCR) for detection of the shigatoxin gene stx2 from the same sample

Indirect (serological) detection

1. Detection of ant-LPS-IgM-antibodies against E.coli Serogroups (once markedly increased titre/concentration, e.g., using ELISA, Western Blot)
2. Marked change between two consecutive samples in titreconcentrarion of anti-LPS-IgG-antibodies against E.coli serogroups e.g.; using ELISA)

Suspect HUS case: Case with a clinical picture of acute enteropahogenic HUS as assessed by the attending physician, but not formally meeting the clinical criteria (at least two of three) identified above, are classified as suspect cases regardless of laboratory confirmation.

Haemolytic uraemic syndrome (HUS): It is a life-threatening disease characterized by acute renal failure (uraemia), haemolytic anaemia, and a low platelet count (thrombocytopenia). It results from EHEC infection, and it is estimated that up to 10% of EHEC-affected patients may develop HUS. The mortality rate has decreased during the last few years and with appropriate treatment is between the 3% and 5%.

It can cause neurological complications (such as seizure, stroke and coma) in 25% of HUS patients and chronic renal sequelae, usually mild, in around 50% of survivors. EHEC or STEC is a severe strain of E. coli bacterium that is commonly found in the gut of animals, mainly ruminants. EHEC produces toxins, known as verotoxins or Shiga-like toxins because of their similarity to the toxins produced by Shigella dysenteriae. They can cause severe foodborne disease. STEC is transmitted to humans primarily through consumption of contaminated foods, such as raw or undercooked ground meat products and raw milk, contaminated water, direct contact with animals or contact with infected people. Symptoms of disease include abdominal cramps and diarrhoea, which may be bloody. Fever and vomiting may also occur.

Since epidemiological week 23, the number of new HUS and non-HUS STEC cases has declined significantly in the European Union states. Nevertheless, the cumulative number of cases from Germany continues to rise, primarily owing to delays in notification. Investigations conducted by the German authorities indicate that the vehicle of the bacterium responsible for the outbreak, is bean and seed sprouts.

On 24 June, France reported a cluster of 8 cases, all adults (six women and two men) presenting bloody diarrhea; of which seven have developed HUS. E. coli O104:H4 has been confirmed in three patients. Preliminary investigative findings suggest that locally grown sprouts might be involved.

In the Americas Region, a total of nine E. coli O104:H4 STEC cases have been identified, of which six cases are confirmed (five in the United States and one in Canada).

In Haiti,during the fourth EW of 2011 Haiti registered a decrease in the weekly incidence rate at the national level, which went from 13.6 cholera cases per 10,000 inhabitants in EW 3 to 8.1 cases per 10,000 inhabitants in EW 4. At department level, three departments (Artibonite, Grande Anse, Nord and Sud) increased their weekly incidence rate. The in-hospital case fatality rate at the national level in EW 4 of 2011 was 1.0%.

While in the Dominican Republic, the Ministry of Public Health informed that since EW 45 of 2010 to EW 4 of 2011, there were 336 cases confirmed by laboratory and one death that happened in EW 2.

During Epidemiological Week 7 of 2011, at the national level, Haiti registered an increase in the weekly incidence rate, which increased from 5.1 cholera cases per 10,000 inhabitants in EW 6 to 10.2 cases per 10,000 inhabitants in EW 7. This was linked to an increase of 4.2% in the new cases registered as compared to the previous week. At the sub-national level, five departments (Centre, Nippes, Ouest, Sud y Nord) registered an increase in their weekly incidence rate.

While in the Dominican Republic, the Ministry of Health reported a total of 470 laboratory-confirmed cases of cholera, including four fatal cases, since the beginning of the outbreak up to EW 7.