Saturday, February 13, 2016

Brazil: The MOH Addresses The Larvacide Debate

# 11,012

Over the past couple of days a report from the Argentine environmental activist website Red Universitaria de Ambiente y Salud – Medicos de pueblos fumigados called REPORT from Physicians in the Crop-Sprayed Town regarding Dengue-Zika, microcephaly, and massive spraying with chemical poisons has been making huge waves, with many activist websites promoting the document.

The gist of it is the authors believe the larvacide Pyriproxyfen, which has been used on some drinking water supplies in Brazil, is a more likely cause of microcephaly than the Zika virus.

You can read it for yourself, but other than its introduction to Northeastern Brazil in 2014 - about the same time as the Zika virus arrived - the evidence for causation seems pretty thin. One does hope that all reasonable possibilities are being looked at - not just Zika - but whether this qualifies . . . I've no idea. 

It does, however, tap into a very popular sentiment - the growing distrust of the agro-chemical industry - and is therefore getting a lot of play.

Enough that today, the Minister of Health for the southern state of Rio Grande De Sol ordered the temporary suspension of the use of the larvacide for use on drinking waster pending an investigation.

A fairly easy decision for Rio Grande De Sol, as they reportedly rarely use the chemical.  They also only have one microcephalic birth reported, for whatever that is worth.

First the official (translated) statement, followed by the Brazilian MOH's response.

Secretary announced the suspension of larvicidal in water for human consumption during d-day to combat Aedes aegypti Mosquito

Is temporarily suspended in Rio Grande do Sul the use in drinking water of Pyriproxyfen larvicidal, used to stop the development of larvae of the Aedes aegypti mosquito. This was announced this Saturday (13) by the Secretary John Gabbardo of Kings, at the opening of d-day to combat Mosquito. The decision is due to the assumption that the substance may enhance the brain malformation caused by zika virus, raised by argentina medical Physicians in the Crop-Sprayed Towns. The suspension has already been communicated to the 19 regional Health company departments of the State, which shall inform the Municipal Surveillance.

The larvicidal was used on a small scale in Rio Grande do Sul, only in specific cases, when it is not possible to avoid the accumulation of water or remove the containers, such as fountains and cement pots in cemeteries. "We decided to suspend the use of the product in water for human consumption until it has a position of the Ministry of health and therefore strengthen further the appeal to the population to that eliminates any possible outbreak of the mosquito," explained the Secretary. According to the data from environmental monitoring, 75% of the foci are located in residential or domestic environments.

Within minutes of this announcement, many advocates of the theory were declaring victory on Twitter, calling Zika a hoax and blaming the government. The Brazilian MOH responded to the RS MOH's decision, with the following statement.

Registration Date: 02/13/2016 15:02:14 the change in the 02/13/2016 16:02:23
There is no epidemiological studies showing the association between use of pyriproxifen and microcephaly. The Ministry of Health only uses larvicides recommended by the World Health Organization (WHO). Products undergo a rigorous evaluation process of the World Health Organization Pesticed Evaluation Scheme (WHOPES).  The pyriproxifen is among the products approved by that committee and also is certified by ANVISA (National Health Surveillance Agency), which assesses the safety of the larvicide in Brazil. 

Unlike the relationship between the Zika virus and microcephaly, which has had its confirmation attested in tests that indicated the presence of the virus in samples of blood, tissue and amniotic fluid, the association between the use of pyriproxifen and microcephaly has no scientific basis. Importantly, some localities that do not use pyriproxifen were also reported cases of microcephaly.

The Secretary of State of Rio Grande do Sul Health (SES / RS), as the local health authority, is empowered to use the product purchased and distributed the Ministry of Health or develop alternative strategies.

It is noteworthy that the Ministry of Health recommends only the use of larvicides in special situations where there is water storage need and deposits may not be physically protected.

It is important to remember that to eradicate the Aedes aegypti and all its potential breeding, the adoption of a routine is necessary with simple steps to eliminate containers that hold standing water. Fifteen minutes of inspection are enough to keep the environment clean. Little plates with plant pots, garbage cans, buckets, drains, gutters, bottles, tires and even toys can be the villains and serve as breeding grounds for mosquito larvae. Other individual protection initiatives can also complement the prevention of diseases such as the use of repellents and insecticides to the environment.

Check WHO report on the use of pyriproxifen:

Although the evidence for Zika being the cause of microcephaly in Brazil continues to grow, the notion that this larvacide may be a factor is probably not going away anytime soon.

CDC Advice: Pregnant And Living In A Zika Prone Area


Four weeks ago the CDC released their interim travel recommendations on Zika, recommending that Pregnant women in any trimester should consider postponing travel to the areas where Zika virus transmission is ongoing.

With the continued expansion of the virus, however, in the months and years to come it is likely that millions of pregnant women will see the virus come to them. 

For Americans, the greatest risk right now is in Puerto Rico (see MMWR: Local Transmission Of Zika Virus In Puerto Rico), but it wouldn't be terribly surprising to eventually see limited outbreaks in Florida, Texas, Hawaii, and other states where the Aedes mosquito can be found.

With that eventuality in mind, the CDC has begun producing public health messaging for  pregnant women who live in areas with potential Zika exposure. 


WHO Interim Case Definition For Zika Virus Disease

Zika Rash - Credit Wikipedia


The World Health Organization has released an interim case definition for identifying suspected, probable, and confirmed Zika Virus Disease infection. 

Since the majority of cases are expected to be asymptomatic or mild - and given the limited availability of laboratory testing - most infections will never be identified, much less confirmed.

We see a similar situation every year in the United States with the West Nile Virus.  Only about 20% ever develop symptoms, and the vast majority of those are mild cases – called West Nile Fever – with probably only 2%-3% of those being identified.

Serious illness - due to neuroinvasive WNV - accounts for less than 1% of all cases.  In 2015, 1,360 neuroinvasive WNV cases were reported in the United States, resulting in 119 deaths.

Which means that there were probably more than 100,000 mild West Nile Fever cases that went unreported last year. It is likely that more than a million Americans have been infected with the West Nile Virus over the past 16 years, and never even knew it. 

Although we are still learning about the Zika virus, the same pattern appears to be true in Central and South America, with only a very small percent of cases experiencing serious illness or complications.

Zika virus disease

Interim case definition
12 February 2015

These interim case definitions have been developed for the purpose of providing global standardization for classification and reporting of Zika virus cases. WHO guidance for the surveillance of Zika virus disease is currently being developed.
WHO will periodically review these interim case definitions and update them as new information becomes available.

Suspected case

A person presenting with rash and/or fever and at least one of the following signs or symptoms:
  • arthralgia; or
  • arthritis; or
  • conjunctivitis (non-purulent/hyperaemic).

Probable case

A suspected case with presence of IgM antibody against Zika virus1 and an epidemiological link2

Confirmed case

A person with laboratory confirmation of recent Zika virus infection:
  • presence of Zika virus RNA or antigen in serum or other samples (e.g. saliva, tissues, urine, whole blood); or
  • IgM antibody against Zika virus positive and PRNT90 for Zika virus with titre ≥20 and Zika virus PRNT90 titre ratio ≥ 4 compared to other flaviviruses; and exclusion of other flaviviruses


1 With no evidence of infection with other flaviviruses
2 Contact with a confirmed case, or a history of residing in or travelling to an area with local transmission of Zika virus within two weeks prior to onset of symptoms.

WHO Zika SitRep - Feb 12th

# 11,009

The WHO released their weekly Situation Report on the Zika Virus very late last night, which can be found on their Microcephaly/Zika virus web page in the form of a 6 page PDF file.

You'll want to download the entire report, but I've posted the summary below.

Zika situation report

12 February 2016

Zika and potential complications

  • WHO has called for a coordinated and multisectoral response through an inter-agency Strategic Response Framework focusing on response, surveillance and research.
  • 39 countries have reported locally acquired circulation of the virus since January 2007. Geographical distribution of the virus has steadily expanded.
  • Six countries (Brazil, French Polynesia, El Salvador, Venezuela, Colombia and Suriname) have reported an increase in the incidence of cases of microcephaly and/or Guillain-Barré syndrome (GBS) in conjunction with an outbreak of the Zika virus. Puerto Rico and Martinique have reported cases of GBS associated with Zika virus infection without an increase of incidence. No scientific evidence to date confirms a link between Zika virus and microcephaly or GBS.
  • Women’s reproductive health has been thrust into the limelight with the spread of the Zika virus. The latest evidence suggests that Zika virus infection during pregnancy may be linked to microcephaly in newborn babies.
  • WHO advice on travel to Zika-affected countries includes advice for pregnant women as well as women who are trying to become pregnant and their sexual partners.

Friday, February 12, 2016

MMWR: Local Transmission Of Zika Virus In Puerto Rico

Credi MMWR


The CDC has published, late this afternoon, an extensive MMWR review of local acquisition of the Zika virus in the U.S. Territory of Puerto Rico - to date involving 30 individuals - including one pregnant woman.

The review, charts, and map are far too large to excerpt here effectively, so I'll simply direct my readers to follow the link. I have excerpted the summary.

Local Transmission of Zika Virus — Puerto Rico, November 23, 2015–January 28, 2016
FEBRUARY 12, 2016
On December 31, 2015, the Puerto Rico Department of Health reported the first locally acquired case of Zika virus disease in a jurisdiction of the United States in a patient from southeastern Puerto Rico. Zika virus is expected to continue to spread throughout the territory, and the 3.5 million residents of Puerto Rico, including approximately 43,000 pregnant women per year, are at risk for Zika virus infection.

Dana L. Thomas, MD1,2; Tyler M. Sharp, PhD3; Jomil Torres, MS1; Paige A. Armstrong, MD4; Jorge Munoz-Jordan, PhD3; Kyle R. Ryff, MPH1; Alma Martinez-Quiñones, MPH5; José Arias-Berríos, MD6; Marrielle Mayshack1,7; Glenn J. Garayalde, MD8; Sonia Saavedra, MD, PhD8; Carlos A. Luciano, MD6; Miguel Valencia-Prado5; Steve Waterman, MD3; Brenda Rivera-García, DVM1


What is already known about this topic?Zika virus emerged in the Region of the Americas in mid-2015, and since then, outbreaks have occurred in multiple South American and Caribbean countries and territories. Zika virus infection appears to be related with increased risk for fetal microcephaly and Guillain-Barré syndrome.
What is added by this report?The first locally acquired case of Zika virus disease in Puerto Rico was identified in early December 2015. During the subsequent months, 29 additional laboratory-confirmed cases have been detected, including in one pregnant woman and in a man with Guillain-Barré syndrome.

What are the implications for public health practice?Clinicians in Puerto Rico and other clinicians evaluating patients with recent travel to Puerto Rico should report all cases of suspected Zika virus disease to public health authorities. Residents of and visitors to Puerto Rico should strictly follow steps to avoid mosquito bites including using air conditioning or window and door screens when indoors, wearing long sleeves and pants, using permethrin-treated clothing and gear, and using insect repellents. When used according to the product label, Environmental Protection Agency-registered insect repellents are safe for pregnant women.

Brazil MOH: Epi Week 5 Microcephaly report


The weekly reporting on microcephaly cases from Brazil's MOH started out being posted  on Tuesdays last December, shifted to Wednesdays in January, while this week's report has run the latest to date - appearing on Friday.

With the removal of both confirmed and discarded cases from the Total Under Investigation each week, the numbers tend to bounce around.  But this week's report adds 296 new cases to the investigation, leaving 3862 cases under investigation.

Out of 1,227 cases that have been investigated, 462 (37.6%) have been confirmed as microcephaly or other CNS disorders. A state-by-state listing of cases can be found at the link below.

New report shows that 462 cases have been confirmed to microcephaly or other disorders of the central nervous system, 41 with respect to the Zika virus. Notified, they were discarded 765
The Ministry of Health and the states investigating 3,852 suspected cases of microcephaly across the country. The new report released on Friday (12) points out, too, that 462 cases have had microcephaly confirmation and / or other disorders of the central nervous system, and 41 with respect to the Zika virus. This week 24 new cases were confirmed, compared with the previous week.

Other 765 cases reported were discarded because they had normal exams, or submit microcefalias and / or changes in the central nervous system by an infectious causes. In all, 5,079 suspected cases of microcephaly have been recorded since the start of the investigation in October 22, 2015 until February 6, 2016. Of this total, 62.5% of cases (3,174) were reported in 2015 and 37.5% ( 1,905) in the year 2016.

The state of Pernambuco remains with the largest number of confirmed cases in relation to the Zika virus (33), followed by Rio Grande do Norte (4), Paraíba (2) and Ceará and Pará with one case each. Amapá and Amazonas are the only states of the federation which has no record of suspected cases of microcephaly.

In total, 91 deaths were reported by microcephaly and / or alteration of the central nervous system after birth (stillbirth) or during pregnancy (miscarriage). Of these, 24 were investigated and confirmed for microcephaly and / or alteration of the central nervous system, of which eight were discarded. Another 59 are still under investigation.

It should be noted that the Ministry of Health is investigating all cases of microcephaly and other disorders of the central nervous system, informed by the states and the possible relationship with the Zika virus and other congenital infections. Microcephaly can be caused by various infectious agents beyond Zika, such as syphilis, toxoplasmosis, Other Infectious Agents, Rubella, Cytomegalovirus and Herpes Viral.

According to the report, the 462 confirmed cases were reported in 175 municipalities in 13 states: Alagoas, Bahia, Ceará, Espírito Santo, Goiás, Mato Grosso do Sul, Pará, Paraíba, Pernambuco, Piauí, Rio Grande do Norte, Rio de Janeiro and Rio Grande do Sul. the Northeast region has the largest number of confirmed cases and Pernambuco continues with the highest number of confirmed cases (167), followed by the states of Bahia (101), Rio Grande do Norte (70), Paraíba (54), Piauí (29) and Alagoas (21).

So far, they are with indigenous circulation of Zika virus 22 units of the federation. They are: Goiás, Minas Gerais, Federal District, Mato Grosso do Sul, Roraima, Amazonas, Pará, Rondônia, Mato Grosso, Tocantins, Maranhão, Piauí, Ceará, Rio Grande do Norte, Paraiba, Pernambuco, Alagoas, Bahia, Espírito Santo , Rio de Janeiro, Sao Paulo and Parana. 
(Continue . . . )