MER – MIDDLEEAST RESPIRATORY SYNDROME
Caused by a coronavirus, this lung infection originated in 2012 on the Arabian Peninsula. As of May, 2014, MERS has infected more than 530 people worldwide and killed 145. In May evidence was presented that the first case had been spread from one person to anther inside the US, possibly from a handshake. An Illinois man had 2 brief business meetings with the first US MERS patient, an Indiana man who lived in Saudi Arabia.
A lot is still not understood about this virus – including how widely it could spread in the US. All active cases are currently in the Middle East.
Symptoms. most have flu-like signs, such as fever, cough and chills, and have difficulty breathing. People present from mild to the more severe and 20% are completely asymptomatic.
Treatment. There are no drugs or vaccines. Healthy people with strong immune systems are better able to fight off milder infections.
June 2015. An outbreak of MERS is the largest yet outside of the Middle East with 30 confirmed cases and two deaths. 1,300 have been quarantined and 500 schools closed trying to contain the outbreak.
INFECTIONS SPREAD BY MOSQUITOES and OTHER INSECTS
1. DENGUE FEVER (break bone fever)
Aedes aegypti and Aedes aldopictus mosquitoes – aggressive day-time feeder that bites most in the first 2-3hrs after dawn and in the mid-to-late afternoon. Common in urban areas. No vaccine available. Found in tropical and subtropical regions of Africa, the Americas, Asia, the Caribbean, and the Pacific Islands – with the highest risk in SE Asia and Latin America. Frontal headaches and muscle aches are major symptoms. Can be reinfected.
2. CHIKUNGUNYA FEVER
Same mosquito as dengue. Increased risk in tropical rainy season. No vaccine available. Found in Africa, Asia, Latin America and most recently, the Caribbean. Joint pain is common and may persist for months. Can only be contracted once.
3. ZIKA VIRUS.
Same mosquito as Dengue and Chikungunya. Started in Brazil and has since spread through South America, Central America, Southern USA, and Africa. Only 1/5 have symptoms. Rarely it can cause a neurological condition that may lead to temporary paralysis and death. It is sexually spread for up to 2 months after infection but that is very rare and preventable with condoms. Infection of pregnant women has risk of producing microcephaly in the infants. Over 4000 affected infants have been born in Brazil to early 2016. Microcephaly produces severe mental retardation with large social costs for nonproductive dependent people.
Should you go to the Olympics? (Rio de Janeiro Aug 5- 20 2016) In May, 200 experts (mostly ethicists) argued that holding the games as planned is “unethical” because it will speed up the spread of the Zika virus – many of the 500,000 foreigners who attend will get infected and then spread Zika back home. But this is drastic thinking. Pregnant women are advised to avoid travel to areas where Zika is being transmitted, including Rio. 500,000 is a large number but still less than .25% of all those who travel each year to places already affected by Zika. Cancelling or moving the Olympics will not significantly alter the spread of Zika. The virus is now present in nearly 60 countries and people will continue to travel to and from these, games or no games. Risk for almost everyone else is near zero if they take the recommended precautions.
Symptoms of dengue, chikungunya and zika: start 2-14 days after being bit and last 7-10 days. Severity depends on the virus and individual’s immune response. Sudden onset of high fever, severe muscle and/or joint pains, generalized weakness, headache, nausea and vomiting, rash.
A. aegypti is a tricky insect to get rid of (it has been called the “cockroach” of mosquitoes). Mopping up all stagnant water is key along with insecticide spraying. This El Nino season has brought more rain to Rio and mosquitoes have been more plentiful. The number of cases of dengue has been nearly double those in the same period last year. August though tends to be a dry month. A more sensible reason for concern is Brazil often lies with official information.
4. YELLLOW FEVER
Aedes aegypti mosquito – day-time feeder, risk in South America and Africa (urban/jungle/sylvatic/savannah) only. Vaccine is valid 10 days after vaccination and lasts 10 years (the vaccine provides lifetime protection but border requirements still require boosters every 10 years). After receiving the vaccination, you will be given a stamped and signed “International Certificate of Vaccination” (yellow card) that is required as proof of vaccination to enter certain countries. The vaccine is not 100% effective.
History: It used to be common in many places where it is now not seen. In 1793, an outbreak in Philadelphia killed 5,000 (1/10th of the population), in New Orleans in 1853, 9,000 died. Port cities of Europe had outbreaks – one in Barcelona in 1821 killed thousands.
Fumigation eradicated it in the N Hemisphere by the mid 20th century. Cuba was the source of many epidemics eliminated the same way. Vaccination in France’s West African colonies from 1933-61 caused it to virtually disappear from the continent. With decolonization, vaccination rates plummeted and the disease reappeared. In South America, it is present in remote jungle areas and travellers can bring it to cities.
Potentially fatal with no specific treatment only supportive. 80,000 Africans die every year of it which is a scandal as it is prevented by a single inoculation and it risks spreading to Asia where it has never before taken hold.
The latest epidemic is in Angola – since Dec 2015, 2,300 cases and 300 deaths. Angola has very fragmented health care and possibly 50-500 go unreported for each reported case. Early symptoms: high temperature, nausea, vomiting and muscle pain – reasonably mild and last few days. In 15%, returns with a vengeance with severe abdominal pain, jaundice, bleeding internally and from eyes, mouth and nose and about half of these people die.
The UN has shipped 9million doses of vaccine to Angola, enough for 1/3 of population and 1/5th of world’s supply. Supplies may run out. A few cases have been reported in Kenya and 450 in Congo. Booming trade in forged vaccination certificates may allow spread to Zambia and Namibia. Vaccination is important as soon as possible as Asian workers in Angola can spread the disease back home. The use of vaccine in all African countries where YF is endemic could slash the number of cases. WHO with others hopes to cover the continent by 2020 at a cost of $300m.
The vaccine has only 4 sources so spread to Asia would be problematic. Can use a low dose of 1/5th normal to make the vaccine go further. China has had a few cases, all from workers returning from Angola. Once yellow fever is established in a tropical country, it is almost impossible to eradicate. Monkeys act as the reservoir of the disease and spread is from jungle to cities. A aegypti is found across much of southern Asia and monkeys are available for a reservoir
Female Anopheles mosquito – night-time biter between late afternoon and morning, risk higher in rural areas, during or soon after rainy season, and only at altitudes <2500m. No vaccine but medication to prevent and treat available. 6. JAPANESE ENCEPHALITIS
Culex mosquito – bites primarily at dusk and dawn, risk greatest in South Asia, SE Asia, Western Pacific, in rural agricultural areas and during May-Oct for most regions but can occur throughout year. Vaccine available.
7. WEST NILE VIRUS
Culex pipines mosquito – night-time feeder, world-wide including North America. No vaccine available.
8. LYME DISEASE ticks
9. TICK-BORNE ENCEPHALITIS
Ticks – Risk in Eurasian forest belt of Europe, Russia, Ukraine, Baltic States, greatest March to November. Vaccine available in Europe.
Sandfly – Americas, Africa, Mediterranean, Middle East, India
11. TRYPANOSOMIASIS (AFRICAN SLEEPING SICKNESS)
Tsetse fly – Rural sub-Saharan Africa
12. ONCHOCERCIASIS (RIVER BLINDNESS)
Black fly – Central America
PREVENTING INSECT BITES
PEOPLE MOSQUITOES LIKE TO BITE — 3000 species worldwide and only a few hundred bite people.
1. CO2 is the most significant attractant – if overweight or heavy, just exercised or hyperactive, you put off more CO2
2. Type O blood more favoured than type A
3. Some people put off attracting pheronomes
4. Drinking beer attracts mosquitos
TOPICAL REPELLENTS – Apply 15-30 minutes after sunscreen. Combined products are not recommended.
1. Icaridin (PiACTIVE): 1-piperidine-carboxylic acid, 2-(2-hydroxy-ethyl – Now the preferred repellent for use in children 6mos to 2yrs of age, with DEET as a second choice.
2. DEET: N,N-diethyl-m-toluamide – the most widely used and available and effective repellent. Products with higher concentrations are not more effective but last longer. Products with greater than 30% DEET are not necessary.
3. PMD Lemon-Eucalyptus Oil (Natrapel): Provides protection for about 4-6 hours. Not for children less than 3 years of age or application more than twice per day.
4. Citronella and Soybean Oil: Don’t provide sufficient protection against bites and not recommended for travellers that require good protection.
BED NETS treated with insecticide are recommended if traveling in areas endemic for malaria.
CLOTHING TREATMENT: Permethrin is a safe insecticide available in many forms for soaking or spraying clothing or as pre-treated clothing.
Sleep in closed (screens windows and doors) air-conditioned rooms or use impregnated nets.
Burn mosquito coils during the evening
Avoid dark colours and perfumed products (soaps, shampoos, deodorants).
Cover as much skin as possible. Wear closed shoes and socks