Archive for immunity

Chikungunya Fever

Posted in Health/Diseases, Latest of Asienreisender with tags , , , , , , , , , , , , , , , , , , , , , , , on August 8, 2013 by Thim Kwai

Chikungunya fever is another tropical, mosquito-born disease. It’s endemic in Southeast Asia, India and great parts of Africa.

Chikungunya is a virus which was discovered in 1953, first documented in Thailand in 1958. Most of the population in Indochina is probably immune against the disease. Though, tourists and travellers from other world regions are usually not immune. The disease is spreading out to the southern parts of Southeast Asia. In the last years there were considerable numbers of cases of chikungunya in Indonesia, Malaysia, the Philippines, Burma/Myanmar, Cambodia and Thailand, certainly also in Singapore. Between 2001 and 2003 there was a chikungunya epidemy on Java. In May 2009 there was an outbreak in Trang / Thailand, in 2012 in parts of Cambodia with 1,500 reported cases. Chikungunya appeared the first time in Cambodia in 1961.

Chikungunya is transfered by various kinds of mosquitoes, including the aggressive Asian tiger mosquito (Stegomyia albopicta, or aedes albopictus), which transferes dengue fever and a number of other diseases as well. Other vectors of the chikungunya virus are primates and rodents.

Recently a virus mutation happened, which is particularly well transfered by the Asian tiger mosquito. It’s pathogenicity is higher than those of the other, older variations.

The outspread of the Asian tiger mosquito in the last years, also into south Europe, is supposed to be responsible for the chikungunya epidemy in summer 2007 in Ravenna, Italy. Possibly the disease will spread out into more regions in Europe and north America in the next years.

Transfer

Course of Disease

Diagnosis

Therapy

Prevention

Peculiarities

Know…

This is only a part of the illustrated article ‘Chikungunya’. Read the whole article on Chikungunya Fever by Asienreisender.

Keep yourself up-to-date

Check the list of recently published articles on a great variety of Southeast Asian themes. All of them are richly illustrated: Asienreisender

Malaria by Asienreisender

Posted in Health/Diseases, Latest of Asienreisender with tags , , , , , , , , , , , , , , , , , , , , , , on July 29, 2013 by Thim Kwai

Malaria is an infectious parasitic disease. It’s naturally transfered by a female mosquito of the kind anopheles from man to man. Another way of transfer can be by blood transfusion or other injections (with used syringes) with parasite – containing blood. Smallest amounts of blood already allow a transfer. Pregnant mothers can in certain cases transfer malaria to their child, but it’s not necessarily so.

A poster warning before mosquitoes. Seen at a hospital in Chumpon, south Thailand. Image by Asienreisender, 2012

The development of the parasite happens exclusively inside anopheles mosquitoes and human bodies. There are three different kinds of malaria. Meaningful for travellers in Southeast Asia is malaria tropica, the most dangerous one. The others are malaria tertiana (which was widespread also in Europe, up to middle- and northern Europe until the first half of the 20th century) and malaria quartana.

Famous malaria patients of the European past were Albrecht Duerer, Oliver Cromwell and Friedrich Schiller. Malaria was finally extinct from Europe not before the 1960s due to the ‘Global Malaria Eradiction Program’ (see below).

A famous Asian malaria victim was Mohandas Gandhi (1869 – 1948), who suffered a severe attack in Aga Khan Palace in Pune in 1942, where he was held as a political prisoner.

All these three kinds of malaria are human-specific, means they don’t infect animals (apart from very few exceptions at monkeys, some of them observed at macaques in Southeast Asia).

Anopheles mosquitoes are (together with aedes und culex mosquitoes) among the most widespread mosquito kinds. There are 360 different kinds of anopheles mosquitoes alone in the world, of whom 45 potentially carry malaria. Their habitats are not limited to the tropes and subtropes, but spread out until the borders of arctic regions.

Around 40% of the global human population lives in areas infested with malaria, of whom 300 – 500 million people are infected (according to the Robert Koch Institute, Berlin). More than 80% of them live in tropical Africa, 13.8% live in Asia.

In mountainous areas above 1.500m, near the equator from 2.500m on anopheles mosquitoes do not appear anymore. Malaria is pandemic in almost whole Southeast Asia. Indonesia and Burma / Myanmar have here by distance the most cases in percentage of the population. A growing resistance to antimalarials are a challenge in the Greater Mekong Sub-Region.

The exciter for malaria tropica is the parasite plasmodium falciparum, the most lethal one among the four plasmodium parasites. Estimated 1.8 million people died in 2004 worldwide, 1.2 million in 2010 due to malaria.

Let’s assume that a biting mosquito is sucking blood. When the bitten human is malaria infected, the mosquito sucks with the blood the exciters which transfer within 8 to 16 days inside the mosquito into another phase and next to it’s final stage. When it gets injected then into another humans blood circulation, reaching there the human liver, it’s again breeding and spreading out into the vascular system. The perpetuation of the circle is then completed.

Read here more on the feeding habits of mosquitoes.

Know…

This is only the first chapter of the illustrated article ‘Malaria in Southeast Asia’. Read the whole article on Malaria in Southeast Asia by Asienreisender.

The following chapters are:

Malaria Prevention by Asienreisender
Malaria Immunity Asienreisender
Malaria Diagnosis by Asienreisender
Malaria Pathogenesis by Asienreisender
Malaria Therapy by Asienreisender
The ‘Global Malaria Eradiction Program’ by Asienreisender

Keep yourself up-to-date

Check the list of recently published articles on a great variety of Southeast Asian themes. All of them are richly illustrated: Asienreisender