As this suggests, girls’ and women’s low social and economic status also fosters the spread of HIV/AIDS in Africa. In countries where girls and women have low status, they may face physical violence if they ask a husband or other sexual partner to use a condom, find that male teachers demand sex as a requirement for attending school, or be pressured into marriages or sexual relationships with older men who are more likely to be infected. In addition, because their low status of- ten keeps them from accessing medical care, women are more likely than men to have untreated STDs that can produce open sores and thus increase the chances of infection for any woman who is exposed to HIV.
Sexual behavior patterns also play a role in the epidemic. Current research suggests that risks of infection are greater in Africa not because the average number of sexual partners is high there but because long-term, concurrent sexual partners are more common . In Western countries, individuals typically have serial sexual partners—one after another—such as a first mar- riage followed by a brief sexual relationship or two and then a second marriage. In contrast, in parts of Africa (especially sub-Saharan Africa), individuals often have long-term concurrent sexual partners: multiple sexual relationships during overlapping time periods.
Concurrent partnerships increase the chances of spreading HIV/AIDS for two reasons. First, people around the world typically use condoms early in relationships but stop doing so if the relationship continues. Consequently, persons in long-term concurrent relationships are more likely than those in short-term monogamous relationships to reach the point where they stop using condoms. Second, HIV/AIDS is most easily transmitted only when an individual is healthy enough to have an active sex life and has a “high viral load” (i.e., has many HIV cells in his or her body). If an individual hits that peak transmission point while he or she has concurrent sexual partners, then all of those partners—and all of their partners—will be at risk.
Tuberculosis Each year, tuberculosis infects around 10 million people and kills 1 million or so. The disease is most common in Asia, followed by Africa. Tuberculosis is particularly devastating because, like HIV/ AIDS, it typically hits people during their prime work years, so it sharply curtails family incomes.
Because of a consolidated, worldwide effort to make powerful treatment available even in poor regions, rates of tuberculosis have been falling for the past two decades in most of the world. However, because HIV/AIDS makes individuals more susceptible to other infections, tuberculosis continues to increase in those African nations where HIV/AIDS is most common.
Diarrheal Diseases In the more developed nations, diarrhea typically causes only passing discomfort. In the less developed nations, diarrheal diseases are the second leading cause of death among children younger than age five.
Diarrhea is a symptom, not a disease, and can result from infection with any of several bacteria, viruses, or parasites. Diarrhea kills through dehydration and electrolytic imbalance. It also leads to malnutrition when affected children not only eat less but also absorb fewer nutrients from the foods they do eat. In turn, malnutrition leaves children susceptible to other fatal illnesses. Con- versely, other illnesses can leave children susceptible to both diarrheal diseases and malnutrition.
Diarrheal diseases (including dysentery, cholera, and infection with Escherichia coli) occur when individuals ingest contaminated water or foods. The likelihood of severe diarrhea is greatest when families lack refrigerators, sanitary toilets, suf- ficient fuel to cook foods thoroughly, or safe water for cooking and cleaning. WHO estimates that around 2 billion people lack access to “improved” water supplies, and many more lack access to truly safe water. The number of persons without safe water is greatest in Asia, but the percentage of those without safe water is highest in sub-Saharan Africa.
Survival rates for children with diarrheal diseases in less developed na- tions have improved rapidly in recent years. Before the 1960s, those suffering from diarrheal diseases could be treated only by using expensive intravenous fluids, thus making treatment unfeasible for many in the less developed na- tions. Since then, however, scientists have developed saline solutions and pea- nut butter pastes that keep children alive at least as well as more expensive treatments.
Malaria Each year, around 200 million people become infected with malaria, and approximately one-half million—mostly African children—die from the re- sulting anemia, general debility, or brain infections. In addition, millions more find themselves unable to work because of continuing malarial chills and fevers, or die because malaria leaves them susceptible to other fatal illnesses.
Malaria poses the greatest threat to pregnant women, infants, and young chil- dren. Among pregnant women, malaria increases the risks of miscarriage, anemia, and premature labor, each of which increases the risk of potentially fatal hemor- rhaging. Infants born to malaria-infected women typically have lower than aver- age birth weight and hence a higher chance of death or disability.
Malaria is caused by protozoan parasites belonging to the genus Plasmodium. Malaria is transmitted only by Anopheles mosquitoes and consequently exists only where those mosquitoes live. The disease cycle begins when a mosquito bites an infected individual and ingests the parasite from the individual’s blood. The par- asite reproduces in the mosquito’s stomach and then migrates to the mosquito’s salivary glands. The next time the mosquito bites someone, it transmits the parasite to that person.
Because of this transmission cycle, eliminating Anopheles mosquitoes will eliminate malaria. Since the 1940s, antimalaria campaigns have depended heavily on pesticides to kill mosquitoes. Although such campaigns initially work well, over time pesticide-resistant mosquitoes evolve, and the pesticides lose their potency. As a result, nations must constantly search for new and more toxic pesticides, each of which can endanger birds, fish, and insects that benefit hu- mans. Because of these problems, some recent campaigns have instead focused on encouraging the use of insect repellents, mosquito netting, and screens to prevent infection. These campaigns also have focused on encouraging the use of drugs such as chloroquine and mefloquine, which can both prevent and treat malaria. Unfortunately, because these drugs can cause debilitating side effects and cost more than many residents of developing nations can afford, infected individuals often stop taking the drugs before they are cured. This continual undertreatment of malaria, like the undertreatment of tuberculosis, has encouraged the evolution of drug-resistant malaria.
Zika Zika virus burst into the news in 2015 when Brazil was hit with an epi- demic of babies born with tiny heads and brains, leaving them with severe neu- rological and physical problems. Researchers quickly traced these problems to prenatal infection with Zika, which can be spread by mosquitoes and through unprotected sexual intercourse. Zika can also lead to serious neurological prob- lems in infected adults.
To date there is neither a vaccine nor a treatment for Zika. Instead, govern- ments and health authorities have relied on warning individuals to avoid both mosquitoes and unprotected sex. These measures, however, are almost meaningless for those most at risk For example, many poor people in places like rural Brazil cannot afford to follow WHO’s recom- mendations to avoid mosquitoes by using air-conditioning and insect repellant, wearing only clothes that have no holes in them, and avoiding areas where water must be carried home in buckets.
Similarly, in developing nations where Zika is common, women have been warned to avoid unprotected sex, avoid pregnancy, and consider abortion. Yet many poor women lack the power to force men to use condoms and lack access to birth control or abortion (whether because of cost or because it is illegal). Nor has there been much effort to help families care for children with devastat- ing disabilities. This is a classic case of defining something as a personal problem rather than as a public issue. A more sociological approach would be to focus on strategies such as eliminating areas where mosquitoes breed and changing laws and health care systems to give women access to the information and care that they need.