13 Diseases You Can Get From Mosquitoes - Outbreak News Today

How Ignorance And Gender Inequality Thwart Treatment Of A Widespread Illness

Credit: Chiara Zarmati

On a visit to a woman at home in rural Zambia, community-health worker Janet Chisaila unpacks a bag that contains swabs, sample pots and a 3D-printed model of a vagina and cervix. Using the model, Chisaila explains how to use the swabs to take genital samples. The woman then goes to a private area to do her sampling. Later, she visits the local health clinic, where Chisaila's colleague Alice Mwale, a nurse, takes digital photographs of the woman's cervix, which are then uploaded to a secure platform. Thousands of miles away, at the London School of Hygiene & Tropical Medicine, clinician and principal investigator Amaya Bustinduy logs in to the platform to review the images and offer advice.

Part of Nature Outlook: Neglected tropical diseases

The woman is one of around 2,500 taking part in a study1 called Zipime Weka Schista! (Do self-testing, sister!), which aims to transform the diagnosis of a little-known neglected tropical disease (NTD) called female genital schistosomiasis (FGS). By combining FGS screening with testing for HIV, human papillomavirus (HPV) and a sexually transmitted disease called trichomoniasis in a single visit, the tests are striking a blow for gender equality and women's sexual- and reproductive-health rights. "This approach has empowered the women to know about these diseases," says Chisaila. "They have been given the confidence to talk about some of these health issues and have access to treatment and care."

FGS is a debilitating gynaecological condition caused by chronic infection with a parasitic disease known as schistosomiasis. Painful and stigmatizing, the disease is associated with reduced fertility and miscarriage. Infection increases the risk of contracting HIV, and probably HPV and cervical cancer as well. Although it was first recorded2 125 years ago, few people — even health-care workers in regions where the condition is thought to be most common — are aware that it exists. "FGS is neglected, under-researched and overlooked in endemic countries," says Kwame Shanaube, clinical epidemiologist and site coordinator of the Zipime Weka Schista! Study at Zambart, a Zambian non-governmental public-health research organization in Lusaka that specializes in public health and grew out of a collaboration between the University of Zambia's School of Medicine and the London School of Hygiene & Tropical Medicine.

Women and girls are vulnerable to FGS both because of their sex and because of socially determined roles and expectations that increase their exposure to infection and make it difficult for them to access treatment or talk about their symptoms. The social roles of women expose them more often to infection, and make it harder to access prevention and treatment, or even to talk about their symptoms than do those of men. "It's very hard for women to talk about painful sex and sub-fertility in contexts where it's hard to access a health-care provider," says Sally Theobald at the Liverpool School of Tropical Medicine, UK, who studies gender inequity and health systems. "So it is this chronic pain and rights issues that have been going on for decades and decades."

FGS is a disease of compounded neglect: ignored because it is an illness found mainly in low-income countries; overlooked because of a lack of awareness; stigmatized because it pertains to sexual health; and further neglected because it affects women, especially low-income and marginalized women, whose health is chronically underfunded and under-researched. Tackling it is therefore not merely a biomedical problem, but also one that involves addressing gender inequality and the sexual and reproductive health rights of women and girls.

An insidious disease

Schistosomiasis, also called bilharzia, is caused by parasitic worms known as schistosomes. The species that causes FGS, Schistosoma haematobium, infests freshwater lakes and rivers. The larvae burrow through a person's skin, making their way to a collection of veins around the bladder and pelvic organs. There, the larvae mature into adults, each the size of a grain of rice, and mate. Each female worm lays hundreds of eggs. These work their way through the bladder wall with the aid of sharp spines and destructive enzymes. Once in the bladder, the eggs are released through urination into the environment to start the cycle anew.

In some societies, girls are expected to fetch the family's water.Credit: Simon Townsley/Panos Pictures

Left untreated, the infection becomes chronic. "These worms can live in your bloodstream for 30 or 40 years," says Evan Secor, a parasitologist at the US Centers for Disease Control and Prevention in Atlanta, Georgia. Between 30% and 75% of women infected with S. Haematobium go on to develop FGS, which occurs when schistosome eggs end up trapped in the tissues of the reproductive system, including the cervix, vagina and fallopian tubes. These trapped eggs cause pain and become surrounded by immune cells, forming inflamed nodules called granulomas, which in turn can lead to scarring. Men can also get genital schistosomiasis, particularly those whose occupations put them at increased risk, such as freshwater fishermen.

Only about 15,000 women and girls in endemic areas have been included in study surveys for FGS, so there are no precise figures for the prevalence of the condition, says Bustinduy. Estimates suggest that between 30 million and 56 million women globally have FGS, most of them in sub-Saharan Africa.

Part of the problem lies in the difficulty of diagnosing the disease. Conventional approaches involve inspecting the cervix with an instrument known as a colposcope, or taking a biopsy and sending it to a lab to look for schistosome eggs under a microscope. But these tools are rarely available in endemic areas — colposcopes are expensive and require specialized gynaecological training to use.

Looking for schistosome eggs in urine samples is cheap, but misses most FGS cases because the correlation between eggs in urine and FGS is only about 20–30% . Molecular testing to detect schistosome DNA in samples such as urine is much more reliable but requires specialist facilities and expensive reagents. Facilities such as these are also usually found only in hospitals, which can be hard for people with low incomes to travel to. And gynaecological examination of girls and young women before they are sexually active is unacceptable in some cultures.

Diagnostic delays mean that, even after standard treatment with a drug called praziquantel that kills the adult worms, women can have permanent tissue damage. Delphine Pedeboy-Knoetze, who grew up in France but who now lives and works in South Africa, had FGS that went undiagnosed for several months. She still experiences chronic pain six years later. "It's extremely demoralizing, because nobody can establish what's wrong," she says. Consultations with multiple specialists in various countries have yielded no answers. This adds to the mental-health burden of FGS. "It's the loneliness of it," she says. "That's the scariest feeling, because you think, 'Oh wow, I really am on my own'."

An array of neglect

The astonishing lack of awareness of FGS among health workers starts with education. FGS is not mentioned in many medical textbooks and rarely forms part of medical training. The classic symptom of urogenital schistosomiasis is blood in the urine, which can be confused with menstruation or 'spotting'. This means that the disease is assumed to affect men only. "Health professionals do not have FGS in their radar of diagnosis," says Motto Nganda, a clinician at the Liverpool School of Tropical Medicine who has studied how to integrate FGS management into primary health-care settings in Liberia.

Schistosoma larvae can burrow through a person's skin.Credit: LENNART NILSSON, TT/SCIENCE PHOTO LIBRARY

This means that genital symptoms can be wrongly attributed to sexually-transmitted infections, with the result that women are not only given ineffective treatment, but also stigmatized. Teenage girls report being scolded by clinic nurses who assume that the girls have had premarital sex, while older women (or their partners) have been accused of infidelity. Pedeboy-Knoetze, for example, was told that she had herpes and to be suspicious of her partner.

Larger political decisions have also shaped the neglect of FGS, says Laura Dean, who studies person-centred health-system responses to NTDs at the Liverpool School of Tropical Medicine. Mass drug-administration is the main effort to control NTDs that can be tackled in this way, including schistosomiasis, she says. The approach is designed to prevent and treat these diseases in endemic areas. This is an essential strategy and one that should be continued, Dean says. However, it isn't a magic bullet that, in isolation, can prevent continuous cycles of reinfection — particularly for a disease such as schistosomiasis that is closely linked to the broader environment and access to clean water, sanitation and hygiene. People who cannot access these programmes, or for whom the drugs don't work, can develop chronic morbidities. This risk is especially high for diseases such as schistosomiasis in which there is a high risk of reinfection3.

Compounding all of these factors is gender: the social expectations and roles that societies attribute to men and women (and people of other genders). Gender is increasingly being recognized as a key factor that affects an individual's vulnerability to NTDs, and FGS is a classic example. "Gender norms in many contexts mean that much of the work done by women in households and communities involves a lot of interaction with water," says Theobald. This includes doing the family's laundry and fetching water from local rivers and ponds. "So there's ongoing exposure to schistosomiasis in multiple ways."

Gender also affects access to treatment and health care. For schistosomiasis, this involves the mass administration of praziquantel in vulnerable populations4. This is often delivered to children in schools, but girls are less likely to attend school than are boys, says Secor. Gender inequality also affects how women experience the disease once they have it. "It brings subfertility, it brings painful sex, it brings discharge, and it's in a context where there's so much pressure to conceive," says Theobald. For example, in some parts of Liberia and Nigeria, a woman's social status is linked to fertility and her ability to have children. As a result of poor sexual and reproductive health, including pregnancy complications or infertility, women with FGS can be ostracized, accused of witchcraft, and faced with the loss of their homes and partners5.

"The fact that there's a parasite that's easily treatable with a dose of praziquantel that costs very little and that can change the outcome of a woman's life, and we're not doing that, is absolutely shocking," says Pedeboy-Knoetze. "Shame on the global-health community and shame on the medical community for this."

Attack on all fronts

All of this means that programmes to tackle FGS need to build in social, political and cultural factors, as well as biomedical ones. They also need to work with the clinical resources that are available in endemic areas. In the past few years, a number of projects have piloted ways to do this. The Zipime Weka Schista! Study, for example, uses culturally appropriate ways to raise awareness of FGS. Drama groups perform songs and dances in areas such as community marketplaces to draw in members of the public and communicate messages about FGS. Community workers then go door to door to offer more information and to recruit study participants.

A health worker at a medical centre in Zimbabwe tests for schistosome parasites.Credit: Xinhua/Shutterstock

Reactions from the communities have been positive, says Rhoda Ndubani, a social scientist and study manager of Zipime Weka Schista! At Zambart. The project is reducing stigma around these diseases and giving women the confidence to talk about them and seek treatment, she adds. It's also empowering the nurses and community midwives. "It's really helping us because, before, I did not know that women can actually get schistosomiasis," says Mwale. Training and handheld colposcopes are already allowing nurses to make FGS diagnoses independently and to administer praziquantel immediately.

Similar messages came out of a study in Liberia. Nganda, Dean and their colleagues piloted a clinical-care package in primary-care settings, which included an FGS symptoms checklist, training in simple gynaecological examinations and treatment guides. Importantly, the package included training traditional midwives, who are trusted in local communities. The study diagnosed and treated 245 women and girls over a period of 6 months, during routine primary health care6. A related study5 in Nigeria returned similar findings. "It's showing what is possible to do within different under-resourced health systems," says Theobald.

Making diagnoses in primary-care settings that are accessible to women is key. "We're trying to steer away from using hospitals as much as possible, because that is really when the bottleneck comes in," says Bustinduy. The goal, she says, is to instead promote the use of rural clinics staffed with midwives and nurses. It's also about making the FGS diagnosis less reliant on clinical examinations, which can result in varying diagnoses depending on the physicians, adds Secor, who chairs a World Health Organization diagnostic advisory panel for FGS diagnostics. "We're really trying to move to something that's a little bit more objective," he says.

Taking inspiration from other self-sampling programmes, such as those in place for HPV and HIV, Bustinduy and her colleagues conducted a study of around 600 women to explore the use of self-sampled genital swabs and DNA testing7. The BILHIV (bilharzia and HIV) study showed that participants readily accepted self-sampling, that it was as good as clinical sampling at detecting FGS, and, therefore, that home-based self-sampling could present a scalable way of diagnosing FGS in endemic regions. In further experiments, the BILHIV study investigated a lower cost alternative to the DNA-amplifying technique PCR called recombinase polymerase amplification (RPA). Unlike PCR, RPA works at room temperature, and is rapid and highly portable. The findings suggested that RPA was a viable alternative to PCR, and could form part of a portable laboratory to be used at point of care8.

FGS is associated with other genital infections, such as HIV, HPV (the main cause of cervical cancer) and trichomoniasis. The Zipime Weka Schista! Study therefore aims to see whether testing for all four could be integrated into a single home visit. Like the BILHIV study, the approach is getting a positive reaction from women — especially the self-sampling aspect. "For many, it is the first time they have been screened in this way," says Chisaila.

Scaling up

There are signs that the condition is slowly starting to shed its neglected status: its association with HIV has brought the sexual and reproductive health communities together, and advocacy by FGS researchers is moving the issue up national and international health agendas. In January, for example, a government committee report recommended that FGS be integrated into the UK government's sexual and reproductive rights aid programmes. Witnesses testifying to the committee advocated moving away from a focus on individual diseases to a patient-centred one — FGS often falls into a gap between NTD and sexual-health programmes. The Joint United Nations Programme on HIV/AIDS has also recognized the need for FGS integration.

Science has its part to play, too. One aspect is in finding ways to help women like Pedeboy-Knoetze who have tissue damage. "We don't really have a good way to treat that chronic, longer, more severe pathology," says Secor. Another is finding ways to prevent the disease, such as vaccination. Adding these to mass drug-administration programmes could reduce the risk of reinfection and help to cut the cycle of transmission. Three vaccines are currently undergoing development. Although each targets the Schistosoma mansoni parasite, which causes intestinal schistosomiasis, one of them also protects against S. Haematobium. This vaccine, called Sm-p80 (SchistoShield), is in phase I trials.

More diagnostics are also in the works. DNA swabs are thought not to work well in advanced FGS, because the eggs are walled inside scar tissue, so researchers are exploring two other approaches. One is a test for schistosome antigens in the blood that is scheduled to go into field trials in the next few months, says Secor. Another approach, one Secor's team is taking, is testing for anti-schistosome antibodies. Although these don't necessarily reveal whether a person has an active infection (antibodies persist for a long time), such tests could be easy to incorporate into routine clinical screening, such as prenatal visits. Tests under development include lateral-flow tests similar to pregnancy tests or those used to rapidly detect COVID-19 (ref. 9). These tests can detect antibodies or schistosome antigens and are easy for users to interpret, and would ideally cost less than US$1 per test, says Secor. "I'm optimistic," he says, "but we're not there yet."

Complicating matters is that any new approaches to diagnosing and treating FGS must be adapted to the realities of living in some of the poorest, most marginalized communities in the world. "If we can do that, it's a win–win for gender equity, rights and social justice," says Theobald. "It's a win–win for responsive, effective, person-centred health systems."

A Rare Tropical Cyclone Landfall Is On Tap For Tanzania

After suffering at least 155 deaths since March from disastrous floods, Tanzania is bracing for the approach of what could be the strongest tropical cyclone to affect the region in modern recordkeeping, with torrential rains in excess of 10 inches (254 mm) likely along its path.

The climate is changing, and our journalists are here to help you make sense of it. Sign up for our newsletters and never miss a story.

As of 8 a.M. EDT Friday (12 UTC), the Joint Typhoon Warning Center placed the center of Tropical Cyclone Hidaya about 210 miles east-southeast of Dar es Salaam, the capital and largest city of Tanzania. Top sustained winds were 85 mph, making Hidaya the equivalent of a Category 1 hurricane.

Hidaya was moving west at about 7 mph but is expected to gain speed and angle slightly north of west, which would bring it onshore just south of Dar es Salaam on Saturday night local time. As it approaches the coast, Hidaya will be traversing very warm sea surface temperatures of around 30°C (86°F), around 1°C (1.8°F) above average. Fortunately, deep ocean heat content will be relatively low along Hidaya's path, and dry air and moderate wind shear are expected to rapidly weaken the storm as it approaches the coast. Even so, given its potency early Friday, Hidaya could still be at tropical storm strength when it makes landfall.

Heavy rains from Hidaya threaten to exacerbate what is already the planet's deadliest weather disaster of 2024: Exceptionally heavy rains during the April portion of the annual spring rainy season in Kenya, Tanzania, and Somalia, which have triggered floods that have left 476 people dead or missing. The death toll is the highest in Kenya, with 181 dead and 91 missing. An additional 42 people died there when a dam burst on April 29. The April flood death toll is 155 in Tanzania, and seven in Somalia. In the Conversation, a hydrology consultant says that the floods "expose decades of poor urban planning and bad land management" in Kenya.

Heavy rains in Kenya's "long rains" season – which typically runs from March to May — have left at least 181 people dead and 125 injured in what is one of the East African nation's worst flooding incidents in recent memory. Https://t.Co/bwvDjTYh6g pic.Twitter.Com/2F2ApXtmRC

— ABC News (@ABC) May 2, 2024

As discussed in our January post, Africa has suffered an unprecedented number of deadly weather-related disasters over the past two years; an astonishing 23% of the continent's 30 deadliest weather-related disasters since 1900 have occurred in the past two years. All of these disasters killed over 500 people, with climate change found to be a contributing factor in four of the ones from 2021-2023.

An uncommonly strong cyclone for its location

The NOAA Historical Hurricanes Tracks website shows that close to a dozen named storms have been recorded within a 235-mile radius of Dar es Salaam (including all of the Tanzania coastline), going back as far as an unnamed system in 1952. However, none of the systems within that radius were analyzed with top sustained winds any higher than 40 mph (minimal tropical-storm strength), and most were tropical depressions, as shown in Figure 1 below. So Hidaya is not only packing unprecedented strength for its track, but it has a legitimate chance of becoming Tanzania's strongest tropical cyclone landfall in modern records. (Update: Eye on the Storm reader Ryan1000 points us to a 1984 National Weather Digest article on the 1952 storm. It includes a ship report of a 958-mb pressure from this storm when it was about 50 miles east of Tanzania, which would imply that winds were potentially above hurricane strength as it approached the coast.)

Tropical cyclones are rare near Tanzania because is it so close to the equator (Hidaya was located at 8.2°S at 8 a.M. EDT Friday).

The most recent tropical cyclone to make landfall in Tanzania was Tropical Cyclone Jobo, which peaked as a mid-strength tropical storm well offshore and made landfall as a tropical depression about 100 miles south of Dar es Salaam on April 24, 2021, leading to 22 deaths in Tanzania. As for that unnamed 1952 tropical storm, it made landfall at minimal strength, with top sustained winds of 40 mph.

Figure 1. All named systems in modern tropical cyclone recordkeeping observed within 235 miles of Dar es Salaam, Tanzania. Tracks in green are tropical storms and those in blue are tropical depressions. (Image credit: NOAA Historical Hurricane Tracks) A landscape primed for flooding after months of moisture enhanced by El Niño

Tanzania is near the end of its longer wet season, which typically runs from March into May. The shorter of the two annual wet seasons runs from October to December, and its rains are typically intensified during El Niño events, which was the case in 2023. Floodlist reported at least 89 flood-related fatalities in Tanzania from October into early December. The impacts have been even worse and have expanded into broader parts of East Africa during the longer wet season of 2024.

The heaviest rains and worst impacts from Hidaya will likely be confined to an east-west corridor across southern Tanzania and northern Mozambique, south of Dar es Salaam. Unfortunately, this may coincide with one of the areas hardest hit by recent rains and floods: the Rufiji district, where tens of thousands of people are reportedly in need of food, shelter, water, and health care. Hidaya is embedded in a rich field of deep atmospheric moisture, and it could produce rains in excess of 10 inches (254 mm) near the coast.

Figure 2. Total precipitation for the 5-day period ending at 0Z Wednesday, May 8, as predicted by the 0Z Friday, May 3, run of the GFS model. At center is a corridor of rains exceeding 300 millimeters, or 11.81 inches, extending into southern Tanzania along the path of Tropical Cyclone Hidaya. (Image credit: tropicaltidbits.Com)

Hidaya is arriving near the end of a less-active-than-usual year for tropical cyclones across the Southern Hemisphere. According to the real-time statistics site at Colorado State University, accumulated cyclone energy for the climatological year thus far (July 1 – May 2) was roughly 75% of the 1991-2020 average in both the South Indian and South Pacific basins.

The Southern Hemisphere's strongest tropical cyclone of the 2023-24 year to date has been Djoungou, which peaked in the remote South Indian Ocean as a Category 4 equivalent with top 1-minute sustained winds of 130 mph.

We help millions of people understand climate change and what to do about it. Help us reach even more people like you.

Health Beat: 8 Factors That Cause Early Death

The average person in the US will live to celebrate their 76th birthday. That's according to the Center for Disease Control (CDC.)

What's more? There's a 30 percent chance you will see your 90th birthday. And more people than ever before are making it to 100.

But experts say there is a big difference when it comes to how long you will live if you're black. A new study reveals eight factors that play a role when it comes to race and mortality.

A new study out of Tulane University reports black adults who live in the US have a 59 percent higher risk of premature death than white adults.

"We wanted to do a big study to try to see if we could explain what is actually responsible for the differences," said Joshua Bundy, assistant professor of epidemiology at Tulane University School of Public Health and Tropical Medicine.

Bundy believes disparities in eight social economic factors are to blame and they are all interrelated.

"Those who don't have any high school education at all are at the highest risk." Bundy said.

Education impacts employment, which impacts healthcare.

"Maybe you then don't have access to health insurance," added Bundy.

Income impacts access to healthy choices.

"Maybe there are good interventions for food security, like providing food assistance programs and things like that." Bundy said.

The study found home ownership is an indicator of what people can and cannot afford. Even marital status matters.

"Being married may offer social support. There has been a lot of debate on whether this is some kind of genetic reason, if it's based on your genes, if it's something that's predetermined or because of biology, or even just things like behavioral and lifestyle factors that may be different. But what our study is really saying is that it's really explained all by social factors." explained Bundy.

Bundy believes by knowing how these things impact our lives, we can work to build systems to solve these disparities, and hopefully see more people, of all races, live longer, healthier lives.

The CDC is also focusing on social determinants of health with their Healthy People 2030 initiative.

They're using data driven facts to help policymakers address the race-based mortality gap in the next decade.

Professor Bundy says there is zero difference between black and white adults for mortality risk once these eight factors are dealt with.

---